1 files changed, 456 insertions, 0 deletions
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
new file mode 100644
index 0000000..f41335b
--- /dev/null
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -0,0 +1,456 @@
+#ifndef ASMARM_DMA_MAPPING_H
+#define ASMARM_DMA_MAPPING_H
+
+#ifdef __KERNEL__
+
+#include <linux/mm.h> /* need struct page */
+
+#include <linux/scatterlist.h>
+
+/*
+ * DMA-consistent mapping functions.  These allocate/free a region of
+ * uncached, unwrite-buffered mapped memory space for use with DMA
+ * devices.  This is the "generic" version.  The PCI specific version
+ * is in pci.h
+ *
+ * Note: Drivers should NOT use this function directly, as it will break
+ * platforms with CONFIG_DMABOUNCE.
+ * Use the driver DMA support - see dma-mapping.h (dma_sync_*)
+ */
+extern void dma_cache_maint(const void *kaddr, size_t size, int rw);
+
+/*
+ * Return whether the given device DMA address mask can be supported
+ * properly.  For example, if your device can only drive the low 24-bits
+ * during bus mastering, then you would pass 0x00ffffff as the mask
+ * to this function.
+ *
+ * FIXME: This should really be a platform specific issue - we should
+ * return false if GFP_DMA allocations may not satisfy the supplied 'mask'.
+ */
+static inline int dma_supported(struct device *dev, u64 mask)
+{
+	return dev->dma_mask && *dev->dma_mask != 0;
+}
+
+static inline int dma_set_mask(struct device *dev, u64 dma_mask)
+{
+	if (!dev->dma_mask || !dma_supported(dev, dma_mask))
+		return -EIO;
+
+	*dev->dma_mask = dma_mask;
+
+	return 0;
+}
+
+static inline int dma_get_cache_alignment(void)
+{
+	return 32;
+}
+
+static inline int dma_is_consistent(struct device *dev, dma_addr_t handle)
+{
+	return !!arch_is_coherent();
+}
+
+/*
+ * DMA errors are defined by all-bits-set in the DMA address.
+ */
+static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
+{
+	return dma_addr == ~0;
+}
+
+/*
+ * Dummy noncoherent implementation.  We don't provide a dma_cache_sync
+ * function so drivers using this API are highlighted with build warnings.
+ */
+static inline void *
+dma_alloc_noncoherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp)
+{
+	return NULL;
+}
+
+static inline void
+dma_free_noncoherent(struct device *dev, size_t size, void *cpu_addr,
+		     dma_addr_t handle)
+{
+}
+
+/**
+ * dma_alloc_coherent - allocate consistent memory for DMA
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @size: required memory size
+ * @handle: bus-specific DMA address
+ *
+ * Allocate some uncached, unbuffered memory for a device for
+ * performing DMA.  This function allocates pages, and will
+ * return the CPU-viewed address, and sets @handle to be the
+ * device-viewed address.
+ */
+extern void *
+dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp);
+
+/**
+ * dma_free_coherent - free memory allocated by dma_alloc_coherent
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @size: size of memory originally requested in dma_alloc_coherent
+ * @cpu_addr: CPU-view address returned from dma_alloc_coherent
+ * @handle: device-view address returned from dma_alloc_coherent
+ *
+ * Free (and unmap) a DMA buffer previously allocated by
+ * dma_alloc_coherent().
+ *
+ * References to memory and mappings associated with cpu_addr/handle
+ * during and after this call executing are illegal.
+ */
+extern void
+dma_free_coherent(struct device *dev, size_t size, void *cpu_addr,
+		  dma_addr_t handle);
+
+/**
+ * dma_mmap_coherent - map a coherent DMA allocation into user space
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @vma: vm_area_struct describing requested user mapping
+ * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
+ * @handle: device-view address returned from dma_alloc_coherent
+ * @size: size of memory originally requested in dma_alloc_coherent
+ *
+ * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
+ * into user space.  The coherent DMA buffer must not be freed by the
+ * driver until the user space mapping has been released.
+ */
+int dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
+		      void *cpu_addr, dma_addr_t handle, size_t size);
+
+
+/**
+ * dma_alloc_writecombine - allocate writecombining memory for DMA
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @size: required memory size
+ * @handle: bus-specific DMA address
+ *
+ * Allocate some uncached, buffered memory for a device for
+ * performing DMA.  This function allocates pages, and will
+ * return the CPU-viewed address, and sets @handle to be the
+ * device-viewed address.
+ */
+extern void *
+dma_alloc_writecombine(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp);
+
+#define dma_free_writecombine(dev,size,cpu_addr,handle) \
+	dma_free_coherent(dev,size,cpu_addr,handle)
+
+int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma,
+			  void *cpu_addr, dma_addr_t handle, size_t size);
+
+
+/**
+ * dma_map_single - map a single buffer for streaming DMA
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @cpu_addr: CPU direct mapped address of buffer
+ * @size: size of buffer to map
+ * @dir: DMA transfer direction
+ *
+ * Ensure that any data held in the cache is appropriately discarded
+ * or written back.
+ *
+ * The device owns this memory once this call has completed.  The CPU
+ * can regain ownership by calling dma_unmap_single() or
+ * dma_sync_single_for_cpu().
+ */
+#ifndef CONFIG_DMABOUNCE
+static inline dma_addr_t
+dma_map_single(struct device *dev, void *cpu_addr, size_t size,
+	       enum dma_data_direction dir)
+{
+	if (!arch_is_coherent())
+		dma_cache_maint(cpu_addr, size, dir);
+
+	return virt_to_dma(dev, (unsigned long)cpu_addr);
+}
+#else
+extern dma_addr_t dma_map_single(struct device *,void *, size_t, enum dma_data_direction);
+#endif
+
+/**
+ * dma_map_page - map a portion of a page for streaming DMA
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @page: page that buffer resides in
+ * @offset: offset into page for start of buffer
+ * @size: size of buffer to map
+ * @dir: DMA transfer direction
+ *
+ * Ensure that any data held in the cache is appropriately discarded
+ * or written back.
+ *
+ * The device owns this memory once this call has completed.  The CPU
+ * can regain ownership by calling dma_unmap_page() or
+ * dma_sync_single_for_cpu().
+ */
+static inline dma_addr_t
+dma_map_page(struct device *dev, struct page *page,
+	     unsigned long offset, size_t size,
+	     enum dma_data_direction dir)
+{
+	return dma_map_single(dev, page_address(page) + offset, size, (int)dir);
+}
+
+/**
+ * dma_unmap_single - unmap a single buffer previously mapped
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @handle: DMA address of buffer
+ * @size: size of buffer to map
+ * @dir: DMA transfer direction
+ *
+ * Unmap a single streaming mode DMA translation.  The handle and size
+ * must match what was provided in the previous dma_map_single() call.
+ * All other usages are undefined.
+ *
+ * After this call, reads by the CPU to the buffer are guaranteed to see
+ * whatever the device wrote there.
+ */
+#ifndef CONFIG_DMABOUNCE
+static inline void
+dma_unmap_single(struct device *dev, dma_addr_t handle, size_t size,
+		 enum dma_data_direction dir)
+{
+	/* nothing to do */
+}
+#else
+extern void dma_unmap_single(struct device *, dma_addr_t, size_t, enum dma_data_direction);
+#endif
+
+/**
+ * dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @handle: DMA address of buffer
+ * @size: size of buffer to map
+ * @dir: DMA transfer direction
+ *
+ * Unmap a single streaming mode DMA translation.  The handle and size
+ * must match what was provided in the previous dma_map_single() call.
+ * All other usages are undefined.
+ *
+ * After this call, reads by the CPU to the buffer are guaranteed to see
+ * whatever the device wrote there.
+ */
+static inline void
+dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
+	       enum dma_data_direction dir)
+{
+	dma_unmap_single(dev, handle, size, (int)dir);
+}
+
+/**
+ * dma_map_sg - map a set of SG buffers for streaming mode DMA
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @sg: list of buffers
+ * @nents: number of buffers to map
+ * @dir: DMA transfer direction
+ *
+ * Map a set of buffers described by scatterlist in streaming
+ * mode for DMA.  This is the scatter-gather version of the
+ * above dma_map_single interface.  Here the scatter gather list
+ * elements are each tagged with the appropriate dma address
+ * and length.  They are obtained via sg_dma_{address,length}(SG).
+ *
+ * NOTE: An implementation may be able to use a smaller number of
+ *       DMA address/length pairs than there are SG table elements.
+ *       (for example via virtual mapping capabilities)
+ *       The routine returns the number of addr/length pairs actually
+ *       used, at most nents.
+ *
+ * Device ownership issues as mentioned above for dma_map_single are
+ * the same here.
+ */
+#ifndef CONFIG_DMABOUNCE
+static inline int
+dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
+	   enum dma_data_direction dir)
+{
+	int i;
+
+	for (i = 0; i < nents; i++, sg++) {
+		char *virt;
+
+		sg->dma_address = page_to_dma(dev, sg_page(sg)) + sg->offset;
+		virt = sg_virt(sg);
+
+		if (!arch_is_coherent())
+			dma_cache_maint(virt, sg->length, dir);
+	}
+
+	return nents;
+}
+#else
+extern int dma_map_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
+#endif
+
+/**
+ * dma_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @sg: list of buffers
+ * @nents: number of buffers to map
+ * @dir: DMA transfer direction
+ *
+ * Unmap a set of streaming mode DMA translations.
+ * Again, CPU read rules concerning calls here are the same as for
+ * dma_unmap_single() above.
+ */
+#ifndef CONFIG_DMABOUNCE
+static inline void
+dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
+	     enum dma_data_direction dir)
+{
+
+	/* nothing to do */
+}
+#else
+extern void dma_unmap_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
+#endif
+
+
+/**
+ * dma_sync_single_for_cpu
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @handle: DMA address of buffer
+ * @size: size of buffer to map
+ * @dir: DMA transfer direction
+ *
+ * Make physical memory consistent for a single streaming mode DMA
+ * translation after a transfer.
+ *
+ * If you perform a dma_map_single() but wish to interrogate the
+ * buffer using the cpu, yet do not wish to teardown the PCI dma
+ * mapping, you must call this function before doing so.  At the
+ * next point you give the PCI dma address back to the card, you
+ * must first the perform a dma_sync_for_device, and then the
+ * device again owns the buffer.
+ */
+#ifndef CONFIG_DMABOUNCE
+static inline void
+dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle, size_t size,
+			enum dma_data_direction dir)
+{
+	if (!arch_is_coherent())
+		dma_cache_maint((void *)dma_to_virt(dev, handle), size, dir);
+}
+
+static inline void
+dma_sync_single_for_device(struct device *dev, dma_addr_t handle, size_t size,
+			   enum dma_data_direction dir)
+{
+	if (!arch_is_coherent())
+		dma_cache_maint((void *)dma_to_virt(dev, handle), size, dir);
+}
+#else
+extern void dma_sync_single_for_cpu(struct device*, dma_addr_t, size_t, enum dma_data_direction);
+extern void dma_sync_single_for_device(struct device*, dma_addr_t, size_t, enum dma_data_direction);
+#endif
+
+
+/**
+ * dma_sync_sg_for_cpu
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @sg: list of buffers
+ * @nents: number of buffers to map
+ * @dir: DMA transfer direction
+ *
+ * Make physical memory consistent for a set of streaming
+ * mode DMA translations after a transfer.
+ *
+ * The same as dma_sync_single_for_* but for a scatter-gather list,
+ * same rules and usage.
+ */
+#ifndef CONFIG_DMABOUNCE
+static inline void
+dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nents,
+		    enum dma_data_direction dir)
+{
+	int i;
+
+	for (i = 0; i < nents; i++, sg++) {
+		char *virt = sg_virt(sg);
+		if (!arch_is_coherent())
+			dma_cache_maint(virt, sg->length, dir);
+	}
+}
+
+static inline void
+dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents,
+		       enum dma_data_direction dir)
+{
+	int i;
+
+	for (i = 0; i < nents; i++, sg++) {
+		char *virt = sg_virt(sg);
+		if (!arch_is_coherent())
+			dma_cache_maint(virt, sg->length, dir);
+	}
+}
+#else
+extern void dma_sync_sg_for_cpu(struct device*, struct scatterlist*, int, enum dma_data_direction);
+extern void dma_sync_sg_for_device(struct device*, struct scatterlist*, int, enum dma_data_direction);
+#endif
+
+#ifdef CONFIG_DMABOUNCE
+/*
+ * For SA-1111, IXP425, and ADI systems  the dma-mapping functions are "magic"
+ * and utilize bounce buffers as needed to work around limited DMA windows.
+ *
+ * On the SA-1111, a bug limits DMA to only certain regions of RAM.
+ * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
+ * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
+ *
+ * The following are helper functions used by the dmabounce subystem
+ *
+ */
+
+/**
+ * dmabounce_register_dev
+ *
+ * @dev: valid struct device pointer
+ * @small_buf_size: size of buffers to use with small buffer pool
+ * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
+ *
+ * This function should be called by low-level platform code to register
+ * a device as requireing DMA buffer bouncing. The function will allocate
+ * appropriate DMA pools for the device.
+ *
+ */
+extern int dmabounce_register_dev(struct device *, unsigned long, unsigned long);
+
+/**
+ * dmabounce_unregister_dev
+ *
+ * @dev: valid struct device pointer
+ *
+ * This function should be called by low-level platform code when device
+ * that was previously registered with dmabounce_register_dev is removed
+ * from the system.
+ *
+ */
+extern void dmabounce_unregister_dev(struct device *);
+
+/**
+ * dma_needs_bounce
+ *
+ * @dev: valid struct device pointer
+ * @dma_handle: dma_handle of unbounced buffer
+ * @size: size of region being mapped
+ *
+ * Platforms that utilize the dmabounce mechanism must implement
+ * this function.
+ *
+ * The dmabounce routines call this function whenever a dma-mapping
+ * is requested to determine whether a given buffer needs to be bounced
+ * or not. The function must return 0 if the buffer is OK for
+ * DMA access and 1 if the buffer needs to be bounced.
+ *
+ */
+extern int dma_needs_bounce(struct device*, dma_addr_t, size_t);
+#endif /* CONFIG_DMABOUNCE */
+
+#endif /* __KERNEL__ */
+#endif