nios2: DMA mapping API

This patch adds support for the DMA mapping API.

Signed-off-by: Ley Foon Tan <lftan@altera.com>

diff --git a/arch/nios2/include/asm/dma-mapping.h b/arch/nios2/include/asm/dma-mapping.h
new file mode 100644 (file)
index 0000000..b556723
--- /dev/null
+++ b/arch/nios2/include/asm/dma-mapping.h
@@ -0,0 +1,140 @@
+/*
+ * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
+ * Copyright (C) 2009 Wind River Systems Inc
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License.  See the file COPYING in the main directory of this
+ * archive for more details.
+ */
+
+#ifndef _ASM_NIOS2_DMA_MAPPING_H
+#define _ASM_NIOS2_DMA_MAPPING_H
+
+#include <linux/scatterlist.h>
+#include <linux/cache.h>
+#include <asm/cacheflush.h>
+
+static inline void __dma_sync_for_device(void *vaddr, size_t size,
+                             enum dma_data_direction direction)
+{
+       switch (direction) {
+       case DMA_FROM_DEVICE:
+               invalidate_dcache_range((unsigned long)vaddr,
+                       (unsigned long)(vaddr + size));
+               break;
+       case DMA_TO_DEVICE:
+               /*
+                * We just need to flush the caches here , but Nios2 flush
+                * instruction will do both writeback and invalidate.
+                */
+       case DMA_BIDIRECTIONAL: /* flush and invalidate */
+               flush_dcache_range((unsigned long)vaddr,
+                       (unsigned long)(vaddr + size));
+               break;
+       default:
+               BUG();
+       }
+}
+
+static inline void __dma_sync_for_cpu(void *vaddr, size_t size,
+                             enum dma_data_direction direction)
+{
+       switch (direction) {
+       case DMA_BIDIRECTIONAL:
+       case DMA_FROM_DEVICE:
+               invalidate_dcache_range((unsigned long)vaddr,
+                       (unsigned long)(vaddr + size));
+               break;
+       case DMA_TO_DEVICE:
+               break;
+       default:
+               BUG();
+       }
+}
+
+#define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
+#define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
+
+void *dma_alloc_coherent(struct device *dev, size_t size,
+                          dma_addr_t *dma_handle, gfp_t flag);
+
+void dma_free_coherent(struct device *dev, size_t size,
+                        void *vaddr, dma_addr_t dma_handle);
+
+static inline dma_addr_t dma_map_single(struct device *dev, void *ptr,
+                                       size_t size,
+                                       enum dma_data_direction direction)
+{
+       BUG_ON(!valid_dma_direction(direction));
+       __dma_sync_for_device(ptr, size, direction);
+       return virt_to_phys(ptr);
+}
+
+static inline void dma_unmap_single(struct device *dev, dma_addr_t dma_addr,
+                               size_t size, enum dma_data_direction direction)
+{
+}
+
+extern int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
+       enum dma_data_direction direction);
+extern dma_addr_t dma_map_page(struct device *dev, struct page *page,
+       unsigned long offset, size_t size, enum dma_data_direction direction);
+extern void dma_unmap_page(struct device *dev, dma_addr_t dma_address,
+       size_t size, enum dma_data_direction direction);
+extern void dma_unmap_sg(struct device *dev, struct scatterlist *sg,
+       int nhwentries, enum dma_data_direction direction);
+extern void dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
+       size_t size, enum dma_data_direction direction);
+extern void dma_sync_single_for_device(struct device *dev,
+       dma_addr_t dma_handle, size_t size, enum dma_data_direction direction);
+extern void dma_sync_single_range_for_cpu(struct device *dev,
+       dma_addr_t dma_handle, unsigned long offset, size_t size,
+       enum dma_data_direction direction);
+extern void dma_sync_single_range_for_device(struct device *dev,
+       dma_addr_t dma_handle, unsigned long offset, size_t size,
+       enum dma_data_direction direction);
+extern void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
+       int nelems, enum dma_data_direction direction);
+extern void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
+       int nelems, enum dma_data_direction direction);
+
+static inline int dma_supported(struct device *dev, u64 mask)
+{
+       return 1;
+}
+
+static inline int dma_set_mask(struct device *dev, u64 mask)
+{
+       if (!dev->dma_mask || !dma_supported(dev, mask))
+               return -EIO;
+
+       *dev->dma_mask = mask;
+
+       return 0;
+}
+
+static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
+{
+       return 0;
+}
+
+/*
+* dma_alloc_noncoherent() returns non-cacheable memory, so there's no need to
+* do any flushing here.
+*/
+static inline void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
+                                 enum dma_data_direction direction)
+{
+}
+
+/* drivers/base/dma-mapping.c */
+extern int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
+               void *cpu_addr, dma_addr_t dma_addr, size_t size);
+extern int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
+               void *cpu_addr, dma_addr_t dma_addr,
+               size_t size);
+
+#define dma_mmap_coherent(d, v, c, h, s) dma_common_mmap(d, v, c, h, s)
+#define dma_get_sgtable(d, t, v, h, s) dma_common_get_sgtable(d, t, v, h, s)
+
+#endif /* _ASM_NIOS2_DMA_MAPPING_H */

diff --git a/arch/nios2/mm/dma-mapping.c b/arch/nios2/mm/dma-mapping.c
new file mode 100644 (file)
index 0000000..ac5da75
--- /dev/null
+++ b/arch/nios2/mm/dma-mapping.c
@@ -0,0 +1,186 @@
+/*
+ * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
+ * Copyright (C) 2009 Wind River Systems Inc
+ *  Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
+ *
+ * Based on DMA code from MIPS.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/export.h>
+#include <linux/string.h>
+#include <linux/scatterlist.h>
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+#include <linux/cache.h>
+#include <asm/cacheflush.h>
+
+
+void *dma_alloc_coherent(struct device *dev, size_t size,
+                           dma_addr_t *dma_handle, gfp_t gfp)
+{
+       void *ret;
+
+       /* ignore region specifiers */
+       gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
+
+       /* optimized page clearing */
+       gfp |= __GFP_ZERO;
+
+       if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
+               gfp |= GFP_DMA;
+
+       ret = (void *) __get_free_pages(gfp, get_order(size));
+       if (ret != NULL) {
+               *dma_handle = virt_to_phys(ret);
+               flush_dcache_range((unsigned long) ret,
+                       (unsigned long) ret + size);
+               ret = UNCAC_ADDR(ret);
+       }
+
+       return ret;
+}
+EXPORT_SYMBOL(dma_alloc_coherent);
+
+void dma_free_coherent(struct device *dev, size_t size, void *vaddr,
+                       dma_addr_t dma_handle)
+{
+       unsigned long addr = (unsigned long) CAC_ADDR((unsigned long) vaddr);
+
+       free_pages(addr, get_order(size));
+}
+EXPORT_SYMBOL(dma_free_coherent);
+
+int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
+               enum dma_data_direction direction)
+{
+       int i;
+
+       BUG_ON(!valid_dma_direction(direction));
+
+       for_each_sg(sg, sg, nents, i) {
+               void *addr;
+
+               addr = sg_virt(sg);
+               if (addr) {
+                       __dma_sync_for_device(addr, sg->length, direction);
+                       sg->dma_address = sg_phys(sg);
+               }
+       }
+
+       return nents;
+}
+EXPORT_SYMBOL(dma_map_sg);
+
+dma_addr_t dma_map_page(struct device *dev, struct page *page,
+                       unsigned long offset, size_t size,
+                       enum dma_data_direction direction)
+{
+       void *addr;
+
+       BUG_ON(!valid_dma_direction(direction));
+
+       addr = page_address(page) + offset;
+       __dma_sync_for_device(addr, size, direction);
+
+       return page_to_phys(page) + offset;
+}
+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)
+{
+       BUG_ON(!valid_dma_direction(direction));
+
+       __dma_sync_for_cpu(phys_to_virt(dma_address), size, direction);
+}
+EXPORT_SYMBOL(dma_unmap_page);
+
+void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
+                 enum dma_data_direction direction)
+{
+       void *addr;
+       int i;
+
+       BUG_ON(!valid_dma_direction(direction));
+
+       if (direction == DMA_TO_DEVICE)
+               return;
+
+       for_each_sg(sg, sg, nhwentries, i) {
+               addr = sg_virt(sg);
+               if (addr)
+                       __dma_sync_for_cpu(addr, sg->length, direction);
+       }
+}
+EXPORT_SYMBOL(dma_unmap_sg);
+
+void dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
+                            size_t size, enum dma_data_direction direction)
+{
+       BUG_ON(!valid_dma_direction(direction));
+
+       __dma_sync_for_cpu(phys_to_virt(dma_handle), size, direction);
+}
+EXPORT_SYMBOL(dma_sync_single_for_cpu);
+
+void dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle,
+                               size_t size, enum dma_data_direction direction)
+{
+       BUG_ON(!valid_dma_direction(direction));
+
+       __dma_sync_for_device(phys_to_virt(dma_handle), size, direction);
+}
+EXPORT_SYMBOL(dma_sync_single_for_device);
+
+void dma_sync_single_range_for_cpu(struct device *dev, dma_addr_t dma_handle,
+                                       unsigned long offset, size_t size,
+                                       enum dma_data_direction direction)
+{
+       BUG_ON(!valid_dma_direction(direction));
+
+       __dma_sync_for_cpu(phys_to_virt(dma_handle), size, direction);
+}
+EXPORT_SYMBOL(dma_sync_single_range_for_cpu);
+
+void dma_sync_single_range_for_device(struct device *dev, dma_addr_t dma_handle,
+                                       unsigned long offset, size_t size,
+                                       enum dma_data_direction direction)
+{
+       BUG_ON(!valid_dma_direction(direction));
+
+       __dma_sync_for_device(phys_to_virt(dma_handle), size, direction);
+}
+EXPORT_SYMBOL(dma_sync_single_range_for_device);
+
+void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems,
+                        enum dma_data_direction direction)
+{
+       int i;
+
+       BUG_ON(!valid_dma_direction(direction));
+
+       /* Make sure that gcc doesn't leave the empty loop body.  */
+       for_each_sg(sg, sg, nelems, i)
+               __dma_sync_for_cpu(sg_virt(sg), sg->length, direction);
+}
+EXPORT_SYMBOL(dma_sync_sg_for_cpu);
+
+void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
+                               int nelems, enum dma_data_direction direction)
+{
+       int i;
+
+       BUG_ON(!valid_dma_direction(direction));
+
+       /* Make sure that gcc doesn't leave the empty loop body.  */
+       for_each_sg(sg, sg, nelems, i)
+               __dma_sync_for_device(sg_virt(sg), sg->length, direction);
+
+}
+EXPORT_SYMBOL(dma_sync_sg_for_device);