LCOV - code coverage report
Current view: top level - arch/x86/include/asm - tlbflush.h (source / functions) Hit Total Coverage
Test: combined.info Lines: 68 114 59.6 %
Date: 2022-04-01 13:59:58 Functions: 8 8 100.0 %
Branches: 13 42 31.0 %

           Branch data     Line data    Source code
       1                 :            : /* SPDX-License-Identifier: GPL-2.0 */
       2                 :            : #ifndef _ASM_X86_TLBFLUSH_H
       3                 :            : #define _ASM_X86_TLBFLUSH_H
       4                 :            : 
       5                 :            : #include <linux/mm.h>
       6                 :            : #include <linux/sched.h>
       7                 :            : 
       8                 :            : #include <asm/processor.h>
       9                 :            : #include <asm/cpufeature.h>
      10                 :            : #include <asm/special_insns.h>
      11                 :            : #include <asm/smp.h>
      12                 :            : #include <asm/invpcid.h>
      13                 :            : #include <asm/pti.h>
      14                 :            : #include <asm/processor-flags.h>
      15                 :            : 
      16                 :            : /*
      17                 :            :  * The x86 feature is called PCID (Process Context IDentifier). It is similar
      18                 :            :  * to what is traditionally called ASID on the RISC processors.
      19                 :            :  *
      20                 :            :  * We don't use the traditional ASID implementation, where each process/mm gets
      21                 :            :  * its own ASID and flush/restart when we run out of ASID space.
      22                 :            :  *
      23                 :            :  * Instead we have a small per-cpu array of ASIDs and cache the last few mm's
      24                 :            :  * that came by on this CPU, allowing cheaper switch_mm between processes on
      25                 :            :  * this CPU.
      26                 :            :  *
      27                 :            :  * We end up with different spaces for different things. To avoid confusion we
      28                 :            :  * use different names for each of them:
      29                 :            :  *
      30                 :            :  * ASID  - [0, TLB_NR_DYN_ASIDS-1]
      31                 :            :  *         the canonical identifier for an mm
      32                 :            :  *
      33                 :            :  * kPCID - [1, TLB_NR_DYN_ASIDS]
      34                 :            :  *         the value we write into the PCID part of CR3; corresponds to the
      35                 :            :  *         ASID+1, because PCID 0 is special.
      36                 :            :  *
      37                 :            :  * uPCID - [2048 + 1, 2048 + TLB_NR_DYN_ASIDS]
      38                 :            :  *         for KPTI each mm has two address spaces and thus needs two
      39                 :            :  *         PCID values, but we can still do with a single ASID denomination
      40                 :            :  *         for each mm. Corresponds to kPCID + 2048.
      41                 :            :  *
      42                 :            :  */
      43                 :            : 
      44                 :            : /* There are 12 bits of space for ASIDS in CR3 */
      45                 :            : #define CR3_HW_ASID_BITS                12
      46                 :            : 
      47                 :            : /*
      48                 :            :  * When enabled, PAGE_TABLE_ISOLATION consumes a single bit for
      49                 :            :  * user/kernel switches
      50                 :            :  */
      51                 :            : #ifdef CONFIG_PAGE_TABLE_ISOLATION
      52                 :            : # define PTI_CONSUMED_PCID_BITS 1
      53                 :            : #else
      54                 :            : # define PTI_CONSUMED_PCID_BITS 0
      55                 :            : #endif
      56                 :            : 
      57                 :            : #define CR3_AVAIL_PCID_BITS (X86_CR3_PCID_BITS - PTI_CONSUMED_PCID_BITS)
      58                 :            : 
      59                 :            : /*
      60                 :            :  * ASIDs are zero-based: 0->MAX_AVAIL_ASID are valid.  -1 below to account
      61                 :            :  * for them being zero-based.  Another -1 is because PCID 0 is reserved for
      62                 :            :  * use by non-PCID-aware users.
      63                 :            :  */
      64                 :            : #define MAX_ASID_AVAILABLE ((1 << CR3_AVAIL_PCID_BITS) - 2)
      65                 :            : 
      66                 :            : /*
      67                 :            :  * 6 because 6 should be plenty and struct tlb_state will fit in two cache
      68                 :            :  * lines.
      69                 :            :  */
      70                 :            : #define TLB_NR_DYN_ASIDS        6
      71                 :            : 
      72                 :            : /*
      73                 :            :  * Given @asid, compute kPCID
      74                 :            :  */
      75                 :          0 : static inline u16 kern_pcid(u16 asid)
      76                 :            : {
      77                 :          0 :         VM_WARN_ON_ONCE(asid > MAX_ASID_AVAILABLE);
      78                 :            : 
      79                 :            : #ifdef CONFIG_PAGE_TABLE_ISOLATION
      80                 :            :         /*
      81                 :            :          * Make sure that the dynamic ASID space does not confict with the
      82                 :            :          * bit we are using to switch between user and kernel ASIDs.
      83                 :            :          */
      84                 :          0 :         BUILD_BUG_ON(TLB_NR_DYN_ASIDS >= (1 << X86_CR3_PTI_PCID_USER_BIT));
      85                 :            : 
      86                 :            :         /*
      87                 :            :          * The ASID being passed in here should have respected the
      88                 :            :          * MAX_ASID_AVAILABLE and thus never have the switch bit set.
      89                 :            :          */
      90                 :          0 :         VM_WARN_ON_ONCE(asid & (1 << X86_CR3_PTI_PCID_USER_BIT));
      91                 :            : #endif
      92                 :            :         /*
      93                 :            :          * The dynamically-assigned ASIDs that get passed in are small
      94                 :            :          * (<TLB_NR_DYN_ASIDS).  They never have the high switch bit set,
      95                 :            :          * so do not bother to clear it.
      96                 :            :          *
      97                 :            :          * If PCID is on, ASID-aware code paths put the ASID+1 into the
      98                 :            :          * PCID bits.  This serves two purposes.  It prevents a nasty
      99                 :            :          * situation in which PCID-unaware code saves CR3, loads some other
     100                 :            :          * value (with PCID == 0), and then restores CR3, thus corrupting
     101                 :            :          * the TLB for ASID 0 if the saved ASID was nonzero.  It also means
     102                 :            :          * that any bugs involving loading a PCID-enabled CR3 with
     103                 :            :          * CR4.PCIDE off will trigger deterministically.
     104                 :            :          */
     105                 :          0 :         return asid + 1;
     106                 :            : }
     107                 :            : 
     108                 :            : /*
     109                 :            :  * Given @asid, compute uPCID
     110                 :            :  */
     111                 :          0 : static inline u16 user_pcid(u16 asid)
     112                 :            : {
     113                 :          0 :         u16 ret = kern_pcid(asid);
     114                 :            : #ifdef CONFIG_PAGE_TABLE_ISOLATION
     115                 :          0 :         ret |= 1 << X86_CR3_PTI_PCID_USER_BIT;
     116                 :            : #endif
     117                 :          0 :         return ret;
     118                 :            : }
     119                 :            : 
     120                 :            : struct pgd_t;
     121                 :    3383059 : static inline unsigned long build_cr3(pgd_t *pgd, u16 asid)
     122                 :            : {
     123      [ -  +  - ]:    3383059 :         if (static_cpu_has(X86_FEATURE_PCID)) {
     124         [ #  # ]:          0 :                 return __sme_pa(pgd) | kern_pcid(asid);
     125                 :            :         } else {
     126                 :    3383059 :                 VM_WARN_ON_ONCE(asid != 0);
     127         [ +  + ]:    6766118 :                 return __sme_pa(pgd);
     128                 :            :         }
     129                 :            : }
     130                 :            : 
     131                 :          0 : static inline unsigned long build_cr3_noflush(pgd_t *pgd, u16 asid)
     132                 :            : {
     133                 :          0 :         VM_WARN_ON_ONCE(asid > MAX_ASID_AVAILABLE);
     134                 :            :         /*
     135                 :            :          * Use boot_cpu_has() instead of this_cpu_has() as this function
     136                 :            :          * might be called during early boot. This should work even after
     137                 :            :          * boot because all CPU's the have same capabilities:
     138                 :            :          */
     139                 :          0 :         VM_WARN_ON_ONCE(!boot_cpu_has(X86_FEATURE_PCID));
     140         [ #  # ]:          0 :         return __sme_pa(pgd) | kern_pcid(asid) | CR3_NOFLUSH;
     141                 :            : }
     142                 :            : 
     143                 :            : #ifdef CONFIG_PARAVIRT
     144                 :            : #include <asm/paravirt.h>
     145                 :            : #else
     146                 :            : #define __flush_tlb() __native_flush_tlb()
     147                 :            : #define __flush_tlb_global() __native_flush_tlb_global()
     148                 :            : #define __flush_tlb_one_user(addr) __native_flush_tlb_one_user(addr)
     149                 :            : #endif
     150                 :            : 
     151                 :            : struct tlb_context {
     152                 :            :         u64 ctx_id;
     153                 :            :         u64 tlb_gen;
     154                 :            : };
     155                 :            : 
     156                 :            : struct tlb_state {
     157                 :            :         /*
     158                 :            :          * cpu_tlbstate.loaded_mm should match CR3 whenever interrupts
     159                 :            :          * are on.  This means that it may not match current->active_mm,
     160                 :            :          * which will contain the previous user mm when we're in lazy TLB
     161                 :            :          * mode even if we've already switched back to swapper_pg_dir.
     162                 :            :          *
     163                 :            :          * During switch_mm_irqs_off(), loaded_mm will be set to
     164                 :            :          * LOADED_MM_SWITCHING during the brief interrupts-off window
     165                 :            :          * when CR3 and loaded_mm would otherwise be inconsistent.  This
     166                 :            :          * is for nmi_uaccess_okay()'s benefit.
     167                 :            :          */
     168                 :            :         struct mm_struct *loaded_mm;
     169                 :            : 
     170                 :            : #define LOADED_MM_SWITCHING ((struct mm_struct *)1UL)
     171                 :            : 
     172                 :            :         /* Last user mm for optimizing IBPB */
     173                 :            :         union {
     174                 :            :                 struct mm_struct        *last_user_mm;
     175                 :            :                 unsigned long           last_user_mm_ibpb;
     176                 :            :         };
     177                 :            : 
     178                 :            :         u16 loaded_mm_asid;
     179                 :            :         u16 next_asid;
     180                 :            : 
     181                 :            :         /*
     182                 :            :          * We can be in one of several states:
     183                 :            :          *
     184                 :            :          *  - Actively using an mm.  Our CPU's bit will be set in
     185                 :            :          *    mm_cpumask(loaded_mm) and is_lazy == false;
     186                 :            :          *
     187                 :            :          *  - Not using a real mm.  loaded_mm == &init_mm.  Our CPU's bit
     188                 :            :          *    will not be set in mm_cpumask(&init_mm) and is_lazy == false.
     189                 :            :          *
     190                 :            :          *  - Lazily using a real mm.  loaded_mm != &init_mm, our bit
     191                 :            :          *    is set in mm_cpumask(loaded_mm), but is_lazy == true.
     192                 :            :          *    We're heuristically guessing that the CR3 load we
     193                 :            :          *    skipped more than makes up for the overhead added by
     194                 :            :          *    lazy mode.
     195                 :            :          */
     196                 :            :         bool is_lazy;
     197                 :            : 
     198                 :            :         /*
     199                 :            :          * If set we changed the page tables in such a way that we
     200                 :            :          * needed an invalidation of all contexts (aka. PCIDs / ASIDs).
     201                 :            :          * This tells us to go invalidate all the non-loaded ctxs[]
     202                 :            :          * on the next context switch.
     203                 :            :          *
     204                 :            :          * The current ctx was kept up-to-date as it ran and does not
     205                 :            :          * need to be invalidated.
     206                 :            :          */
     207                 :            :         bool invalidate_other;
     208                 :            : 
     209                 :            :         /*
     210                 :            :          * Mask that contains TLB_NR_DYN_ASIDS+1 bits to indicate
     211                 :            :          * the corresponding user PCID needs a flush next time we
     212                 :            :          * switch to it; see SWITCH_TO_USER_CR3.
     213                 :            :          */
     214                 :            :         unsigned short user_pcid_flush_mask;
     215                 :            : 
     216                 :            :         /*
     217                 :            :          * Access to this CR4 shadow and to H/W CR4 is protected by
     218                 :            :          * disabling interrupts when modifying either one.
     219                 :            :          */
     220                 :            :         unsigned long cr4;
     221                 :            : 
     222                 :            :         /*
     223                 :            :          * This is a list of all contexts that might exist in the TLB.
     224                 :            :          * There is one per ASID that we use, and the ASID (what the
     225                 :            :          * CPU calls PCID) is the index into ctxts.
     226                 :            :          *
     227                 :            :          * For each context, ctx_id indicates which mm the TLB's user
     228                 :            :          * entries came from.  As an invariant, the TLB will never
     229                 :            :          * contain entries that are out-of-date as when that mm reached
     230                 :            :          * the tlb_gen in the list.
     231                 :            :          *
     232                 :            :          * To be clear, this means that it's legal for the TLB code to
     233                 :            :          * flush the TLB without updating tlb_gen.  This can happen
     234                 :            :          * (for now, at least) due to paravirt remote flushes.
     235                 :            :          *
     236                 :            :          * NB: context 0 is a bit special, since it's also used by
     237                 :            :          * various bits of init code.  This is fine -- code that
     238                 :            :          * isn't aware of PCID will end up harmlessly flushing
     239                 :            :          * context 0.
     240                 :            :          */
     241                 :            :         struct tlb_context ctxs[TLB_NR_DYN_ASIDS];
     242                 :            : };
     243                 :            : DECLARE_PER_CPU_SHARED_ALIGNED(struct tlb_state, cpu_tlbstate);
     244                 :            : 
     245                 :            : /*
     246                 :            :  * Blindly accessing user memory from NMI context can be dangerous
     247                 :            :  * if we're in the middle of switching the current user task or
     248                 :            :  * switching the loaded mm.  It can also be dangerous if we
     249                 :            :  * interrupted some kernel code that was temporarily using a
     250                 :            :  * different mm.
     251                 :            :  */
     252                 :          0 : static inline bool nmi_uaccess_okay(void)
     253                 :            : {
     254                 :          0 :         struct mm_struct *loaded_mm = this_cpu_read(cpu_tlbstate.loaded_mm);
     255         [ #  # ]:          0 :         struct mm_struct *current_mm = current->mm;
     256                 :            : 
     257                 :          0 :         VM_WARN_ON_ONCE(!loaded_mm);
     258                 :            : 
     259                 :            :         /*
     260                 :            :          * The condition we want to check is
     261                 :            :          * current_mm->pgd == __va(read_cr3_pa()).  This may be slow, though,
     262                 :            :          * if we're running in a VM with shadow paging, and nmi_uaccess_okay()
     263                 :            :          * is supposed to be reasonably fast.
     264                 :            :          *
     265                 :            :          * Instead, we check the almost equivalent but somewhat conservative
     266                 :            :          * condition below, and we rely on the fact that switch_mm_irqs_off()
     267                 :            :          * sets loaded_mm to LOADED_MM_SWITCHING before writing to CR3.
     268                 :            :          */
     269         [ #  # ]:          0 :         if (loaded_mm != current_mm)
     270                 :            :                 return false;
     271                 :            : 
     272                 :            :         VM_WARN_ON_ONCE(current_mm->pgd != __va(read_cr3_pa()));
     273                 :            : 
     274                 :            :         return true;
     275                 :            : }
     276                 :            : 
     277                 :            : #define nmi_uaccess_okay nmi_uaccess_okay
     278                 :            : 
     279                 :            : /* Initialize cr4 shadow for this CPU. */
     280                 :          0 : static inline void cr4_init_shadow(void)
     281                 :            : {
     282                 :          0 :         this_cpu_write(cpu_tlbstate.cr4, __read_cr4());
     283                 :            : }
     284                 :            : 
     285                 :        234 : static inline void __cr4_set(unsigned long cr4)
     286                 :            : {
     287                 :        234 :         lockdep_assert_irqs_disabled();
     288                 :        468 :         this_cpu_write(cpu_tlbstate.cr4, cr4);
     289                 :        234 :         __write_cr4(cr4);
     290                 :        234 : }
     291                 :            : 
     292                 :            : /* Set in this cpu's CR4. */
     293                 :        390 : static inline void cr4_set_bits_irqsoff(unsigned long mask)
     294                 :            : {
     295                 :        390 :         unsigned long cr4;
     296                 :            : 
     297                 :        780 :         cr4 = this_cpu_read(cpu_tlbstate.cr4);
     298         [ +  + ]:        390 :         if ((cr4 | mask) != cr4)
     299                 :        234 :                 __cr4_set(cr4 | mask);
     300                 :            : }
     301                 :            : 
     302                 :            : /* Clear in this cpu's CR4. */
     303                 :    3383137 : static inline void cr4_clear_bits_irqsoff(unsigned long mask)
     304                 :            : {
     305                 :    3383137 :         unsigned long cr4;
     306                 :            : 
     307                 :    3383293 :         cr4 = this_cpu_read(cpu_tlbstate.cr4);
     308         [ -  + ]:    3383137 :         if ((cr4 & ~mask) != cr4)
     309                 :          0 :                 __cr4_set(cr4 & ~mask);
     310                 :            : }
     311                 :            : 
     312                 :            : /* Set in this cpu's CR4. */
     313                 :        390 : static inline void cr4_set_bits(unsigned long mask)
     314                 :            : {
     315                 :        390 :         unsigned long flags;
     316                 :            : 
     317                 :        390 :         local_irq_save(flags);
     318                 :        390 :         cr4_set_bits_irqsoff(mask);
     319                 :        390 :         local_irq_restore(flags);
     320                 :        390 : }
     321                 :            : 
     322                 :            : /* Clear in this cpu's CR4. */
     323                 :        156 : static inline void cr4_clear_bits(unsigned long mask)
     324                 :            : {
     325                 :        156 :         unsigned long flags;
     326                 :            : 
     327                 :        156 :         local_irq_save(flags);
     328                 :        156 :         cr4_clear_bits_irqsoff(mask);
     329                 :        156 :         local_irq_restore(flags);
     330                 :        156 : }
     331                 :            : 
     332                 :          0 : static inline void cr4_toggle_bits_irqsoff(unsigned long mask)
     333                 :            : {
     334                 :          0 :         unsigned long cr4;
     335                 :            : 
     336                 :          0 :         cr4 = this_cpu_read(cpu_tlbstate.cr4);
     337                 :          0 :         __cr4_set(cr4 ^ mask);
     338                 :          0 : }
     339                 :            : 
     340                 :            : /* Read the CR4 shadow. */
     341                 :          0 : static inline unsigned long cr4_read_shadow(void)
     342                 :            : {
     343         [ #  # ]:          0 :         return this_cpu_read(cpu_tlbstate.cr4);
     344                 :            : }
     345                 :            : 
     346                 :            : /*
     347                 :            :  * Mark all other ASIDs as invalid, preserves the current.
     348                 :            :  */
     349                 :          0 : static inline void invalidate_other_asid(void)
     350                 :            : {
     351                 :          0 :         this_cpu_write(cpu_tlbstate.invalidate_other, true);
     352                 :          0 : }
     353                 :            : 
     354                 :            : /*
     355                 :            :  * Save some of cr4 feature set we're using (e.g.  Pentium 4MB
     356                 :            :  * enable and PPro Global page enable), so that any CPU's that boot
     357                 :            :  * up after us can get the correct flags.  This should only be used
     358                 :            :  * during boot on the boot cpu.
     359                 :            :  */
     360                 :            : extern unsigned long mmu_cr4_features;
     361                 :            : extern u32 *trampoline_cr4_features;
     362                 :            : 
     363                 :        156 : static inline void cr4_set_bits_and_update_boot(unsigned long mask)
     364                 :            : {
     365                 :        156 :         mmu_cr4_features |= mask;
     366   [ -  +  -  + ]:        156 :         if (trampoline_cr4_features)
     367                 :          0 :                 *trampoline_cr4_features = mmu_cr4_features;
     368                 :        156 :         cr4_set_bits(mask);
     369                 :         78 : }
     370                 :            : 
     371                 :            : extern void initialize_tlbstate_and_flush(void);
     372                 :            : 
     373                 :            : /*
     374                 :            :  * Given an ASID, flush the corresponding user ASID.  We can delay this
     375                 :            :  * until the next time we switch to it.
     376                 :            :  *
     377                 :            :  * See SWITCH_TO_USER_CR3.
     378                 :            :  */
     379                 :    4193789 : static inline void invalidate_user_asid(u16 asid)
     380                 :            : {
     381                 :            :         /* There is no user ASID if address space separation is off */
     382                 :    4193789 :         if (!IS_ENABLED(CONFIG_PAGE_TABLE_ISOLATION))
     383                 :            :                 return;
     384                 :            : 
     385                 :            :         /*
     386                 :            :          * We only have a single ASID if PCID is off and the CR3
     387                 :            :          * write will have flushed it.
     388                 :            :          */
     389      [ -  -  + ]:    4193789 :         if (!cpu_feature_enabled(X86_FEATURE_PCID))
     390                 :            :                 return;
     391                 :            : 
     392      [ #  #  # ]:          0 :         if (!static_cpu_has(X86_FEATURE_PTI))
     393                 :            :                 return;
     394                 :            : 
     395                 :          0 :         __set_bit(kern_pcid(asid),
     396                 :          0 :                   (unsigned long *)this_cpu_ptr(&cpu_tlbstate.user_pcid_flush_mask));
     397                 :            : }
     398                 :            : 
     399                 :            : /*
     400                 :            :  * flush the entire current user mapping
     401                 :            :  */
     402                 :     810808 : static inline void __native_flush_tlb(void)
     403                 :            : {
     404                 :            :         /*
     405                 :            :          * Preemption or interrupts must be disabled to protect the access
     406                 :            :          * to the per CPU variable and to prevent being preempted between
     407                 :            :          * read_cr3() and write_cr3().
     408                 :            :          */
     409                 :     810808 :         WARN_ON_ONCE(preemptible());
     410                 :            : 
     411                 :     810808 :         invalidate_user_asid(this_cpu_read(cpu_tlbstate.loaded_mm_asid));
     412                 :            : 
     413                 :            :         /* If current->mm == NULL then the read_cr3() "borrows" an mm */
     414                 :     810808 :         native_write_cr3(__native_read_cr3());
     415                 :            : }
     416                 :            : 
     417                 :            : /*
     418                 :            :  * flush everything
     419                 :            :  */
     420                 :       4641 : static inline void __native_flush_tlb_global(void)
     421                 :            : {
     422                 :       4641 :         unsigned long cr4, flags;
     423                 :            : 
     424      [ -  +  - ]:       4641 :         if (static_cpu_has(X86_FEATURE_INVPCID)) {
     425                 :            :                 /*
     426                 :            :                  * Using INVPCID is considerably faster than a pair of writes
     427                 :            :                  * to CR4 sandwiched inside an IRQ flag save/restore.
     428                 :            :                  *
     429                 :            :                  * Note, this works with CR4.PCIDE=0 or 1.
     430                 :            :                  */
     431                 :          0 :                 invpcid_flush_all();
     432                 :          0 :                 return;
     433                 :            :         }
     434                 :            : 
     435                 :            :         /*
     436                 :            :          * Read-modify-write to CR4 - protect it from preemption and
     437                 :            :          * from interrupts. (Use the raw variant because this code can
     438                 :            :          * be called from deep inside debugging code.)
     439                 :            :          */
     440                 :       4641 :         raw_local_irq_save(flags);
     441                 :            : 
     442                 :       4641 :         cr4 = this_cpu_read(cpu_tlbstate.cr4);
     443                 :            :         /* toggle PGE */
     444                 :       4641 :         native_write_cr4(cr4 ^ X86_CR4_PGE);
     445                 :            :         /* write old PGE again and flush TLBs */
     446                 :       4641 :         native_write_cr4(cr4);
     447                 :            : 
     448                 :       4641 :         raw_local_irq_restore(flags);
     449                 :            : }
     450                 :            : 
     451                 :            : /*
     452                 :            :  * flush one page in the user mapping
     453                 :            :  */
     454                 :   14412080 : static inline void __native_flush_tlb_one_user(unsigned long addr)
     455                 :            : {
     456                 :   14412080 :         u32 loaded_mm_asid = this_cpu_read(cpu_tlbstate.loaded_mm_asid);
     457                 :            : 
     458                 :   14412080 :         asm volatile("invlpg (%0)" ::"r" (addr) : "memory");
     459                 :            : 
     460      [ -  -  + ]:   14412080 :         if (!static_cpu_has(X86_FEATURE_PTI))
     461                 :            :                 return;
     462                 :            : 
     463                 :            :         /*
     464                 :            :          * Some platforms #GP if we call invpcid(type=1/2) before CR4.PCIDE=1.
     465                 :            :          * Just use invalidate_user_asid() in case we are called early.
     466                 :            :          */
     467         [ #  # ]:          0 :         if (!this_cpu_has(X86_FEATURE_INVPCID_SINGLE))
     468                 :          0 :                 invalidate_user_asid(loaded_mm_asid);
     469                 :            :         else
     470                 :          0 :                 invpcid_flush_one(user_pcid(loaded_mm_asid), addr);
     471                 :            : }
     472                 :            : 
     473                 :            : /*
     474                 :            :  * flush everything
     475                 :            :  */
     476                 :       4641 : static inline void __flush_tlb_all(void)
     477                 :            : {
     478                 :            :         /*
     479                 :            :          * This is to catch users with enabled preemption and the PGE feature
     480                 :            :          * and don't trigger the warning in __native_flush_tlb().
     481                 :            :          */
     482                 :       4641 :         VM_WARN_ON_ONCE(preemptible());
     483                 :            : 
     484         [ +  - ]:       4641 :         if (boot_cpu_has(X86_FEATURE_PGE)) {
     485                 :       4641 :                 __flush_tlb_global();
     486                 :            :         } else {
     487                 :            :                 /*
     488                 :            :                  * !PGE -> !PCID (setup_pcid()), thus every flush is total.
     489                 :            :                  */
     490                 :          0 :                 __flush_tlb();
     491                 :            :         }
     492                 :       4641 : }
     493                 :            : 
     494                 :            : /*
     495                 :            :  * flush one page in the kernel mapping
     496                 :            :  */
     497                 :    3542430 : static inline void __flush_tlb_one_kernel(unsigned long addr)
     498                 :            : {
     499                 :    3542430 :         count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ONE);
     500                 :            : 
     501                 :            :         /*
     502                 :            :          * If PTI is off, then __flush_tlb_one_user() is just INVLPG or its
     503                 :            :          * paravirt equivalent.  Even with PCID, this is sufficient: we only
     504                 :            :          * use PCID if we also use global PTEs for the kernel mapping, and
     505                 :            :          * INVLPG flushes global translations across all address spaces.
     506                 :            :          *
     507                 :            :          * If PTI is on, then the kernel is mapped with non-global PTEs, and
     508                 :            :          * __flush_tlb_one_user() will flush the given address for the current
     509                 :            :          * kernel address space and for its usermode counterpart, but it does
     510                 :            :          * not flush it for other address spaces.
     511                 :            :          */
     512                 :    3542430 :         __flush_tlb_one_user(addr);
     513                 :            : 
     514      [ -  -  + ]:    3542430 :         if (!static_cpu_has(X86_FEATURE_PTI))
     515                 :            :                 return;
     516                 :            : 
     517                 :            :         /*
     518                 :            :          * See above.  We need to propagate the flush to all other address
     519                 :            :          * spaces.  In principle, we only need to propagate it to kernelmode
     520                 :            :          * address spaces, but the extra bookkeeping we would need is not
     521                 :            :          * worth it.
     522                 :            :          */
     523                 :          0 :         invalidate_other_asid();
     524                 :            : }
     525                 :            : 
     526                 :            : #define TLB_FLUSH_ALL   -1UL
     527                 :            : 
     528                 :            : /*
     529                 :            :  * TLB flushing:
     530                 :            :  *
     531                 :            :  *  - flush_tlb_all() flushes all processes TLBs
     532                 :            :  *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
     533                 :            :  *  - flush_tlb_page(vma, vmaddr) flushes one page
     534                 :            :  *  - flush_tlb_range(vma, start, end) flushes a range of pages
     535                 :            :  *  - flush_tlb_kernel_range(start, end) flushes a range of kernel pages
     536                 :            :  *  - flush_tlb_others(cpumask, info) flushes TLBs on other cpus
     537                 :            :  *
     538                 :            :  * ..but the i386 has somewhat limited tlb flushing capabilities,
     539                 :            :  * and page-granular flushes are available only on i486 and up.
     540                 :            :  */
     541                 :            : struct flush_tlb_info {
     542                 :            :         /*
     543                 :            :          * We support several kinds of flushes.
     544                 :            :          *
     545                 :            :          * - Fully flush a single mm.  .mm will be set, .end will be
     546                 :            :          *   TLB_FLUSH_ALL, and .new_tlb_gen will be the tlb_gen to
     547                 :            :          *   which the IPI sender is trying to catch us up.
     548                 :            :          *
     549                 :            :          * - Partially flush a single mm.  .mm will be set, .start and
     550                 :            :          *   .end will indicate the range, and .new_tlb_gen will be set
     551                 :            :          *   such that the changes between generation .new_tlb_gen-1 and
     552                 :            :          *   .new_tlb_gen are entirely contained in the indicated range.
     553                 :            :          *
     554                 :            :          * - Fully flush all mms whose tlb_gens have been updated.  .mm
     555                 :            :          *   will be NULL, .end will be TLB_FLUSH_ALL, and .new_tlb_gen
     556                 :            :          *   will be zero.
     557                 :            :          */
     558                 :            :         struct mm_struct        *mm;
     559                 :            :         unsigned long           start;
     560                 :            :         unsigned long           end;
     561                 :            :         u64                     new_tlb_gen;
     562                 :            :         unsigned int            stride_shift;
     563                 :            :         bool                    freed_tables;
     564                 :            : };
     565                 :            : 
     566                 :            : #define local_flush_tlb() __flush_tlb()
     567                 :            : 
     568                 :            : #define flush_tlb_mm(mm)                                                \
     569                 :            :                 flush_tlb_mm_range(mm, 0UL, TLB_FLUSH_ALL, 0UL, true)
     570                 :            : 
     571                 :            : #define flush_tlb_range(vma, start, end)                                \
     572                 :            :         flush_tlb_mm_range((vma)->vm_mm, start, end,                 \
     573                 :            :                            ((vma)->vm_flags & VM_HUGETLB)                \
     574                 :            :                                 ? huge_page_shift(hstate_vma(vma))      \
     575                 :            :                                 : PAGE_SHIFT, false)
     576                 :            : 
     577                 :            : extern void flush_tlb_all(void);
     578                 :            : extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
     579                 :            :                                 unsigned long end, unsigned int stride_shift,
     580                 :            :                                 bool freed_tables);
     581                 :            : extern void flush_tlb_kernel_range(unsigned long start, unsigned long end);
     582                 :            : 
     583                 :    1385354 : static inline void flush_tlb_page(struct vm_area_struct *vma, unsigned long a)
     584                 :            : {
     585                 :    1385354 :         flush_tlb_mm_range(vma->vm_mm, a, a + PAGE_SIZE, PAGE_SHIFT, false);
     586                 :    1385354 : }
     587                 :            : 
     588                 :            : void native_flush_tlb_others(const struct cpumask *cpumask,
     589                 :            :                              const struct flush_tlb_info *info);
     590                 :            : 
     591                 :   10792730 : static inline u64 inc_mm_tlb_gen(struct mm_struct *mm)
     592                 :            : {
     593                 :            :         /*
     594                 :            :          * Bump the generation count.  This also serves as a full barrier
     595                 :            :          * that synchronizes with switch_mm(): callers are required to order
     596                 :            :          * their read of mm_cpumask after their writes to the paging
     597                 :            :          * structures.
     598                 :            :          */
     599                 :   10792730 :         return atomic64_inc_return(&mm->context.tlb_gen);
     600                 :            : }
     601                 :            : 
     602                 :          0 : static inline void arch_tlbbatch_add_mm(struct arch_tlbflush_unmap_batch *batch,
     603                 :            :                                         struct mm_struct *mm)
     604                 :            : {
     605                 :          0 :         inc_mm_tlb_gen(mm);
     606                 :          0 :         cpumask_or(&batch->cpumask, &batch->cpumask, mm_cpumask(mm));
     607                 :            : }
     608                 :            : 
     609                 :            : extern void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch);
     610                 :            : 
     611                 :            : #ifndef CONFIG_PARAVIRT
     612                 :            : #define flush_tlb_others(mask, info)    \
     613                 :            :         native_flush_tlb_others(mask, info)
     614                 :            : 
     615                 :            : #define paravirt_tlb_remove_table(tlb, page) \
     616                 :            :         tlb_remove_page(tlb, (void *)(page))
     617                 :            : #endif
     618                 :            : 
     619                 :            : #endif /* _ASM_X86_TLBFLUSH_H */

Generated by: LCOV version 1.14