MIPS: consolidate the swiotlb implementations

Octeon and Loongson share exactly the same code, move it into a common
implementation, and use that implementation directly from get_arch_dma_ops.

Also provide the expected dma-direct.h helpers directly instead of
delegating to platform dma-coherence.h headers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Patchwork: https://patchwork.linux-mips.org/patch/19534/
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: iommu@lists.linux-foundation.org
Cc: linux-mips@linux-mips.org

2 files changed, 62 insertions, 0 deletions

diff --git a/arch/mips/mm/Makefile b/arch/mips/mm/Makefile
index c463bdad45c7..b87e4258fd78 100644
--- a/arch/mips/mm/Makefile
+++ b/arch/mips/mm/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_32BIT)		+= ioremap.o pgtable-32.o
 obj-$(CONFIG_64BIT)		+= pgtable-64.o
 obj-$(CONFIG_HIGHMEM)		+= highmem.o
 obj-$(CONFIG_HUGETLB_PAGE)	+= hugetlbpage.o
+obj-$(CONFIG_SWIOTLB)		+= dma-swiotlb.o
 
 obj-$(CONFIG_CPU_R4K_CACHE_TLB) += c-r4k.o cex-gen.o tlb-r4k.o
 obj-$(CONFIG_CPU_R3000)		+= c-r3k.o tlb-r3k.o
diff --git a/arch/mips/mm/dma-swiotlb.c b/arch/mips/mm/dma-swiotlb.c
new file mode 100644
index 000000000000..6014ed3479fd
--- /dev/null
+++ b/arch/mips/mm/dma-swiotlb.c
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/dma-mapping.h>
+#include <linux/swiotlb.h>
+
+static void *mips_swiotlb_alloc(struct device *dev, size_t size,
+		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
+{
+	void *ret = swiotlb_alloc(dev, size, dma_handle, gfp, attrs);
+
+	mb();
+	return ret;
+}
+
+static dma_addr_t mips_swiotlb_map_page(struct device *dev,
+		struct page *page, unsigned long offset, size_t size,
+		enum dma_data_direction dir, unsigned long attrs)
+{
+	dma_addr_t daddr = swiotlb_map_page(dev, page, offset, size,
+					dir, attrs);
+	mb();
+	return daddr;
+}
+
+static int mips_swiotlb_map_sg(struct device *dev, struct scatterlist *sg,
+		int nents, enum dma_data_direction dir, unsigned long attrs)
+{
+	int r = swiotlb_map_sg_attrs(dev, sg, nents, dir, attrs);
+	mb();
+
+	return r;
+}
+
+static void mips_swiotlb_sync_single_for_device(struct device *dev,
+		dma_addr_t dma_handle, size_t size, enum dma_data_direction dir)
+{
+	swiotlb_sync_single_for_device(dev, dma_handle, size, dir);
+	mb();
+}
+
+static void mips_swiotlb_sync_sg_for_device(struct device *dev,
+		struct scatterlist *sg, int nents, enum dma_data_direction dir)
+{
+	swiotlb_sync_sg_for_device(dev, sg, nents, dir);
+	mb();
+}
+
+const struct dma_map_ops mips_swiotlb_ops = {
+	.alloc			= mips_swiotlb_alloc,
+	.free			= swiotlb_free,
+	.map_page		= mips_swiotlb_map_page,
+	.unmap_page		= swiotlb_unmap_page,
+	.map_sg			= mips_swiotlb_map_sg,
+	.unmap_sg		= swiotlb_unmap_sg_attrs,
+	.sync_single_for_cpu	= swiotlb_sync_single_for_cpu,
+	.sync_single_for_device	= mips_swiotlb_sync_single_for_device,
+	.sync_sg_for_cpu	= swiotlb_sync_sg_for_cpu,
+	.sync_sg_for_device	= mips_swiotlb_sync_sg_for_device,
+	.mapping_error		= swiotlb_dma_mapping_error,
+	.dma_supported		= swiotlb_dma_supported,
+};
+EXPORT_SYMBOL(mips_swiotlb_ops);