openrisc: provide dma_map_ops

This switches OpenRISC over to fully using the generic dma-mapping
framework.  This was almost already the case as the architecture's
implementation was essentially a copy of the generic header.

This also brings this architecture in line with the recent changes
to dma_map_ops (adding attributes to ops->alloc).

Signed-off-by: Jonas Bonn <jonas@southpole.se>

1 files changed, 73 insertions, 36 deletions

diff --git a/arch/openrisc/kernel/dma.c b/arch/openrisc/kernel/dma.c
index f1c8ee2895d0..0b77ddb1ee07 100644
--- a/arch/openrisc/kernel/dma.c
+++ b/arch/openrisc/kernel/dma.c
@@ -21,13 +21,16 @@
 
 #include <linux/dma-mapping.h>
 #include <linux/dma-debug.h>
+#include <linux/export.h>
+#include <linux/dma-attrs.h>
 
 #include <asm/cpuinfo.h>
 #include <asm/spr_defs.h>
 #include <asm/tlbflush.h>
 
-static int page_set_nocache(pte_t *pte, unsigned long addr,
-                            unsigned long next, struct mm_walk *walk)
+static int
+page_set_nocache(pte_t *pte, unsigned long addr,
+                 unsigned long next, struct mm_walk *walk)
 {
         unsigned long cl;
 
@@ -46,8 +49,9 @@ static int page_set_nocache(pte_t *pte, unsigned long addr,
         return 0;
 }
 
-static int page_clear_nocache(pte_t *pte, unsigned long addr,
-                              unsigned long next, struct mm_walk *walk)
+static int
+page_clear_nocache(pte_t *pte, unsigned long addr,
+                   unsigned long next, struct mm_walk *walk)
 {
         pte_val(*pte) &= ~_PAGE_CI;
 
@@ -67,9 +71,19 @@ static int page_clear_nocache(pte_t *pte, unsigned long addr,
  * cache-inhibit bit on those pages, and makes sure that the pages are
  * flushed out of the cache before they are used.
  *
+ * If the NON_CONSISTENT attribute is set, then this function just
+ * returns "normal", cachable memory.
+ *
+ * There are additional flags WEAK_ORDERING and WRITE_COMBINE to take
+ * into consideration here, too.  All current known implementations of
+ * the OR1K support only strongly ordered memory accesses, so that flag
+ * is being ignored for now; uncached but write-combined memory is a
+ * missing feature of the OR1K.
  */
-void *or1k_dma_alloc_coherent(struct device *dev, size_t size,
-                              dma_addr_t *dma_handle, gfp_t gfp)
+static void *
+or1k_dma_alloc(struct device *dev, size_t size,
+               dma_addr_t *dma_handle, gfp_t gfp,
+               struct dma_attrs *attrs)
 {
         unsigned long va;
         void *page;
@@ -87,20 +101,23 @@ void *or1k_dma_alloc_coherent(struct device *dev, size_t size,
 
         va = (unsigned long)page;
 
-        /*
-         * We need to iterate through the pages, clearing the dcache for
-         * them and setting the cache-inhibit bit.
-         */
-        if (walk_page_range(va, va + size, &walk)) {
-                free_pages_exact(page, size);
-                return NULL;
+        if (!dma_get_attr(DMA_ATTR_NON_CONSISTENT, attrs)) {
+                /*
+                 * We need to iterate through the pages, clearing the dcache for
+                 * them and setting the cache-inhibit bit.
+                 */
+                if (walk_page_range(va, va + size, &walk)) {
+                        free_pages_exact(page, size);
+                        return NULL;
+                }
         }
 
         return (void *)va;
 }
 
-void or1k_dma_free_coherent(struct device *dev, size_t size, void *vaddr,
-                            dma_addr_t dma_handle)
+static void
+or1k_dma_free(struct device *dev, size_t size, void *vaddr,
+              dma_addr_t dma_handle, struct dma_attrs *attrs)
 {
         unsigned long va = (unsigned long)vaddr;
         struct mm_walk walk = {
@@ -108,16 +125,19 @@ void or1k_dma_free_coherent(struct device *dev, size_t size, void *vaddr,
                 .mm = &init_mm
         };
 
-        /* walk_page_range shouldn't be able to fail here */
-        WARN_ON(walk_page_range(va, va + size, &walk));
+        if (!dma_get_attr(DMA_ATTR_NON_CONSISTENT, attrs)) {
+                /* walk_page_range shouldn't be able to fail here */
+                WARN_ON(walk_page_range(va, va + size, &walk));
+        }
 
         free_pages_exact(vaddr, size);
 }
 
-dma_addr_t or1k_map_page(struct device *dev, struct page *page,
-                         unsigned long offset, size_t size,
-                         enum dma_data_direction dir,
-                         struct dma_attrs *attrs)
+static dma_addr_t
+or1k_map_page(struct device *dev, struct page *page,
+              unsigned long offset, size_t size,
+              enum dma_data_direction dir,
+              struct dma_attrs *attrs)
 {
         unsigned long cl;
         dma_addr_t addr = page_to_phys(page) + offset;
@@ -147,16 +167,18 @@ dma_addr_t or1k_map_page(struct device *dev, struct page *page,
         return addr;
 }
 
-void or1k_unmap_page(struct device *dev, dma_addr_t dma_handle,
-                     size_t size, enum dma_data_direction dir,
-                     struct dma_attrs *attrs)
+static void
+or1k_unmap_page(struct device *dev, dma_addr_t dma_handle,
+                size_t size, enum dma_data_direction dir,
+                struct dma_attrs *attrs)
 {
         /* Nothing special to do here... */
 }
 
-int or1k_map_sg(struct device *dev, struct scatterlist *sg,
-                int nents, enum dma_data_direction dir,
-                struct dma_attrs *attrs)
+static int
+or1k_map_sg(struct device *dev, struct scatterlist *sg,
+            int nents, enum dma_data_direction dir,
+            struct dma_attrs *attrs)
 {
         struct scatterlist *s;
         int i;
@@ -169,9 +191,10 @@ int or1k_map_sg(struct device *dev, struct scatterlist *sg,
         return nents;
 }
 
-void or1k_unmap_sg(struct device *dev, struct scatterlist *sg,
-                   int nents, enum dma_data_direction dir,
-                   struct dma_attrs *attrs)
+static void
+or1k_unmap_sg(struct device *dev, struct scatterlist *sg,
+              int nents, enum dma_data_direction dir,
+              struct dma_attrs *attrs)
 {
         struct scatterlist *s;
         int i;
@@ -181,9 +204,10 @@ void or1k_unmap_sg(struct device *dev, struct scatterlist *sg,
         }
 }
 
-void or1k_sync_single_for_cpu(struct device *dev,
-                              dma_addr_t dma_handle, size_t size,
-                              enum dma_data_direction dir)
+static void
+or1k_sync_single_for_cpu(struct device *dev,
+                         dma_addr_t dma_handle, size_t size,
+                         enum dma_data_direction dir)
 {
         unsigned long cl;
         dma_addr_t addr = dma_handle;
@@ -193,9 +217,10 @@ void or1k_sync_single_for_cpu(struct device *dev,
                 mtspr(SPR_DCBIR, cl);
 }
 
-void or1k_sync_single_for_device(struct device *dev,
-                                 dma_addr_t dma_handle, size_t size,
-                                 enum dma_data_direction dir)
+static void
+or1k_sync_single_for_device(struct device *dev,
+                            dma_addr_t dma_handle, size_t size,
+                            enum dma_data_direction dir)
 {
         unsigned long cl;
         dma_addr_t addr = dma_handle;
@@ -205,6 +230,18 @@ void or1k_sync_single_for_device(struct device *dev,
                 mtspr(SPR_DCBFR, cl);
 }
 
+struct dma_map_ops or1k_dma_map_ops = {
+        .alloc = or1k_dma_alloc,
+        .free = or1k_dma_free,
+        .map_page = or1k_map_page,
+        .unmap_page = or1k_unmap_page,
+        .map_sg = or1k_map_sg,
+        .unmap_sg = or1k_unmap_sg,
+        .sync_single_for_cpu = or1k_sync_single_for_cpu,
+        .sync_single_for_device = or1k_sync_single_for_device,
+};
+EXPORT_SYMBOL(or1k_dma_map_ops);
+
 /* Number of entries preallocated for DMA-API debugging */
 #define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)