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>
mcrne p15, 0, r1, c7, c15, 1 @ clean & invalidate unified line
#endif
1:
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
#ifdef HARVARD_CACHE
mcr p15, 0, r0, c7, c6, 1 @ invalidate D line
#else
v6_dma_clean_range:
bic r0, r0, #D_CACHE_LINE_SIZE - 1
1:
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
#ifdef HARVARD_CACHE
mcr p15, 0, r0, c7, c10, 1 @ clean D line
#else
ENTRY(v6_dma_flush_range)
bic r0, r0, #D_CACHE_LINE_SIZE - 1
1:
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
#ifdef HARVARD_CACHE
mcr p15, 0, r0, c7, c14, 1 @ clean & invalidate D line
#else
add r1, r1, r0
teq r2, #DMA_FROM_DEVICE
beq v6_dma_inv_range
add r1, r1, r0
teq r2, #DMA_FROM_DEVICE
beq v6_dma_inv_range
+ teq r2, #DMA_TO_DEVICE
+ beq v6_dma_clean_range
+ b v6_dma_flush_range
ENDPROC(v6_dma_map_area)
/*
ENDPROC(v6_dma_map_area)
/*
* - dir - DMA direction
*/
ENTRY(v6_dma_unmap_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)
mov pc, lr
ENDPROC(v6_dma_unmap_area)