diff options
| -rw-r--r-- | arch/arm/Kconfig | 10 | ||||
| -rw-r--r-- | arch/arm/include/asm/highmem.h | 7 | ||||
| -rw-r--r-- | arch/arm/include/asm/mmu_context.h | 2 | ||||
| -rw-r--r-- | arch/arm/include/asm/tlbflush.h | 15 | ||||
| -rw-r--r-- | arch/arm/kernel/smp_tlb.c | 66 | ||||
| -rw-r--r-- | arch/arm/mm/context.c | 3 |
6 files changed, 102 insertions, 1 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 12ea3b3d49a..1cacda426a0 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1439,6 +1439,16 @@ config ARM_ERRATA_775420 to deadlock. This workaround puts DSB before executing ISB if an abort may occur on cache maintenance. +config ARM_ERRATA_798181 + bool "ARM errata: TLBI/DSB failure on Cortex-A15" + depends on CPU_V7 && SMP + help + On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not + adequately shooting down all use of the old entries. This + option enables the Linux kernel workaround for this erratum + which sends an IPI to the CPUs that are running the same ASID + as the one being invalidated. + endmenu source "arch/arm/common/Kconfig" diff --git a/arch/arm/include/asm/highmem.h b/arch/arm/include/asm/highmem.h index 8c5e828f484..91b99abe7a9 100644 --- a/arch/arm/include/asm/highmem.h +++ b/arch/arm/include/asm/highmem.h @@ -41,6 +41,13 @@ extern void kunmap_high(struct page *page); #endif #endif +/* + * Needed to be able to broadcast the TLB invalidation for kmap. + */ +#ifdef CONFIG_ARM_ERRATA_798181 +#undef ARCH_NEEDS_KMAP_HIGH_GET +#endif + #ifdef ARCH_NEEDS_KMAP_HIGH_GET extern void *kmap_high_get(struct page *page); #else diff --git a/arch/arm/include/asm/mmu_context.h b/arch/arm/include/asm/mmu_context.h index 863a6611323..a7b85e0d0cc 100644 --- a/arch/arm/include/asm/mmu_context.h +++ b/arch/arm/include/asm/mmu_context.h @@ -27,6 +27,8 @@ void __check_vmalloc_seq(struct mm_struct *mm); void check_and_switch_context(struct mm_struct *mm, struct task_struct *tsk); #define init_new_context(tsk,mm) ({ atomic64_set(&mm->context.id, 0); 0; }) +DECLARE_PER_CPU(atomic64_t, active_asids); + #else /* !CONFIG_CPU_HAS_ASID */ #ifdef CONFIG_MMU diff --git a/arch/arm/include/asm/tlbflush.h b/arch/arm/include/asm/tlbflush.h index 4db8c8820f0..9e9c041358c 100644 --- a/arch/arm/include/asm/tlbflush.h +++ b/arch/arm/include/asm/tlbflush.h @@ -450,6 +450,21 @@ static inline void local_flush_bp_all(void) isb(); } +#ifdef CONFIG_ARM_ERRATA_798181 +static inline void dummy_flush_tlb_a15_erratum(void) +{ + /* + * Dummy TLBIMVAIS. Using the unmapped address 0 and ASID 0. + */ + asm("mcr p15, 0, %0, c8, c3, 1" : : "r" (0)); + dsb(); +} +#else +static inline void dummy_flush_tlb_a15_erratum(void) +{ +} +#endif + /* * flush_pmd_entry * diff --git a/arch/arm/kernel/smp_tlb.c b/arch/arm/kernel/smp_tlb.c index bd030053139..e82e1d24877 100644 --- a/arch/arm/kernel/smp_tlb.c +++ b/arch/arm/kernel/smp_tlb.c @@ -12,6 +12,7 @@ #include <asm/smp_plat.h> #include <asm/tlbflush.h> +#include <asm/mmu_context.h> /**********************************************************************/ @@ -69,12 +70,72 @@ static inline void ipi_flush_bp_all(void *ignored) local_flush_bp_all(); } +#ifdef CONFIG_ARM_ERRATA_798181 +static int erratum_a15_798181(void) +{ + unsigned int midr = read_cpuid_id(); + + /* Cortex-A15 r0p0..r3p2 affected */ + if ((midr & 0xff0ffff0) != 0x410fc0f0 || midr > 0x413fc0f2) + return 0; + return 1; +} +#else +static int erratum_a15_798181(void) +{ + return 0; +} +#endif + +static void ipi_flush_tlb_a15_erratum(void *arg) +{ + dmb(); +} + +static void broadcast_tlb_a15_erratum(void) +{ + if (!erratum_a15_798181()) + return; + + dummy_flush_tlb_a15_erratum(); + smp_call_function_many(cpu_online_mask, ipi_flush_tlb_a15_erratum, + NULL, 1); +} + +static void broadcast_tlb_mm_a15_erratum(struct mm_struct *mm) +{ + int cpu; + cpumask_t mask = { CPU_BITS_NONE }; + + if (!erratum_a15_798181()) + return; + + dummy_flush_tlb_a15_erratum(); + for_each_online_cpu(cpu) { + if (cpu == smp_processor_id()) + continue; + /* + * We only need to send an IPI if the other CPUs are running + * the same ASID as the one being invalidated. There is no + * need for locking around the active_asids check since the + * switch_mm() function has at least one dmb() (as required by + * this workaround) in case a context switch happens on + * another CPU after the condition below. + */ + if (atomic64_read(&mm->context.id) == + atomic64_read(&per_cpu(active_asids, cpu))) + cpumask_set_cpu(cpu, &mask); + } + smp_call_function_many(&mask, ipi_flush_tlb_a15_erratum, NULL, 1); +} + void flush_tlb_all(void) { if (tlb_ops_need_broadcast()) on_each_cpu(ipi_flush_tlb_all, NULL, 1); else local_flush_tlb_all(); + broadcast_tlb_a15_erratum(); } void flush_tlb_mm(struct mm_struct *mm) @@ -83,6 +144,7 @@ void flush_tlb_mm(struct mm_struct *mm) on_each_cpu_mask(mm_cpumask(mm), ipi_flush_tlb_mm, mm, 1); else local_flush_tlb_mm(mm); + broadcast_tlb_mm_a15_erratum(mm); } void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr) @@ -95,6 +157,7 @@ void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr) &ta, 1); } else local_flush_tlb_page(vma, uaddr); + broadcast_tlb_mm_a15_erratum(vma->vm_mm); } void flush_tlb_kernel_page(unsigned long kaddr) @@ -105,6 +168,7 @@ void flush_tlb_kernel_page(unsigned long kaddr) on_each_cpu(ipi_flush_tlb_kernel_page, &ta, 1); } else local_flush_tlb_kernel_page(kaddr); + broadcast_tlb_a15_erratum(); } void flush_tlb_range(struct vm_area_struct *vma, @@ -119,6 +183,7 @@ void flush_tlb_range(struct vm_area_struct *vma, &ta, 1); } else local_flush_tlb_range(vma, start, end); + broadcast_tlb_mm_a15_erratum(vma->vm_mm); } void flush_tlb_kernel_range(unsigned long start, unsigned long end) @@ -130,6 +195,7 @@ void flush_tlb_kernel_range(unsigned long start, unsigned long end) on_each_cpu(ipi_flush_tlb_kernel_range, &ta, 1); } else local_flush_tlb_kernel_range(start, end); + broadcast_tlb_a15_erratum(); } void flush_bp_all(void) diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c index a5a4b2bc42b..2ac37372ef5 100644 --- a/arch/arm/mm/context.c +++ b/arch/arm/mm/context.c @@ -48,7 +48,7 @@ static DEFINE_RAW_SPINLOCK(cpu_asid_lock); static atomic64_t asid_generation = ATOMIC64_INIT(ASID_FIRST_VERSION); static DECLARE_BITMAP(asid_map, NUM_USER_ASIDS); -static DEFINE_PER_CPU(atomic64_t, active_asids); +DEFINE_PER_CPU(atomic64_t, active_asids); static DEFINE_PER_CPU(u64, reserved_asids); static cpumask_t tlb_flush_pending; @@ -215,6 +215,7 @@ void check_and_switch_context(struct mm_struct *mm, struct task_struct *tsk) if (cpumask_test_and_clear_cpu(cpu, &tlb_flush_pending)) { local_flush_bp_all(); local_flush_tlb_all(); + dummy_flush_tlb_a15_erratum(); } atomic64_set(&per_cpu(active_asids, cpu), asid); |