diff options
Diffstat (limited to 'arch/arm/mm')
| -rw-r--r-- | arch/arm/mm/Kconfig | 18 | ||||
| -rw-r--r-- | arch/arm/mm/cache-v6.S | 31 |
2 files changed, 0 insertions, 49 deletions
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig index c164cde50243..2b6f50dd5478 100644 --- a/arch/arm/mm/Kconfig +++ b/arch/arm/mm/Kconfig @@ -937,24 +937,6 @@ config VDSO You must have glibc 2.22 or later for programs to seamlessly take advantage of this. -config DMA_CACHE_RWFO - bool "Enable read/write for ownership DMA cache maintenance" - depends on CPU_V6K && SMP - default y - help - The Snoop Control Unit on ARM11MPCore does not detect the - cache maintenance operations and the dma_{map,unmap}_area() - functions may leave stale cache entries on other CPUs. By - enabling this option, Read or Write For Ownership in the ARMv6 - DMA cache maintenance functions is performed. These LDR/STR - instructions change the cache line state to shared or modified - so that the cache operation has the desired effect. - - Note that the workaround is only valid on processors that do - not perform speculative loads into the D-cache. For such - processors, if cache maintenance operations are not broadcast - in hardware, other workarounds are needed (e.g. cache - maintenance broadcasting in software via FIQ). config OUTER_CACHE bool diff --git a/arch/arm/mm/cache-v6.S b/arch/arm/mm/cache-v6.S index 250c83bf7158..44211d8a296f 100644 --- a/arch/arm/mm/cache-v6.S +++ b/arch/arm/mm/cache-v6.S @@ -201,10 +201,6 @@ ENTRY(v6_flush_kern_dcache_area) * - 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 @@ -213,10 +209,6 @@ v6_dma_inv_range: mcrne p15, 0, r0, c7, c11, 1 @ clean unified line #endif tst r1, #D_CACHE_LINE_SIZE - 1 -#ifdef CONFIG_DMA_CACHE_RWFO - ldrbne r2, [r1, #-1] @ read for ownership - strbne 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 @@ -231,10 +223,6 @@ v6_dma_inv_range: #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 @@ -248,9 +236,6 @@ v6_dma_inv_range: v6_dma_clean_range: bic r0, r0, #D_CACHE_LINE_SIZE - 1 1: -#ifdef CONFIG_DMA_CACHE_RWFO - ldr r2, [r0] @ read for ownership -#endif #ifdef HARVARD_CACHE mcr p15, 0, r0, c7, c10, 1 @ clean D line #else @@ -269,10 +254,6 @@ v6_dma_clean_range: * - 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 HARVARD_CACHE @@ -282,10 +263,6 @@ ENTRY(v6_dma_flush_range) #endif add r0, r0, #D_CACHE_LINE_SIZE cmp r0, r1 -#ifdef CONFIG_DMA_CACHE_RWFO - ldrblo r2, [r0] @ read for ownership - strblo r2, [r0] @ write for ownership -#endif blo 1b mov r0, #0 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer @@ -301,13 +278,7 @@ ENTRY(v6_dma_map_area) add r1, r1, r0 teq r2, #DMA_FROM_DEVICE beq v6_dma_inv_range -#ifndef CONFIG_DMA_CACHE_RWFO b v6_dma_clean_range -#else - teq r2, #DMA_TO_DEVICE - beq v6_dma_clean_range - b v6_dma_flush_range -#endif ENDPROC(v6_dma_map_area) /* @@ -317,11 +288,9 @@ ENDPROC(v6_dma_map_area) * - dir - DMA direction */ ENTRY(v6_dma_unmap_area) -#ifndef CONFIG_DMA_CACHE_RWFO add r1, r1, r0 teq r2, #DMA_TO_DEVICE bne v6_dma_inv_range -#endif ret lr ENDPROC(v6_dma_unmap_area) |