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authorBecky Bruce <becky.bruce@freescale.com>2008-09-08 11:09:52 +0200
committerKumar Gala <galak@kernel.crashing.org>2008-09-24 23:26:41 +0200
commit7c05d7e08d907d66b8e18515572f42c71fb709fe (patch)
tree6f5c6549f6d515c38a0ece662da4ae1f1ec43579 /arch/powerpc/kernel/dma.c
parentMerge branch 'powerpc-next' of master.kernel.org:/pub/scm/linux/kernel/git/ga... (diff)
downloadlinux-7c05d7e08d907d66b8e18515572f42c71fb709fe.tar.xz
linux-7c05d7e08d907d66b8e18515572f42c71fb709fe.zip
powerpc: Rename dma_64.c to dma.c
This is in preparation for the merge of the 32 and 64-bit dma code in arch/powerpc. Signed-off-by: Becky Bruce <becky.bruce@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/dma.c')
-rw-r--r--arch/powerpc/kernel/dma.c200
1 files changed, 200 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c
new file mode 100644
index 000000000000..ae5708e3a312
--- /dev/null
+++ b/arch/powerpc/kernel/dma.c
@@ -0,0 +1,200 @@
+/*
+ * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corporation
+ *
+ * Provide default implementations of the DMA mapping callbacks for
+ * directly mapped busses and busses using the iommu infrastructure
+ */
+
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <asm/bug.h>
+#include <asm/iommu.h>
+#include <asm/abs_addr.h>
+
+/*
+ * Generic iommu implementation
+ */
+
+/* Allocates a contiguous real buffer and creates mappings over it.
+ * Returns the virtual address of the buffer and sets dma_handle
+ * to the dma address (mapping) of the first page.
+ */
+static void *dma_iommu_alloc_coherent(struct device *dev, size_t size,
+ dma_addr_t *dma_handle, gfp_t flag)
+{
+ return iommu_alloc_coherent(dev, dev->archdata.dma_data, size,
+ dma_handle, device_to_mask(dev), flag,
+ dev->archdata.numa_node);
+}
+
+static void dma_iommu_free_coherent(struct device *dev, size_t size,
+ void *vaddr, dma_addr_t dma_handle)
+{
+ iommu_free_coherent(dev->archdata.dma_data, size, vaddr, dma_handle);
+}
+
+/* Creates TCEs for a user provided buffer. The user buffer must be
+ * contiguous real kernel storage (not vmalloc). The address of the buffer
+ * passed here is the kernel (virtual) address of the buffer. The buffer
+ * need not be page aligned, the dma_addr_t returned will point to the same
+ * byte within the page as vaddr.
+ */
+static dma_addr_t dma_iommu_map_single(struct device *dev, void *vaddr,
+ size_t size,
+ enum dma_data_direction direction,
+ struct dma_attrs *attrs)
+{
+ return iommu_map_single(dev, dev->archdata.dma_data, vaddr, size,
+ device_to_mask(dev), direction, attrs);
+}
+
+
+static void dma_iommu_unmap_single(struct device *dev, dma_addr_t dma_handle,
+ size_t size,
+ enum dma_data_direction direction,
+ struct dma_attrs *attrs)
+{
+ iommu_unmap_single(dev->archdata.dma_data, dma_handle, size, direction,
+ attrs);
+}
+
+
+static int dma_iommu_map_sg(struct device *dev, struct scatterlist *sglist,
+ int nelems, enum dma_data_direction direction,
+ struct dma_attrs *attrs)
+{
+ return iommu_map_sg(dev, dev->archdata.dma_data, sglist, nelems,
+ device_to_mask(dev), direction, attrs);
+}
+
+static void dma_iommu_unmap_sg(struct device *dev, struct scatterlist *sglist,
+ int nelems, enum dma_data_direction direction,
+ struct dma_attrs *attrs)
+{
+ iommu_unmap_sg(dev->archdata.dma_data, sglist, nelems, direction,
+ attrs);
+}
+
+/* We support DMA to/from any memory page via the iommu */
+static int dma_iommu_dma_supported(struct device *dev, u64 mask)
+{
+ struct iommu_table *tbl = dev->archdata.dma_data;
+
+ if (!tbl || tbl->it_offset > mask) {
+ printk(KERN_INFO
+ "Warning: IOMMU offset too big for device mask\n");
+ if (tbl)
+ printk(KERN_INFO
+ "mask: 0x%08lx, table offset: 0x%08lx\n",
+ mask, tbl->it_offset);
+ else
+ printk(KERN_INFO "mask: 0x%08lx, table unavailable\n",
+ mask);
+ return 0;
+ } else
+ return 1;
+}
+
+struct dma_mapping_ops dma_iommu_ops = {
+ .alloc_coherent = dma_iommu_alloc_coherent,
+ .free_coherent = dma_iommu_free_coherent,
+ .map_single = dma_iommu_map_single,
+ .unmap_single = dma_iommu_unmap_single,
+ .map_sg = dma_iommu_map_sg,
+ .unmap_sg = dma_iommu_unmap_sg,
+ .dma_supported = dma_iommu_dma_supported,
+};
+EXPORT_SYMBOL(dma_iommu_ops);
+
+/*
+ * Generic direct DMA implementation
+ *
+ * This implementation supports a per-device offset that can be applied if
+ * the address at which memory is visible to devices is not 0. Platform code
+ * can set archdata.dma_data to an unsigned long holding the offset. By
+ * default the offset is zero.
+ */
+
+static unsigned long get_dma_direct_offset(struct device *dev)
+{
+ return (unsigned long)dev->archdata.dma_data;
+}
+
+static void *dma_direct_alloc_coherent(struct device *dev, size_t size,
+ dma_addr_t *dma_handle, gfp_t flag)
+{
+ struct page *page;
+ void *ret;
+ int node = dev->archdata.numa_node;
+
+ page = alloc_pages_node(node, flag, get_order(size));
+ if (page == NULL)
+ return NULL;
+ ret = page_address(page);
+ memset(ret, 0, size);
+ *dma_handle = virt_to_abs(ret) + get_dma_direct_offset(dev);
+
+ return ret;
+}
+
+static void dma_direct_free_coherent(struct device *dev, size_t size,
+ void *vaddr, dma_addr_t dma_handle)
+{
+ free_pages((unsigned long)vaddr, get_order(size));
+}
+
+static dma_addr_t dma_direct_map_single(struct device *dev, void *ptr,
+ size_t size,
+ enum dma_data_direction direction,
+ struct dma_attrs *attrs)
+{
+ return virt_to_abs(ptr) + get_dma_direct_offset(dev);
+}
+
+static void dma_direct_unmap_single(struct device *dev, dma_addr_t dma_addr,
+ size_t size,
+ enum dma_data_direction direction,
+ struct dma_attrs *attrs)
+{
+}
+
+static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
+ int nents, enum dma_data_direction direction,
+ struct dma_attrs *attrs)
+{
+ struct scatterlist *sg;
+ int i;
+
+ for_each_sg(sgl, sg, nents, i) {
+ sg->dma_address = sg_phys(sg) + get_dma_direct_offset(dev);
+ sg->dma_length = sg->length;
+ }
+
+ return nents;
+}
+
+static void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sg,
+ int nents, enum dma_data_direction direction,
+ struct dma_attrs *attrs)
+{
+}
+
+static int dma_direct_dma_supported(struct device *dev, u64 mask)
+{
+ /* Could be improved to check for memory though it better be
+ * done via some global so platforms can set the limit in case
+ * they have limited DMA windows
+ */
+ return mask >= DMA_32BIT_MASK;
+}
+
+struct dma_mapping_ops dma_direct_ops = {
+ .alloc_coherent = dma_direct_alloc_coherent,
+ .free_coherent = dma_direct_free_coherent,
+ .map_single = dma_direct_map_single,
+ .unmap_single = dma_direct_unmap_single,
+ .map_sg = dma_direct_map_sg,
+ .unmap_sg = dma_direct_unmap_sg,
+ .dma_supported = dma_direct_dma_supported,
+};
+EXPORT_SYMBOL(dma_direct_ops);