Check whether the TLB operations need broadcasting on SMP systems
ARMv7 SMP hardware can handle the TLB maintenance operations
broadcasting in hardware so that the software can avoid the costly IPIs.
This patch adds the necessary checks (the MMFR3 CPUID register) to avoid
the broadcasting if already supported by the hardware.
(this patch is based on the work done by Tony Thompson @ ARM)
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm/include/asm/cputype.h b/arch/arm/include/asm/cputype.h
index 7b9d27e..b3e656c 100644
--- a/arch/arm/include/asm/cputype.h
+++ b/arch/arm/include/asm/cputype.h
@@ -8,6 +8,21 @@
#define CPUID_TCM 2
#define CPUID_TLBTYPE 3
+#define CPUID_EXT_PFR0 "c1, 0"
+#define CPUID_EXT_PFR1 "c1, 1"
+#define CPUID_EXT_DFR0 "c1, 2"
+#define CPUID_EXT_AFR0 "c1, 3"
+#define CPUID_EXT_MMFR0 "c1, 4"
+#define CPUID_EXT_MMFR1 "c1, 5"
+#define CPUID_EXT_MMFR2 "c1, 6"
+#define CPUID_EXT_MMFR3 "c1, 7"
+#define CPUID_EXT_ISAR0 "c2, 0"
+#define CPUID_EXT_ISAR1 "c2, 1"
+#define CPUID_EXT_ISAR2 "c2, 2"
+#define CPUID_EXT_ISAR3 "c2, 3"
+#define CPUID_EXT_ISAR4 "c2, 4"
+#define CPUID_EXT_ISAR5 "c2, 5"
+
#ifdef CONFIG_CPU_CP15
#define read_cpuid(reg) \
({ \
@@ -18,9 +33,19 @@
: "cc"); \
__val; \
})
+#define read_cpuid_ext(ext_reg) \
+ ({ \
+ unsigned int __val; \
+ asm("mrc p15, 0, %0, c0, " ext_reg \
+ : "=r" (__val) \
+ : \
+ : "cc"); \
+ __val; \
+ })
#else
extern unsigned int processor_id;
#define read_cpuid(reg) (processor_id)
+#define read_cpuid_ext(reg) 0
#endif
/*
diff --git a/arch/arm/include/asm/tlbflush.h b/arch/arm/include/asm/tlbflush.h
index a622180..c964f3f 100644
--- a/arch/arm/include/asm/tlbflush.h
+++ b/arch/arm/include/asm/tlbflush.h
@@ -40,6 +40,12 @@
#define TLB_V6_I_ASID (1 << 18)
#define TLB_BTB (1 << 28)
+
+/* 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_L2CLEAN_FR (1 << 29) /* Feroceon */
#define TLB_DCLEAN (1 << 30)
#define TLB_WB (1 << 31)
@@ -176,9 +182,17 @@
# define v6wbi_always_flags (-1UL)
#endif
+#ifdef CONFIG_SMP
+#define v7wbi_tlb_flags (TLB_WB | TLB_DCLEAN | TLB_BTB | \
+ TLB_V7_UIS_FULL | TLB_V7_UIS_PAGE | TLB_V7_UIS_ASID)
+#else
+#define v7wbi_tlb_flags (TLB_WB | TLB_DCLEAN | TLB_BTB | \
+ TLB_V6_U_FULL | TLB_V6_U_PAGE | TLB_V6_U_ASID)
+#endif
+
#ifdef CONFIG_CPU_TLB_V7
-# define v7wbi_possible_flags v6wbi_tlb_flags
-# define v7wbi_always_flags v6wbi_tlb_flags
+# define v7wbi_possible_flags v7wbi_tlb_flags
+# define v7wbi_always_flags v7wbi_tlb_flags
# ifdef _TLB
# define MULTI_TLB 1
# else
@@ -316,6 +330,8 @@
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");
if (tlb_flag(TLB_BTB)) {
/* flush the branch target cache */
@@ -351,6 +367,8 @@
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))
+ asm("mcr p15, 0, %0, c8, c3, 2" : : "r" (asid) : "cc");
if (tlb_flag(TLB_BTB)) {
/* flush the branch target cache */
@@ -389,6 +407,8 @@
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))
+ asm("mcr p15, 0, %0, c8, c3, 1" : : "r" (uaddr) : "cc");
if (tlb_flag(TLB_BTB)) {
/* flush the branch target cache */
@@ -424,6 +444,8 @@
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");
if (tlb_flag(TLB_BTB)) {
/* flush the branch target cache */
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 6014dfd..ece658e 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -32,6 +32,7 @@
#include <asm/processor.h>
#include <asm/tlbflush.h>
#include <asm/ptrace.h>
+#include <asm/cputype.h>
/*
* as from 2.5, kernels no longer have an init_tasks structure
@@ -545,6 +546,12 @@
unsigned long ta_end;
};
+/* all SMP configurations have the extended CPUID registers */
+static inline int tlb_ops_need_broadcast(void)
+{
+ return ((read_cpuid_ext(CPUID_EXT_MMFR3) >> 12) & 0xf) < 2;
+}
+
static inline void ipi_flush_tlb_all(void *ignored)
{
local_flush_tlb_all();
@@ -587,51 +594,61 @@
void flush_tlb_all(void)
{
- on_each_cpu(ipi_flush_tlb_all, NULL, 1);
+ if (tlb_ops_need_broadcast())
+ on_each_cpu(ipi_flush_tlb_all, NULL, 1);
+ else
+ local_flush_tlb_all();
}
void flush_tlb_mm(struct mm_struct *mm)
{
- on_each_cpu_mask(ipi_flush_tlb_mm, mm, 1, &mm->cpu_vm_mask);
+ if (tlb_ops_need_broadcast())
+ on_each_cpu_mask(ipi_flush_tlb_mm, mm, 1, &mm->cpu_vm_mask);
+ else
+ local_flush_tlb_mm(mm);
}
void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)
{
- struct tlb_args ta;
-
- ta.ta_vma = vma;
- ta.ta_start = uaddr;
-
- on_each_cpu_mask(ipi_flush_tlb_page, &ta, 1, &vma->vm_mm->cpu_vm_mask);
+ if (tlb_ops_need_broadcast()) {
+ struct tlb_args ta;
+ ta.ta_vma = vma;
+ ta.ta_start = uaddr;
+ on_each_cpu_mask(ipi_flush_tlb_page, &ta, 1, &vma->vm_mm->cpu_vm_mask);
+ } else
+ local_flush_tlb_page(vma, uaddr);
}
void flush_tlb_kernel_page(unsigned long kaddr)
{
- struct tlb_args ta;
-
- ta.ta_start = kaddr;
-
- on_each_cpu(ipi_flush_tlb_kernel_page, &ta, 1);
+ if (tlb_ops_need_broadcast()) {
+ struct tlb_args ta;
+ ta.ta_start = kaddr;
+ on_each_cpu(ipi_flush_tlb_kernel_page, &ta, 1);
+ } else
+ local_flush_tlb_kernel_page(kaddr);
}
void flush_tlb_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
- struct tlb_args ta;
-
- ta.ta_vma = vma;
- ta.ta_start = start;
- ta.ta_end = end;
-
- on_each_cpu_mask(ipi_flush_tlb_range, &ta, 1, &vma->vm_mm->cpu_vm_mask);
+ if (tlb_ops_need_broadcast()) {
+ struct tlb_args ta;
+ ta.ta_vma = vma;
+ ta.ta_start = start;
+ ta.ta_end = end;
+ on_each_cpu_mask(ipi_flush_tlb_range, &ta, 1, &vma->vm_mm->cpu_vm_mask);
+ } else
+ local_flush_tlb_range(vma, start, end);
}
void flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
- struct tlb_args ta;
-
- ta.ta_start = start;
- ta.ta_end = end;
-
- on_each_cpu(ipi_flush_tlb_kernel_range, &ta, 1);
+ if (tlb_ops_need_broadcast()) {
+ struct tlb_args ta;
+ ta.ta_start = start;
+ ta.ta_end = end;
+ on_each_cpu(ipi_flush_tlb_kernel_range, &ta, 1);
+ } else
+ local_flush_tlb_kernel_range(start, end);
}
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 3397f1e..c3f7375 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -176,8 +176,8 @@
*/
__v7_setup:
#ifdef CONFIG_SMP
- mrc p15, 0, r0, c1, c0, 1 @ Enable SMP/nAMP mode
- orr r0, r0, #(0x1 << 6)
+ mrc p15, 0, r0, c1, c0, 1 @ Enable SMP/nAMP mode and
+ orr r0, r0, #(1 << 6) | (1 << 0) @ TLB ops broadcasting
mcr p15, 0, r0, c1, c0, 1
#endif
adr r12, __v7_setup_stack @ the local stack
diff --git a/arch/arm/mm/tlb-v7.S b/arch/arm/mm/tlb-v7.S
index b637e73..a26a605 100644
--- a/arch/arm/mm/tlb-v7.S
+++ b/arch/arm/mm/tlb-v7.S
@@ -42,9 +42,11 @@
mov r1, r1, lsl #PAGE_SHIFT
vma_vm_flags r2, r2 @ get vma->vm_flags
1:
- mcr p15, 0, r0, c8, c6, 1 @ TLB invalidate D MVA (was 1)
- tst r2, #VM_EXEC @ Executable area ?
- mcrne p15, 0, r0, c8, c5, 1 @ TLB invalidate I MVA (was 1)
+#ifdef CONFIG_SMP
+ mcr p15, 0, r0, c8, c3, 1 @ TLB invalidate U MVA (shareable)
+#else
+ mcr p15, 0, r0, c8, c7, 1 @ TLB invalidate U MVA
+#endif
add r0, r0, #PAGE_SZ
cmp r0, r1
blo 1b
@@ -69,8 +71,11 @@
mov r0, r0, lsl #PAGE_SHIFT
mov r1, r1, lsl #PAGE_SHIFT
1:
- mcr p15, 0, r0, c8, c6, 1 @ TLB invalidate D MVA
- mcr p15, 0, r0, c8, c5, 1 @ TLB invalidate I MVA
+#ifdef CONFIG_SMP
+ mcr p15, 0, r0, c8, c3, 1 @ TLB invalidate U MVA (shareable)
+#else
+ mcr p15, 0, r0, c8, c7, 1 @ TLB invalidate U MVA
+#endif
add r0, r0, #PAGE_SZ
cmp r0, r1
blo 1b
@@ -87,5 +92,5 @@
ENTRY(v7wbi_tlb_fns)
.long v7wbi_flush_user_tlb_range
.long v7wbi_flush_kern_tlb_range
- .long v6wbi_tlb_flags
+ .long v7wbi_tlb_flags
.size v7wbi_tlb_fns, . - v7wbi_tlb_fns