[PATCH 5.8 306/633] dmaengine: ioat: Allocate correct size for descriptor chunk

Greg Kroah-Hartman
2020-10-27T16:56:34Z

From: Logan Gunthorpe <logang@deltatee.com>

[ Upstream commit 028926e4ac8f21af343c25794117fd13c08b1712 ]

dma_alloc_coherent() is called with a fixed SZ_2M size, but frees happen
with IOAT_CHUNK_SIZE. Recently, IOAT_CHUNK_SIZE was reduced to 512M but
the allocation did not change. To fix, change to using the
IOAT_CHUNK_SIZE define.

This was caught with the upcoming patchset for converting Intel platforms to the
dma-iommu implementation. It has a warning when the unmapped size differs from
the mapped size.

Fixes: a02254f8a676 ("dmaengine: ioat: Decreasing allocation chunk size 2M->512K")
Suggested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/intel-gfx/776771a2-247a-d1be-d882-bee02d919ae0@deltatee.com/
Link: https://lore.kernel.org/r/20200922200844.2982-1-logang@deltatee.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/dma/ioat/dma.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/ioat/dma.c b/drivers/dma/ioat/dma.c
index fd782aee02d92..98c56606ab1a9 100644
--- a/drivers/dma/ioat/dma.c
+++ b/drivers/dma/ioat/dma.c
@@ -389,7 +389,7 @@ ioat_alloc_ring(struct dma_chan *c, int order, gfp_t flags)
struct ioat_descs *descs = &ioat_chan->descs[i];

descs->virt = dma_alloc_coherent(to_dev(ioat_chan),
- SZ_2M, &descs->hw, flags);
+ IOAT_CHUNK_SIZE, &descs->hw, flags);
if (!descs->virt) {
int idx;

--
2.25.1