LCOV - code coverage report
Current view: top level - drivers/acpi - cppc_acpi.c (source / functions) Hit Total Coverage
Test: combined.info Lines: 18 554 3.2 %
Date: 2022-04-01 14:35:51 Functions: 1 28 3.6 %
Branches: 1 407 0.2 %

           Branch data     Line data    Source code
       1                 :            : // SPDX-License-Identifier: GPL-2.0-only
       2                 :            : /*
       3                 :            :  * CPPC (Collaborative Processor Performance Control) methods used by CPUfreq drivers.
       4                 :            :  *
       5                 :            :  * (C) Copyright 2014, 2015 Linaro Ltd.
       6                 :            :  * Author: Ashwin Chaugule <ashwin.chaugule@linaro.org>
       7                 :            :  *
       8                 :            :  * CPPC describes a few methods for controlling CPU performance using
       9                 :            :  * information from a per CPU table called CPC. This table is described in
      10                 :            :  * the ACPI v5.0+ specification. The table consists of a list of
      11                 :            :  * registers which may be memory mapped or hardware registers and also may
      12                 :            :  * include some static integer values.
      13                 :            :  *
      14                 :            :  * CPU performance is on an abstract continuous scale as against a discretized
      15                 :            :  * P-state scale which is tied to CPU frequency only. In brief, the basic
      16                 :            :  * operation involves:
      17                 :            :  *
      18                 :            :  * - OS makes a CPU performance request. (Can provide min and max bounds)
      19                 :            :  *
      20                 :            :  * - Platform (such as BMC) is free to optimize request within requested bounds
      21                 :            :  *   depending on power/thermal budgets etc.
      22                 :            :  *
      23                 :            :  * - Platform conveys its decision back to OS
      24                 :            :  *
      25                 :            :  * The communication between OS and platform occurs through another medium
      26                 :            :  * called (PCC) Platform Communication Channel. This is a generic mailbox like
      27                 :            :  * mechanism which includes doorbell semantics to indicate register updates.
      28                 :            :  * See drivers/mailbox/pcc.c for details on PCC.
      29                 :            :  *
      30                 :            :  * Finer details about the PCC and CPPC spec are available in the ACPI v5.1 and
      31                 :            :  * above specifications.
      32                 :            :  */
      33                 :            : 
      34                 :            : #define pr_fmt(fmt)     "ACPI CPPC: " fmt
      35                 :            : 
      36                 :            : #include <linux/cpufreq.h>
      37                 :            : #include <linux/delay.h>
      38                 :            : #include <linux/iopoll.h>
      39                 :            : #include <linux/ktime.h>
      40                 :            : #include <linux/rwsem.h>
      41                 :            : #include <linux/wait.h>
      42                 :            : 
      43                 :            : #include <acpi/cppc_acpi.h>
      44                 :            : 
      45                 :            : struct cppc_pcc_data {
      46                 :            :         struct mbox_chan *pcc_channel;
      47                 :            :         void __iomem *pcc_comm_addr;
      48                 :            :         bool pcc_channel_acquired;
      49                 :            :         unsigned int deadline_us;
      50                 :            :         unsigned int pcc_mpar, pcc_mrtt, pcc_nominal;
      51                 :            : 
      52                 :            :         bool pending_pcc_write_cmd;     /* Any pending/batched PCC write cmds? */
      53                 :            :         bool platform_owns_pcc;         /* Ownership of PCC subspace */
      54                 :            :         unsigned int pcc_write_cnt;     /* Running count of PCC write commands */
      55                 :            : 
      56                 :            :         /*
      57                 :            :          * Lock to provide controlled access to the PCC channel.
      58                 :            :          *
      59                 :            :          * For performance critical usecases(currently cppc_set_perf)
      60                 :            :          *      We need to take read_lock and check if channel belongs to OSPM
      61                 :            :          * before reading or writing to PCC subspace
      62                 :            :          *      We need to take write_lock before transferring the channel
      63                 :            :          * ownership to the platform via a Doorbell
      64                 :            :          *      This allows us to batch a number of CPPC requests if they happen
      65                 :            :          * to originate in about the same time
      66                 :            :          *
      67                 :            :          * For non-performance critical usecases(init)
      68                 :            :          *      Take write_lock for all purposes which gives exclusive access
      69                 :            :          */
      70                 :            :         struct rw_semaphore pcc_lock;
      71                 :            : 
      72                 :            :         /* Wait queue for CPUs whose requests were batched */
      73                 :            :         wait_queue_head_t pcc_write_wait_q;
      74                 :            :         ktime_t last_cmd_cmpl_time;
      75                 :            :         ktime_t last_mpar_reset;
      76                 :            :         int mpar_count;
      77                 :            :         int refcount;
      78                 :            : };
      79                 :            : 
      80                 :            : /* Array to represent the PCC channel per subspace ID */
      81                 :            : static struct cppc_pcc_data *pcc_data[MAX_PCC_SUBSPACES];
      82                 :            : /* The cpu_pcc_subspace_idx contains per CPU subspace ID */
      83                 :            : static DEFINE_PER_CPU(int, cpu_pcc_subspace_idx);
      84                 :            : 
      85                 :            : /*
      86                 :            :  * The cpc_desc structure contains the ACPI register details
      87                 :            :  * as described in the per CPU _CPC tables. The details
      88                 :            :  * include the type of register (e.g. PCC, System IO, FFH etc.)
      89                 :            :  * and destination addresses which lets us READ/WRITE CPU performance
      90                 :            :  * information using the appropriate I/O methods.
      91                 :            :  */
      92                 :            : static DEFINE_PER_CPU(struct cpc_desc *, cpc_desc_ptr);
      93                 :            : 
      94                 :            : /* pcc mapped address + header size + offset within PCC subspace */
      95                 :            : #define GET_PCC_VADDR(offs, pcc_ss_id) (pcc_data[pcc_ss_id]->pcc_comm_addr + \
      96                 :            :                                                 0x8 + (offs))
      97                 :            : 
      98                 :            : /* Check if a CPC register is in PCC */
      99                 :            : #define CPC_IN_PCC(cpc) ((cpc)->type == ACPI_TYPE_BUFFER &&          \
     100                 :            :                                 (cpc)->cpc_entry.reg.space_id ==     \
     101                 :            :                                 ACPI_ADR_SPACE_PLATFORM_COMM)
     102                 :            : 
     103                 :            : /* Evalutes to True if reg is a NULL register descriptor */
     104                 :            : #define IS_NULL_REG(reg) ((reg)->space_id ==  ACPI_ADR_SPACE_SYSTEM_MEMORY && \
     105                 :            :                                 (reg)->address == 0 &&                       \
     106                 :            :                                 (reg)->bit_width == 0 &&             \
     107                 :            :                                 (reg)->bit_offset == 0 &&            \
     108                 :            :                                 (reg)->access_width == 0)
     109                 :            : 
     110                 :            : /* Evalutes to True if an optional cpc field is supported */
     111                 :            : #define CPC_SUPPORTED(cpc) ((cpc)->type == ACPI_TYPE_INTEGER ?               \
     112                 :            :                                 !!(cpc)->cpc_entry.int_value :               \
     113                 :            :                                 !IS_NULL_REG(&(cpc)->cpc_entry.reg))
     114                 :            : /*
     115                 :            :  * Arbitrary Retries in case the remote processor is slow to respond
     116                 :            :  * to PCC commands. Keeping it high enough to cover emulators where
     117                 :            :  * the processors run painfully slow.
     118                 :            :  */
     119                 :            : #define NUM_RETRIES 500ULL
     120                 :            : 
     121                 :            : struct cppc_attr {
     122                 :            :         struct attribute attr;
     123                 :            :         ssize_t (*show)(struct kobject *kobj,
     124                 :            :                         struct attribute *attr, char *buf);
     125                 :            :         ssize_t (*store)(struct kobject *kobj,
     126                 :            :                         struct attribute *attr, const char *c, ssize_t count);
     127                 :            : };
     128                 :            : 
     129                 :            : #define define_one_cppc_ro(_name)               \
     130                 :            : static struct cppc_attr _name =                 \
     131                 :            : __ATTR(_name, 0444, show_##_name, NULL)
     132                 :            : 
     133                 :            : #define to_cpc_desc(a) container_of(a, struct cpc_desc, kobj)
     134                 :            : 
     135                 :            : #define show_cppc_data(access_fn, struct_name, member_name)             \
     136                 :            :         static ssize_t show_##member_name(struct kobject *kobj,         \
     137                 :            :                                         struct attribute *attr, char *buf) \
     138                 :            :         {                                                               \
     139                 :            :                 struct cpc_desc *cpc_ptr = to_cpc_desc(kobj);           \
     140                 :            :                 struct struct_name st_name = {0};                       \
     141                 :            :                 int ret;                                                \
     142                 :            :                                                                         \
     143                 :            :                 ret = access_fn(cpc_ptr->cpu_id, &st_name);              \
     144                 :            :                 if (ret)                                                \
     145                 :            :                         return ret;                                     \
     146                 :            :                                                                         \
     147                 :            :                 return scnprintf(buf, PAGE_SIZE, "%llu\n",            \
     148                 :            :                                 (u64)st_name.member_name);              \
     149                 :            :         }                                                               \
     150                 :            :         define_one_cppc_ro(member_name)
     151                 :            : 
     152         [ #  # ]:          0 : show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, highest_perf);
     153         [ #  # ]:          0 : show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, lowest_perf);
     154         [ #  # ]:          0 : show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, nominal_perf);
     155         [ #  # ]:          0 : show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, lowest_nonlinear_perf);
     156         [ #  # ]:          0 : show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, lowest_freq);
     157         [ #  # ]:          0 : show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, nominal_freq);
     158                 :            : 
     159         [ #  # ]:          0 : show_cppc_data(cppc_get_perf_ctrs, cppc_perf_fb_ctrs, reference_perf);
     160         [ #  # ]:          0 : show_cppc_data(cppc_get_perf_ctrs, cppc_perf_fb_ctrs, wraparound_time);
     161                 :            : 
     162                 :          0 : static ssize_t show_feedback_ctrs(struct kobject *kobj,
     163                 :            :                 struct attribute *attr, char *buf)
     164                 :            : {
     165                 :          0 :         struct cpc_desc *cpc_ptr = to_cpc_desc(kobj);
     166                 :          0 :         struct cppc_perf_fb_ctrs fb_ctrs = {0};
     167                 :          0 :         int ret;
     168                 :            : 
     169                 :          0 :         ret = cppc_get_perf_ctrs(cpc_ptr->cpu_id, &fb_ctrs);
     170         [ #  # ]:          0 :         if (ret)
     171                 :          0 :                 return ret;
     172                 :            : 
     173                 :          0 :         return scnprintf(buf, PAGE_SIZE, "ref:%llu del:%llu\n",
     174                 :            :                         fb_ctrs.reference, fb_ctrs.delivered);
     175                 :            : }
     176                 :            : define_one_cppc_ro(feedback_ctrs);
     177                 :            : 
     178                 :            : static struct attribute *cppc_attrs[] = {
     179                 :            :         &feedback_ctrs.attr,
     180                 :            :         &reference_perf.attr,
     181                 :            :         &wraparound_time.attr,
     182                 :            :         &highest_perf.attr,
     183                 :            :         &lowest_perf.attr,
     184                 :            :         &lowest_nonlinear_perf.attr,
     185                 :            :         &nominal_perf.attr,
     186                 :            :         &nominal_freq.attr,
     187                 :            :         &lowest_freq.attr,
     188                 :            :         NULL
     189                 :            : };
     190                 :            : 
     191                 :            : static struct kobj_type cppc_ktype = {
     192                 :            :         .sysfs_ops = &kobj_sysfs_ops,
     193                 :            :         .default_attrs = cppc_attrs,
     194                 :            : };
     195                 :            : 
     196                 :          0 : static int check_pcc_chan(int pcc_ss_id, bool chk_err_bit)
     197                 :            : {
     198                 :          0 :         int ret, status;
     199                 :          0 :         struct cppc_pcc_data *pcc_ss_data = pcc_data[pcc_ss_id];
     200                 :          0 :         struct acpi_pcct_shared_memory __iomem *generic_comm_base =
     201                 :            :                 pcc_ss_data->pcc_comm_addr;
     202                 :            : 
     203         [ #  # ]:          0 :         if (!pcc_ss_data->platform_owns_pcc)
     204                 :            :                 return 0;
     205                 :            : 
     206                 :            :         /*
     207                 :            :          * Poll PCC status register every 3us(delay_us) for maximum of
     208                 :            :          * deadline_us(timeout_us) until PCC command complete bit is set(cond)
     209                 :            :          */
     210   [ #  #  #  #  :          0 :         ret = readw_relaxed_poll_timeout(&generic_comm_base->status, status,
                   #  # ]
     211                 :            :                                         status & PCC_CMD_COMPLETE_MASK, 3,
     212                 :            :                                         pcc_ss_data->deadline_us);
     213                 :            : 
     214         [ #  # ]:          0 :         if (likely(!ret)) {
     215                 :          0 :                 pcc_ss_data->platform_owns_pcc = false;
     216   [ #  #  #  # ]:          0 :                 if (chk_err_bit && (status & PCC_ERROR_MASK))
     217                 :          0 :                         ret = -EIO;
     218                 :            :         }
     219                 :            : 
     220         [ #  # ]:          0 :         if (unlikely(ret))
     221                 :          0 :                 pr_err("PCC check channel failed for ss: %d. ret=%d\n",
     222                 :            :                        pcc_ss_id, ret);
     223                 :            : 
     224                 :            :         return ret;
     225                 :            : }
     226                 :            : 
     227                 :            : /*
     228                 :            :  * This function transfers the ownership of the PCC to the platform
     229                 :            :  * So it must be called while holding write_lock(pcc_lock)
     230                 :            :  */
     231                 :          0 : static int send_pcc_cmd(int pcc_ss_id, u16 cmd)
     232                 :            : {
     233                 :          0 :         int ret = -EIO, i;
     234                 :          0 :         struct cppc_pcc_data *pcc_ss_data = pcc_data[pcc_ss_id];
     235                 :          0 :         struct acpi_pcct_shared_memory *generic_comm_base =
     236                 :            :                 (struct acpi_pcct_shared_memory *)pcc_ss_data->pcc_comm_addr;
     237                 :          0 :         unsigned int time_delta;
     238                 :            : 
     239                 :            :         /*
     240                 :            :          * For CMD_WRITE we know for a fact the caller should have checked
     241                 :            :          * the channel before writing to PCC space
     242                 :            :          */
     243         [ #  # ]:          0 :         if (cmd == CMD_READ) {
     244                 :            :                 /*
     245                 :            :                  * If there are pending cpc_writes, then we stole the channel
     246                 :            :                  * before write completion, so first send a WRITE command to
     247                 :            :                  * platform
     248                 :            :                  */
     249         [ #  # ]:          0 :                 if (pcc_ss_data->pending_pcc_write_cmd)
     250                 :          0 :                         send_pcc_cmd(pcc_ss_id, CMD_WRITE);
     251                 :            : 
     252                 :          0 :                 ret = check_pcc_chan(pcc_ss_id, false);
     253         [ #  # ]:          0 :                 if (ret)
     254                 :          0 :                         goto end;
     255                 :            :         } else /* CMD_WRITE */
     256                 :          0 :                 pcc_ss_data->pending_pcc_write_cmd = FALSE;
     257                 :            : 
     258                 :            :         /*
     259                 :            :          * Handle the Minimum Request Turnaround Time(MRTT)
     260                 :            :          * "The minimum amount of time that OSPM must wait after the completion
     261                 :            :          * of a command before issuing the next command, in microseconds"
     262                 :            :          */
     263         [ #  # ]:          0 :         if (pcc_ss_data->pcc_mrtt) {
     264                 :          0 :                 time_delta = ktime_us_delta(ktime_get(),
     265                 :            :                                             pcc_ss_data->last_cmd_cmpl_time);
     266         [ #  # ]:          0 :                 if (pcc_ss_data->pcc_mrtt > time_delta)
     267   [ #  #  #  # ]:          0 :                         udelay(pcc_ss_data->pcc_mrtt - time_delta);
     268                 :            :         }
     269                 :            : 
     270                 :            :         /*
     271                 :            :          * Handle the non-zero Maximum Periodic Access Rate(MPAR)
     272                 :            :          * "The maximum number of periodic requests that the subspace channel can
     273                 :            :          * support, reported in commands per minute. 0 indicates no limitation."
     274                 :            :          *
     275                 :            :          * This parameter should be ideally zero or large enough so that it can
     276                 :            :          * handle maximum number of requests that all the cores in the system can
     277                 :            :          * collectively generate. If it is not, we will follow the spec and just
     278                 :            :          * not send the request to the platform after hitting the MPAR limit in
     279                 :            :          * any 60s window
     280                 :            :          */
     281         [ #  # ]:          0 :         if (pcc_ss_data->pcc_mpar) {
     282         [ #  # ]:          0 :                 if (pcc_ss_data->mpar_count == 0) {
     283                 :          0 :                         time_delta = ktime_ms_delta(ktime_get(),
     284                 :            :                                                     pcc_ss_data->last_mpar_reset);
     285   [ #  #  #  # ]:          0 :                         if ((time_delta < 60 * MSEC_PER_SEC) && pcc_ss_data->last_mpar_reset) {
     286                 :          0 :                                 pr_debug("PCC cmd for subspace %d not sent due to MPAR limit",
     287                 :            :                                          pcc_ss_id);
     288                 :          0 :                                 ret = -EIO;
     289                 :          0 :                                 goto end;
     290                 :            :                         }
     291                 :          0 :                         pcc_ss_data->last_mpar_reset = ktime_get();
     292                 :          0 :                         pcc_ss_data->mpar_count = pcc_ss_data->pcc_mpar;
     293                 :            :                 }
     294                 :          0 :                 pcc_ss_data->mpar_count--;
     295                 :            :         }
     296                 :            : 
     297                 :            :         /* Write to the shared comm region. */
     298                 :          0 :         writew_relaxed(cmd, &generic_comm_base->command);
     299                 :            : 
     300                 :            :         /* Flip CMD COMPLETE bit */
     301                 :          0 :         writew_relaxed(0, &generic_comm_base->status);
     302                 :            : 
     303                 :          0 :         pcc_ss_data->platform_owns_pcc = true;
     304                 :            : 
     305                 :            :         /* Ring doorbell */
     306                 :          0 :         ret = mbox_send_message(pcc_ss_data->pcc_channel, &cmd);
     307         [ #  # ]:          0 :         if (ret < 0) {
     308                 :          0 :                 pr_err("Err sending PCC mbox message. ss: %d cmd:%d, ret:%d\n",
     309                 :            :                        pcc_ss_id, cmd, ret);
     310                 :          0 :                 goto end;
     311                 :            :         }
     312                 :            : 
     313                 :            :         /* wait for completion and check for PCC errro bit */
     314                 :          0 :         ret = check_pcc_chan(pcc_ss_id, true);
     315                 :            : 
     316         [ #  # ]:          0 :         if (pcc_ss_data->pcc_mrtt)
     317                 :          0 :                 pcc_ss_data->last_cmd_cmpl_time = ktime_get();
     318                 :            : 
     319         [ #  # ]:          0 :         if (pcc_ss_data->pcc_channel->mbox->txdone_irq)
     320                 :          0 :                 mbox_chan_txdone(pcc_ss_data->pcc_channel, ret);
     321                 :            :         else
     322                 :          0 :                 mbox_client_txdone(pcc_ss_data->pcc_channel, ret);
     323                 :            : 
     324                 :          0 : end:
     325         [ #  # ]:          0 :         if (cmd == CMD_WRITE) {
     326         [ #  # ]:          0 :                 if (unlikely(ret)) {
     327         [ #  # ]:          0 :                         for_each_possible_cpu(i) {
     328                 :          0 :                                 struct cpc_desc *desc = per_cpu(cpc_desc_ptr, i);
     329         [ #  # ]:          0 :                                 if (!desc)
     330                 :          0 :                                         continue;
     331                 :            : 
     332         [ #  # ]:          0 :                                 if (desc->write_cmd_id == pcc_ss_data->pcc_write_cnt)
     333                 :          0 :                                         desc->write_cmd_status = ret;
     334                 :            :                         }
     335                 :            :                 }
     336                 :          0 :                 pcc_ss_data->pcc_write_cnt++;
     337                 :          0 :                 wake_up_all(&pcc_ss_data->pcc_write_wait_q);
     338                 :            :         }
     339                 :            : 
     340                 :          0 :         return ret;
     341                 :            : }
     342                 :            : 
     343                 :          0 : static void cppc_chan_tx_done(struct mbox_client *cl, void *msg, int ret)
     344                 :            : {
     345                 :          0 :         if (ret < 0)
     346                 :            :                 pr_debug("TX did not complete: CMD sent:%x, ret:%d\n",
     347                 :            :                                 *(u16 *)msg, ret);
     348                 :            :         else
     349                 :            :                 pr_debug("TX completed. CMD sent:%x, ret:%d\n",
     350                 :            :                                 *(u16 *)msg, ret);
     351                 :          0 : }
     352                 :            : 
     353                 :            : struct mbox_client cppc_mbox_cl = {
     354                 :            :         .tx_done = cppc_chan_tx_done,
     355                 :            :         .knows_txdone = true,
     356                 :            : };
     357                 :            : 
     358                 :          0 : static int acpi_get_psd(struct cpc_desc *cpc_ptr, acpi_handle handle)
     359                 :            : {
     360                 :          0 :         int result = -EFAULT;
     361                 :          0 :         acpi_status status = AE_OK;
     362                 :          0 :         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
     363                 :          0 :         struct acpi_buffer format = {sizeof("NNNNN"), "NNNNN"};
     364                 :          0 :         struct acpi_buffer state = {0, NULL};
     365                 :          0 :         union acpi_object  *psd = NULL;
     366                 :          0 :         struct acpi_psd_package *pdomain;
     367                 :            : 
     368                 :          0 :         status = acpi_evaluate_object_typed(handle, "_PSD", NULL,
     369                 :            :                                             &buffer, ACPI_TYPE_PACKAGE);
     370         [ #  # ]:          0 :         if (status == AE_NOT_FOUND)     /* _PSD is optional */
     371                 :            :                 return 0;
     372         [ #  # ]:          0 :         if (ACPI_FAILURE(status))
     373                 :            :                 return -ENODEV;
     374                 :            : 
     375                 :          0 :         psd = buffer.pointer;
     376   [ #  #  #  # ]:          0 :         if (!psd || psd->package.count != 1) {
     377                 :          0 :                 pr_debug("Invalid _PSD data\n");
     378                 :          0 :                 goto end;
     379                 :            :         }
     380                 :            : 
     381                 :          0 :         pdomain = &(cpc_ptr->domain_info);
     382                 :            : 
     383                 :          0 :         state.length = sizeof(struct acpi_psd_package);
     384                 :          0 :         state.pointer = pdomain;
     385                 :            : 
     386                 :          0 :         status = acpi_extract_package(&(psd->package.elements[0]),
     387                 :            :                 &format, &state);
     388         [ #  # ]:          0 :         if (ACPI_FAILURE(status)) {
     389                 :          0 :                 pr_debug("Invalid _PSD data for CPU:%d\n", cpc_ptr->cpu_id);
     390                 :          0 :                 goto end;
     391                 :            :         }
     392                 :            : 
     393         [ #  # ]:          0 :         if (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES) {
     394                 :          0 :                 pr_debug("Unknown _PSD:num_entries for CPU:%d\n", cpc_ptr->cpu_id);
     395                 :          0 :                 goto end;
     396                 :            :         }
     397                 :            : 
     398         [ #  # ]:          0 :         if (pdomain->revision != ACPI_PSD_REV0_REVISION) {
     399                 :          0 :                 pr_debug("Unknown _PSD:revision for CPU: %d\n", cpc_ptr->cpu_id);
     400                 :          0 :                 goto end;
     401                 :            :         }
     402                 :            : 
     403                 :          0 :         if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
     404         [ #  # ]:          0 :             pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
     405                 :            :             pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
     406                 :          0 :                 pr_debug("Invalid _PSD:coord_type for CPU:%d\n", cpc_ptr->cpu_id);
     407                 :          0 :                 goto end;
     408                 :            :         }
     409                 :            : 
     410                 :            :         result = 0;
     411                 :          0 : end:
     412                 :          0 :         kfree(buffer.pointer);
     413                 :          0 :         return result;
     414                 :            : }
     415                 :            : 
     416                 :            : /**
     417                 :            :  * acpi_get_psd_map - Map the CPUs in a common freq domain.
     418                 :            :  * @all_cpu_data: Ptrs to CPU specific CPPC data including PSD info.
     419                 :            :  *
     420                 :            :  *      Return: 0 for success or negative value for err.
     421                 :            :  */
     422                 :          0 : int acpi_get_psd_map(struct cppc_cpudata **all_cpu_data)
     423                 :            : {
     424                 :          0 :         int count_target;
     425                 :          0 :         int retval = 0;
     426                 :          0 :         unsigned int i, j;
     427                 :          0 :         cpumask_var_t covered_cpus;
     428                 :          0 :         struct cppc_cpudata *pr, *match_pr;
     429                 :          0 :         struct acpi_psd_package *pdomain;
     430                 :          0 :         struct acpi_psd_package *match_pdomain;
     431                 :          0 :         struct cpc_desc *cpc_ptr, *match_cpc_ptr;
     432                 :            : 
     433                 :          0 :         if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))
     434                 :            :                 return -ENOMEM;
     435                 :            : 
     436                 :            :         /*
     437                 :            :          * Now that we have _PSD data from all CPUs, let's setup P-state
     438                 :            :          * domain info.
     439                 :            :          */
     440         [ #  # ]:          0 :         for_each_possible_cpu(i) {
     441                 :          0 :                 pr = all_cpu_data[i];
     442         [ #  # ]:          0 :                 if (!pr)
     443                 :          0 :                         continue;
     444                 :            : 
     445         [ #  # ]:          0 :                 if (cpumask_test_cpu(i, covered_cpus))
     446                 :          0 :                         continue;
     447                 :            : 
     448                 :          0 :                 cpc_ptr = per_cpu(cpc_desc_ptr, i);
     449         [ #  # ]:          0 :                 if (!cpc_ptr) {
     450                 :          0 :                         retval = -EFAULT;
     451                 :          0 :                         goto err_ret;
     452                 :            :                 }
     453                 :            : 
     454                 :          0 :                 pdomain = &(cpc_ptr->domain_info);
     455                 :          0 :                 cpumask_set_cpu(i, pr->shared_cpu_map);
     456                 :          0 :                 cpumask_set_cpu(i, covered_cpus);
     457         [ #  # ]:          0 :                 if (pdomain->num_processors <= 1)
     458                 :          0 :                         continue;
     459                 :            : 
     460                 :            :                 /* Validate the Domain info */
     461                 :          0 :                 count_target = pdomain->num_processors;
     462         [ #  # ]:          0 :                 if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL)
     463                 :          0 :                         pr->shared_type = CPUFREQ_SHARED_TYPE_ALL;
     464         [ #  # ]:          0 :                 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL)
     465                 :          0 :                         pr->shared_type = CPUFREQ_SHARED_TYPE_HW;
     466         [ #  # ]:          0 :                 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY)
     467                 :          0 :                         pr->shared_type = CPUFREQ_SHARED_TYPE_ANY;
     468                 :            : 
     469         [ #  # ]:          0 :                 for_each_possible_cpu(j) {
     470         [ #  # ]:          0 :                         if (i == j)
     471                 :          0 :                                 continue;
     472                 :            : 
     473                 :          0 :                         match_cpc_ptr = per_cpu(cpc_desc_ptr, j);
     474         [ #  # ]:          0 :                         if (!match_cpc_ptr) {
     475                 :          0 :                                 retval = -EFAULT;
     476                 :          0 :                                 goto err_ret;
     477                 :            :                         }
     478                 :            : 
     479                 :          0 :                         match_pdomain = &(match_cpc_ptr->domain_info);
     480         [ #  # ]:          0 :                         if (match_pdomain->domain != pdomain->domain)
     481                 :          0 :                                 continue;
     482                 :            : 
     483                 :            :                         /* Here i and j are in the same domain */
     484         [ #  # ]:          0 :                         if (match_pdomain->num_processors != count_target) {
     485                 :          0 :                                 retval = -EFAULT;
     486                 :          0 :                                 goto err_ret;
     487                 :            :                         }
     488                 :            : 
     489         [ #  # ]:          0 :                         if (pdomain->coord_type != match_pdomain->coord_type) {
     490                 :          0 :                                 retval = -EFAULT;
     491                 :          0 :                                 goto err_ret;
     492                 :            :                         }
     493                 :            : 
     494                 :          0 :                         cpumask_set_cpu(j, covered_cpus);
     495                 :          0 :                         cpumask_set_cpu(j, pr->shared_cpu_map);
     496                 :            :                 }
     497                 :            : 
     498         [ #  # ]:          0 :                 for_each_possible_cpu(j) {
     499         [ #  # ]:          0 :                         if (i == j)
     500                 :          0 :                                 continue;
     501                 :            : 
     502                 :          0 :                         match_pr = all_cpu_data[j];
     503         [ #  # ]:          0 :                         if (!match_pr)
     504                 :          0 :                                 continue;
     505                 :            : 
     506                 :          0 :                         match_cpc_ptr = per_cpu(cpc_desc_ptr, j);
     507         [ #  # ]:          0 :                         if (!match_cpc_ptr) {
     508                 :          0 :                                 retval = -EFAULT;
     509                 :          0 :                                 goto err_ret;
     510                 :            :                         }
     511                 :            : 
     512                 :          0 :                         match_pdomain = &(match_cpc_ptr->domain_info);
     513         [ #  # ]:          0 :                         if (match_pdomain->domain != pdomain->domain)
     514                 :          0 :                                 continue;
     515                 :            : 
     516                 :          0 :                         match_pr->shared_type = pr->shared_type;
     517                 :          0 :                         cpumask_copy(match_pr->shared_cpu_map,
     518                 :            :                                      pr->shared_cpu_map);
     519                 :            :                 }
     520                 :            :         }
     521                 :            : 
     522                 :          0 : err_ret:
     523         [ #  # ]:          0 :         for_each_possible_cpu(i) {
     524                 :          0 :                 pr = all_cpu_data[i];
     525         [ #  # ]:          0 :                 if (!pr)
     526                 :          0 :                         continue;
     527                 :            : 
     528                 :            :                 /* Assume no coordination on any error parsing domain info */
     529         [ #  # ]:          0 :                 if (retval) {
     530                 :          0 :                         cpumask_clear(pr->shared_cpu_map);
     531                 :          0 :                         cpumask_set_cpu(i, pr->shared_cpu_map);
     532                 :          0 :                         pr->shared_type = CPUFREQ_SHARED_TYPE_ALL;
     533                 :            :                 }
     534                 :            :         }
     535                 :            : 
     536                 :          0 :         free_cpumask_var(covered_cpus);
     537                 :          0 :         return retval;
     538                 :            : }
     539                 :            : EXPORT_SYMBOL_GPL(acpi_get_psd_map);
     540                 :            : 
     541                 :          0 : static int register_pcc_channel(int pcc_ss_idx)
     542                 :            : {
     543                 :          0 :         struct acpi_pcct_hw_reduced *cppc_ss;
     544                 :          0 :         u64 usecs_lat;
     545                 :            : 
     546         [ #  # ]:          0 :         if (pcc_ss_idx >= 0) {
     547                 :          0 :                 pcc_data[pcc_ss_idx]->pcc_channel =
     548                 :          0 :                         pcc_mbox_request_channel(&cppc_mbox_cl,     pcc_ss_idx);
     549                 :            : 
     550         [ #  # ]:          0 :                 if (IS_ERR(pcc_data[pcc_ss_idx]->pcc_channel)) {
     551                 :          0 :                         pr_err("Failed to find PCC channel for subspace %d\n",
     552                 :            :                                pcc_ss_idx);
     553                 :          0 :                         return -ENODEV;
     554                 :            :                 }
     555                 :            : 
     556                 :            :                 /*
     557                 :            :                  * The PCC mailbox controller driver should
     558                 :            :                  * have parsed the PCCT (global table of all
     559                 :            :                  * PCC channels) and stored pointers to the
     560                 :            :                  * subspace communication region in con_priv.
     561                 :            :                  */
     562                 :          0 :                 cppc_ss = (pcc_data[pcc_ss_idx]->pcc_channel)->con_priv;
     563                 :            : 
     564         [ #  # ]:          0 :                 if (!cppc_ss) {
     565                 :          0 :                         pr_err("No PCC subspace found for %d CPPC\n",
     566                 :            :                                pcc_ss_idx);
     567                 :          0 :                         return -ENODEV;
     568                 :            :                 }
     569                 :            : 
     570                 :            :                 /*
     571                 :            :                  * cppc_ss->latency is just a Nominal value. In reality
     572                 :            :                  * the remote processor could be much slower to reply.
     573                 :            :                  * So add an arbitrary amount of wait on top of Nominal.
     574                 :            :                  */
     575                 :          0 :                 usecs_lat = NUM_RETRIES * cppc_ss->latency;
     576                 :          0 :                 pcc_data[pcc_ss_idx]->deadline_us = usecs_lat;
     577                 :          0 :                 pcc_data[pcc_ss_idx]->pcc_mrtt = cppc_ss->min_turnaround_time;
     578                 :          0 :                 pcc_data[pcc_ss_idx]->pcc_mpar = cppc_ss->max_access_rate;
     579                 :          0 :                 pcc_data[pcc_ss_idx]->pcc_nominal = cppc_ss->latency;
     580                 :            : 
     581                 :          0 :                 pcc_data[pcc_ss_idx]->pcc_comm_addr =
     582                 :          0 :                         acpi_os_ioremap(cppc_ss->base_address, cppc_ss->length);
     583         [ #  # ]:          0 :                 if (!pcc_data[pcc_ss_idx]->pcc_comm_addr) {
     584                 :          0 :                         pr_err("Failed to ioremap PCC comm region mem for %d\n",
     585                 :            :                                pcc_ss_idx);
     586                 :          0 :                         return -ENOMEM;
     587                 :            :                 }
     588                 :            : 
     589                 :            :                 /* Set flag so that we don't come here for each CPU. */
     590                 :          0 :                 pcc_data[pcc_ss_idx]->pcc_channel_acquired = true;
     591                 :            :         }
     592                 :            : 
     593                 :            :         return 0;
     594                 :            : }
     595                 :            : 
     596                 :            : /**
     597                 :            :  * cpc_ffh_supported() - check if FFH reading supported
     598                 :            :  *
     599                 :            :  * Check if the architecture has support for functional fixed hardware
     600                 :            :  * read/write capability.
     601                 :            :  *
     602                 :            :  * Return: true for supported, false for not supported
     603                 :            :  */
     604                 :          0 : bool __weak cpc_ffh_supported(void)
     605                 :            : {
     606                 :          0 :         return false;
     607                 :            : }
     608                 :            : 
     609                 :            : /**
     610                 :            :  * pcc_data_alloc() - Allocate the pcc_data memory for pcc subspace
     611                 :            :  *
     612                 :            :  * Check and allocate the cppc_pcc_data memory.
     613                 :            :  * In some processor configurations it is possible that same subspace
     614                 :            :  * is shared between multiple CPUs. This is seen especially in CPUs
     615                 :            :  * with hardware multi-threading support.
     616                 :            :  *
     617                 :            :  * Return: 0 for success, errno for failure
     618                 :            :  */
     619                 :          0 : int pcc_data_alloc(int pcc_ss_id)
     620                 :            : {
     621         [ #  # ]:          0 :         if (pcc_ss_id < 0 || pcc_ss_id >= MAX_PCC_SUBSPACES)
     622                 :            :                 return -EINVAL;
     623                 :            : 
     624         [ #  # ]:          0 :         if (pcc_data[pcc_ss_id]) {
     625                 :          0 :                 pcc_data[pcc_ss_id]->refcount++;
     626                 :            :         } else {
     627                 :          0 :                 pcc_data[pcc_ss_id] = kzalloc(sizeof(struct cppc_pcc_data),
     628                 :            :                                               GFP_KERNEL);
     629         [ #  # ]:          0 :                 if (!pcc_data[pcc_ss_id])
     630                 :            :                         return -ENOMEM;
     631                 :          0 :                 pcc_data[pcc_ss_id]->refcount++;
     632                 :            :         }
     633                 :            : 
     634                 :            :         return 0;
     635                 :            : }
     636                 :            : 
     637                 :            : /* Check if CPPC revision + num_ent combination is supported */
     638                 :          0 : static bool is_cppc_supported(int revision, int num_ent)
     639                 :            : {
     640                 :          0 :         int expected_num_ent;
     641                 :            : 
     642                 :          0 :         switch (revision) {
     643                 :            :         case CPPC_V2_REV:
     644                 :            :                 expected_num_ent = CPPC_V2_NUM_ENT;
     645                 :            :                 break;
     646                 :          0 :         case CPPC_V3_REV:
     647                 :          0 :                 expected_num_ent = CPPC_V3_NUM_ENT;
     648                 :          0 :                 break;
     649                 :            :         default:
     650                 :            :                 pr_debug("Firmware exports unsupported CPPC revision: %d\n",
     651                 :            :                         revision);
     652                 :            :                 return false;
     653                 :            :         }
     654                 :            : 
     655         [ #  # ]:          0 :         if (expected_num_ent != num_ent) {
     656                 :            :                 pr_debug("Firmware exports %d entries. Expected: %d for CPPC rev:%d\n",
     657                 :            :                         num_ent, expected_num_ent, revision);
     658                 :            :                 return false;
     659                 :            :         }
     660                 :            : 
     661                 :            :         return true;
     662                 :            : }
     663                 :            : 
     664                 :            : /*
     665                 :            :  * An example CPC table looks like the following.
     666                 :            :  *
     667                 :            :  *      Name(_CPC, Package()
     668                 :            :  *                      {
     669                 :            :  *                      17,
     670                 :            :  *                      NumEntries
     671                 :            :  *                      1,
     672                 :            :  *                      // Revision
     673                 :            :  *                      ResourceTemplate(){Register(PCC, 32, 0, 0x120, 2)},
     674                 :            :  *                      // Highest Performance
     675                 :            :  *                      ResourceTemplate(){Register(PCC, 32, 0, 0x124, 2)},
     676                 :            :  *                      // Nominal Performance
     677                 :            :  *                      ResourceTemplate(){Register(PCC, 32, 0, 0x128, 2)},
     678                 :            :  *                      // Lowest Nonlinear Performance
     679                 :            :  *                      ResourceTemplate(){Register(PCC, 32, 0, 0x12C, 2)},
     680                 :            :  *                      // Lowest Performance
     681                 :            :  *                      ResourceTemplate(){Register(PCC, 32, 0, 0x130, 2)},
     682                 :            :  *                      // Guaranteed Performance Register
     683                 :            :  *                      ResourceTemplate(){Register(PCC, 32, 0, 0x110, 2)},
     684                 :            :  *                      // Desired Performance Register
     685                 :            :  *                      ResourceTemplate(){Register(SystemMemory, 0, 0, 0, 0)},
     686                 :            :  *                      ..
     687                 :            :  *                      ..
     688                 :            :  *                      ..
     689                 :            :  *
     690                 :            :  *              }
     691                 :            :  * Each Register() encodes how to access that specific register.
     692                 :            :  * e.g. a sample PCC entry has the following encoding:
     693                 :            :  *
     694                 :            :  *      Register (
     695                 :            :  *              PCC,
     696                 :            :  *              AddressSpaceKeyword
     697                 :            :  *              8,
     698                 :            :  *              //RegisterBitWidth
     699                 :            :  *              8,
     700                 :            :  *              //RegisterBitOffset
     701                 :            :  *              0x30,
     702                 :            :  *              //RegisterAddress
     703                 :            :  *              9
     704                 :            :  *              //AccessSize (subspace ID)
     705                 :            :  *              0
     706                 :            :  *              )
     707                 :            :  *      }
     708                 :            :  */
     709                 :            : 
     710                 :            : /**
     711                 :            :  * acpi_cppc_processor_probe - Search for per CPU _CPC objects.
     712                 :            :  * @pr: Ptr to acpi_processor containing this CPU's logical ID.
     713                 :            :  *
     714                 :            :  *      Return: 0 for success or negative value for err.
     715                 :            :  */
     716                 :         21 : int acpi_cppc_processor_probe(struct acpi_processor *pr)
     717                 :            : {
     718                 :         21 :         struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
     719                 :         21 :         union acpi_object *out_obj, *cpc_obj;
     720                 :         21 :         struct cpc_desc *cpc_ptr;
     721                 :         21 :         struct cpc_reg *gas_t;
     722                 :         21 :         struct device *cpu_dev;
     723                 :         21 :         acpi_handle handle = pr->handle;
     724                 :         21 :         unsigned int num_ent, i, cpc_rev;
     725                 :         21 :         int pcc_subspace_id = -1;
     726                 :         21 :         acpi_status status;
     727                 :         21 :         int ret = -EFAULT;
     728                 :            : 
     729                 :            :         /* Parse the ACPI _CPC table for this CPU. */
     730                 :         21 :         status = acpi_evaluate_object_typed(handle, "_CPC", NULL, &output,
     731                 :            :                         ACPI_TYPE_PACKAGE);
     732         [ +  - ]:         21 :         if (ACPI_FAILURE(status)) {
     733                 :         21 :                 ret = -ENODEV;
     734                 :         21 :                 goto out_buf_free;
     735                 :            :         }
     736                 :            : 
     737                 :          0 :         out_obj = (union acpi_object *) output.pointer;
     738                 :            : 
     739                 :          0 :         cpc_ptr = kzalloc(sizeof(struct cpc_desc), GFP_KERNEL);
     740         [ #  # ]:          0 :         if (!cpc_ptr) {
     741                 :          0 :                 ret = -ENOMEM;
     742                 :          0 :                 goto out_buf_free;
     743                 :            :         }
     744                 :            : 
     745                 :            :         /* First entry is NumEntries. */
     746                 :          0 :         cpc_obj = &out_obj->package.elements[0];
     747         [ #  # ]:          0 :         if (cpc_obj->type == ACPI_TYPE_INTEGER)      {
     748                 :          0 :                 num_ent = cpc_obj->integer.value;
     749                 :            :         } else {
     750                 :          0 :                 pr_debug("Unexpected entry type(%d) for NumEntries\n",
     751                 :            :                                 cpc_obj->type);
     752                 :          0 :                 goto out_free;
     753                 :            :         }
     754                 :          0 :         cpc_ptr->num_entries = num_ent;
     755                 :            : 
     756                 :            :         /* Second entry should be revision. */
     757                 :          0 :         cpc_obj = &out_obj->package.elements[1];
     758         [ #  # ]:          0 :         if (cpc_obj->type == ACPI_TYPE_INTEGER)      {
     759                 :          0 :                 cpc_rev = cpc_obj->integer.value;
     760                 :            :         } else {
     761                 :          0 :                 pr_debug("Unexpected entry type(%d) for Revision\n",
     762                 :            :                                 cpc_obj->type);
     763                 :          0 :                 goto out_free;
     764                 :            :         }
     765                 :          0 :         cpc_ptr->version = cpc_rev;
     766                 :            : 
     767      [ #  #  # ]:          0 :         if (!is_cppc_supported(cpc_rev, num_ent))
     768                 :          0 :                 goto out_free;
     769                 :            : 
     770                 :            :         /* Iterate through remaining entries in _CPC */
     771         [ #  # ]:          0 :         for (i = 2; i < num_ent; i++) {
     772                 :          0 :                 cpc_obj = &out_obj->package.elements[i];
     773                 :            : 
     774         [ #  # ]:          0 :                 if (cpc_obj->type == ACPI_TYPE_INTEGER)      {
     775                 :          0 :                         cpc_ptr->cpc_regs[i-2].type = ACPI_TYPE_INTEGER;
     776                 :          0 :                         cpc_ptr->cpc_regs[i-2].cpc_entry.int_value = cpc_obj->integer.value;
     777         [ #  # ]:          0 :                 } else if (cpc_obj->type == ACPI_TYPE_BUFFER) {
     778                 :          0 :                         gas_t = (struct cpc_reg *)
     779                 :            :                                 cpc_obj->buffer.pointer;
     780                 :            : 
     781                 :            :                         /*
     782                 :            :                          * The PCC Subspace index is encoded inside
     783                 :            :                          * the CPC table entries. The same PCC index
     784                 :            :                          * will be used for all the PCC entries,
     785                 :            :                          * so extract it only once.
     786                 :            :                          */
     787         [ #  # ]:          0 :                         if (gas_t->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) {
     788         [ #  # ]:          0 :                                 if (pcc_subspace_id < 0) {
     789                 :          0 :                                         pcc_subspace_id = gas_t->access_width;
     790         [ #  # ]:          0 :                                         if (pcc_data_alloc(pcc_subspace_id))
     791                 :          0 :                                                 goto out_free;
     792         [ #  # ]:          0 :                                 } else if (pcc_subspace_id != gas_t->access_width) {
     793                 :          0 :                                         pr_debug("Mismatched PCC ids.\n");
     794                 :          0 :                                         goto out_free;
     795                 :            :                                 }
     796         [ #  # ]:          0 :                         } else if (gas_t->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
     797         [ #  # ]:          0 :                                 if (gas_t->address) {
     798                 :          0 :                                         void __iomem *addr;
     799                 :            : 
     800                 :          0 :                                         addr = ioremap(gas_t->address, gas_t->bit_width/8);
     801         [ #  # ]:          0 :                                         if (!addr)
     802                 :          0 :                                                 goto out_free;
     803                 :          0 :                                         cpc_ptr->cpc_regs[i-2].sys_mem_vaddr = addr;
     804                 :            :                                 }
     805                 :            :                         } else {
     806   [ #  #  #  # ]:          0 :                                 if (gas_t->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE || !cpc_ffh_supported()) {
     807                 :            :                                         /* Support only PCC ,SYS MEM and FFH type regs */
     808                 :          0 :                                         pr_debug("Unsupported register type: %d\n", gas_t->space_id);
     809                 :          0 :                                         goto out_free;
     810                 :            :                                 }
     811                 :            :                         }
     812                 :            : 
     813                 :          0 :                         cpc_ptr->cpc_regs[i-2].type = ACPI_TYPE_BUFFER;
     814                 :          0 :                         memcpy(&cpc_ptr->cpc_regs[i-2].cpc_entry.reg, gas_t, sizeof(*gas_t));
     815                 :            :                 } else {
     816                 :          0 :                         pr_debug("Err in entry:%d in CPC table of CPU:%d \n", i, pr->id);
     817                 :          0 :                         goto out_free;
     818                 :            :                 }
     819                 :            :         }
     820                 :          0 :         per_cpu(cpu_pcc_subspace_idx, pr->id) = pcc_subspace_id;
     821                 :            : 
     822                 :            :         /*
     823                 :            :          * Initialize the remaining cpc_regs as unsupported.
     824                 :            :          * Example: In case FW exposes CPPC v2, the below loop will initialize
     825                 :            :          * LOWEST_FREQ and NOMINAL_FREQ regs as unsupported
     826                 :            :          */
     827         [ #  # ]:          0 :         for (i = num_ent - 2; i < MAX_CPC_REG_ENT; i++) {
     828                 :          0 :                 cpc_ptr->cpc_regs[i].type = ACPI_TYPE_INTEGER;
     829                 :          0 :                 cpc_ptr->cpc_regs[i].cpc_entry.int_value = 0;
     830                 :            :         }
     831                 :            : 
     832                 :            : 
     833                 :            :         /* Store CPU Logical ID */
     834                 :          0 :         cpc_ptr->cpu_id = pr->id;
     835                 :            : 
     836                 :            :         /* Parse PSD data for this CPU */
     837                 :          0 :         ret = acpi_get_psd(cpc_ptr, handle);
     838         [ #  # ]:          0 :         if (ret)
     839                 :          0 :                 goto out_free;
     840                 :            : 
     841                 :            :         /* Register PCC channel once for all PCC subspace ID. */
     842   [ #  #  #  # ]:          0 :         if (pcc_subspace_id >= 0 && !pcc_data[pcc_subspace_id]->pcc_channel_acquired) {
     843                 :          0 :                 ret = register_pcc_channel(pcc_subspace_id);
     844         [ #  # ]:          0 :                 if (ret)
     845                 :          0 :                         goto out_free;
     846                 :            : 
     847                 :          0 :                 init_rwsem(&pcc_data[pcc_subspace_id]->pcc_lock);
     848                 :          0 :                 init_waitqueue_head(&pcc_data[pcc_subspace_id]->pcc_write_wait_q);
     849                 :            :         }
     850                 :            : 
     851                 :            :         /* Everything looks okay */
     852                 :          0 :         pr_debug("Parsed CPC struct for CPU: %d\n", pr->id);
     853                 :            : 
     854                 :            :         /* Add per logical CPU nodes for reading its feedback counters. */
     855                 :          0 :         cpu_dev = get_cpu_device(pr->id);
     856         [ #  # ]:          0 :         if (!cpu_dev) {
     857                 :          0 :                 ret = -EINVAL;
     858                 :          0 :                 goto out_free;
     859                 :            :         }
     860                 :            : 
     861                 :            :         /* Plug PSD data into this CPU's CPC descriptor. */
     862                 :          0 :         per_cpu(cpc_desc_ptr, pr->id) = cpc_ptr;
     863                 :            : 
     864                 :          0 :         ret = kobject_init_and_add(&cpc_ptr->kobj, &cppc_ktype, &cpu_dev->kobj,
     865                 :            :                         "acpi_cppc");
     866         [ #  # ]:          0 :         if (ret) {
     867                 :          0 :                 per_cpu(cpc_desc_ptr, pr->id) = NULL;
     868                 :          0 :                 goto out_free;
     869                 :            :         }
     870                 :            : 
     871                 :          0 :         kfree(output.pointer);
     872                 :          0 :         return 0;
     873                 :            : 
     874                 :          0 : out_free:
     875                 :            :         /* Free all the mapped sys mem areas for this CPU */
     876         [ #  # ]:          0 :         for (i = 2; i < cpc_ptr->num_entries; i++) {
     877                 :          0 :                 void __iomem *addr = cpc_ptr->cpc_regs[i-2].sys_mem_vaddr;
     878                 :            : 
     879         [ #  # ]:          0 :                 if (addr)
     880                 :          0 :                         iounmap(addr);
     881                 :            :         }
     882                 :          0 :         kfree(cpc_ptr);
     883                 :            : 
     884                 :         21 : out_buf_free:
     885                 :         21 :         kfree(output.pointer);
     886                 :         21 :         return ret;
     887                 :            : }
     888                 :            : EXPORT_SYMBOL_GPL(acpi_cppc_processor_probe);
     889                 :            : 
     890                 :            : /**
     891                 :            :  * acpi_cppc_processor_exit - Cleanup CPC structs.
     892                 :            :  * @pr: Ptr to acpi_processor containing this CPU's logical ID.
     893                 :            :  *
     894                 :            :  * Return: Void
     895                 :            :  */
     896                 :          0 : void acpi_cppc_processor_exit(struct acpi_processor *pr)
     897                 :            : {
     898                 :          0 :         struct cpc_desc *cpc_ptr;
     899                 :          0 :         unsigned int i;
     900                 :          0 :         void __iomem *addr;
     901                 :          0 :         int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, pr->id);
     902                 :            : 
     903   [ #  #  #  # ]:          0 :         if (pcc_ss_id >=0 && pcc_data[pcc_ss_id]) {
     904         [ #  # ]:          0 :                 if (pcc_data[pcc_ss_id]->pcc_channel_acquired) {
     905                 :          0 :                         pcc_data[pcc_ss_id]->refcount--;
     906         [ #  # ]:          0 :                         if (!pcc_data[pcc_ss_id]->refcount) {
     907                 :          0 :                                 pcc_mbox_free_channel(pcc_data[pcc_ss_id]->pcc_channel);
     908                 :          0 :                                 kfree(pcc_data[pcc_ss_id]);
     909                 :          0 :                                 pcc_data[pcc_ss_id] = NULL;
     910                 :            :                         }
     911                 :            :                 }
     912                 :            :         }
     913                 :            : 
     914                 :          0 :         cpc_ptr = per_cpu(cpc_desc_ptr, pr->id);
     915         [ #  # ]:          0 :         if (!cpc_ptr)
     916                 :            :                 return;
     917                 :            : 
     918                 :            :         /* Free all the mapped sys mem areas for this CPU */
     919         [ #  # ]:          0 :         for (i = 2; i < cpc_ptr->num_entries; i++) {
     920                 :          0 :                 addr = cpc_ptr->cpc_regs[i-2].sys_mem_vaddr;
     921         [ #  # ]:          0 :                 if (addr)
     922                 :          0 :                         iounmap(addr);
     923                 :            :         }
     924                 :            : 
     925                 :          0 :         kobject_put(&cpc_ptr->kobj);
     926                 :          0 :         kfree(cpc_ptr);
     927                 :            : }
     928                 :            : EXPORT_SYMBOL_GPL(acpi_cppc_processor_exit);
     929                 :            : 
     930                 :            : /**
     931                 :            :  * cpc_read_ffh() - Read FFH register
     932                 :            :  * @cpunum:     CPU number to read
     933                 :            :  * @reg:        cppc register information
     934                 :            :  * @val:        place holder for return value
     935                 :            :  *
     936                 :            :  * Read bit_width bits from a specified address and bit_offset
     937                 :            :  *
     938                 :            :  * Return: 0 for success and error code
     939                 :            :  */
     940                 :          0 : int __weak cpc_read_ffh(int cpunum, struct cpc_reg *reg, u64 *val)
     941                 :            : {
     942                 :          0 :         return -ENOTSUPP;
     943                 :            : }
     944                 :            : 
     945                 :            : /**
     946                 :            :  * cpc_write_ffh() - Write FFH register
     947                 :            :  * @cpunum:     CPU number to write
     948                 :            :  * @reg:        cppc register information
     949                 :            :  * @val:        value to write
     950                 :            :  *
     951                 :            :  * Write value of bit_width bits to a specified address and bit_offset
     952                 :            :  *
     953                 :            :  * Return: 0 for success and error code
     954                 :            :  */
     955                 :          0 : int __weak cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val)
     956                 :            : {
     957                 :          0 :         return -ENOTSUPP;
     958                 :            : }
     959                 :            : 
     960                 :            : /*
     961                 :            :  * Since cpc_read and cpc_write are called while holding pcc_lock, it should be
     962                 :            :  * as fast as possible. We have already mapped the PCC subspace during init, so
     963                 :            :  * we can directly write to it.
     964                 :            :  */
     965                 :            : 
     966                 :          0 : static int cpc_read(int cpu, struct cpc_register_resource *reg_res, u64 *val)
     967                 :            : {
     968                 :          0 :         int ret_val = 0;
     969                 :          0 :         void __iomem *vaddr = 0;
     970                 :          0 :         int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu);
     971                 :          0 :         struct cpc_reg *reg = &reg_res->cpc_entry.reg;
     972                 :            : 
     973         [ #  # ]:          0 :         if (reg_res->type == ACPI_TYPE_INTEGER) {
     974                 :          0 :                 *val = reg_res->cpc_entry.int_value;
     975                 :          0 :                 return ret_val;
     976                 :            :         }
     977                 :            : 
     978                 :          0 :         *val = 0;
     979   [ #  #  #  # ]:          0 :         if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM && pcc_ss_id >= 0)
     980                 :          0 :                 vaddr = GET_PCC_VADDR(reg->address, pcc_ss_id);
     981         [ #  # ]:          0 :         else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
     982                 :          0 :                 vaddr = reg_res->sys_mem_vaddr;
     983         [ #  # ]:          0 :         else if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE)
     984                 :          0 :                 return cpc_read_ffh(cpu, reg, val);
     985                 :            :         else
     986                 :          0 :                 return acpi_os_read_memory((acpi_physical_address)reg->address,
     987                 :          0 :                                 val, reg->bit_width);
     988                 :            : 
     989   [ #  #  #  #  :          0 :         switch (reg->bit_width) {
                      # ]
     990                 :            :                 case 8:
     991                 :          0 :                         *val = readb_relaxed(vaddr);
     992                 :          0 :                         break;
     993                 :            :                 case 16:
     994                 :          0 :                         *val = readw_relaxed(vaddr);
     995                 :          0 :                         break;
     996                 :            :                 case 32:
     997                 :          0 :                         *val = readl_relaxed(vaddr);
     998                 :          0 :                         break;
     999                 :            :                 case 64:
    1000                 :          0 :                         *val = readq_relaxed(vaddr);
    1001                 :          0 :                         break;
    1002                 :            :                 default:
    1003                 :            :                         pr_debug("Error: Cannot read %u bit width from PCC for ss: %d\n",
    1004                 :            :                                  reg->bit_width, pcc_ss_id);
    1005                 :            :                         ret_val = -EFAULT;
    1006                 :            :         }
    1007                 :            : 
    1008                 :            :         return ret_val;
    1009                 :            : }
    1010                 :            : 
    1011                 :          0 : static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
    1012                 :            : {
    1013                 :          0 :         int ret_val = 0;
    1014                 :          0 :         void __iomem *vaddr = 0;
    1015                 :          0 :         int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu);
    1016                 :          0 :         struct cpc_reg *reg = &reg_res->cpc_entry.reg;
    1017                 :            : 
    1018   [ #  #  #  # ]:          0 :         if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM && pcc_ss_id >= 0)
    1019                 :          0 :                 vaddr = GET_PCC_VADDR(reg->address, pcc_ss_id);
    1020         [ #  # ]:          0 :         else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
    1021                 :          0 :                 vaddr = reg_res->sys_mem_vaddr;
    1022         [ #  # ]:          0 :         else if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE)
    1023                 :          0 :                 return cpc_write_ffh(cpu, reg, val);
    1024                 :            :         else
    1025                 :          0 :                 return acpi_os_write_memory((acpi_physical_address)reg->address,
    1026                 :          0 :                                 val, reg->bit_width);
    1027                 :            : 
    1028   [ #  #  #  #  :          0 :         switch (reg->bit_width) {
                      # ]
    1029                 :          0 :                 case 8:
    1030                 :          0 :                         writeb_relaxed(val, vaddr);
    1031                 :            :                         break;
    1032                 :          0 :                 case 16:
    1033                 :          0 :                         writew_relaxed(val, vaddr);
    1034                 :            :                         break;
    1035                 :          0 :                 case 32:
    1036                 :          0 :                         writel_relaxed(val, vaddr);
    1037                 :            :                         break;
    1038                 :            :                 case 64:
    1039                 :          0 :                         writeq_relaxed(val, vaddr);
    1040                 :            :                         break;
    1041                 :            :                 default:
    1042                 :            :                         pr_debug("Error: Cannot write %u bit width to PCC for ss: %d\n",
    1043                 :            :                                  reg->bit_width, pcc_ss_id);
    1044                 :            :                         ret_val = -EFAULT;
    1045                 :            :                         break;
    1046                 :            :         }
    1047                 :            : 
    1048                 :            :         return ret_val;
    1049                 :            : }
    1050                 :            : 
    1051                 :            : /**
    1052                 :            :  * cppc_get_desired_perf - Get the value of desired performance register.
    1053                 :            :  * @cpunum: CPU from which to get desired performance.
    1054                 :            :  * @desired_perf: address of a variable to store the returned desired performance
    1055                 :            :  *
    1056                 :            :  * Return: 0 for success, -EIO otherwise.
    1057                 :            :  */
    1058                 :          0 : int cppc_get_desired_perf(int cpunum, u64 *desired_perf)
    1059                 :            : {
    1060                 :          0 :         struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum);
    1061                 :          0 :         int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum);
    1062                 :          0 :         struct cpc_register_resource *desired_reg;
    1063                 :          0 :         struct cppc_pcc_data *pcc_ss_data = NULL;
    1064                 :            : 
    1065                 :          0 :         desired_reg = &cpc_desc->cpc_regs[DESIRED_PERF];
    1066                 :            : 
    1067   [ #  #  #  # ]:          0 :         if (CPC_IN_PCC(desired_reg)) {
    1068                 :          0 :                 int ret = 0;
    1069                 :            : 
    1070         [ #  # ]:          0 :                 if (pcc_ss_id < 0)
    1071                 :            :                         return -EIO;
    1072                 :            : 
    1073                 :          0 :                 pcc_ss_data = pcc_data[pcc_ss_id];
    1074                 :            : 
    1075                 :          0 :                 down_write(&pcc_ss_data->pcc_lock);
    1076                 :            : 
    1077         [ #  # ]:          0 :                 if (send_pcc_cmd(pcc_ss_id, CMD_READ) >= 0)
    1078                 :          0 :                         cpc_read(cpunum, desired_reg, desired_perf);
    1079                 :            :                 else
    1080                 :            :                         ret = -EIO;
    1081                 :            : 
    1082                 :          0 :                 up_write(&pcc_ss_data->pcc_lock);
    1083                 :            : 
    1084                 :          0 :                 return ret;
    1085                 :            :         }
    1086                 :            : 
    1087                 :          0 :         cpc_read(cpunum, desired_reg, desired_perf);
    1088                 :            : 
    1089                 :          0 :         return 0;
    1090                 :            : }
    1091                 :            : EXPORT_SYMBOL_GPL(cppc_get_desired_perf);
    1092                 :            : 
    1093                 :            : /**
    1094                 :            :  * cppc_get_perf_caps - Get a CPU's performance capabilities.
    1095                 :            :  * @cpunum: CPU from which to get capabilities info.
    1096                 :            :  * @perf_caps: ptr to cppc_perf_caps. See cppc_acpi.h
    1097                 :            :  *
    1098                 :            :  * Return: 0 for success with perf_caps populated else -ERRNO.
    1099                 :            :  */
    1100                 :          0 : int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
    1101                 :            : {
    1102                 :          0 :         struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum);
    1103                 :          0 :         struct cpc_register_resource *highest_reg, *lowest_reg,
    1104                 :            :                 *lowest_non_linear_reg, *nominal_reg, *guaranteed_reg,
    1105                 :            :                 *low_freq_reg = NULL, *nom_freq_reg = NULL;
    1106                 :          0 :         u64 high, low, guaranteed, nom, min_nonlinear, low_f = 0, nom_f = 0;
    1107                 :          0 :         int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum);
    1108                 :          0 :         struct cppc_pcc_data *pcc_ss_data = NULL;
    1109                 :          0 :         int ret = 0, regs_in_pcc = 0;
    1110                 :            : 
    1111         [ #  # ]:          0 :         if (!cpc_desc) {
    1112                 :            :                 pr_debug("No CPC descriptor for CPU:%d\n", cpunum);
    1113                 :            :                 return -ENODEV;
    1114                 :            :         }
    1115                 :            : 
    1116                 :          0 :         highest_reg = &cpc_desc->cpc_regs[HIGHEST_PERF];
    1117                 :          0 :         lowest_reg = &cpc_desc->cpc_regs[LOWEST_PERF];
    1118                 :          0 :         lowest_non_linear_reg = &cpc_desc->cpc_regs[LOW_NON_LINEAR_PERF];
    1119                 :          0 :         nominal_reg = &cpc_desc->cpc_regs[NOMINAL_PERF];
    1120                 :          0 :         low_freq_reg = &cpc_desc->cpc_regs[LOWEST_FREQ];
    1121                 :          0 :         nom_freq_reg = &cpc_desc->cpc_regs[NOMINAL_FREQ];
    1122                 :          0 :         guaranteed_reg = &cpc_desc->cpc_regs[GUARANTEED_PERF];
    1123                 :            : 
    1124                 :            :         /* Are any of the regs PCC ?*/
    1125   [ #  #  #  #  :          0 :         if (CPC_IN_PCC(highest_reg) || CPC_IN_PCC(lowest_reg) ||
             #  #  #  # ]
    1126   [ #  #  #  #  :          0 :                 CPC_IN_PCC(lowest_non_linear_reg) || CPC_IN_PCC(nominal_reg) ||
             #  #  #  # ]
    1127   [ #  #  #  #  :          0 :                 CPC_IN_PCC(low_freq_reg) || CPC_IN_PCC(nom_freq_reg)) {
             #  #  #  # ]
    1128         [ #  # ]:          0 :                 if (pcc_ss_id < 0) {
    1129                 :            :                         pr_debug("Invalid pcc_ss_id\n");
    1130                 :            :                         return -ENODEV;
    1131                 :            :                 }
    1132                 :          0 :                 pcc_ss_data = pcc_data[pcc_ss_id];
    1133                 :          0 :                 regs_in_pcc = 1;
    1134                 :          0 :                 down_write(&pcc_ss_data->pcc_lock);
    1135                 :            :                 /* Ring doorbell once to update PCC subspace */
    1136         [ #  # ]:          0 :                 if (send_pcc_cmd(pcc_ss_id, CMD_READ) < 0) {
    1137                 :          0 :                         ret = -EIO;
    1138                 :          0 :                         goto out_err;
    1139                 :            :                 }
    1140                 :            :         }
    1141                 :            : 
    1142                 :          0 :         cpc_read(cpunum, highest_reg, &high);
    1143                 :          0 :         perf_caps->highest_perf = high;
    1144                 :            : 
    1145                 :          0 :         cpc_read(cpunum, lowest_reg, &low);
    1146                 :          0 :         perf_caps->lowest_perf = low;
    1147                 :            : 
    1148                 :          0 :         cpc_read(cpunum, nominal_reg, &nom);
    1149                 :          0 :         perf_caps->nominal_perf = nom;
    1150                 :            : 
    1151         [ #  # ]:          0 :         if (guaranteed_reg->type != ACPI_TYPE_BUFFER  ||
    1152   [ #  #  #  #  :          0 :             IS_NULL_REG(&guaranteed_reg->cpc_entry.reg)) {
                   #  # ]
    1153                 :          0 :                 perf_caps->guaranteed_perf = 0;
    1154                 :            :         } else {
    1155                 :          0 :                 cpc_read(cpunum, guaranteed_reg, &guaranteed);
    1156                 :          0 :                 perf_caps->guaranteed_perf = guaranteed;
    1157                 :            :         }
    1158                 :            : 
    1159                 :          0 :         cpc_read(cpunum, lowest_non_linear_reg, &min_nonlinear);
    1160                 :          0 :         perf_caps->lowest_nonlinear_perf = min_nonlinear;
    1161                 :            : 
    1162   [ #  #  #  #  :          0 :         if (!high || !low || !nom || !min_nonlinear)
             #  #  #  # ]
    1163                 :          0 :                 ret = -EFAULT;
    1164                 :            : 
    1165                 :            :         /* Read optional lowest and nominal frequencies if present */
    1166   [ #  #  #  #  :          0 :         if (CPC_SUPPORTED(low_freq_reg))
          #  #  #  #  #  
                      # ]
    1167                 :          0 :                 cpc_read(cpunum, low_freq_reg, &low_f);
    1168                 :            : 
    1169   [ #  #  #  #  :          0 :         if (CPC_SUPPORTED(nom_freq_reg))
          #  #  #  #  #  
                      # ]
    1170                 :          0 :                 cpc_read(cpunum, nom_freq_reg, &nom_f);
    1171                 :            : 
    1172                 :          0 :         perf_caps->lowest_freq = low_f;
    1173                 :          0 :         perf_caps->nominal_freq = nom_f;
    1174                 :            : 
    1175                 :            : 
    1176                 :          0 : out_err:
    1177         [ #  # ]:          0 :         if (regs_in_pcc)
    1178                 :          0 :                 up_write(&pcc_ss_data->pcc_lock);
    1179                 :            :         return ret;
    1180                 :            : }
    1181                 :            : EXPORT_SYMBOL_GPL(cppc_get_perf_caps);
    1182                 :            : 
    1183                 :            : /**
    1184                 :            :  * cppc_get_perf_ctrs - Read a CPU's performance feedback counters.
    1185                 :            :  * @cpunum: CPU from which to read counters.
    1186                 :            :  * @perf_fb_ctrs: ptr to cppc_perf_fb_ctrs. See cppc_acpi.h
    1187                 :            :  *
    1188                 :            :  * Return: 0 for success with perf_fb_ctrs populated else -ERRNO.
    1189                 :            :  */
    1190                 :          0 : int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs)
    1191                 :            : {
    1192                 :          0 :         struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum);
    1193                 :          0 :         struct cpc_register_resource *delivered_reg, *reference_reg,
    1194                 :            :                 *ref_perf_reg, *ctr_wrap_reg;
    1195                 :          0 :         int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum);
    1196                 :          0 :         struct cppc_pcc_data *pcc_ss_data = NULL;
    1197                 :          0 :         u64 delivered, reference, ref_perf, ctr_wrap_time;
    1198                 :          0 :         int ret = 0, regs_in_pcc = 0;
    1199                 :            : 
    1200         [ #  # ]:          0 :         if (!cpc_desc) {
    1201                 :            :                 pr_debug("No CPC descriptor for CPU:%d\n", cpunum);
    1202                 :            :                 return -ENODEV;
    1203                 :            :         }
    1204                 :            : 
    1205                 :          0 :         delivered_reg = &cpc_desc->cpc_regs[DELIVERED_CTR];
    1206                 :          0 :         reference_reg = &cpc_desc->cpc_regs[REFERENCE_CTR];
    1207                 :          0 :         ref_perf_reg = &cpc_desc->cpc_regs[REFERENCE_PERF];
    1208                 :          0 :         ctr_wrap_reg = &cpc_desc->cpc_regs[CTR_WRAP_TIME];
    1209                 :            : 
    1210                 :            :         /*
    1211                 :            :          * If reference perf register is not supported then we should
    1212                 :            :          * use the nominal perf value
    1213                 :            :          */
    1214   [ #  #  #  #  :          0 :         if (!CPC_SUPPORTED(ref_perf_reg))
          #  #  #  #  #  
                      # ]
    1215                 :          0 :                 ref_perf_reg = &cpc_desc->cpc_regs[NOMINAL_PERF];
    1216                 :            : 
    1217                 :            :         /* Are any of the regs PCC ?*/
    1218   [ #  #  #  #  :          0 :         if (CPC_IN_PCC(delivered_reg) || CPC_IN_PCC(reference_reg) ||
             #  #  #  # ]
    1219   [ #  #  #  #  :          0 :                 CPC_IN_PCC(ctr_wrap_reg) || CPC_IN_PCC(ref_perf_reg)) {
             #  #  #  # ]
    1220         [ #  # ]:          0 :                 if (pcc_ss_id < 0) {
    1221                 :            :                         pr_debug("Invalid pcc_ss_id\n");
    1222                 :            :                         return -ENODEV;
    1223                 :            :                 }
    1224                 :          0 :                 pcc_ss_data = pcc_data[pcc_ss_id];
    1225                 :          0 :                 down_write(&pcc_ss_data->pcc_lock);
    1226                 :          0 :                 regs_in_pcc = 1;
    1227                 :            :                 /* Ring doorbell once to update PCC subspace */
    1228         [ #  # ]:          0 :                 if (send_pcc_cmd(pcc_ss_id, CMD_READ) < 0) {
    1229                 :          0 :                         ret = -EIO;
    1230                 :          0 :                         goto out_err;
    1231                 :            :                 }
    1232                 :            :         }
    1233                 :            : 
    1234                 :          0 :         cpc_read(cpunum, delivered_reg, &delivered);
    1235                 :          0 :         cpc_read(cpunum, reference_reg, &reference);
    1236                 :          0 :         cpc_read(cpunum, ref_perf_reg, &ref_perf);
    1237                 :            : 
    1238                 :            :         /*
    1239                 :            :          * Per spec, if ctr_wrap_time optional register is unsupported, then the
    1240                 :            :          * performance counters are assumed to never wrap during the lifetime of
    1241                 :            :          * platform
    1242                 :            :          */
    1243                 :          0 :         ctr_wrap_time = (u64)(~((u64)0));
    1244   [ #  #  #  #  :          0 :         if (CPC_SUPPORTED(ctr_wrap_reg))
          #  #  #  #  #  
                      # ]
    1245                 :          0 :                 cpc_read(cpunum, ctr_wrap_reg, &ctr_wrap_time);
    1246                 :            : 
    1247   [ #  #  #  #  :          0 :         if (!delivered || !reference || !ref_perf) {
                   #  # ]
    1248                 :          0 :                 ret = -EFAULT;
    1249                 :          0 :                 goto out_err;
    1250                 :            :         }
    1251                 :            : 
    1252                 :          0 :         perf_fb_ctrs->delivered = delivered;
    1253                 :          0 :         perf_fb_ctrs->reference = reference;
    1254                 :          0 :         perf_fb_ctrs->reference_perf = ref_perf;
    1255                 :          0 :         perf_fb_ctrs->wraparound_time = ctr_wrap_time;
    1256                 :          0 : out_err:
    1257         [ #  # ]:          0 :         if (regs_in_pcc)
    1258                 :          0 :                 up_write(&pcc_ss_data->pcc_lock);
    1259                 :            :         return ret;
    1260                 :            : }
    1261                 :            : EXPORT_SYMBOL_GPL(cppc_get_perf_ctrs);
    1262                 :            : 
    1263                 :            : /**
    1264                 :            :  * cppc_set_perf - Set a CPU's performance controls.
    1265                 :            :  * @cpu: CPU for which to set performance controls.
    1266                 :            :  * @perf_ctrls: ptr to cppc_perf_ctrls. See cppc_acpi.h
    1267                 :            :  *
    1268                 :            :  * Return: 0 for success, -ERRNO otherwise.
    1269                 :            :  */
    1270                 :          0 : int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
    1271                 :            : {
    1272                 :          0 :         struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu);
    1273                 :          0 :         struct cpc_register_resource *desired_reg;
    1274                 :          0 :         int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu);
    1275                 :          0 :         struct cppc_pcc_data *pcc_ss_data = NULL;
    1276                 :          0 :         int ret = 0;
    1277                 :            : 
    1278         [ #  # ]:          0 :         if (!cpc_desc) {
    1279                 :            :                 pr_debug("No CPC descriptor for CPU:%d\n", cpu);
    1280                 :            :                 return -ENODEV;
    1281                 :            :         }
    1282                 :            : 
    1283                 :          0 :         desired_reg = &cpc_desc->cpc_regs[DESIRED_PERF];
    1284                 :            : 
    1285                 :            :         /*
    1286                 :            :          * This is Phase-I where we want to write to CPC registers
    1287                 :            :          * -> We want all CPUs to be able to execute this phase in parallel
    1288                 :            :          *
    1289                 :            :          * Since read_lock can be acquired by multiple CPUs simultaneously we
    1290                 :            :          * achieve that goal here
    1291                 :            :          */
    1292   [ #  #  #  # ]:          0 :         if (CPC_IN_PCC(desired_reg)) {
    1293         [ #  # ]:          0 :                 if (pcc_ss_id < 0) {
    1294                 :            :                         pr_debug("Invalid pcc_ss_id\n");
    1295                 :            :                         return -ENODEV;
    1296                 :            :                 }
    1297                 :          0 :                 pcc_ss_data = pcc_data[pcc_ss_id];
    1298                 :          0 :                 down_read(&pcc_ss_data->pcc_lock); /* BEGIN Phase-I */
    1299         [ #  # ]:          0 :                 if (pcc_ss_data->platform_owns_pcc) {
    1300                 :          0 :                         ret = check_pcc_chan(pcc_ss_id, false);
    1301         [ #  # ]:          0 :                         if (ret) {
    1302                 :          0 :                                 up_read(&pcc_ss_data->pcc_lock);
    1303                 :          0 :                                 return ret;
    1304                 :            :                         }
    1305                 :            :                 }
    1306                 :            :                 /*
    1307                 :            :                  * Update the pending_write to make sure a PCC CMD_READ will not
    1308                 :            :                  * arrive and steal the channel during the switch to write lock
    1309                 :            :                  */
    1310                 :          0 :                 pcc_ss_data->pending_pcc_write_cmd = true;
    1311                 :          0 :                 cpc_desc->write_cmd_id = pcc_ss_data->pcc_write_cnt;
    1312                 :          0 :                 cpc_desc->write_cmd_status = 0;
    1313                 :            :         }
    1314                 :            : 
    1315                 :            :         /*
    1316                 :            :          * Skip writing MIN/MAX until Linux knows how to come up with
    1317                 :            :          * useful values.
    1318                 :            :          */
    1319                 :          0 :         cpc_write(cpu, desired_reg, perf_ctrls->desired_perf);
    1320                 :            : 
    1321   [ #  #  #  # ]:          0 :         if (CPC_IN_PCC(desired_reg))
    1322                 :          0 :                 up_read(&pcc_ss_data->pcc_lock); /* END Phase-I */
    1323                 :            :         /*
    1324                 :            :          * This is Phase-II where we transfer the ownership of PCC to Platform
    1325                 :            :          *
    1326                 :            :          * Short Summary: Basically if we think of a group of cppc_set_perf
    1327                 :            :          * requests that happened in short overlapping interval. The last CPU to
    1328                 :            :          * come out of Phase-I will enter Phase-II and ring the doorbell.
    1329                 :            :          *
    1330                 :            :          * We have the following requirements for Phase-II:
    1331                 :            :          *     1. We want to execute Phase-II only when there are no CPUs
    1332                 :            :          * currently executing in Phase-I
    1333                 :            :          *     2. Once we start Phase-II we want to avoid all other CPUs from
    1334                 :            :          * entering Phase-I.
    1335                 :            :          *     3. We want only one CPU among all those who went through Phase-I
    1336                 :            :          * to run phase-II
    1337                 :            :          *
    1338                 :            :          * If write_trylock fails to get the lock and doesn't transfer the
    1339                 :            :          * PCC ownership to the platform, then one of the following will be TRUE
    1340                 :            :          *     1. There is at-least one CPU in Phase-I which will later execute
    1341                 :            :          * write_trylock, so the CPUs in Phase-I will be responsible for
    1342                 :            :          * executing the Phase-II.
    1343                 :            :          *     2. Some other CPU has beaten this CPU to successfully execute the
    1344                 :            :          * write_trylock and has already acquired the write_lock. We know for a
    1345                 :            :          * fact it (other CPU acquiring the write_lock) couldn't have happened
    1346                 :            :          * before this CPU's Phase-I as we held the read_lock.
    1347                 :            :          *     3. Some other CPU executing pcc CMD_READ has stolen the
    1348                 :            :          * down_write, in which case, send_pcc_cmd will check for pending
    1349                 :            :          * CMD_WRITE commands by checking the pending_pcc_write_cmd.
    1350                 :            :          * So this CPU can be certain that its request will be delivered
    1351                 :            :          *    So in all cases, this CPU knows that its request will be delivered
    1352                 :            :          * by another CPU and can return
    1353                 :            :          *
    1354                 :            :          * After getting the down_write we still need to check for
    1355                 :            :          * pending_pcc_write_cmd to take care of the following scenario
    1356                 :            :          *    The thread running this code could be scheduled out between
    1357                 :            :          * Phase-I and Phase-II. Before it is scheduled back on, another CPU
    1358                 :            :          * could have delivered the request to Platform by triggering the
    1359                 :            :          * doorbell and transferred the ownership of PCC to platform. So this
    1360                 :            :          * avoids triggering an unnecessary doorbell and more importantly before
    1361                 :            :          * triggering the doorbell it makes sure that the PCC channel ownership
    1362                 :            :          * is still with OSPM.
    1363                 :            :          *   pending_pcc_write_cmd can also be cleared by a different CPU, if
    1364                 :            :          * there was a pcc CMD_READ waiting on down_write and it steals the lock
    1365                 :            :          * before the pcc CMD_WRITE is completed. pcc_send_cmd checks for this
    1366                 :            :          * case during a CMD_READ and if there are pending writes it delivers
    1367                 :            :          * the write command before servicing the read command
    1368                 :            :          */
    1369   [ #  #  #  # ]:          0 :         if (CPC_IN_PCC(desired_reg)) {
    1370         [ #  # ]:          0 :                 if (down_write_trylock(&pcc_ss_data->pcc_lock)) {/* BEGIN Phase-II */
    1371                 :            :                         /* Update only if there are pending write commands */
    1372         [ #  # ]:          0 :                         if (pcc_ss_data->pending_pcc_write_cmd)
    1373                 :          0 :                                 send_pcc_cmd(pcc_ss_id, CMD_WRITE);
    1374                 :          0 :                         up_write(&pcc_ss_data->pcc_lock);        /* END Phase-II */
    1375                 :            :                 } else
    1376                 :            :                         /* Wait until pcc_write_cnt is updated by send_pcc_cmd */
    1377   [ #  #  #  # ]:          0 :                         wait_event(pcc_ss_data->pcc_write_wait_q,
    1378                 :            :                                    cpc_desc->write_cmd_id != pcc_ss_data->pcc_write_cnt);
    1379                 :            : 
    1380                 :            :                 /* send_pcc_cmd updates the status in case of failure */
    1381                 :          0 :                 ret = cpc_desc->write_cmd_status;
    1382                 :            :         }
    1383                 :            :         return ret;
    1384                 :            : }
    1385                 :            : EXPORT_SYMBOL_GPL(cppc_set_perf);
    1386                 :            : 
    1387                 :            : /**
    1388                 :            :  * cppc_get_transition_latency - returns frequency transition latency in ns
    1389                 :            :  *
    1390                 :            :  * ACPI CPPC does not explicitly specifiy how a platform can specify the
    1391                 :            :  * transition latency for perfromance change requests. The closest we have
    1392                 :            :  * is the timing information from the PCCT tables which provides the info
    1393                 :            :  * on the number and frequency of PCC commands the platform can handle.
    1394                 :            :  */
    1395                 :          0 : unsigned int cppc_get_transition_latency(int cpu_num)
    1396                 :            : {
    1397                 :            :         /*
    1398                 :            :          * Expected transition latency is based on the PCCT timing values
    1399                 :            :          * Below are definition from ACPI spec:
    1400                 :            :          * pcc_nominal- Expected latency to process a command, in microseconds
    1401                 :            :          * pcc_mpar   - The maximum number of periodic requests that the subspace
    1402                 :            :          *              channel can support, reported in commands per minute. 0
    1403                 :            :          *              indicates no limitation.
    1404                 :            :          * pcc_mrtt   - The minimum amount of time that OSPM must wait after the
    1405                 :            :          *              completion of a command before issuing the next command,
    1406                 :            :          *              in microseconds.
    1407                 :            :          */
    1408                 :          0 :         unsigned int latency_ns = 0;
    1409                 :          0 :         struct cpc_desc *cpc_desc;
    1410                 :          0 :         struct cpc_register_resource *desired_reg;
    1411                 :          0 :         int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu_num);
    1412                 :          0 :         struct cppc_pcc_data *pcc_ss_data;
    1413                 :            : 
    1414                 :          0 :         cpc_desc = per_cpu(cpc_desc_ptr, cpu_num);
    1415         [ #  # ]:          0 :         if (!cpc_desc)
    1416                 :            :                 return CPUFREQ_ETERNAL;
    1417                 :            : 
    1418                 :          0 :         desired_reg = &cpc_desc->cpc_regs[DESIRED_PERF];
    1419   [ #  #  #  # ]:          0 :         if (!CPC_IN_PCC(desired_reg))
    1420                 :            :                 return CPUFREQ_ETERNAL;
    1421                 :            : 
    1422         [ #  # ]:          0 :         if (pcc_ss_id < 0)
    1423                 :            :                 return CPUFREQ_ETERNAL;
    1424                 :            : 
    1425                 :          0 :         pcc_ss_data = pcc_data[pcc_ss_id];
    1426         [ #  # ]:          0 :         if (pcc_ss_data->pcc_mpar)
    1427                 :          0 :                 latency_ns = 60 * (1000 * 1000 * 1000 / pcc_ss_data->pcc_mpar);
    1428                 :            : 
    1429                 :          0 :         latency_ns = max(latency_ns, pcc_ss_data->pcc_nominal * 1000);
    1430                 :          0 :         latency_ns = max(latency_ns, pcc_ss_data->pcc_mrtt * 1000);
    1431                 :            : 
    1432                 :          0 :         return latency_ns;
    1433                 :            : }
    1434                 :            : EXPORT_SYMBOL_GPL(cppc_get_transition_latency);

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