[ARM] 3356/1: Workaround for the ARM1136 I-cache invalidation problem
Patch from Catalin Marinas
ARM1136 erratum 371025 (category 2) specifies that, under rare
conditions, an invalidate I-cache by MVA (line or range) operation can
fail to invalidate a cache line. The recommended workaround is to
either invalidate the entire I-cache or invalidate the range by
set/way rather than MVA.
Note that for a 16K cache size, invalidating a 4K page by set/way is
equivalent to invalidating the entire I-cache.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mm/cache-v6.S b/arch/arm/mm/cache-v6.S
index d921c10..2c6c2a7 100644
--- a/arch/arm/mm/cache-v6.S
+++ b/arch/arm/mm/cache-v6.S
@@ -96,15 +96,16 @@
#ifdef HARVARD_CACHE
bic r0, r0, #CACHE_LINE_SIZE - 1
1: mcr p15, 0, r0, c7, c10, 1 @ clean D line
- mcr p15, 0, r0, c7, c5, 1 @ invalidate I line
add r0, r0, #CACHE_LINE_SIZE
cmp r0, r1
blo 1b
#endif
- mcr p15, 0, r0, c7, c5, 6 @ invalidate BTB
-#ifdef HARVARD_CACHE
mov r0, #0
+#ifdef HARVARD_CACHE
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
+ mcr p15, 0, r0, c7, c5, 0 @ I+BTB cache invalidate
+#else
+ mcr p15, 0, r0, c7, c5, 6 @ invalidate BTB
#endif
mov pc, lr
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index 330695b..b103e56 100644
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -24,14 +24,16 @@
static void flush_pfn_alias(unsigned long pfn, unsigned long vaddr)
{
unsigned long to = ALIAS_FLUSH_START + (CACHE_COLOUR(vaddr) << PAGE_SHIFT);
+ const int zero = 0;
set_pte(TOP_PTE(to), pfn_pte(pfn, PAGE_KERNEL));
flush_tlb_kernel_page(to);
asm( "mcrr p15, 0, %1, %0, c14\n"
- " mcrr p15, 0, %1, %0, c5\n"
+ " mcr p15, 0, %2, c7, c10, 4\n"
+ " mcr p15, 0, %2, c7, c5, 0\n"
:
- : "r" (to), "r" (to + PAGE_SIZE - L1_CACHE_BYTES)
+ : "r" (to), "r" (to + PAGE_SIZE - L1_CACHE_BYTES), "r" (zero)
: "cc");
}