From 87067a935a174cf5e0b336d338a0ab535ffe199d Mon Sep 17 00:00:00 2001 From: Russell King Date: Sat, 4 Feb 2012 10:55:38 +0000 Subject: ARM: Optimize multi-CPU tlb flushing a little more The compiler does not conditionalize the assembly instructions for the tlb operations, which leads to sub-optimal code being generated when building a kernel for multiple CPUs. We can tweak things fairly simply as the code fragment below shows: 17f8: e3120001 tst r2, #1 ; 0x1 ... 1800: 0a000000 beq 1808 1804: ee061f10 mcr 15, 0, r1, cr6, cr0, {0} 1808: e3120004 tst r2, #4 ; 0x4 180c: 0a000000 beq 1814 1810: ee081f36 mcr 15, 0, r1, cr8, cr6, {1} becomes: 17f0: e3120001 tst r2, #1 ; 0x1 17f4: 1e063f10 mcrne 15, 0, r3, cr6, cr0, {0} 17f8: e3120004 tst r2, #4 ; 0x4 17fc: 1e083f36 mcrne 15, 0, r3, cr8, cr6, {1} Overall, for Realview with V6 and V7 CPUs configured: text data bss dec hex filename 4153998 207340 5371036 9732374 948116 ../build/realview/vmlinux.before 4153366 207332 5371036 9731734 947e96 ../build/realview/vmlinux.after Signed-off-by: Russell King --- arch/arm/include/asm/tlbflush.h | 136 +++++++++++++++++----------------------- 1 file changed, 58 insertions(+), 78 deletions(-) (limited to 'arch/arm/include/asm/tlbflush.h') diff --git a/arch/arm/include/asm/tlbflush.h b/arch/arm/include/asm/tlbflush.h index 02b2f8203982..85fe61e73202 100644 --- a/arch/arm/include/asm/tlbflush.h +++ b/arch/arm/include/asm/tlbflush.h @@ -318,6 +318,21 @@ extern struct cpu_tlb_fns cpu_tlb; #define tlb_flag(f) ((always_tlb_flags & (f)) || (__tlb_flag & possible_tlb_flags & (f))) +#define __tlb_op(f, insnarg, arg) \ + do { \ + if (always_tlb_flags & (f)) \ + asm("mcr " insnarg \ + : : "r" (arg) : "cc"); \ + else if (possible_tlb_flags & (f)) \ + asm("tst %1, %2\n\t" \ + "mcrne " insnarg \ + : : "r" (arg), "r" (__tlb_flag), "Ir" (f) \ + : "cc"); \ + } while (0) + +#define tlb_op(f, regs, arg) __tlb_op(f, "p15, 0, %0, " regs, arg) +#define tlb_l2_op(f, regs, arg) __tlb_op(f, "p15, 1, %0, " regs, arg) + static inline void local_flush_tlb_all(void) { const int zero = 0; @@ -326,16 +341,11 @@ static inline void local_flush_tlb_all(void) if (tlb_flag(TLB_WB)) dsb(); - if (tlb_flag(TLB_V3_FULL)) - asm("mcr p15, 0, %0, c6, c0, 0" : : "r" (zero) : "cc"); - if (tlb_flag(TLB_V4_U_FULL | TLB_V6_U_FULL)) - asm("mcr p15, 0, %0, c8, c7, 0" : : "r" (zero) : "cc"); - if (tlb_flag(TLB_V4_D_FULL | TLB_V6_D_FULL)) - asm("mcr p15, 0, %0, c8, c6, 0" : : "r" (zero) : "cc"); - if (tlb_flag(TLB_V4_I_FULL | TLB_V6_I_FULL)) - asm("mcr p15, 0, %0, c8, c5, 0" : : "r" (zero) : "cc"); - if (tlb_flag(TLB_V7_UIS_FULL)) - asm("mcr p15, 0, %0, c8, c3, 0" : : "r" (zero) : "cc"); + tlb_op(TLB_V3_FULL, "c6, c0, 0", zero); + tlb_op(TLB_V4_U_FULL | TLB_V6_U_FULL, "c8, c7, 0", zero); + tlb_op(TLB_V4_D_FULL | TLB_V6_D_FULL, "c8, c6, 0", zero); + tlb_op(TLB_V4_I_FULL | TLB_V6_I_FULL, "c8, c5, 0", zero); + tlb_op(TLB_V7_UIS_FULL, "c8, c3, 0", zero); if (tlb_flag(TLB_BARRIER)) { dsb(); @@ -352,29 +362,23 @@ static inline void local_flush_tlb_mm(struct mm_struct *mm) if (tlb_flag(TLB_WB)) dsb(); - if (cpumask_test_cpu(get_cpu(), mm_cpumask(mm))) { - if (tlb_flag(TLB_V3_FULL)) - asm("mcr p15, 0, %0, c6, c0, 0" : : "r" (zero) : "cc"); - if (tlb_flag(TLB_V4_U_FULL)) - asm("mcr p15, 0, %0, c8, c7, 0" : : "r" (zero) : "cc"); - if (tlb_flag(TLB_V4_D_FULL)) - asm("mcr p15, 0, %0, c8, c6, 0" : : "r" (zero) : "cc"); - if (tlb_flag(TLB_V4_I_FULL)) - asm("mcr p15, 0, %0, c8, c5, 0" : : "r" (zero) : "cc"); + if (possible_tlb_flags & (TLB_V3_FULL|TLB_V4_U_FULL|TLB_V4_D_FULL|TLB_V4_I_FULL)) { + if (cpumask_test_cpu(get_cpu(), mm_cpumask(mm))) { + tlb_op(TLB_V3_FULL, "c6, c0, 0", zero); + tlb_op(TLB_V4_U_FULL, "c8, c7, 0", zero); + tlb_op(TLB_V4_D_FULL, "c8, c6, 0", zero); + tlb_op(TLB_V4_I_FULL, "c8, c5, 0", zero); + } + put_cpu(); } - put_cpu(); - - if (tlb_flag(TLB_V6_U_ASID)) - asm("mcr p15, 0, %0, c8, c7, 2" : : "r" (asid) : "cc"); - if (tlb_flag(TLB_V6_D_ASID)) - asm("mcr p15, 0, %0, c8, c6, 2" : : "r" (asid) : "cc"); - if (tlb_flag(TLB_V6_I_ASID)) - asm("mcr p15, 0, %0, c8, c5, 2" : : "r" (asid) : "cc"); - if (tlb_flag(TLB_V7_UIS_ASID)) + + tlb_op(TLB_V6_U_ASID, "c8, c7, 2", asid); + tlb_op(TLB_V6_D_ASID, "c8, c6, 2", asid); + tlb_op(TLB_V6_I_ASID, "c8, c5, 2", asid); #ifdef CONFIG_ARM_ERRATA_720789 - asm("mcr p15, 0, %0, c8, c3, 0" : : "r" (zero) : "cc"); + tlb_op(TLB_V7_UIS_ASID, "c8, c3, 0", zero); #else - asm("mcr p15, 0, %0, c8, c3, 2" : : "r" (asid) : "cc"); + tlb_op(TLB_V7_UIS_ASID, "c8, c3, 2", asid); #endif if (tlb_flag(TLB_BARRIER)) @@ -392,30 +396,23 @@ local_flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr) if (tlb_flag(TLB_WB)) dsb(); - if (cpumask_test_cpu(smp_processor_id(), mm_cpumask(vma->vm_mm))) { - if (tlb_flag(TLB_V3_PAGE)) - asm("mcr p15, 0, %0, c6, c0, 0" : : "r" (uaddr) : "cc"); - if (tlb_flag(TLB_V4_U_PAGE)) - asm("mcr p15, 0, %0, c8, c7, 1" : : "r" (uaddr) : "cc"); - if (tlb_flag(TLB_V4_D_PAGE)) - asm("mcr p15, 0, %0, c8, c6, 1" : : "r" (uaddr) : "cc"); - if (tlb_flag(TLB_V4_I_PAGE)) - asm("mcr p15, 0, %0, c8, c5, 1" : : "r" (uaddr) : "cc"); + if (possible_tlb_flags & (TLB_V3_PAGE|TLB_V4_U_PAGE|TLB_V4_D_PAGE|TLB_V4_I_PAGE|TLB_V4_I_FULL) && + cpumask_test_cpu(smp_processor_id(), mm_cpumask(vma->vm_mm))) { + tlb_op(TLB_V3_PAGE, "c6, c0, 0", uaddr); + tlb_op(TLB_V4_U_PAGE, "c8, c7, 1", uaddr); + tlb_op(TLB_V4_D_PAGE, "c8, c6, 1", uaddr); + tlb_op(TLB_V4_I_PAGE, "c8, c5, 1", uaddr); if (!tlb_flag(TLB_V4_I_PAGE) && tlb_flag(TLB_V4_I_FULL)) asm("mcr p15, 0, %0, c8, c5, 0" : : "r" (zero) : "cc"); } - if (tlb_flag(TLB_V6_U_PAGE)) - asm("mcr p15, 0, %0, c8, c7, 1" : : "r" (uaddr) : "cc"); - if (tlb_flag(TLB_V6_D_PAGE)) - asm("mcr p15, 0, %0, c8, c6, 1" : : "r" (uaddr) : "cc"); - if (tlb_flag(TLB_V6_I_PAGE)) - asm("mcr p15, 0, %0, c8, c5, 1" : : "r" (uaddr) : "cc"); - if (tlb_flag(TLB_V7_UIS_PAGE)) + tlb_op(TLB_V6_U_PAGE, "c8, c7, 1", uaddr); + tlb_op(TLB_V6_D_PAGE, "c8, c6, 1", uaddr); + tlb_op(TLB_V6_I_PAGE, "c8, c5, 1", uaddr); #ifdef CONFIG_ARM_ERRATA_720789 - asm("mcr p15, 0, %0, c8, c3, 3" : : "r" (uaddr & PAGE_MASK) : "cc"); + tlb_op(TLB_V7_UIS_PAGE, "c8, c3, 3", uaddr & PAGE_MASK); #else - asm("mcr p15, 0, %0, c8, c3, 1" : : "r" (uaddr) : "cc"); + tlb_op(TLB_V7_UIS_PAGE, "c8, c3, 1", uaddr); #endif if (tlb_flag(TLB_BARRIER)) @@ -432,25 +429,17 @@ static inline void local_flush_tlb_kernel_page(unsigned long kaddr) if (tlb_flag(TLB_WB)) dsb(); - if (tlb_flag(TLB_V3_PAGE)) - asm("mcr p15, 0, %0, c6, c0, 0" : : "r" (kaddr) : "cc"); - if (tlb_flag(TLB_V4_U_PAGE)) - asm("mcr p15, 0, %0, c8, c7, 1" : : "r" (kaddr) : "cc"); - if (tlb_flag(TLB_V4_D_PAGE)) - asm("mcr p15, 0, %0, c8, c6, 1" : : "r" (kaddr) : "cc"); - if (tlb_flag(TLB_V4_I_PAGE)) - asm("mcr p15, 0, %0, c8, c5, 1" : : "r" (kaddr) : "cc"); + tlb_op(TLB_V3_PAGE, "c6, c0, 0", kaddr); + tlb_op(TLB_V4_U_PAGE, "c8, c7, 1", kaddr); + tlb_op(TLB_V4_D_PAGE, "c8, c6, 1", kaddr); + tlb_op(TLB_V4_I_PAGE, "c8, c5, 1", kaddr); if (!tlb_flag(TLB_V4_I_PAGE) && tlb_flag(TLB_V4_I_FULL)) asm("mcr p15, 0, %0, c8, c5, 0" : : "r" (zero) : "cc"); - if (tlb_flag(TLB_V6_U_PAGE)) - asm("mcr p15, 0, %0, c8, c7, 1" : : "r" (kaddr) : "cc"); - if (tlb_flag(TLB_V6_D_PAGE)) - asm("mcr p15, 0, %0, c8, c6, 1" : : "r" (kaddr) : "cc"); - if (tlb_flag(TLB_V6_I_PAGE)) - asm("mcr p15, 0, %0, c8, c5, 1" : : "r" (kaddr) : "cc"); - if (tlb_flag(TLB_V7_UIS_PAGE)) - asm("mcr p15, 0, %0, c8, c3, 1" : : "r" (kaddr) : "cc"); + tlb_op(TLB_V6_U_PAGE, "c8, c7, 1", kaddr); + tlb_op(TLB_V6_D_PAGE, "c8, c6, 1", kaddr); + tlb_op(TLB_V6_I_PAGE, "c8, c5, 1", kaddr); + tlb_op(TLB_V7_UIS_PAGE, "c8, c3, 1", kaddr); if (tlb_flag(TLB_BARRIER)) { dsb(); @@ -475,13 +464,8 @@ static inline void flush_pmd_entry(void *pmd) { const unsigned int __tlb_flag = __cpu_tlb_flags; - if (tlb_flag(TLB_DCLEAN)) - asm("mcr p15, 0, %0, c7, c10, 1 @ flush_pmd" - : : "r" (pmd) : "cc"); - - if (tlb_flag(TLB_L2CLEAN_FR)) - asm("mcr p15, 1, %0, c15, c9, 1 @ L2 flush_pmd" - : : "r" (pmd) : "cc"); + tlb_op(TLB_DCLEAN, "c7, c10, 1 @ flush_pmd", pmd); + tlb_l2_op(TLB_L2CLEAN_FR, "c15, c9, 1 @ L2 flush_pmd", pmd); if (tlb_flag(TLB_WB)) dsb(); @@ -491,15 +475,11 @@ static inline void clean_pmd_entry(void *pmd) { const unsigned int __tlb_flag = __cpu_tlb_flags; - if (tlb_flag(TLB_DCLEAN)) - asm("mcr p15, 0, %0, c7, c10, 1 @ flush_pmd" - : : "r" (pmd) : "cc"); - - if (tlb_flag(TLB_L2CLEAN_FR)) - asm("mcr p15, 1, %0, c15, c9, 1 @ L2 flush_pmd" - : : "r" (pmd) : "cc"); + tlb_op(TLB_DCLEAN, "c7, c10, 1 @ flush_pmd", pmd); + tlb_l2_op(TLB_L2CLEAN_FR, "c15, c9, 1 @ L2 flush_pmd", pmd); } +#undef tlb_op #undef tlb_flag #undef always_tlb_flags #undef possible_tlb_flags -- cgit v1.2.3