aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm/include/asm
diff options
context:
space:
mode:
authorRussell King <rmk+kernel@arm.linux.org.uk>2012-02-04 10:55:38 +0000
committerRussell King <rmk+kernel@arm.linux.org.uk>2012-03-24 09:38:52 +0000
commit87067a935a174cf5e0b336d338a0ab535ffe199d (patch)
tree03a56144e82fb7bfded621e6b291906608aa1d81 /arch/arm/include/asm
parentd9277d51a8eeaa097d3c1385f458c99d65ffc4f4 (diff)
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 <handle_pte_fault+0x194> 1804: ee061f10 mcr 15, 0, r1, cr6, cr0, {0} 1808: e3120004 tst r2, #4 ; 0x4 180c: 0a000000 beq 1814 <handle_pte_fault+0x1a0> 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 <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/include/asm')
-rw-r--r--arch/arm/include/asm/tlbflush.h136
1 files changed, 58 insertions, 78 deletions
diff --git a/arch/arm/include/asm/tlbflush.h b/arch/arm/include/asm/tlbflush.h
index 02b2f820398..85fe61e7320 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