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authorJason Gunthorpe <jgg@mellanox.com>2018-08-16 13:08:18 -0600
committerJason Gunthorpe <jgg@mellanox.com>2018-08-16 13:12:00 -0600
commit89982f7ccee2fcd8fea7936b81eec6defbf0f131 (patch)
treefc553c8d008d24595ad7de0ea0f3b56f656da27c /kernel/dma/virt.c
parenta1ceeca679dccc492235f0f629d9e9f7b3d51ca8 (diff)
parent94710cac0ef4ee177a63b5227664b38c95bbf703 (diff)
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Merge tag 'v4.18' into rdma.git for-next
Resolve merge conflicts from the -rc cycle against the rdma.git tree: Conflicts: drivers/infiniband/core/uverbs_cmd.c - New ifs added to ib_uverbs_ex_create_flow in -rc and for-next - Merge removal of file->ucontext in for-next with new code in -rc drivers/infiniband/core/uverbs_main.c - for-next removed code from ib_uverbs_write() that was modified in for-rc Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'kernel/dma/virt.c')
-rw-r--r--kernel/dma/virt.c59
1 files changed, 59 insertions, 0 deletions
diff --git a/kernel/dma/virt.c b/kernel/dma/virt.c
new file mode 100644
index 000000000000..631ddec4b60a
--- /dev/null
+++ b/kernel/dma/virt.c
@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DMA operations that map to virtual addresses without flushing memory.
+ */
+#include <linux/export.h>
+#include <linux/mm.h>
+#include <linux/dma-mapping.h>
+#include <linux/scatterlist.h>
+
+static void *dma_virt_alloc(struct device *dev, size_t size,
+ dma_addr_t *dma_handle, gfp_t gfp,
+ unsigned long attrs)
+{
+ void *ret;
+
+ ret = (void *)__get_free_pages(gfp, get_order(size));
+ if (ret)
+ *dma_handle = (uintptr_t)ret;
+ return ret;
+}
+
+static void dma_virt_free(struct device *dev, size_t size,
+ void *cpu_addr, dma_addr_t dma_addr,
+ unsigned long attrs)
+{
+ free_pages((unsigned long)cpu_addr, get_order(size));
+}
+
+static dma_addr_t dma_virt_map_page(struct device *dev, struct page *page,
+ unsigned long offset, size_t size,
+ enum dma_data_direction dir,
+ unsigned long attrs)
+{
+ return (uintptr_t)(page_address(page) + offset);
+}
+
+static int dma_virt_map_sg(struct device *dev, struct scatterlist *sgl,
+ int nents, enum dma_data_direction dir,
+ unsigned long attrs)
+{
+ int i;
+ struct scatterlist *sg;
+
+ for_each_sg(sgl, sg, nents, i) {
+ BUG_ON(!sg_page(sg));
+ sg_dma_address(sg) = (uintptr_t)sg_virt(sg);
+ sg_dma_len(sg) = sg->length;
+ }
+
+ return nents;
+}
+
+const struct dma_map_ops dma_virt_ops = {
+ .alloc = dma_virt_alloc,
+ .free = dma_virt_free,
+ .map_page = dma_virt_map_page,
+ .map_sg = dma_virt_map_sg,
+};
+EXPORT_SYMBOL(dma_virt_ops);