Patch "dmaengine: ioat: Allocate correct size for descriptor chunk" has been added to the 5.8-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    dmaengine: ioat: Allocate correct size for descriptor chunk

to the 5.8-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     dmaengine-ioat-allocate-correct-size-for-descriptor-.patch
and it can be found in the queue-5.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit a7d8de71b0488bf85d0b3945f99a7fb0db49b858
Author: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Date:   Tue Sep 22 14:08:44 2020 -0600

    dmaengine: ioat: Allocate correct size for descriptor chunk
    
    [ 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@xxxxxxx>
    Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
    Acked-by: Dave Jiang <dave.jiang@xxxxxxxxx>
    Cc: Vinod Koul <vkoul@xxxxxxxxxx>
    Cc: Dave Jiang <dave.jiang@xxxxxxxxx>
    Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
    Link: https://lore.kernel.org/intel-gfx/776771a2-247a-d1be-d882-bee02d919ae0@xxxxxxxxxxxx/
    Link: https://lore.kernel.org/r/20200922200844.2982-1-logang@xxxxxxxxxxxx
    Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

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;