LCOV - code coverage report
Current view: top level - include/scsi - scsi_host.h (source / functions) Hit Total Coverage
Test: combined.info Lines: 17 24 70.8 %
Date: 2022-04-01 14:58:12 Functions: 0 0 -
Branches: 18 166 10.8 %

           Branch data     Line data    Source code
       1                 :            : /* SPDX-License-Identifier: GPL-2.0 */
       2                 :            : #ifndef _SCSI_SCSI_HOST_H
       3                 :            : #define _SCSI_SCSI_HOST_H
       4                 :            : 
       5                 :            : #include <linux/device.h>
       6                 :            : #include <linux/list.h>
       7                 :            : #include <linux/types.h>
       8                 :            : #include <linux/workqueue.h>
       9                 :            : #include <linux/mutex.h>
      10                 :            : #include <linux/seq_file.h>
      11                 :            : #include <linux/blk-mq.h>
      12                 :            : #include <scsi/scsi.h>
      13                 :            : 
      14                 :            : struct block_device;
      15                 :            : struct completion;
      16                 :            : struct module;
      17                 :            : struct scsi_cmnd;
      18                 :            : struct scsi_device;
      19                 :            : struct scsi_host_cmd_pool;
      20                 :            : struct scsi_target;
      21                 :            : struct Scsi_Host;
      22                 :            : struct scsi_host_cmd_pool;
      23                 :            : struct scsi_transport_template;
      24                 :            : 
      25                 :            : 
      26                 :            : #define SG_ALL  SG_CHUNK_SIZE
      27                 :            : 
      28                 :            : #define MODE_UNKNOWN 0x00
      29                 :            : #define MODE_INITIATOR 0x01
      30                 :            : #define MODE_TARGET 0x02
      31                 :            : 
      32                 :            : struct scsi_host_template {
      33                 :            :         struct module *module;
      34                 :            :         const char *name;
      35                 :            : 
      36                 :            :         /*
      37                 :            :          * The info function will return whatever useful information the
      38                 :            :          * developer sees fit.  If not provided, then the name field will
      39                 :            :          * be used instead.
      40                 :            :          *
      41                 :            :          * Status: OPTIONAL
      42                 :            :          */
      43                 :            :         const char *(* info)(struct Scsi_Host *);
      44                 :            : 
      45                 :            :         /*
      46                 :            :          * Ioctl interface
      47                 :            :          *
      48                 :            :          * Status: OPTIONAL
      49                 :            :          */
      50                 :            :         int (*ioctl)(struct scsi_device *dev, unsigned int cmd,
      51                 :            :                      void __user *arg);
      52                 :            : 
      53                 :            : 
      54                 :            : #ifdef CONFIG_COMPAT
      55                 :            :         /* 
      56                 :            :          * Compat handler. Handle 32bit ABI.
      57                 :            :          * When unknown ioctl is passed return -ENOIOCTLCMD.
      58                 :            :          *
      59                 :            :          * Status: OPTIONAL
      60                 :            :          */
      61                 :            :         int (*compat_ioctl)(struct scsi_device *dev, unsigned int cmd,
      62                 :            :                             void __user *arg);
      63                 :            : #endif
      64                 :            : 
      65                 :            :         /*
      66                 :            :          * The queuecommand function is used to queue up a scsi
      67                 :            :          * command block to the LLDD.  When the driver finished
      68                 :            :          * processing the command the done callback is invoked.
      69                 :            :          *
      70                 :            :          * If queuecommand returns 0, then the driver has accepted the
      71                 :            :          * command.  It must also push it to the HBA if the scsi_cmnd
      72                 :            :          * flag SCMD_LAST is set, or if the driver does not implement
      73                 :            :          * commit_rqs.  The done() function must be called on the command
      74                 :            :          * when the driver has finished with it. (you may call done on the
      75                 :            :          * command before queuecommand returns, but in this case you
      76                 :            :          * *must* return 0 from queuecommand).
      77                 :            :          *
      78                 :            :          * Queuecommand may also reject the command, in which case it may
      79                 :            :          * not touch the command and must not call done() for it.
      80                 :            :          *
      81                 :            :          * There are two possible rejection returns:
      82                 :            :          *
      83                 :            :          *   SCSI_MLQUEUE_DEVICE_BUSY: Block this device temporarily, but
      84                 :            :          *   allow commands to other devices serviced by this host.
      85                 :            :          *
      86                 :            :          *   SCSI_MLQUEUE_HOST_BUSY: Block all devices served by this
      87                 :            :          *   host temporarily.
      88                 :            :          *
      89                 :            :          * For compatibility, any other non-zero return is treated the
      90                 :            :          * same as SCSI_MLQUEUE_HOST_BUSY.
      91                 :            :          *
      92                 :            :          * NOTE: "temporarily" means either until the next command for#
      93                 :            :          * this device/host completes, or a period of time determined by
      94                 :            :          * I/O pressure in the system if there are no other outstanding
      95                 :            :          * commands.
      96                 :            :          *
      97                 :            :          * STATUS: REQUIRED
      98                 :            :          */
      99                 :            :         int (* queuecommand)(struct Scsi_Host *, struct scsi_cmnd *);
     100                 :            : 
     101                 :            :         /*
     102                 :            :          * The commit_rqs function is used to trigger a hardware
     103                 :            :          * doorbell after some requests have been queued with
     104                 :            :          * queuecommand, when an error is encountered before sending
     105                 :            :          * the request with SCMD_LAST set.
     106                 :            :          *
     107                 :            :          * STATUS: OPTIONAL
     108                 :            :          */
     109                 :            :         void (*commit_rqs)(struct Scsi_Host *, u16);
     110                 :            : 
     111                 :            :         /*
     112                 :            :          * This is an error handling strategy routine.  You don't need to
     113                 :            :          * define one of these if you don't want to - there is a default
     114                 :            :          * routine that is present that should work in most cases.  For those
     115                 :            :          * driver authors that have the inclination and ability to write their
     116                 :            :          * own strategy routine, this is where it is specified.  Note - the
     117                 :            :          * strategy routine is *ALWAYS* run in the context of the kernel eh
     118                 :            :          * thread.  Thus you are guaranteed to *NOT* be in an interrupt
     119                 :            :          * handler when you execute this, and you are also guaranteed to
     120                 :            :          * *NOT* have any other commands being queued while you are in the
     121                 :            :          * strategy routine. When you return from this function, operations
     122                 :            :          * return to normal.
     123                 :            :          *
     124                 :            :          * See scsi_error.c scsi_unjam_host for additional comments about
     125                 :            :          * what this function should and should not be attempting to do.
     126                 :            :          *
     127                 :            :          * Status: REQUIRED     (at least one of them)
     128                 :            :          */
     129                 :            :         int (* eh_abort_handler)(struct scsi_cmnd *);
     130                 :            :         int (* eh_device_reset_handler)(struct scsi_cmnd *);
     131                 :            :         int (* eh_target_reset_handler)(struct scsi_cmnd *);
     132                 :            :         int (* eh_bus_reset_handler)(struct scsi_cmnd *);
     133                 :            :         int (* eh_host_reset_handler)(struct scsi_cmnd *);
     134                 :            : 
     135                 :            :         /*
     136                 :            :          * Before the mid layer attempts to scan for a new device where none
     137                 :            :          * currently exists, it will call this entry in your driver.  Should
     138                 :            :          * your driver need to allocate any structs or perform any other init
     139                 :            :          * items in order to send commands to a currently unused target/lun
     140                 :            :          * combo, then this is where you can perform those allocations.  This
     141                 :            :          * is specifically so that drivers won't have to perform any kind of
     142                 :            :          * "is this a new device" checks in their queuecommand routine,
     143                 :            :          * thereby making the hot path a bit quicker.
     144                 :            :          *
     145                 :            :          * Return values: 0 on success, non-0 on failure
     146                 :            :          *
     147                 :            :          * Deallocation:  If we didn't find any devices at this ID, you will
     148                 :            :          * get an immediate call to slave_destroy().  If we find something
     149                 :            :          * here then you will get a call to slave_configure(), then the
     150                 :            :          * device will be used for however long it is kept around, then when
     151                 :            :          * the device is removed from the system (or * possibly at reboot
     152                 :            :          * time), you will then get a call to slave_destroy().  This is
     153                 :            :          * assuming you implement slave_configure and slave_destroy.
     154                 :            :          * However, if you allocate memory and hang it off the device struct,
     155                 :            :          * then you must implement the slave_destroy() routine at a minimum
     156                 :            :          * in order to avoid leaking memory
     157                 :            :          * each time a device is tore down.
     158                 :            :          *
     159                 :            :          * Status: OPTIONAL
     160                 :            :          */
     161                 :            :         int (* slave_alloc)(struct scsi_device *);
     162                 :            : 
     163                 :            :         /*
     164                 :            :          * Once the device has responded to an INQUIRY and we know the
     165                 :            :          * device is online, we call into the low level driver with the
     166                 :            :          * struct scsi_device *.  If the low level device driver implements
     167                 :            :          * this function, it *must* perform the task of setting the queue
     168                 :            :          * depth on the device.  All other tasks are optional and depend
     169                 :            :          * on what the driver supports and various implementation details.
     170                 :            :          * 
     171                 :            :          * Things currently recommended to be handled at this time include:
     172                 :            :          *
     173                 :            :          * 1.  Setting the device queue depth.  Proper setting of this is
     174                 :            :          *     described in the comments for scsi_change_queue_depth.
     175                 :            :          * 2.  Determining if the device supports the various synchronous
     176                 :            :          *     negotiation protocols.  The device struct will already have
     177                 :            :          *     responded to INQUIRY and the results of the standard items
     178                 :            :          *     will have been shoved into the various device flag bits, eg.
     179                 :            :          *     device->sdtr will be true if the device supports SDTR messages.
     180                 :            :          * 3.  Allocating command structs that the device will need.
     181                 :            :          * 4.  Setting the default timeout on this device (if needed).
     182                 :            :          * 5.  Anything else the low level driver might want to do on a device
     183                 :            :          *     specific setup basis...
     184                 :            :          * 6.  Return 0 on success, non-0 on error.  The device will be marked
     185                 :            :          *     as offline on error so that no access will occur.  If you return
     186                 :            :          *     non-0, your slave_destroy routine will never get called for this
     187                 :            :          *     device, so don't leave any loose memory hanging around, clean
     188                 :            :          *     up after yourself before returning non-0
     189                 :            :          *
     190                 :            :          * Status: OPTIONAL
     191                 :            :          */
     192                 :            :         int (* slave_configure)(struct scsi_device *);
     193                 :            : 
     194                 :            :         /*
     195                 :            :          * Immediately prior to deallocating the device and after all activity
     196                 :            :          * has ceased the mid layer calls this point so that the low level
     197                 :            :          * driver may completely detach itself from the scsi device and vice
     198                 :            :          * versa.  The low level driver is responsible for freeing any memory
     199                 :            :          * it allocated in the slave_alloc or slave_configure calls. 
     200                 :            :          *
     201                 :            :          * Status: OPTIONAL
     202                 :            :          */
     203                 :            :         void (* slave_destroy)(struct scsi_device *);
     204                 :            : 
     205                 :            :         /*
     206                 :            :          * Before the mid layer attempts to scan for a new device attached
     207                 :            :          * to a target where no target currently exists, it will call this
     208                 :            :          * entry in your driver.  Should your driver need to allocate any
     209                 :            :          * structs or perform any other init items in order to send commands
     210                 :            :          * to a currently unused target, then this is where you can perform
     211                 :            :          * those allocations.
     212                 :            :          *
     213                 :            :          * Return values: 0 on success, non-0 on failure
     214                 :            :          *
     215                 :            :          * Status: OPTIONAL
     216                 :            :          */
     217                 :            :         int (* target_alloc)(struct scsi_target *);
     218                 :            : 
     219                 :            :         /*
     220                 :            :          * Immediately prior to deallocating the target structure, and
     221                 :            :          * after all activity to attached scsi devices has ceased, the
     222                 :            :          * midlayer calls this point so that the driver may deallocate
     223                 :            :          * and terminate any references to the target.
     224                 :            :          *
     225                 :            :          * Status: OPTIONAL
     226                 :            :          */
     227                 :            :         void (* target_destroy)(struct scsi_target *);
     228                 :            : 
     229                 :            :         /*
     230                 :            :          * If a host has the ability to discover targets on its own instead
     231                 :            :          * of scanning the entire bus, it can fill in this function and
     232                 :            :          * call scsi_scan_host().  This function will be called periodically
     233                 :            :          * until it returns 1 with the scsi_host and the elapsed time of
     234                 :            :          * the scan in jiffies.
     235                 :            :          *
     236                 :            :          * Status: OPTIONAL
     237                 :            :          */
     238                 :            :         int (* scan_finished)(struct Scsi_Host *, unsigned long);
     239                 :            : 
     240                 :            :         /*
     241                 :            :          * If the host wants to be called before the scan starts, but
     242                 :            :          * after the midlayer has set up ready for the scan, it can fill
     243                 :            :          * in this function.
     244                 :            :          *
     245                 :            :          * Status: OPTIONAL
     246                 :            :          */
     247                 :            :         void (* scan_start)(struct Scsi_Host *);
     248                 :            : 
     249                 :            :         /*
     250                 :            :          * Fill in this function to allow the queue depth of this host
     251                 :            :          * to be changeable (on a per device basis).  Returns either
     252                 :            :          * the current queue depth setting (may be different from what
     253                 :            :          * was passed in) or an error.  An error should only be
     254                 :            :          * returned if the requested depth is legal but the driver was
     255                 :            :          * unable to set it.  If the requested depth is illegal, the
     256                 :            :          * driver should set and return the closest legal queue depth.
     257                 :            :          *
     258                 :            :          * Status: OPTIONAL
     259                 :            :          */
     260                 :            :         int (* change_queue_depth)(struct scsi_device *, int);
     261                 :            : 
     262                 :            :         /*
     263                 :            :          * This functions lets the driver expose the queue mapping
     264                 :            :          * to the block layer.
     265                 :            :          *
     266                 :            :          * Status: OPTIONAL
     267                 :            :          */
     268                 :            :         int (* map_queues)(struct Scsi_Host *shost);
     269                 :            : 
     270                 :            :         /*
     271                 :            :          * This function determines the BIOS parameters for a given
     272                 :            :          * harddisk.  These tend to be numbers that are made up by
     273                 :            :          * the host adapter.  Parameters:
     274                 :            :          * size, device, list (heads, sectors, cylinders)
     275                 :            :          *
     276                 :            :          * Status: OPTIONAL
     277                 :            :          */
     278                 :            :         int (* bios_param)(struct scsi_device *, struct block_device *,
     279                 :            :                         sector_t, int []);
     280                 :            : 
     281                 :            :         /*
     282                 :            :          * This function is called when one or more partitions on the
     283                 :            :          * device reach beyond the end of the device.
     284                 :            :          *
     285                 :            :          * Status: OPTIONAL
     286                 :            :          */
     287                 :            :         void (*unlock_native_capacity)(struct scsi_device *);
     288                 :            : 
     289                 :            :         /*
     290                 :            :          * Can be used to export driver statistics and other infos to the
     291                 :            :          * world outside the kernel ie. userspace and it also provides an
     292                 :            :          * interface to feed the driver with information.
     293                 :            :          *
     294                 :            :          * Status: OBSOLETE
     295                 :            :          */
     296                 :            :         int (*show_info)(struct seq_file *, struct Scsi_Host *);
     297                 :            :         int (*write_info)(struct Scsi_Host *, char *, int);
     298                 :            : 
     299                 :            :         /*
     300                 :            :          * This is an optional routine that allows the transport to become
     301                 :            :          * involved when a scsi io timer fires. The return value tells the
     302                 :            :          * timer routine how to finish the io timeout handling.
     303                 :            :          *
     304                 :            :          * Status: OPTIONAL
     305                 :            :          */
     306                 :            :         enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
     307                 :            : 
     308                 :            :         /* This is an optional routine that allows transport to initiate
     309                 :            :          * LLD adapter or firmware reset using sysfs attribute.
     310                 :            :          *
     311                 :            :          * Return values: 0 on success, -ve value on failure.
     312                 :            :          *
     313                 :            :          * Status: OPTIONAL
     314                 :            :          */
     315                 :            : 
     316                 :            :         int (*host_reset)(struct Scsi_Host *shost, int reset_type);
     317                 :            : #define SCSI_ADAPTER_RESET      1
     318                 :            : #define SCSI_FIRMWARE_RESET     2
     319                 :            : 
     320                 :            : 
     321                 :            :         /*
     322                 :            :          * Name of proc directory
     323                 :            :          */
     324                 :            :         const char *proc_name;
     325                 :            : 
     326                 :            :         /*
     327                 :            :          * Used to store the procfs directory if a driver implements the
     328                 :            :          * show_info method.
     329                 :            :          */
     330                 :            :         struct proc_dir_entry *proc_dir;
     331                 :            : 
     332                 :            :         /*
     333                 :            :          * This determines if we will use a non-interrupt driven
     334                 :            :          * or an interrupt driven scheme.  It is set to the maximum number
     335                 :            :          * of simultaneous commands a single hw queue in HBA will accept.
     336                 :            :          */
     337                 :            :         int can_queue;
     338                 :            : 
     339                 :            :         /*
     340                 :            :          * In many instances, especially where disconnect / reconnect are
     341                 :            :          * supported, our host also has an ID on the SCSI bus.  If this is
     342                 :            :          * the case, then it must be reserved.  Please set this_id to -1 if
     343                 :            :          * your setup is in single initiator mode, and the host lacks an
     344                 :            :          * ID.
     345                 :            :          */
     346                 :            :         int this_id;
     347                 :            : 
     348                 :            :         /*
     349                 :            :          * This determines the degree to which the host adapter is capable
     350                 :            :          * of scatter-gather.
     351                 :            :          */
     352                 :            :         unsigned short sg_tablesize;
     353                 :            :         unsigned short sg_prot_tablesize;
     354                 :            : 
     355                 :            :         /*
     356                 :            :          * Set this if the host adapter has limitations beside segment count.
     357                 :            :          */
     358                 :            :         unsigned int max_sectors;
     359                 :            : 
     360                 :            :         /*
     361                 :            :          * Maximum size in bytes of a single segment.
     362                 :            :          */
     363                 :            :         unsigned int max_segment_size;
     364                 :            : 
     365                 :            :         /*
     366                 :            :          * DMA scatter gather segment boundary limit. A segment crossing this
     367                 :            :          * boundary will be split in two.
     368                 :            :          */
     369                 :            :         unsigned long dma_boundary;
     370                 :            : 
     371                 :            :         unsigned long virt_boundary_mask;
     372                 :            : 
     373                 :            :         /*
     374                 :            :          * This specifies "machine infinity" for host templates which don't
     375                 :            :          * limit the transfer size.  Note this limit represents an absolute
     376                 :            :          * maximum, and may be over the transfer limits allowed for
     377                 :            :          * individual devices (e.g. 256 for SCSI-1).
     378                 :            :          */
     379                 :            : #define SCSI_DEFAULT_MAX_SECTORS        1024
     380                 :            : 
     381                 :            :         /*
     382                 :            :          * True if this host adapter can make good use of linked commands.
     383                 :            :          * This will allow more than one command to be queued to a given
     384                 :            :          * unit on a given host.  Set this to the maximum number of command
     385                 :            :          * blocks to be provided for each device.  Set this to 1 for one
     386                 :            :          * command block per lun, 2 for two, etc.  Do not set this to 0.
     387                 :            :          * You should make sure that the host adapter will do the right thing
     388                 :            :          * before you try setting this above 1.
     389                 :            :          */
     390                 :            :         short cmd_per_lun;
     391                 :            : 
     392                 :            :         /*
     393                 :            :          * present contains counter indicating how many boards of this
     394                 :            :          * type were found when we did the scan.
     395                 :            :          */
     396                 :            :         unsigned char present;
     397                 :            : 
     398                 :            :         /* If use block layer to manage tags, this is tag allocation policy */
     399                 :            :         int tag_alloc_policy;
     400                 :            : 
     401                 :            :         /*
     402                 :            :          * Track QUEUE_FULL events and reduce queue depth on demand.
     403                 :            :          */
     404                 :            :         unsigned track_queue_depth:1;
     405                 :            : 
     406                 :            :         /*
     407                 :            :          * This specifies the mode that a LLD supports.
     408                 :            :          */
     409                 :            :         unsigned supported_mode:2;
     410                 :            : 
     411                 :            :         /*
     412                 :            :          * True if this host adapter uses unchecked DMA onto an ISA bus.
     413                 :            :          */
     414                 :            :         unsigned unchecked_isa_dma:1;
     415                 :            : 
     416                 :            :         /*
     417                 :            :          * True for emulated SCSI host adapters (e.g. ATAPI).
     418                 :            :          */
     419                 :            :         unsigned emulated:1;
     420                 :            : 
     421                 :            :         /*
     422                 :            :          * True if the low-level driver performs its own reset-settle delays.
     423                 :            :          */
     424                 :            :         unsigned skip_settle_delay:1;
     425                 :            : 
     426                 :            :         /* True if the controller does not support WRITE SAME */
     427                 :            :         unsigned no_write_same:1;
     428                 :            : 
     429                 :            :         /* True if the low-level driver supports blk-mq only */
     430                 :            :         unsigned force_blk_mq:1;
     431                 :            : 
     432                 :            :         /*
     433                 :            :          * Countdown for host blocking with no commands outstanding.
     434                 :            :          */
     435                 :            :         unsigned int max_host_blocked;
     436                 :            : 
     437                 :            :         /*
     438                 :            :          * Default value for the blocking.  If the queue is empty,
     439                 :            :          * host_blocked counts down in the request_fn until it restarts
     440                 :            :          * host operations as zero is reached.  
     441                 :            :          *
     442                 :            :          * FIXME: This should probably be a value in the template
     443                 :            :          */
     444                 :            : #define SCSI_DEFAULT_HOST_BLOCKED       7
     445                 :            : 
     446                 :            :         /*
     447                 :            :          * Pointer to the sysfs class properties for this host, NULL terminated.
     448                 :            :          */
     449                 :            :         struct device_attribute **shost_attrs;
     450                 :            : 
     451                 :            :         /*
     452                 :            :          * Pointer to the SCSI device properties for this host, NULL terminated.
     453                 :            :          */
     454                 :            :         struct device_attribute **sdev_attrs;
     455                 :            : 
     456                 :            :         /*
     457                 :            :          * Pointer to the SCSI device attribute groups for this host,
     458                 :            :          * NULL terminated.
     459                 :            :          */
     460                 :            :         const struct attribute_group **sdev_groups;
     461                 :            : 
     462                 :            :         /*
     463                 :            :          * Vendor Identifier associated with the host
     464                 :            :          *
     465                 :            :          * Note: When specifying vendor_id, be sure to read the
     466                 :            :          *   Vendor Type and ID formatting requirements specified in
     467                 :            :          *   scsi_netlink.h
     468                 :            :          */
     469                 :            :         u64 vendor_id;
     470                 :            : 
     471                 :            :         /*
     472                 :            :          * Additional per-command data allocated for the driver.
     473                 :            :          */
     474                 :            :         unsigned int cmd_size;
     475                 :            :         struct scsi_host_cmd_pool *cmd_pool;
     476                 :            : 
     477                 :            :         /* Delay for runtime autosuspend */
     478                 :            :         int rpm_autosuspend_delay;
     479                 :            : };
     480                 :            : 
     481                 :            : /*
     482                 :            :  * Temporary #define for host lock push down. Can be removed when all
     483                 :            :  * drivers have been updated to take advantage of unlocked
     484                 :            :  * queuecommand.
     485                 :            :  *
     486                 :            :  */
     487                 :            : #define DEF_SCSI_QCMD(func_name) \
     488                 :            :         int func_name(struct Scsi_Host *shost, struct scsi_cmnd *cmd)   \
     489                 :            :         {                                                               \
     490                 :            :                 unsigned long irq_flags;                                \
     491                 :            :                 int rc;                                                 \
     492                 :            :                 spin_lock_irqsave(shost->host_lock, irq_flags);              \
     493                 :            :                 rc = func_name##_lck (cmd, cmd->scsi_done);                  \
     494                 :            :                 spin_unlock_irqrestore(shost->host_lock, irq_flags); \
     495                 :            :                 return rc;                                              \
     496                 :            :         }
     497                 :            : 
     498                 :            : 
     499                 :            : /*
     500                 :            :  * shost state: If you alter this, you also need to alter scsi_sysfs.c
     501                 :            :  * (for the ascii descriptions) and the state model enforcer:
     502                 :            :  * scsi_host_set_state()
     503                 :            :  */
     504                 :            : enum scsi_host_state {
     505                 :            :         SHOST_CREATED = 1,
     506                 :            :         SHOST_RUNNING,
     507                 :            :         SHOST_CANCEL,
     508                 :            :         SHOST_DEL,
     509                 :            :         SHOST_RECOVERY,
     510                 :            :         SHOST_CANCEL_RECOVERY,
     511                 :            :         SHOST_DEL_RECOVERY,
     512                 :            : };
     513                 :            : 
     514                 :            : struct Scsi_Host {
     515                 :            :         /*
     516                 :            :          * __devices is protected by the host_lock, but you should
     517                 :            :          * usually use scsi_device_lookup / shost_for_each_device
     518                 :            :          * to access it and don't care about locking yourself.
     519                 :            :          * In the rare case of being in irq context you can use
     520                 :            :          * their __ prefixed variants with the lock held. NEVER
     521                 :            :          * access this list directly from a driver.
     522                 :            :          */
     523                 :            :         struct list_head        __devices;
     524                 :            :         struct list_head        __targets;
     525                 :            :         
     526                 :            :         struct list_head        starved_list;
     527                 :            : 
     528                 :            :         spinlock_t              default_lock;
     529                 :            :         spinlock_t              *host_lock;
     530                 :            : 
     531                 :            :         struct mutex            scan_mutex;/* serialize scanning activity */
     532                 :            : 
     533                 :            :         struct list_head        eh_cmd_q;
     534                 :            :         struct task_struct    * ehandler;  /* Error recovery thread. */
     535                 :            :         struct completion     * eh_action; /* Wait for specific actions on the
     536                 :            :                                               host. */
     537                 :            :         wait_queue_head_t       host_wait;
     538                 :            :         struct scsi_host_template *hostt;
     539                 :            :         struct scsi_transport_template *transportt;
     540                 :            : 
     541                 :            :         /* Area to keep a shared tag map */
     542                 :            :         struct blk_mq_tag_set   tag_set;
     543                 :            : 
     544                 :            :         atomic_t host_blocked;
     545                 :            : 
     546                 :            :         unsigned int host_failed;          /* commands that failed.
     547                 :            :                                               protected by host_lock */
     548                 :            :         unsigned int host_eh_scheduled;    /* EH scheduled without command */
     549                 :            :     
     550                 :            :         unsigned int host_no;  /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
     551                 :            : 
     552                 :            :         /* next two fields are used to bound the time spent in error handling */
     553                 :            :         int eh_deadline;
     554                 :            :         unsigned long last_reset;
     555                 :            : 
     556                 :            : 
     557                 :            :         /*
     558                 :            :          * These three parameters can be used to allow for wide scsi,
     559                 :            :          * and for host adapters that support multiple busses
     560                 :            :          * The last two should be set to 1 more than the actual max id
     561                 :            :          * or lun (e.g. 8 for SCSI parallel systems).
     562                 :            :          */
     563                 :            :         unsigned int max_channel;
     564                 :            :         unsigned int max_id;
     565                 :            :         u64 max_lun;
     566                 :            : 
     567                 :            :         /*
     568                 :            :          * This is a unique identifier that must be assigned so that we
     569                 :            :          * have some way of identifying each detected host adapter properly
     570                 :            :          * and uniquely.  For hosts that do not support more than one card
     571                 :            :          * in the system at one time, this does not need to be set.  It is
     572                 :            :          * initialized to 0 in scsi_register.
     573                 :            :          */
     574                 :            :         unsigned int unique_id;
     575                 :            : 
     576                 :            :         /*
     577                 :            :          * The maximum length of SCSI commands that this host can accept.
     578                 :            :          * Probably 12 for most host adapters, but could be 16 for others.
     579                 :            :          * or 260 if the driver supports variable length cdbs.
     580                 :            :          * For drivers that don't set this field, a value of 12 is
     581                 :            :          * assumed.
     582                 :            :          */
     583                 :            :         unsigned short max_cmd_len;
     584                 :            : 
     585                 :            :         int this_id;
     586                 :            :         int can_queue;
     587                 :            :         short cmd_per_lun;
     588                 :            :         short unsigned int sg_tablesize;
     589                 :            :         short unsigned int sg_prot_tablesize;
     590                 :            :         unsigned int max_sectors;
     591                 :            :         unsigned int max_segment_size;
     592                 :            :         unsigned long dma_boundary;
     593                 :            :         unsigned long virt_boundary_mask;
     594                 :            :         /*
     595                 :            :          * In scsi-mq mode, the number of hardware queues supported by the LLD.
     596                 :            :          *
     597                 :            :          * Note: it is assumed that each hardware queue has a queue depth of
     598                 :            :          * can_queue. In other words, the total queue depth per host
     599                 :            :          * is nr_hw_queues * can_queue.
     600                 :            :          */
     601                 :            :         unsigned nr_hw_queues;
     602                 :            :         unsigned active_mode:2;
     603                 :            :         unsigned unchecked_isa_dma:1;
     604                 :            : 
     605                 :            :         /*
     606                 :            :          * Host has requested that no further requests come through for the
     607                 :            :          * time being.
     608                 :            :          */
     609                 :            :         unsigned host_self_blocked:1;
     610                 :            :     
     611                 :            :         /*
     612                 :            :          * Host uses correct SCSI ordering not PC ordering. The bit is
     613                 :            :          * set for the minority of drivers whose authors actually read
     614                 :            :          * the spec ;).
     615                 :            :          */
     616                 :            :         unsigned reverse_ordering:1;
     617                 :            : 
     618                 :            :         /* Task mgmt function in progress */
     619                 :            :         unsigned tmf_in_progress:1;
     620                 :            : 
     621                 :            :         /* Asynchronous scan in progress */
     622                 :            :         unsigned async_scan:1;
     623                 :            : 
     624                 :            :         /* Don't resume host in EH */
     625                 :            :         unsigned eh_noresume:1;
     626                 :            : 
     627                 :            :         /* The controller does not support WRITE SAME */
     628                 :            :         unsigned no_write_same:1;
     629                 :            : 
     630                 :            :         unsigned use_cmd_list:1;
     631                 :            : 
     632                 :            :         /* Host responded with short (<36 bytes) INQUIRY result */
     633                 :            :         unsigned short_inquiry:1;
     634                 :            : 
     635                 :            :         /* The transport requires the LUN bits NOT to be stored in CDB[1] */
     636                 :            :         unsigned no_scsi2_lun_in_cdb:1;
     637                 :            : 
     638                 :            :         /*
     639                 :            :          * Optional work queue to be utilized by the transport
     640                 :            :          */
     641                 :            :         char work_q_name[20];
     642                 :            :         struct workqueue_struct *work_q;
     643                 :            : 
     644                 :            :         /*
     645                 :            :          * Task management function work queue
     646                 :            :          */
     647                 :            :         struct workqueue_struct *tmf_work_q;
     648                 :            : 
     649                 :            :         /*
     650                 :            :          * Value host_blocked counts down from
     651                 :            :          */
     652                 :            :         unsigned int max_host_blocked;
     653                 :            : 
     654                 :            :         /* Protection Information */
     655                 :            :         unsigned int prot_capabilities;
     656                 :            :         unsigned char prot_guard_type;
     657                 :            : 
     658                 :            :         /* legacy crap */
     659                 :            :         unsigned long base;
     660                 :            :         unsigned long io_port;
     661                 :            :         unsigned char n_io_port;
     662                 :            :         unsigned char dma_channel;
     663                 :            :         unsigned int  irq;
     664                 :            :         
     665                 :            : 
     666                 :            :         enum scsi_host_state shost_state;
     667                 :            : 
     668                 :            :         /* ldm bits */
     669                 :            :         struct device           shost_gendev, shost_dev;
     670                 :            : 
     671                 :            :         /*
     672                 :            :          * Points to the transport data (if any) which is allocated
     673                 :            :          * separately
     674                 :            :          */
     675                 :            :         void *shost_data;
     676                 :            : 
     677                 :            :         /*
     678                 :            :          * Points to the physical bus device we'd use to do DMA
     679                 :            :          * Needed just in case we have virtual hosts.
     680                 :            :          */
     681                 :            :         struct device *dma_dev;
     682                 :            : 
     683                 :            :         /*
     684                 :            :          * We should ensure that this is aligned, both for better performance
     685                 :            :          * and also because some compilers (m68k) don't automatically force
     686                 :            :          * alignment to a long boundary.
     687                 :            :          */
     688                 :            :         unsigned long hostdata[0]  /* Used for storage of host specific stuff */
     689                 :            :                 __attribute__ ((aligned (sizeof(unsigned long))));
     690                 :            : };
     691                 :            : 
     692                 :            : #define         class_to_shost(d)       \
     693                 :            :         container_of(d, struct Scsi_Host, shost_dev)
     694                 :            : 
     695                 :            : #define shost_printk(prefix, shost, fmt, a...)  \
     696                 :            :         dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a)
     697                 :            : 
     698                 :          0 : static inline void *shost_priv(struct Scsi_Host *shost)
     699                 :            : {
     700                 :          0 :         return (void *)shost->hostdata;
     701                 :            : }
     702                 :            : 
     703                 :            : int scsi_is_host_device(const struct device *);
     704                 :            : 
     705                 :         45 : static inline struct Scsi_Host *dev_to_shost(struct device *dev)
     706                 :            : {
     707   [ -  +  -  -  :         45 :         while (!scsi_is_host_device(dev)) {
          -  -  -  -  -  
          +  -  +  -  +  
          -  -  -  +  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
             #  #  #  #  
                      # ]
     708   [ #  #  #  #  :          0 :                 if (!dev->parent)
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
             #  #  #  #  
                      # ]
     709                 :            :                         return NULL;
     710                 :            :                 dev = dev->parent;
     711                 :            :         }
     712                 :         45 :         return container_of(dev, struct Scsi_Host, shost_gendev);
     713                 :            : }
     714                 :            : 
     715                 :       3488 : static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
     716                 :            : {
     717                 :       3488 :         return shost->shost_state == SHOST_RECOVERY ||
     718                 :       3488 :                 shost->shost_state == SHOST_CANCEL_RECOVERY ||
     719   [ +  -  +  +  :       3488 :                 shost->shost_state == SHOST_DEL_RECOVERY ||
             +  +  +  - ]
     720                 :            :                 shost->tmf_in_progress;
     721                 :            : }
     722                 :            : 
     723                 :            : extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
     724                 :            : extern void scsi_flush_work(struct Scsi_Host *);
     725                 :            : 
     726                 :            : extern struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *, int);
     727                 :            : extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *,
     728                 :            :                                                struct device *,
     729                 :            :                                                struct device *);
     730                 :            : extern void scsi_scan_host(struct Scsi_Host *);
     731                 :            : extern void scsi_rescan_device(struct device *);
     732                 :            : extern void scsi_remove_host(struct Scsi_Host *);
     733                 :            : extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
     734                 :            : extern int scsi_host_busy(struct Scsi_Host *shost);
     735                 :            : extern void scsi_host_put(struct Scsi_Host *t);
     736                 :            : extern struct Scsi_Host *scsi_host_lookup(unsigned short);
     737                 :            : extern const char *scsi_host_state_name(enum scsi_host_state);
     738                 :            : 
     739                 :          0 : static inline int __must_check scsi_add_host(struct Scsi_Host *host,
     740                 :            :                                              struct device *dev)
     741                 :            : {
     742                 :          0 :         return scsi_add_host_with_dma(host, dev, dev);
     743                 :            : }
     744                 :            : 
     745                 :            : static inline struct device *scsi_get_device(struct Scsi_Host *shost)
     746                 :            : {
     747                 :            :         return shost->shost_gendev.parent;
     748                 :            : }
     749                 :            : 
     750                 :            : /**
     751                 :            :  * scsi_host_scan_allowed - Is scanning of this host allowed
     752                 :            :  * @shost:      Pointer to Scsi_Host.
     753                 :            :  **/
     754                 :          9 : static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)
     755                 :            : {
     756   [ -  -  -  -  :          9 :         return shost->shost_state == SHOST_RUNNING ||
          -  -  -  -  +  
                      - ]
     757                 :            :                shost->shost_state == SHOST_RECOVERY;
     758                 :            : }
     759                 :            : 
     760                 :            : extern void scsi_unblock_requests(struct Scsi_Host *);
     761                 :            : extern void scsi_block_requests(struct Scsi_Host *);
     762                 :            : 
     763                 :            : struct class_container;
     764                 :            : 
     765                 :            : /*
     766                 :            :  * These two functions are used to allocate and free a pseudo device
     767                 :            :  * which will connect to the host adapter itself rather than any
     768                 :            :  * physical device.  You must deallocate when you are done with the
     769                 :            :  * thing.  This physical pseudo-device isn't real and won't be available
     770                 :            :  * from any high-level drivers.
     771                 :            :  */
     772                 :            : extern void scsi_free_host_dev(struct scsi_device *);
     773                 :            : extern struct scsi_device *scsi_get_host_dev(struct Scsi_Host *);
     774                 :            : 
     775                 :            : /*
     776                 :            :  * DIF defines the exchange of protection information between
     777                 :            :  * initiator and SBC block device.
     778                 :            :  *
     779                 :            :  * DIX defines the exchange of protection information between OS and
     780                 :            :  * initiator.
     781                 :            :  */
     782                 :            : enum scsi_host_prot_capabilities {
     783                 :            :         SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */
     784                 :            :         SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */
     785                 :            :         SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */
     786                 :            : 
     787                 :            :         SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */
     788                 :            :         SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */
     789                 :            :         SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */
     790                 :            :         SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */
     791                 :            : };
     792                 :            : 
     793                 :            : /*
     794                 :            :  * SCSI hosts which support the Data Integrity Extensions must
     795                 :            :  * indicate their capabilities by setting the prot_capabilities using
     796                 :            :  * this call.
     797                 :            :  */
     798                 :            : static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask)
     799                 :            : {
     800                 :            :         shost->prot_capabilities = mask;
     801                 :            : }
     802                 :            : 
     803                 :       3410 : static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost)
     804                 :            : {
     805   [ -  +  -  +  :       3410 :         return shost->prot_capabilities;
                   -  + ]
     806                 :            : }
     807                 :            : 
     808                 :          9 : static inline int scsi_host_prot_dma(struct Scsi_Host *shost)
     809                 :            : {
     810         [ -  + ]:          9 :         return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION;
     811                 :            : }
     812                 :            : 
     813                 :       2917 : static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type)
     814                 :            : {
     815                 :       2917 :         static unsigned char cap[] = { 0,
     816                 :            :                                        SHOST_DIF_TYPE1_PROTECTION,
     817                 :            :                                        SHOST_DIF_TYPE2_PROTECTION,
     818                 :            :                                        SHOST_DIF_TYPE3_PROTECTION };
     819                 :            : 
     820   [ +  -  -  - ]:       2917 :         if (target_type >= ARRAY_SIZE(cap))
     821                 :            :                 return 0;
     822                 :            : 
     823   [ -  -  +  -  :       2917 :         return shost->prot_capabilities & cap[target_type] ? target_type : 0;
                   -  - ]
     824                 :            : }
     825                 :            : 
     826                 :          0 : static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type)
     827                 :            : {
     828                 :            : #if defined(CONFIG_BLK_DEV_INTEGRITY)
     829                 :            :         static unsigned char cap[] = { SHOST_DIX_TYPE0_PROTECTION,
     830                 :            :                                        SHOST_DIX_TYPE1_PROTECTION,
     831                 :            :                                        SHOST_DIX_TYPE2_PROTECTION,
     832                 :            :                                        SHOST_DIX_TYPE3_PROTECTION };
     833                 :            : 
     834                 :            :         if (target_type >= ARRAY_SIZE(cap))
     835                 :            :                 return 0;
     836                 :            : 
     837                 :            :         return shost->prot_capabilities & cap[target_type];
     838                 :            : #endif
     839         [ #  # ]:          0 :         return 0;
     840                 :            : }
     841                 :            : 
     842                 :            : /*
     843                 :            :  * All DIX-capable initiators must support the T10-mandated CRC
     844                 :            :  * checksum.  Controllers can optionally implement the IP checksum
     845                 :            :  * scheme which has much lower impact on system performance.  Note
     846                 :            :  * that the main rationale for the checksum is to match integrity
     847                 :            :  * metadata with data.  Detecting bit errors are a job for ECC memory
     848                 :            :  * and buses.
     849                 :            :  */
     850                 :            : 
     851                 :            : enum scsi_host_guard_type {
     852                 :            :         SHOST_DIX_GUARD_CRC = 1 << 0,
     853                 :            :         SHOST_DIX_GUARD_IP  = 1 << 1,
     854                 :            : };
     855                 :            : 
     856                 :            : static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type)
     857                 :            : {
     858                 :            :         shost->prot_guard_type = type;
     859                 :            : }
     860                 :            : 
     861                 :            : static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost)
     862                 :            : {
     863                 :            :         return shost->prot_guard_type;
     864                 :            : }
     865                 :            : 
     866                 :            : extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state);
     867                 :            : 
     868                 :            : #endif /* _SCSI_SCSI_HOST_H */

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