diff options
Diffstat (limited to 'arch/x86/include/asm/tlbflush.h')
| -rw-r--r-- | arch/x86/include/asm/tlbflush.h | 285 |
1 files changed, 258 insertions, 27 deletions
diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h index 8c87a2e0b660..00daedfefc1b 100644 --- a/arch/x86/include/asm/tlbflush.h +++ b/arch/x86/include/asm/tlbflush.h @@ -2,9 +2,11 @@ #ifndef _ASM_X86_TLBFLUSH_H #define _ASM_X86_TLBFLUSH_H -#include <linux/mm.h> +#include <linux/mm_types.h> +#include <linux/mmu_notifier.h> #include <linux/sched.h> +#include <asm/barrier.h> #include <asm/processor.h> #include <asm/cpufeature.h> #include <asm/special_insns.h> @@ -12,10 +14,14 @@ #include <asm/invpcid.h> #include <asm/pti.h> #include <asm/processor-flags.h> +#include <asm/pgtable.h> + +DECLARE_PER_CPU(u64, tlbstate_untag_mask); void __flush_tlb_all(void); #define TLB_FLUSH_ALL -1UL +#define TLB_GENERATION_INVALID 0 void cr4_update_irqsoff(unsigned long set, unsigned long clear); unsigned long cr4_read_shadow(void); @@ -83,30 +89,13 @@ struct tlb_state { /* Last user mm for optimizing IBPB */ union { struct mm_struct *last_user_mm; - unsigned long last_user_mm_ibpb; + unsigned long last_user_mm_spec; }; u16 loaded_mm_asid; u16 next_asid; /* - * We can be in one of several states: - * - * - Actively using an mm. Our CPU's bit will be set in - * mm_cpumask(loaded_mm) and is_lazy == false; - * - * - Not using a real mm. loaded_mm == &init_mm. Our CPU's bit - * will not be set in mm_cpumask(&init_mm) and is_lazy == false. - * - * - Lazily using a real mm. loaded_mm != &init_mm, our bit - * is set in mm_cpumask(loaded_mm), but is_lazy == true. - * We're heuristically guessing that the CR3 load we - * skipped more than makes up for the overhead added by - * lazy mode. - */ - bool is_lazy; - - /* * If set we changed the page tables in such a way that we * needed an invalidation of all contexts (aka. PCIDs / ASIDs). * This tells us to go invalidate all the non-loaded ctxs[] @@ -117,6 +106,16 @@ struct tlb_state { */ bool invalidate_other; +#ifdef CONFIG_ADDRESS_MASKING + /* + * Active LAM mode. + * + * X86_CR3_LAM_U57/U48 shifted right by X86_CR3_LAM_U57_BIT or 0 if LAM + * disabled. + */ + u8 lam; +#endif + /* * Mask that contains TLB_NR_DYN_ASIDS+1 bits to indicate * the corresponding user PCID needs a flush next time we @@ -151,7 +150,27 @@ struct tlb_state { */ struct tlb_context ctxs[TLB_NR_DYN_ASIDS]; }; -DECLARE_PER_CPU_SHARED_ALIGNED(struct tlb_state, cpu_tlbstate); +DECLARE_PER_CPU_ALIGNED(struct tlb_state, cpu_tlbstate); + +struct tlb_state_shared { + /* + * We can be in one of several states: + * + * - Actively using an mm. Our CPU's bit will be set in + * mm_cpumask(loaded_mm) and is_lazy == false; + * + * - Not using a real mm. loaded_mm == &init_mm. Our CPU's bit + * will not be set in mm_cpumask(&init_mm) and is_lazy == false. + * + * - Lazily using a real mm. loaded_mm != &init_mm, our bit + * is set in mm_cpumask(loaded_mm), but is_lazy == true. + * We're heuristically guessing that the CR3 load we + * skipped more than makes up for the overhead added by + * lazy mode. + */ + bool is_lazy; +}; +DECLARE_PER_CPU_SHARED_ALIGNED(struct tlb_state_shared, cpu_tlbstate_shared); bool nmi_uaccess_okay(void); #define nmi_uaccess_okay nmi_uaccess_okay @@ -165,6 +184,9 @@ static inline void cr4_init_shadow(void) extern unsigned long mmu_cr4_features; extern u32 *trampoline_cr4_features; +/* How many pages can be invalidated with one INVLPGB. */ +extern u16 invlpgb_count_max; + extern void initialize_tlbstate_and_flush(void); /* @@ -175,7 +197,7 @@ extern void initialize_tlbstate_and_flush(void); * - flush_tlb_page(vma, vmaddr) flushes one page * - flush_tlb_range(vma, start, end) flushes a range of pages * - flush_tlb_kernel_range(start, end) flushes a range of kernel pages - * - flush_tlb_others(cpumask, info) flushes TLBs on other cpus + * - flush_tlb_multi(cpumask, info) flushes TLBs on multiple cpus * * ..but the i386 has somewhat limited tlb flushing capabilities, * and page-granular flushes are available only on i486 and up. @@ -201,16 +223,83 @@ struct flush_tlb_info { unsigned long start; unsigned long end; u64 new_tlb_gen; - unsigned int stride_shift; - bool freed_tables; + unsigned int initiating_cpu; + u8 stride_shift; + u8 freed_tables; + u8 trim_cpumask; }; void flush_tlb_local(void); void flush_tlb_one_user(unsigned long addr); void flush_tlb_one_kernel(unsigned long addr); -void flush_tlb_others(const struct cpumask *cpumask, +void flush_tlb_multi(const struct cpumask *cpumask, const struct flush_tlb_info *info); +static inline bool is_dyn_asid(u16 asid) +{ + return asid < TLB_NR_DYN_ASIDS; +} + +static inline bool is_global_asid(u16 asid) +{ + return !is_dyn_asid(asid); +} + +#ifdef CONFIG_BROADCAST_TLB_FLUSH +static inline u16 mm_global_asid(struct mm_struct *mm) +{ + u16 asid; + + if (!cpu_feature_enabled(X86_FEATURE_INVLPGB)) + return 0; + + asid = smp_load_acquire(&mm->context.global_asid); + + /* mm->context.global_asid is either 0, or a global ASID */ + VM_WARN_ON_ONCE(asid && is_dyn_asid(asid)); + + return asid; +} + +static inline void mm_init_global_asid(struct mm_struct *mm) +{ + if (cpu_feature_enabled(X86_FEATURE_INVLPGB)) { + mm->context.global_asid = 0; + mm->context.asid_transition = false; + } +} + +static inline void mm_assign_global_asid(struct mm_struct *mm, u16 asid) +{ + /* + * Notably flush_tlb_mm_range() -> broadcast_tlb_flush() -> + * finish_asid_transition() needs to observe asid_transition = true + * once it observes global_asid. + */ + mm->context.asid_transition = true; + smp_store_release(&mm->context.global_asid, asid); +} + +static inline void mm_clear_asid_transition(struct mm_struct *mm) +{ + WRITE_ONCE(mm->context.asid_transition, false); +} + +static inline bool mm_in_asid_transition(struct mm_struct *mm) +{ + if (!cpu_feature_enabled(X86_FEATURE_INVLPGB)) + return false; + + return mm && READ_ONCE(mm->context.asid_transition); +} +#else +static inline u16 mm_global_asid(struct mm_struct *mm) { return 0; } +static inline void mm_init_global_asid(struct mm_struct *mm) { } +static inline void mm_assign_global_asid(struct mm_struct *mm, u16 asid) { } +static inline void mm_clear_asid_transition(struct mm_struct *mm) { } +static inline bool mm_in_asid_transition(struct mm_struct *mm) { return false; } +#endif /* CONFIG_BROADCAST_TLB_FLUSH */ + #ifdef CONFIG_PARAVIRT #include <asm/paravirt.h> #endif @@ -222,7 +311,7 @@ void flush_tlb_others(const struct cpumask *cpumask, flush_tlb_mm_range((vma)->vm_mm, start, end, \ ((vma)->vm_flags & VM_HUGETLB) \ ? huge_page_shift(hstate_vma(vma)) \ - : PAGE_SHIFT, false) + : PAGE_SHIFT, true) extern void flush_tlb_all(void); extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start, @@ -235,6 +324,18 @@ static inline void flush_tlb_page(struct vm_area_struct *vma, unsigned long a) flush_tlb_mm_range(vma->vm_mm, a, a + PAGE_SIZE, PAGE_SHIFT, false); } +static inline bool arch_tlbbatch_should_defer(struct mm_struct *mm) +{ + bool should_defer = false; + + /* If remote CPUs need to be flushed then defer batch the flush */ + if (cpumask_any_but(mm_cpumask(mm), get_cpu()) < nr_cpu_ids) + should_defer = true; + put_cpu(); + + return should_defer; +} + static inline u64 inc_mm_tlb_gen(struct mm_struct *mm) { /* @@ -246,15 +347,145 @@ static inline u64 inc_mm_tlb_gen(struct mm_struct *mm) return atomic64_inc_return(&mm->context.tlb_gen); } -static inline void arch_tlbbatch_add_mm(struct arch_tlbflush_unmap_batch *batch, - struct mm_struct *mm) +static inline void arch_tlbbatch_add_pending(struct arch_tlbflush_unmap_batch *batch, + struct mm_struct *mm, unsigned long start, unsigned long end) { inc_mm_tlb_gen(mm); cpumask_or(&batch->cpumask, &batch->cpumask, mm_cpumask(mm)); + batch->unmapped_pages = true; + mmu_notifier_arch_invalidate_secondary_tlbs(mm, 0, -1UL); } extern void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch); +static inline bool pte_flags_need_flush(unsigned long oldflags, + unsigned long newflags, + bool ignore_access) +{ + /* + * Flags that require a flush when cleared but not when they are set. + * Only include flags that would not trigger spurious page-faults. + * Non-present entries are not cached. Hardware would set the + * dirty/access bit if needed without a fault. + */ + const pteval_t flush_on_clear = _PAGE_DIRTY | _PAGE_PRESENT | + _PAGE_ACCESSED; + const pteval_t software_flags = _PAGE_SOFTW1 | _PAGE_SOFTW2 | + _PAGE_SOFTW3 | _PAGE_SOFTW4 | + _PAGE_SAVED_DIRTY; + const pteval_t flush_on_change = _PAGE_RW | _PAGE_USER | _PAGE_PWT | + _PAGE_PCD | _PAGE_PSE | _PAGE_GLOBAL | _PAGE_PAT | + _PAGE_PAT_LARGE | _PAGE_PKEY_BIT0 | _PAGE_PKEY_BIT1 | + _PAGE_PKEY_BIT2 | _PAGE_PKEY_BIT3 | _PAGE_NX; + unsigned long diff = oldflags ^ newflags; + + BUILD_BUG_ON(flush_on_clear & software_flags); + BUILD_BUG_ON(flush_on_clear & flush_on_change); + BUILD_BUG_ON(flush_on_change & software_flags); + + /* Ignore software flags */ + diff &= ~software_flags; + + if (ignore_access) + diff &= ~_PAGE_ACCESSED; + + /* + * Did any of the 'flush_on_clear' flags was clleared set from between + * 'oldflags' and 'newflags'? + */ + if (diff & oldflags & flush_on_clear) + return true; + + /* Flush on modified flags. */ + if (diff & flush_on_change) + return true; + + /* Ensure there are no flags that were left behind */ + if (IS_ENABLED(CONFIG_DEBUG_VM) && + (diff & ~(flush_on_clear | software_flags | flush_on_change))) { + VM_WARN_ON_ONCE(1); + return true; + } + + return false; +} + +/* + * pte_needs_flush() checks whether permissions were demoted and require a + * flush. It should only be used for userspace PTEs. + */ +static inline bool pte_needs_flush(pte_t oldpte, pte_t newpte) +{ + /* !PRESENT -> * ; no need for flush */ + if (!(pte_flags(oldpte) & _PAGE_PRESENT)) + return false; + + /* PFN changed ; needs flush */ + if (pte_pfn(oldpte) != pte_pfn(newpte)) + return true; + + /* + * check PTE flags; ignore access-bit; see comment in + * ptep_clear_flush_young(). + */ + return pte_flags_need_flush(pte_flags(oldpte), pte_flags(newpte), + true); +} +#define pte_needs_flush pte_needs_flush + +/* + * huge_pmd_needs_flush() checks whether permissions were demoted and require a + * flush. It should only be used for userspace huge PMDs. + */ +static inline bool huge_pmd_needs_flush(pmd_t oldpmd, pmd_t newpmd) +{ + /* !PRESENT -> * ; no need for flush */ + if (!(pmd_flags(oldpmd) & _PAGE_PRESENT)) + return false; + + /* PFN changed ; needs flush */ + if (pmd_pfn(oldpmd) != pmd_pfn(newpmd)) + return true; + + /* + * check PMD flags; do not ignore access-bit; see + * pmdp_clear_flush_young(). + */ + return pte_flags_need_flush(pmd_flags(oldpmd), pmd_flags(newpmd), + false); +} +#define huge_pmd_needs_flush huge_pmd_needs_flush + +#ifdef CONFIG_ADDRESS_MASKING +static inline u64 tlbstate_lam_cr3_mask(void) +{ + u64 lam = this_cpu_read(cpu_tlbstate.lam); + + return lam << X86_CR3_LAM_U57_BIT; +} + +static inline void cpu_tlbstate_update_lam(unsigned long lam, u64 untag_mask) +{ + this_cpu_write(cpu_tlbstate.lam, lam >> X86_CR3_LAM_U57_BIT); + this_cpu_write(tlbstate_untag_mask, untag_mask); +} + +#else + +static inline u64 tlbstate_lam_cr3_mask(void) +{ + return 0; +} + +static inline void cpu_tlbstate_update_lam(unsigned long lam, u64 untag_mask) +{ +} +#endif #endif /* !MODULE */ +static inline void __native_tlb_flush_global(unsigned long cr4) +{ + native_write_cr4(cr4 ^ X86_CR4_PGE); + native_write_cr4(cr4); +} #endif /* _ASM_X86_TLBFLUSH_H */ |