From mboxrd@z Thu Jan 1 00:00:00 1970 From: vbarshak@mvista.com (Valentine Barshak) Date: Wed, 24 Nov 2010 01:28:06 +0300 Subject: [PATCH] ARM: V6 MPCore v6_dma_inv_range RWFO fix Message-ID: <20101123222806.GA22936@mvista.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Cache ownership must be acqired 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 aquired 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. Signed-off-by: Valentine Barshak Signed-off-by: George G. Davis --- arch/arm/mm/cache-v6.S | 16 ++++++++++++---- 1 files changed, 12 insertions(+), 4 deletions(-) diff --git a/arch/arm/mm/cache-v6.S b/arch/arm/mm/cache-v6.S index 99fa688..e0e5c6b 100644 --- a/arch/arm/mm/cache-v6.S +++ b/arch/arm/mm/cache-v6.S @@ -205,6 +205,10 @@ ENTRY(v6_flush_kern_dcache_area) v6_dma_inv_range: tst r0, #D_CACHE_LINE_SIZE - 1 bic r0, r0, #D_CACHE_LINE_SIZE - 1 +#ifdef CONFIG_DMA_CACHE_RWFO + ldr r2, [r0] @ read for ownership + str r2, [r0] @ write for ownership +#endif #ifdef HARVARD_CACHE mcrne p15, 0, r0, c7, c10, 1 @ clean D line #else @@ -212,16 +216,16 @@ v6_dma_inv_range: #endif tst r1, #D_CACHE_LINE_SIZE - 1 bic r1, r1, #D_CACHE_LINE_SIZE - 1 +#ifdef CONFIG_DMA_CACHE_RWFO + ldrne r2, [r1] @ read for ownership + strne r2, [r1] @ write for ownership +#endif #ifdef HARVARD_CACHE mcrne p15, 0, r1, c7, c14, 1 @ clean & invalidate D line #else 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 @@ 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 -- 1.6.0.6