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authorCatalin Marinas <catalin.marinas@arm.com>2010-05-07 16:26:24 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2010-05-08 10:44:30 +0100
commitf4d6477f7f073b99220386d62f5bf54bec3482cc (patch)
tree4c6a13a762f54bfd30550a70226268edcb9d38a7 /arch/arm/mm/cache-v6.S
parentb5a07faadeb4e0cfd6dcee359e501d4755cab875 (diff)
ARM: 6111/1: Implement read/write for ownership in the ARMv6 DMA cache ops
The Snoop Control Unit on the ARM11MPCore hardware does not detect the cache operations and the dma_cache_maint*() functions may leave stale cache entries on other CPUs. The solution implemented in this patch performs a Read or Write For Ownership in the ARMv6 DMA cache maintenance functions. These LDR/STR instructions change the cache line state to shared or exclusive so that the cache maintenance operation has the desired effect. Tested-by: George G. Davis <gdavis@mvista.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm/cache-v6.S')
-rw-r--r--arch/arm/mm/cache-v6.S17
1 files changed, 13 insertions, 4 deletions
diff --git a/arch/arm/mm/cache-v6.S b/arch/arm/mm/cache-v6.S
index 9d89c67a1cc3..e46ecd847138 100644
--- a/arch/arm/mm/cache-v6.S
+++ b/arch/arm/mm/cache-v6.S
@@ -211,6 +211,9 @@ v6_dma_inv_range:
mcrne p15, 0, r1, c7, c15, 1 @ clean & invalidate unified line
#endif
1:
+#ifdef CONFIG_SMP
+ str r0, [r0] @ write for ownership
+#endif
#ifdef HARVARD_CACHE
mcr p15, 0, r0, c7, c6, 1 @ invalidate D line
#else
@@ -231,6 +234,9 @@ v6_dma_inv_range:
v6_dma_clean_range:
bic r0, r0, #D_CACHE_LINE_SIZE - 1
1:
+#ifdef CONFIG_SMP
+ ldr r2, [r0] @ read for ownership
+#endif
#ifdef HARVARD_CACHE
mcr p15, 0, r0, c7, c10, 1 @ clean D line
#else
@@ -251,6 +257,10 @@ v6_dma_clean_range:
ENTRY(v6_dma_flush_range)
bic r0, r0, #D_CACHE_LINE_SIZE - 1
1:
+#ifdef CONFIG_SMP
+ ldr r2, [r0] @ read for ownership
+ str r2, [r0] @ write for ownership
+#endif
#ifdef HARVARD_CACHE
mcr p15, 0, r0, c7, c14, 1 @ clean & invalidate D line
#else
@@ -273,7 +283,9 @@ ENTRY(v6_dma_map_area)
add r1, r1, r0
teq r2, #DMA_FROM_DEVICE
beq v6_dma_inv_range
- b v6_dma_clean_range
+ teq r2, #DMA_TO_DEVICE
+ beq v6_dma_clean_range
+ b v6_dma_flush_range
ENDPROC(v6_dma_map_area)
/*
@@ -283,9 +295,6 @@ ENDPROC(v6_dma_map_area)
* - dir - DMA direction
*/
ENTRY(v6_dma_unmap_area)
- add r1, r1, r0
- teq r2, #DMA_TO_DEVICE
- bne v6_dma_inv_range
mov pc, lr
ENDPROC(v6_dma_unmap_area)

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