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authorChristoph Hellwig <hch@lst.de>2019-09-05 10:04:30 +0200
committerChristoph Hellwig <hch@lst.de>2019-09-11 12:43:27 +0200
commitb4dca1512941aa8fec33c28939abc2bba4a2c78c (patch)
treea4ab4e27ee90a9526cd14d97da94b198d342970b /drivers
parentc9b6180dbf9ab3fef15ec5482997c99b0c762cd1 (diff)
downloadlinux-b4dca1512941aa8fec33c28939abc2bba4a2c78c.tar.bz2
swiotlb-xen: simplify cache maintainance
Now that we know we always have the dma-noncoherent.h helpers available if we are on an architecture with support for non-coherent devices, we can just call them directly, and remove the calls to the dma-direct routines, including the fact that we call the dma_direct_map_page routines but ignore the value returned from it. Instead we now have Xen wrappers for the arch_sync_dma_for_{device,cpu} helpers that call the special Xen versions of those routines for foreign pages. Note that the new helpers get the physical address passed in addition to the dma address to avoid another translation for the local cache maintainance. The pfn_valid checks remain on the dma address as in the old code, even if that looks a little funny. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/xen/swiotlb-xen.c20
1 files changed, 10 insertions, 10 deletions
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index b8808677ae1d..f81031f0c1c7 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -28,6 +28,7 @@
#include <linux/memblock.h>
#include <linux/dma-direct.h>
+#include <linux/dma-noncoherent.h>
#include <linux/export.h>
#include <xen/swiotlb-xen.h>
#include <xen/page.h>
@@ -391,6 +392,7 @@ static dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
if (map == (phys_addr_t)DMA_MAPPING_ERROR)
return DMA_MAPPING_ERROR;
+ phys = map;
dev_addr = xen_phys_to_bus(map);
/*
@@ -402,14 +404,9 @@ static dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
return DMA_MAPPING_ERROR;
}
- page = pfn_to_page(map >> PAGE_SHIFT);
- offset = map & ~PAGE_MASK;
done:
- /*
- * we are not interested in the dma_addr returned by xen_dma_map_page,
- * only in the potential cache flushes executed by the function.
- */
- xen_dma_map_page(dev, page, dev_addr, offset, size, dir, attrs);
+ if (!dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ xen_dma_sync_for_device(dev, dev_addr, phys, size, dir);
return dev_addr;
}
@@ -429,7 +426,8 @@ static void xen_unmap_single(struct device *hwdev, dma_addr_t dev_addr,
BUG_ON(dir == DMA_NONE);
- xen_dma_unmap_page(hwdev, dev_addr, size, dir, attrs);
+ if (!dev_is_dma_coherent(hwdev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ xen_dma_sync_for_cpu(hwdev, dev_addr, paddr, size, dir);
/* NOTE: We use dev_addr here, not paddr! */
if (is_xen_swiotlb_buffer(dev_addr))
@@ -449,7 +447,8 @@ xen_swiotlb_sync_single_for_cpu(struct device *dev, dma_addr_t dma_addr,
{
phys_addr_t paddr = xen_bus_to_phys(dma_addr);
- xen_dma_sync_single_for_cpu(dev, dma_addr, size, dir);
+ if (!dev_is_dma_coherent(dev))
+ xen_dma_sync_for_cpu(dev, dma_addr, paddr, size, dir);
if (is_xen_swiotlb_buffer(dma_addr))
swiotlb_tbl_sync_single(dev, paddr, size, dir, SYNC_FOR_CPU);
@@ -464,7 +463,8 @@ xen_swiotlb_sync_single_for_device(struct device *dev, dma_addr_t dma_addr,
if (is_xen_swiotlb_buffer(dma_addr))
swiotlb_tbl_sync_single(dev, paddr, size, dir, SYNC_FOR_DEVICE);
- xen_dma_sync_single_for_device(dev, dma_addr, size, dir);
+ if (!dev_is_dma_coherent(dev))
+ xen_dma_sync_for_device(dev, dma_addr, paddr, size, dir);
}
/*