From 862c588f062fe9339a180cf6429e4df1855c376a Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Thu, 28 Feb 2013 17:48:11 +0100 Subject: ARM: 7660/1: tlb: add branch predictor maintenance operations The ARM architecture requires explicit branch predictor maintenance when updating an instruction stream for a given virtual address. In reality, this isn't so much of a burden because the branch predictor is flushed during the cache maintenance required to make the new instructions visible to the I-side of the processor. However, there are still some cases where explicit flushing is required, so add a local_bp_flush_all operation to deal with this. Reviewed-by: Catalin Marinas Signed-off-by: Will Deacon Signed-off-by: Russell King --- arch/arm/include/asm/tlbflush.h | 34 ++++++++++++++++++++++++++++------ arch/arm/kernel/smp_tlb.c | 12 ++++++++++++ 2 files changed, 40 insertions(+), 6 deletions(-) diff --git a/arch/arm/include/asm/tlbflush.h b/arch/arm/include/asm/tlbflush.h index 6e924d3a77e..4db8c8820f0 100644 --- a/arch/arm/include/asm/tlbflush.h +++ b/arch/arm/include/asm/tlbflush.h @@ -34,10 +34,13 @@ #define TLB_V6_D_ASID (1 << 17) #define TLB_V6_I_ASID (1 << 18) +#define TLB_V6_BP (1 << 19) + /* Unified Inner Shareable TLB operations (ARMv7 MP extensions) */ -#define TLB_V7_UIS_PAGE (1 << 19) -#define TLB_V7_UIS_FULL (1 << 20) -#define TLB_V7_UIS_ASID (1 << 21) +#define TLB_V7_UIS_PAGE (1 << 20) +#define TLB_V7_UIS_FULL (1 << 21) +#define TLB_V7_UIS_ASID (1 << 22) +#define TLB_V7_UIS_BP (1 << 23) #define TLB_BARRIER (1 << 28) #define TLB_L2CLEAN_FR (1 << 29) /* Feroceon */ @@ -150,7 +153,8 @@ #define v6wbi_tlb_flags (TLB_WB | TLB_DCLEAN | TLB_BARRIER | \ TLB_V6_I_FULL | TLB_V6_D_FULL | \ TLB_V6_I_PAGE | TLB_V6_D_PAGE | \ - TLB_V6_I_ASID | TLB_V6_D_ASID) + TLB_V6_I_ASID | TLB_V6_D_ASID | \ + TLB_V6_BP) #ifdef CONFIG_CPU_TLB_V6 # define v6wbi_possible_flags v6wbi_tlb_flags @@ -166,9 +170,11 @@ #endif #define v7wbi_tlb_flags_smp (TLB_WB | TLB_DCLEAN | TLB_BARRIER | \ - TLB_V7_UIS_FULL | TLB_V7_UIS_PAGE | TLB_V7_UIS_ASID) + TLB_V7_UIS_FULL | TLB_V7_UIS_PAGE | \ + TLB_V7_UIS_ASID | TLB_V7_UIS_BP) #define v7wbi_tlb_flags_up (TLB_WB | TLB_DCLEAN | TLB_BARRIER | \ - TLB_V6_U_FULL | TLB_V6_U_PAGE | TLB_V6_U_ASID) + TLB_V6_U_FULL | TLB_V6_U_PAGE | \ + TLB_V6_U_ASID | TLB_V6_BP) #ifdef CONFIG_CPU_TLB_V7 @@ -430,6 +436,20 @@ static inline void local_flush_tlb_kernel_page(unsigned long kaddr) } } +static inline void local_flush_bp_all(void) +{ + const int zero = 0; + const unsigned int __tlb_flag = __cpu_tlb_flags; + + if (tlb_flag(TLB_V7_UIS_BP)) + asm("mcr p15, 0, %0, c7, c1, 6" : : "r" (zero)); + else if (tlb_flag(TLB_V6_BP)) + asm("mcr p15, 0, %0, c7, c5, 6" : : "r" (zero)); + + if (tlb_flag(TLB_BARRIER)) + isb(); +} + /* * flush_pmd_entry * @@ -480,6 +500,7 @@ static inline void clean_pmd_entry(void *pmd) #define flush_tlb_kernel_page local_flush_tlb_kernel_page #define flush_tlb_range local_flush_tlb_range #define flush_tlb_kernel_range local_flush_tlb_kernel_range +#define flush_bp_all local_flush_bp_all #else extern void flush_tlb_all(void); extern void flush_tlb_mm(struct mm_struct *mm); @@ -487,6 +508,7 @@ extern void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr); extern void flush_tlb_kernel_page(unsigned long kaddr); extern void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end); extern void flush_tlb_kernel_range(unsigned long start, unsigned long end); +extern void flush_bp_all(void); #endif /* diff --git a/arch/arm/kernel/smp_tlb.c b/arch/arm/kernel/smp_tlb.c index 02c5d2ce23b..bd030053139 100644 --- a/arch/arm/kernel/smp_tlb.c +++ b/arch/arm/kernel/smp_tlb.c @@ -64,6 +64,11 @@ static inline void ipi_flush_tlb_kernel_range(void *arg) local_flush_tlb_kernel_range(ta->ta_start, ta->ta_end); } +static inline void ipi_flush_bp_all(void *ignored) +{ + local_flush_bp_all(); +} + void flush_tlb_all(void) { if (tlb_ops_need_broadcast()) @@ -127,3 +132,10 @@ void flush_tlb_kernel_range(unsigned long start, unsigned long end) local_flush_tlb_kernel_range(start, end); } +void flush_bp_all(void) +{ + if (tlb_ops_need_broadcast()) + on_each_cpu(ipi_flush_bp_all, NULL, 1); + else + local_flush_bp_all(); +} -- cgit v1.2.3