From 8920572c08859a104f18af29740fa711e6f605ea Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Tue, 13 Jul 2021 19:55:07 +0800 Subject: [PATCH] powerpc/64s/radix: refactor TLB flush type selection mainline inclusion from mainline-v5.12-rc1 commit 26418b36a11f2eaf2556aa8cefe86132907e311f category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I3ZFUI CVE: NA ------------------------------------------------- The logic to decide what kind of TLB flush is required (local, global, or IPI) is spread multiple times over the several kinds of TLB flushes. Move it all into a single function which may issue IPIs if necessary, and also returns a flush type that is to be used. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201217134731.488135-3-npiggin@gmail.com Signed-off-by: Liu Shixin Reviewed-by: Chen Wandun Signed-off-by: Zheng Zengkai --- arch/powerpc/mm/book3s64/radix_tlb.c | 176 ++++++++++++++------------- 1 file changed, 94 insertions(+), 82 deletions(-) diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c b/arch/powerpc/mm/book3s64/radix_tlb.c index b487b489d4b6..87691a5a698a 100644 --- a/arch/powerpc/mm/book3s64/radix_tlb.c +++ b/arch/powerpc/mm/book3s64/radix_tlb.c @@ -618,15 +618,6 @@ void radix__local_flush_tlb_page(struct vm_area_struct *vma, unsigned long vmadd } EXPORT_SYMBOL(radix__local_flush_tlb_page); -static bool mm_is_singlethreaded(struct mm_struct *mm) -{ - if (atomic_read(&mm->context.copros) > 0) - return false; - if (atomic_read(&mm->mm_users) <= 1 && current->mm == mm) - return true; - return false; -} - static bool mm_needs_flush_escalation(struct mm_struct *mm) { /* @@ -683,10 +674,58 @@ static void exit_flush_lazy_tlbs(struct mm_struct *mm) smp_call_function_many(mm_cpumask(mm), do_exit_flush_lazy_tlb, (void *)mm, 1); } +#else /* CONFIG_SMP */ +static inline void exit_flush_lazy_tlbs(struct mm_struct *mm) { } +#endif /* CONFIG_SMP */ + +enum tlb_flush_type { + FLUSH_TYPE_LOCAL, + FLUSH_TYPE_GLOBAL, +}; + +static enum tlb_flush_type flush_type_needed(struct mm_struct *mm, bool fullmm) +{ + if (mm_is_thread_local(mm)) + return FLUSH_TYPE_LOCAL; + + /* Coprocessors require TLBIE to invalidate nMMU. */ + if (atomic_read(&mm->context.copros) > 0) + return FLUSH_TYPE_GLOBAL; + + /* + * In the fullmm case there's no point doing the exit_flush_lazy_tlbs + * because the mm is being taken down anyway, and a TLBIE tends to + * be faster than an IPI+TLBIEL. + */ + if (fullmm) + return FLUSH_TYPE_GLOBAL; + + /* + * If we are running the only thread of a single-threaded process, + * then we should almost always be able to trim off the rest of the + * CPU mask (except in the case of use_mm() races), so always try + * trimming the mask. + */ + if (atomic_read(&mm->mm_users) <= 1 && current->mm == mm) { + exit_flush_lazy_tlbs(mm); + /* + * use_mm() race could prevent IPIs from being able to clear + * the cpumask here, however those users are established + * after our first check (and so after the PTEs are removed), + * and the TLB still gets flushed by the IPI, so this CPU + * will only require a local flush. + */ + return FLUSH_TYPE_LOCAL; + } + + return FLUSH_TYPE_GLOBAL; +} +#ifdef CONFIG_SMP void radix__flush_tlb_mm(struct mm_struct *mm) { unsigned long pid; + enum tlb_flush_type type; pid = mm->context.id; if (unlikely(pid == MMU_NO_CONTEXT)) @@ -694,16 +733,13 @@ void radix__flush_tlb_mm(struct mm_struct *mm) preempt_disable(); /* - * Order loads of mm_cpumask vs previous stores to clear ptes before - * the invalidate. See barrier in switch_mm_irqs_off + * Order loads of mm_cpumask (in flush_type_needed) vs previous + * stores to clear ptes before the invalidate. See barrier in + * switch_mm_irqs_off */ smp_mb(); - if (!mm_is_thread_local(mm)) { - if (unlikely(mm_is_singlethreaded(mm))) { - exit_flush_lazy_tlbs(mm); - goto local; - } - + type = flush_type_needed(mm, false); + if (type == FLUSH_TYPE_GLOBAL) { if (!mmu_has_feature(MMU_FTR_GTSE)) { unsigned long tgt = H_RPTI_TARGET_CMMU; @@ -720,7 +756,6 @@ void radix__flush_tlb_mm(struct mm_struct *mm) _tlbiel_pid_multicast(mm, pid, RIC_FLUSH_TLB); } } else { -local: _tlbiel_pid(pid, RIC_FLUSH_TLB); } preempt_enable(); @@ -730,6 +765,7 @@ EXPORT_SYMBOL(radix__flush_tlb_mm); static void __flush_all_mm(struct mm_struct *mm, bool fullmm) { unsigned long pid; + enum tlb_flush_type type; pid = mm->context.id; if (unlikely(pid == MMU_NO_CONTEXT)) @@ -737,13 +773,8 @@ static void __flush_all_mm(struct mm_struct *mm, bool fullmm) preempt_disable(); smp_mb(); /* see radix__flush_tlb_mm */ - if (!mm_is_thread_local(mm)) { - if (unlikely(mm_is_singlethreaded(mm))) { - if (!fullmm) { - exit_flush_lazy_tlbs(mm); - goto local; - } - } + type = flush_type_needed(mm, fullmm); + if (type == FLUSH_TYPE_GLOBAL) { if (!mmu_has_feature(MMU_FTR_GTSE)) { unsigned long tgt = H_RPTI_TARGET_CMMU; unsigned long type = H_RPTI_TYPE_TLB | H_RPTI_TYPE_PWC | @@ -758,7 +789,6 @@ static void __flush_all_mm(struct mm_struct *mm, bool fullmm) else _tlbiel_pid_multicast(mm, pid, RIC_FLUSH_ALL); } else { -local: _tlbiel_pid(pid, RIC_FLUSH_ALL); } preempt_enable(); @@ -774,6 +804,7 @@ void radix__flush_tlb_page_psize(struct mm_struct *mm, unsigned long vmaddr, int psize) { unsigned long pid; + enum tlb_flush_type type; pid = mm->context.id; if (unlikely(pid == MMU_NO_CONTEXT)) @@ -781,11 +812,8 @@ void radix__flush_tlb_page_psize(struct mm_struct *mm, unsigned long vmaddr, preempt_disable(); smp_mb(); /* see radix__flush_tlb_mm */ - if (!mm_is_thread_local(mm)) { - if (unlikely(mm_is_singlethreaded(mm))) { - exit_flush_lazy_tlbs(mm); - goto local; - } + type = flush_type_needed(mm, false); + if (type == FLUSH_TYPE_GLOBAL) { if (!mmu_has_feature(MMU_FTR_GTSE)) { unsigned long tgt, pg_sizes, size; @@ -803,7 +831,6 @@ void radix__flush_tlb_page_psize(struct mm_struct *mm, unsigned long vmaddr, else _tlbiel_va_multicast(mm, vmaddr, pid, psize, RIC_FLUSH_TLB); } else { -local: _tlbiel_va(vmaddr, pid, psize, RIC_FLUSH_TLB); } preempt_enable(); @@ -819,8 +846,6 @@ void radix__flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr) } EXPORT_SYMBOL(radix__flush_tlb_page); -#else /* CONFIG_SMP */ -static inline void exit_flush_lazy_tlbs(struct mm_struct *mm) { } #endif /* CONFIG_SMP */ static void do_tlbiel_kernel(void *info) @@ -884,7 +909,9 @@ static inline void __radix__flush_tlb_range(struct mm_struct *mm, unsigned int page_shift = mmu_psize_defs[mmu_virtual_psize].shift; unsigned long page_size = 1UL << page_shift; unsigned long nr_pages = (end - start) >> page_shift; - bool local, full; + bool fullmm = (end == TLB_FLUSH_ALL); + bool flush_pid; + enum tlb_flush_type type; pid = mm->context.id; if (unlikely(pid == MMU_NO_CONTEXT)) @@ -892,24 +919,16 @@ static inline void __radix__flush_tlb_range(struct mm_struct *mm, preempt_disable(); smp_mb(); /* see radix__flush_tlb_mm */ - if (!mm_is_thread_local(mm)) { - if (unlikely(mm_is_singlethreaded(mm))) { - if (end != TLB_FLUSH_ALL) { - exit_flush_lazy_tlbs(mm); - goto is_local; - } - } - local = false; - full = (end == TLB_FLUSH_ALL || - nr_pages > tlb_single_page_flush_ceiling); - } else { -is_local: - local = true; - full = (end == TLB_FLUSH_ALL || - nr_pages > tlb_local_single_page_flush_ceiling); - } + type = flush_type_needed(mm, fullmm); + + if (fullmm) + flush_pid = true; + else if (type == FLUSH_TYPE_GLOBAL) + flush_pid = nr_pages > tlb_single_page_flush_ceiling; + else + flush_pid = nr_pages > tlb_local_single_page_flush_ceiling; - if (!mmu_has_feature(MMU_FTR_GTSE) && !local) { + if (!mmu_has_feature(MMU_FTR_GTSE) && type == FLUSH_TYPE_GLOBAL) { unsigned long tgt = H_RPTI_TARGET_CMMU; unsigned long pg_sizes = psize_to_rpti_pgsize(mmu_virtual_psize); @@ -919,8 +938,8 @@ static inline void __radix__flush_tlb_range(struct mm_struct *mm, tgt |= H_RPTI_TARGET_NMMU; pseries_rpt_invalidate(pid, tgt, H_RPTI_TYPE_TLB, pg_sizes, start, end); - } else if (full) { - if (local) { + } else if (flush_pid) { + if (type == FLUSH_TYPE_LOCAL) { _tlbiel_pid(pid, RIC_FLUSH_TLB); } else { if (cputlb_use_tlbie()) { @@ -943,7 +962,7 @@ static inline void __radix__flush_tlb_range(struct mm_struct *mm, hflush = true; } - if (local) { + if (type == FLUSH_TYPE_LOCAL) { asm volatile("ptesync": : :"memory"); __tlbiel_va_range(start, end, pid, page_size, mmu_virtual_psize); if (hflush) @@ -1076,32 +1095,28 @@ static __always_inline void __radix__flush_tlb_range_psize(struct mm_struct *mm, unsigned int page_shift = mmu_psize_defs[psize].shift; unsigned long page_size = 1UL << page_shift; unsigned long nr_pages = (end - start) >> page_shift; - bool local, full; + bool fullmm = (end == TLB_FLUSH_ALL); + bool flush_pid; + enum tlb_flush_type type; pid = mm->context.id; if (unlikely(pid == MMU_NO_CONTEXT)) return; + fullmm = (end == TLB_FLUSH_ALL); + preempt_disable(); smp_mb(); /* see radix__flush_tlb_mm */ - if (!mm_is_thread_local(mm)) { - if (unlikely(mm_is_singlethreaded(mm))) { - if (end != TLB_FLUSH_ALL) { - exit_flush_lazy_tlbs(mm); - goto is_local; - } - } - local = false; - full = (end == TLB_FLUSH_ALL || - nr_pages > tlb_single_page_flush_ceiling); - } else { -is_local: - local = true; - full = (end == TLB_FLUSH_ALL || - nr_pages > tlb_local_single_page_flush_ceiling); - } + type = flush_type_needed(mm, fullmm); - if (!mmu_has_feature(MMU_FTR_GTSE) && !local) { + if (fullmm) + flush_pid = true; + else if (type == FLUSH_TYPE_GLOBAL) + flush_pid = nr_pages > tlb_single_page_flush_ceiling; + else + flush_pid = nr_pages > tlb_local_single_page_flush_ceiling; + + if (!mmu_has_feature(MMU_FTR_GTSE) && type == FLUSH_TYPE_GLOBAL) { unsigned long tgt = H_RPTI_TARGET_CMMU; unsigned long type = H_RPTI_TYPE_TLB; unsigned long pg_sizes = psize_to_rpti_pgsize(psize); @@ -1111,8 +1126,8 @@ static __always_inline void __radix__flush_tlb_range_psize(struct mm_struct *mm, if (atomic_read(&mm->context.copros) > 0) tgt |= H_RPTI_TARGET_NMMU; pseries_rpt_invalidate(pid, tgt, type, pg_sizes, start, end); - } else if (full) { - if (local) { + } else if (flush_pid) { + if (type == FLUSH_TYPE_LOCAL) { _tlbiel_pid(pid, also_pwc ? RIC_FLUSH_ALL : RIC_FLUSH_TLB); } else { if (cputlb_use_tlbie()) { @@ -1128,7 +1143,7 @@ static __always_inline void __radix__flush_tlb_range_psize(struct mm_struct *mm, } } else { - if (local) + if (type == FLUSH_TYPE_LOCAL) _tlbiel_va_range(start, end, pid, page_size, psize, also_pwc); else if (cputlb_use_tlbie()) _tlbie_va_range(start, end, pid, page_size, psize, also_pwc); @@ -1155,6 +1170,7 @@ static void radix__flush_tlb_pwc_range_psize(struct mm_struct *mm, unsigned long void radix__flush_tlb_collapsed_pmd(struct mm_struct *mm, unsigned long addr) { unsigned long pid, end; + enum tlb_flush_type type; pid = mm->context.id; if (unlikely(pid == MMU_NO_CONTEXT)) @@ -1171,11 +1187,8 @@ void radix__flush_tlb_collapsed_pmd(struct mm_struct *mm, unsigned long addr) /* Otherwise first do the PWC, then iterate the pages. */ preempt_disable(); smp_mb(); /* see radix__flush_tlb_mm */ - if (!mm_is_thread_local(mm)) { - if (unlikely(mm_is_singlethreaded(mm))) { - exit_flush_lazy_tlbs(mm); - goto local; - } + type = flush_type_needed(mm, false); + if (type == FLUSH_TYPE_GLOBAL) { if (!mmu_has_feature(MMU_FTR_GTSE)) { unsigned long tgt, type, pg_sizes; @@ -1194,7 +1207,6 @@ void radix__flush_tlb_collapsed_pmd(struct mm_struct *mm, unsigned long addr) _tlbiel_va_range_multicast(mm, addr, end, pid, PAGE_SIZE, mmu_virtual_psize, true); } else { -local: _tlbiel_va_range(addr, end, pid, PAGE_SIZE, mmu_virtual_psize, true); } -- GitLab