summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorChristoph Hellwig <hch@lst.de>2019-04-11 09:19:59 +0200
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2019-05-02 19:51:47 -0400
commit2e12dceef3d3fb8d796e384aa242062d1643cad4 (patch)
treeb19dd8bb8c250b2bf0439952dac3ee95a292e8b4
parent8b35d9feed8e4e66dc4048f776c356e26e2a8216 (diff)
downloadlinux-stable-2e12dceef3d3fb8d796e384aa242062d1643cad4.tar.gz
linux-stable-2e12dceef3d3fb8d796e384aa242062d1643cad4.tar.bz2
linux-stable-2e12dceef3d3fb8d796e384aa242062d1643cad4.zip
swiotlb-xen: simplify the DMA sync method implementations
Get rid of the grand multiplexer and implement the sync_single_for_cpu and sync_single_for_device methods directly, and then loop over them for the scatterlist based variants. Note that this also loses a few comments related to highlevel DMA API concepts, which have nothing to do with the swiotlb-xen implementation details. Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
-rw-r--r--drivers/xen/swiotlb-xen.c84
1 files changed, 28 insertions, 56 deletions
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index e40bf1b707e3..ba558094d0e6 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -452,48 +452,28 @@ static void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
xen_unmap_single(hwdev, dev_addr, size, dir, attrs);
}
-/*
- * Make physical memory consistent for a single streaming mode DMA translation
- * after a transfer.
- *
- * If you perform a xen_swiotlb_map_page() but wish to interrogate the buffer
- * using the cpu, yet do not wish to teardown the dma mapping, you must
- * call this function before doing so. At the next point you give the dma
- * address back to the card, you must first perform a
- * xen_swiotlb_dma_sync_for_device, and then the device again owns the buffer
- */
static void
-xen_swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,
- size_t size, enum dma_data_direction dir,
- enum dma_sync_target target)
+xen_swiotlb_sync_single_for_cpu(struct device *dev, dma_addr_t dma_addr,
+ size_t size, enum dma_data_direction dir)
{
- phys_addr_t paddr = xen_bus_to_phys(dev_addr);
+ phys_addr_t paddr = xen_bus_to_phys(dma_addr);
- BUG_ON(dir == DMA_NONE);
-
- if (target == SYNC_FOR_CPU)
- xen_dma_sync_single_for_cpu(hwdev, dev_addr, size, dir);
+ xen_dma_sync_single_for_cpu(dev, dma_addr, size, dir);
- /* NOTE: We use dev_addr here, not paddr! */
- if (is_xen_swiotlb_buffer(dev_addr))
- swiotlb_tbl_sync_single(hwdev, paddr, size, dir, target);
-
- if (target == SYNC_FOR_DEVICE)
- xen_dma_sync_single_for_device(hwdev, dev_addr, size, dir);
+ if (is_xen_swiotlb_buffer(dma_addr))
+ swiotlb_tbl_sync_single(dev, paddr, size, dir, SYNC_FOR_CPU);
}
-void
-xen_swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
- size_t size, enum dma_data_direction dir)
+static void
+xen_swiotlb_sync_single_for_device(struct device *dev, dma_addr_t dma_addr,
+ size_t size, enum dma_data_direction dir)
{
- xen_swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_CPU);
-}
+ phys_addr_t paddr = xen_bus_to_phys(dma_addr);
-void
-xen_swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr,
- size_t size, enum dma_data_direction dir)
-{
- xen_swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_DEVICE);
+ 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);
}
/*
@@ -538,38 +518,30 @@ out_unmap:
return 0;
}
-/*
- * Make physical memory consistent for a set of streaming mode DMA translations
- * after a transfer.
- *
- * The same as swiotlb_sync_single_* but for a scatter-gather list, same rules
- * and usage.
- */
static void
-xen_swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl,
- int nelems, enum dma_data_direction dir,
- enum dma_sync_target target)
+xen_swiotlb_sync_sg_for_cpu(struct device *dev, struct scatterlist *sgl,
+ int nelems, enum dma_data_direction dir)
{
struct scatterlist *sg;
int i;
- for_each_sg(sgl, sg, nelems, i)
- xen_swiotlb_sync_single(hwdev, sg->dma_address,
- sg_dma_len(sg), dir, target);
-}
-
-static void
-xen_swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg,
- int nelems, enum dma_data_direction dir)
-{
- xen_swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_CPU);
+ for_each_sg(sgl, sg, nelems, i) {
+ xen_swiotlb_sync_single_for_cpu(dev, sg->dma_address,
+ sg->length, dir);
+ }
}
static void
-xen_swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
+xen_swiotlb_sync_sg_for_device(struct device *dev, struct scatterlist *sgl,
int nelems, enum dma_data_direction dir)
{
- xen_swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_DEVICE);
+ struct scatterlist *sg;
+ int i;
+
+ for_each_sg(sgl, sg, nelems, i) {
+ xen_swiotlb_sync_single_for_device(dev, sg->dma_address,
+ sg->length, dir);
+ }
}
/*