2.6.35-longterm review patch. If anyone has any objections, please let me know.
------------------ From: Valentine Barshak <[email protected]> commit 85b093bcc5322baa811a03ec73de0909c157f181 upstream. 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. Signed-off-by: Valentine Barshak <[email protected]> Signed-off-by: George G. Davis <[email protected]> Acked-by: Catalin Marinas <[email protected]> Signed-off-by: Russell King <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> Signed-off-by: Andi Kleen <[email protected]> --- arch/arm/mm/cache-v6.S | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-) Index: linux-2.6.35.y/arch/arm/mm/cache-v6.S =================================================================== --- linux-2.6.35.y.orig/arch/arm/mm/cache-v6.S +++ linux-2.6.35.y/arch/arm/mm/cache-v6.S @@ -196,6 +196,10 @@ 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 @@ -204,6 +208,10 @@ 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 + 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 @@ -211,10 +219,6 @@ v6_dma_inv_range: 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 @@ -222,6 +226,10 @@ 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 @@ -256,12 +264,12 @@ v6_dma_clean_range: * - end - virtual end address of region */ ENTRY(v6_dma_flush_range) - 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 + 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 mcr p15, 0, r0, c7, c14, 1 @ clean & invalidate D line #else @@ -269,6 +277,10 @@ ENTRY(v6_dma_flush_range) #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 _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
