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[ARM] 4129/1: Add barriers after the TLB operations
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The architecture specification states that TLB operations are
guaranteed to be complete only after the execution of a DSB (Data
Synchronisation Barrier, former Data Write Barrier or Drain Write
Buffer). The branch target cache invalidation is also needed. The ISB
(Instruction Synchronisation Barrier, formerly Prefetch Flush) is
needed unless there will be a return from exception before the
corresponding mapping is used (i.e. user mappings).

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Catalin Marinas authored and Russell King committed Feb 8, 2007
1 parent 9d99df4 commit e6a5d66
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Showing 2 changed files with 42 additions and 12 deletions.
4 changes: 4 additions & 0 deletions arch/arm/mm/tlb-v6.S
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Original file line number Diff line number Diff line change
Expand Up @@ -53,6 +53,8 @@ ENTRY(v6wbi_flush_user_tlb_range)
add r0, r0, #PAGE_SZ
cmp r0, r1
blo 1b
mcr p15, 0, ip, c7, c5, 6 @ flush BTAC/BTB
mcr p15, 0, ip, c7, c10, 4 @ data synchronization barrier
mov pc, lr

/*
Expand Down Expand Up @@ -80,7 +82,9 @@ ENTRY(v6wbi_flush_kern_tlb_range)
add r0, r0, #PAGE_SZ
cmp r0, r1
blo 1b
mcr p15, 0, r2, c7, c5, 6 @ flush BTAC/BTB
mcr p15, 0, r2, c7, c10, 4 @ data synchronization barrier
mcr p15, 0, r2, c7, c5, 4 @ prefetch flush
mov pc, lr

.section ".text.init", #alloc, #execinstr
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50 changes: 38 additions & 12 deletions include/asm-arm/tlbflush.h
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Original file line number Diff line number Diff line change
Expand Up @@ -247,7 +247,7 @@ static inline void local_flush_tlb_all(void)
const unsigned int __tlb_flag = __cpu_tlb_flags;

if (tlb_flag(TLB_WB))
asm("mcr p15, 0, %0, c7, c10, 4" : : "r" (zero) : "cc");
dsb();

if (tlb_flag(TLB_V3_FULL))
asm("mcr p15, 0, %0, c6, c0, 0" : : "r" (zero) : "cc");
Expand All @@ -257,6 +257,15 @@ static inline void local_flush_tlb_all(void)
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_V6_I_FULL | TLB_V6_D_FULL |
TLB_V6_I_PAGE | TLB_V6_D_PAGE |
TLB_V6_I_ASID | TLB_V6_D_ASID)) {
/* flush the branch target cache */
asm("mcr p15, 0, %0, c7, c5, 6" : : "r" (zero) : "cc");
dsb();
isb();
}
}

static inline void local_flush_tlb_mm(struct mm_struct *mm)
Expand All @@ -266,7 +275,7 @@ static inline void local_flush_tlb_mm(struct mm_struct *mm)
const unsigned int __tlb_flag = __cpu_tlb_flags;

if (tlb_flag(TLB_WB))
asm("mcr p15, 0, %0, c7, c10, 4" : : "r" (zero) : "cc");
dsb();

if (cpu_isset(smp_processor_id(), mm->cpu_vm_mask)) {
if (tlb_flag(TLB_V3_FULL))
Expand All @@ -285,6 +294,14 @@ static inline void local_flush_tlb_mm(struct mm_struct *mm)
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_V6_I_FULL | TLB_V6_D_FULL |
TLB_V6_I_PAGE | TLB_V6_D_PAGE |
TLB_V6_I_ASID | TLB_V6_D_ASID)) {
/* flush the branch target cache */
asm("mcr p15, 0, %0, c7, c5, 6" : : "r" (zero) : "cc");
dsb();
}
}

static inline void
Expand All @@ -296,7 +313,7 @@ local_flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)
uaddr = (uaddr & PAGE_MASK) | ASID(vma->vm_mm);

if (tlb_flag(TLB_WB))
asm("mcr p15, 0, %0, c7, c10, 4" : : "r" (zero));
dsb();

if (cpu_isset(smp_processor_id(), vma->vm_mm->cpu_vm_mask)) {
if (tlb_flag(TLB_V3_PAGE))
Expand All @@ -317,6 +334,14 @@ local_flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)
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_V6_I_FULL | TLB_V6_D_FULL |
TLB_V6_I_PAGE | TLB_V6_D_PAGE |
TLB_V6_I_ASID | TLB_V6_D_ASID)) {
/* flush the branch target cache */
asm("mcr p15, 0, %0, c7, c5, 6" : : "r" (zero) : "cc");
dsb();
}
}

static inline void local_flush_tlb_kernel_page(unsigned long kaddr)
Expand All @@ -327,7 +352,7 @@ static inline void local_flush_tlb_kernel_page(unsigned long kaddr)
kaddr &= PAGE_MASK;

if (tlb_flag(TLB_WB))
asm("mcr p15, 0, %0, c7, c10, 4" : : "r" (zero) : "cc");
dsb();

if (tlb_flag(TLB_V3_PAGE))
asm("mcr p15, 0, %0, c6, c0, 0" : : "r" (kaddr) : "cc");
Expand All @@ -347,11 +372,14 @@ static inline void local_flush_tlb_kernel_page(unsigned long kaddr)
if (tlb_flag(TLB_V6_I_PAGE))
asm("mcr p15, 0, %0, c8, c5, 1" : : "r" (kaddr) : "cc");

/* The ARM ARM states that the completion of a TLB maintenance
* operation is only guaranteed by a DSB instruction
*/
if (tlb_flag(TLB_V6_U_PAGE | TLB_V6_D_PAGE | TLB_V6_I_PAGE))
asm("mcr p15, 0, %0, c7, c10, 4" : : "r" (zero) : "cc");
if (tlb_flag(TLB_V6_I_FULL | TLB_V6_D_FULL |
TLB_V6_I_PAGE | TLB_V6_D_PAGE |
TLB_V6_I_ASID | TLB_V6_D_ASID)) {
/* flush the branch target cache */
asm("mcr p15, 0, %0, c7, c5, 6" : : "r" (zero) : "cc");
dsb();
isb();
}
}

/*
Expand All @@ -369,15 +397,13 @@ static inline void local_flush_tlb_kernel_page(unsigned long kaddr)
*/
static inline void flush_pmd_entry(pmd_t *pmd)
{
const unsigned int zero = 0;
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_WB))
asm("mcr p15, 0, %0, c7, c10, 4 @ flush_pmd"
: : "r" (zero) : "cc");
dsb();
}

static inline void clean_pmd_entry(pmd_t *pmd)
Expand Down

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