ioatdma: add ioat_raid_enabled module parameter Commit f26df1a1 added a 64-byte alignment requirement for legacy operations to work around a silicon errata when mixing legacy and RAID descriptors. Passing ioat_raid_enabled=0 now disables RAID offload entirely in the ioatdma driver so that legacy operations (memcpy, etc.) can work without alignment restrictions anymore.
Signed-off-by: Brice Goglin <[email protected]> --- drivers/dma/ioat/dma_v3.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) Index: b/drivers/dma/ioat/dma_v3.c =================================================================== --- a/drivers/dma/ioat/dma_v3.c 2013-07-31 23:06:24.163810000 +0200 +++ b/drivers/dma/ioat/dma_v3.c 2013-07-31 23:47:54.246719841 +0200 @@ -67,6 +67,11 @@ #include "dma.h" #include "dma_v2.h" +static int ioat_raid_enabled = 1; +module_param(ioat_raid_enabled, int, 0444); +MODULE_PARM_DESC(ioat_raid_enabled, + "control support of RAID offload (default: 1)"); + /* ioat hardware assumes at least two sources for raid operations */ #define src_cnt_to_sw(x) ((x) + 2) #define src_cnt_to_hw(x) ((x) - 2) @@ -1775,7 +1780,7 @@ int ioat3_dma_probe(struct ioatdma_devic dma->device_alloc_chan_resources = ioat2_alloc_chan_resources; dma->device_free_chan_resources = ioat2_free_chan_resources; - if (is_xeon_cb32(pdev)) + if (is_xeon_cb32(pdev) && ioat_raid_enabled) dma->copy_align = 6; dma_cap_set(DMA_INTERRUPT, dma->cap_mask); @@ -1783,7 +1788,7 @@ int ioat3_dma_probe(struct ioatdma_devic device->cap = readl(device->reg_base + IOAT_DMA_CAP_OFFSET); - if (is_bwd_noraid(pdev)) + if (!ioat_raid_enabled || is_bwd_noraid(pdev)) device->cap &= ~(IOAT_CAP_XOR | IOAT_CAP_PQ | IOAT_CAP_RAID16SS); /* dca is incompatible with raid operations */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
