ARM: 6535/1: V6 MPCore v6_dma_inv_range and v6_dma_flush_range RWFO fix
Cache ownership must be acquired by reading/writing data from the
cache line to make cache operation have the desired effect on the
SMP MPCore CPU. However, the ownership is never acquired in the
v6_dma_inv_range function when cleaning the first line and
flushing the last one, in case the address is not aligned
to D_CACHE_LINE_SIZE boundary.
Fix this by reading/writing data if needed, before performing
cache operations.
While at it, fix v6_dma_flush_range to prevent RWFO outside
the buffer.
Cc: stable@kernel.org
Signed-off-by: Valentine Barshak <vbarshak@mvista.com>
Signed-off-by: George G. Davis <gdavis@mvista.com>
Acked-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 99fa688..c96fa1b 100644
--- a/arch/arm/mm/cache-v6.S
+++ b/arch/arm/mm/cache-v6.S
@@ -203,6 +203,10 @@
* - end - virtual end address of region
*/
v6_dma_inv_range:
+#ifdef CONFIG_DMA_CACHE_RWFO
+ ldrb r2, [r0] @ read for ownership
+ strb r2, [r0] @ write for ownership
+#endif
tst r0, #D_CACHE_LINE_SIZE - 1
bic r0, r0, #D_CACHE_LINE_SIZE - 1
#ifdef HARVARD_CACHE
@@ -211,6 +215,10 @@
mcrne p15, 0, r0, c7, c11, 1 @ clean unified line
#endif
tst r1, #D_CACHE_LINE_SIZE - 1
+#ifdef CONFIG_DMA_CACHE_RWFO
+ ldrneb r2, [r1, #-1] @ read for ownership
+ strneb r2, [r1, #-1] @ write for ownership
+#endif
bic r1, r1, #D_CACHE_LINE_SIZE - 1
#ifdef HARVARD_CACHE
mcrne p15, 0, r1, c7, c14, 1 @ clean & invalidate D line
@@ -218,10 +226,6 @@
mcrne p15, 0, r1, c7, c15, 1 @ clean & invalidate unified line
#endif
1:
-#ifdef CONFIG_DMA_CACHE_RWFO
- ldr r2, [r0] @ read for ownership
- str r2, [r0] @ write for ownership
-#endif
#ifdef HARVARD_CACHE
mcr p15, 0, r0, c7, c6, 1 @ invalidate D line
#else
@@ -229,6 +233,10 @@
#endif
add r0, r0, #D_CACHE_LINE_SIZE
cmp r0, r1
+#ifdef CONFIG_DMA_CACHE_RWFO
+ ldrlo r2, [r0] @ read for ownership
+ strlo r2, [r0] @ write for ownership
+#endif
blo 1b
mov r0, #0
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
@@ -263,12 +271,12 @@
* - end - virtual end address of region
*/
ENTRY(v6_dma_flush_range)
+#ifdef CONFIG_DMA_CACHE_RWFO
+ ldrb r2, [r0] @ read for ownership
+ strb r2, [r0] @ write for ownership
+#endif
bic r0, r0, #D_CACHE_LINE_SIZE - 1
1:
-#ifdef CONFIG_DMA_CACHE_RWFO
- 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
@@ -276,6 +284,10 @@
#endif
add r0, r0, #D_CACHE_LINE_SIZE
cmp r0, r1
+#ifdef CONFIG_DMA_CACHE_RWFO
+ ldrlob r2, [r0] @ read for ownership
+ strlob r2, [r0] @ write for ownership
+#endif
blo 1b
mov r0, #0
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer