/*
- * Copyright (C) 2004 IBM Corporation
+ * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corporation
*
- * Implements the generic device dma API for ppc64. Handles
- * the pci and vio busses
+ * 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 the busses we support */
-#include <linux/pci.h>
-#include <asm/vio.h>
-#include <asm/scatterlist.h>
#include <asm/bug.h>
+#include <asm/iommu.h>
+#include <asm/abs_addr.h>
-static struct dma_mapping_ops *get_dma_ops(struct device *dev)
+/*
+ * Generic iommu implementation
+ */
+
+static inline unsigned long device_to_mask(struct device *dev)
{
-#ifdef CONFIG_PCI
- if (dev->bus == &pci_bus_type)
- return &pci_dma_ops;
-#endif
-#ifdef CONFIG_IBMVIO
- if (dev->bus == &vio_bus_type)
- return &vio_dma_ops;
-#endif
- return NULL;
+ if (dev->dma_mask && *dev->dma_mask)
+ return *dev->dma_mask;
+ /* Assume devices without mask can take 32 bit addresses */
+ return 0xfffffffful;
}
-int dma_supported(struct device *dev, u64 mask)
-{
- struct dma_mapping_ops *dma_ops = get_dma_ops(dev);
- if (dma_ops)
- return dma_ops->dma_supported(dev, mask);
- BUG();
- return 0;
+/* 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->archdata.dma_data, size, dma_handle,
+ device_to_mask(dev), flag,
+ dev->archdata.numa_node);
}
-EXPORT_SYMBOL(dma_supported);
-int dma_set_mask(struct device *dev, u64 dma_mask)
+static void dma_iommu_free_coherent(struct device *dev, size_t size,
+ void *vaddr, dma_addr_t dma_handle)
{
-#ifdef CONFIG_PCI
- if (dev->bus == &pci_bus_type)
- return pci_set_dma_mask(to_pci_dev(dev), dma_mask);
-#endif
-#ifdef CONFIG_IBMVIO
- if (dev->bus == &vio_bus_type)
- return -EIO;
-#endif /* CONFIG_IBMVIO */
- BUG();
- return 0;
+ iommu_free_coherent(dev->archdata.dma_data, size, vaddr, dma_handle);
}
-EXPORT_SYMBOL(dma_set_mask);
-void *dma_alloc_coherent(struct device *dev, size_t size,
- dma_addr_t *dma_handle, gfp_t flag)
+/* 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_mapping_ops *dma_ops = get_dma_ops(dev);
-
- if (dma_ops)
- return dma_ops->alloc_coherent(dev, size, dma_handle, flag);
- BUG();
- return NULL;
+ return iommu_map_single(dev->archdata.dma_data, vaddr, size,
+ device_to_mask(dev), direction);
}
-EXPORT_SYMBOL(dma_alloc_coherent);
-void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr,
- dma_addr_t dma_handle)
-{
- struct dma_mapping_ops *dma_ops = get_dma_ops(dev);
- if (dma_ops)
- dma_ops->free_coherent(dev, size, cpu_addr, dma_handle);
- else
- BUG();
+static void dma_iommu_unmap_single(struct device *dev, dma_addr_t dma_handle,
+ size_t size,
+ enum dma_data_direction direction)
+{
+ iommu_unmap_single(dev->archdata.dma_data, dma_handle, size, direction);
}
-EXPORT_SYMBOL(dma_free_coherent);
-dma_addr_t dma_map_single(struct device *dev, void *cpu_addr, size_t size,
- enum dma_data_direction direction)
-{
- struct dma_mapping_ops *dma_ops = get_dma_ops(dev);
- if (dma_ops)
- return dma_ops->map_single(dev, cpu_addr, size, direction);
- BUG();
- return (dma_addr_t)0;
+static int dma_iommu_map_sg(struct device *dev, struct scatterlist *sglist,
+ int nelems, enum dma_data_direction direction)
+{
+ return iommu_map_sg(dev->archdata.dma_data, sglist, nelems,
+ device_to_mask(dev), direction);
}
-EXPORT_SYMBOL(dma_map_single);
-void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
- enum dma_data_direction direction)
+static void dma_iommu_unmap_sg(struct device *dev, struct scatterlist *sglist,
+ int nelems, enum dma_data_direction direction)
{
- struct dma_mapping_ops *dma_ops = get_dma_ops(dev);
+ iommu_unmap_sg(dev->archdata.dma_data, sglist, nelems, direction);
+}
- if (dma_ops)
- dma_ops->unmap_single(dev, dma_addr, size, direction);
- else
- BUG();
+/* 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;
}
-EXPORT_SYMBOL(dma_unmap_single);
-dma_addr_t dma_map_page(struct device *dev, struct page *page,
- unsigned long offset, size_t size,
- enum dma_data_direction direction)
+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 global offset that can be applied if
+ * the address at which memory is visible to devices is not 0.
+ */
+unsigned long dma_direct_offset;
+
+static void *dma_direct_alloc_coherent(struct device *dev, size_t size,
+ dma_addr_t *dma_handle, gfp_t flag)
{
- struct dma_mapping_ops *dma_ops = get_dma_ops(dev);
+ struct page *page;
+ void *ret;
+ int node = dev->archdata.numa_node;
+
+ /* TODO: Maybe use the numa node here too ? */
+ 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) | dma_direct_offset;
+
+ return ret;
+}
- if (dma_ops)
- return dma_ops->map_single(dev,
- (page_address(page) + offset), size, direction);
- BUG();
- return (dma_addr_t)0;
+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));
}
-EXPORT_SYMBOL(dma_map_page);
-void dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
- enum dma_data_direction direction)
+static dma_addr_t dma_direct_map_single(struct device *dev, void *ptr,
+ size_t size,
+ enum dma_data_direction direction)
{
- struct dma_mapping_ops *dma_ops = get_dma_ops(dev);
+ return virt_to_abs(ptr) | dma_direct_offset;
+}
- if (dma_ops)
- dma_ops->unmap_single(dev, dma_address, size, direction);
- else
- BUG();
+static void dma_direct_unmap_single(struct device *dev, dma_addr_t dma_addr,
+ size_t size,
+ enum dma_data_direction direction)
+{
}
-EXPORT_SYMBOL(dma_unmap_page);
-int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
- enum dma_data_direction direction)
+static int dma_direct_map_sg(struct device *dev, struct scatterlist *sg,
+ int nents, enum dma_data_direction direction)
{
- struct dma_mapping_ops *dma_ops = get_dma_ops(dev);
+ int i;
+
+ for (i = 0; i < nents; i++, sg++) {
+ sg->dma_address = (page_to_phys(sg->page) + sg->offset) |
+ dma_direct_offset;
+ sg->dma_length = sg->length;
+ }
- if (dma_ops)
- return dma_ops->map_sg(dev, sg, nents, direction);
- BUG();
- return 0;
+ return nents;
}
-EXPORT_SYMBOL(dma_map_sg);
-void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
- enum dma_data_direction direction)
+static void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sg,
+ int nents, enum dma_data_direction direction)
{
- struct dma_mapping_ops *dma_ops = get_dma_ops(dev);
+}
- if (dma_ops)
- dma_ops->unmap_sg(dev, sg, nhwentries, direction);
- else
- BUG();
+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;
}
-EXPORT_SYMBOL(dma_unmap_sg);
+
+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);
projects / linux-drm-fsl-dcu.git / blobdiff