powerpc/dma: split the two __dma_alloc_coherent implementations

The implemementation for the CONFIG_NOT_COHERENT_CACHE case doesn't share
any code with the one for systems with coherent caches.  Split it off
and merge it with the helpers in dma-noncoherent.c that have no other
callers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/dma-mapping.h

@@ -39,9 +39,6 @@ extern int dma_nommu_mmap_coherent(struct device *dev,
  * to ensure it is consistent.
  */
 struct device;
-extern void *__dma_alloc_coherent(struct device *dev, size_t size,
-				  dma_addr_t *handle, gfp_t gfp);
-extern void __dma_free_coherent(size_t size, void *vaddr);
 extern void __dma_sync(void *vaddr, size_t size, int direction);
 extern void __dma_sync_page(struct page *page, unsigned long offset,
 				 size_t size, int direction);
@@ -52,8 +49,6 @@ extern unsigned long __dma_get_coherent_pfn(unsigned long cpu_addr);
  * Cache coherent cores.
  */
 
-#define __dma_alloc_coherent(dev, gfp, size, handle)	NULL
-#define __dma_free_coherent(size, addr)		((void)0)
 #define __dma_sync(addr, size, rw)		((void)0)
 #define __dma_sync_page(pg, off, sz, rw)	((void)0)
 

arch/powerpc/kernel/dma.c

@@ -62,18 +62,12 @@ static int dma_nommu_dma_supported(struct device *dev, u64 mask)
 #endif
 }
 
+#ifndef CONFIG_NOT_COHERENT_CACHE
 void *__dma_nommu_alloc_coherent(struct device *dev, size_t size,
 				  dma_addr_t *dma_handle, gfp_t flag,
 				  unsigned long attrs)
 {
 	void *ret;
-#ifdef CONFIG_NOT_COHERENT_CACHE
-	ret = __dma_alloc_coherent(dev, size, dma_handle, flag);
-	if (ret == NULL)
-		return NULL;
-	*dma_handle += get_dma_offset(dev);
-	return ret;
-#else
 	struct page *page;
 	int node = dev_to_node(dev);
 #ifdef CONFIG_FSL_SOC
@@ -113,19 +107,15 @@ void *__dma_nommu_alloc_coherent(struct device *dev, size_t size,
 	*dma_handle = __pa(ret) + get_dma_offset(dev);
 
 	return ret;
-#endif
 }
 
 void __dma_nommu_free_coherent(struct device *dev, size_t size,
 				void *vaddr, dma_addr_t dma_handle,
 				unsigned long attrs)
 {
-#ifdef CONFIG_NOT_COHERENT_CACHE
-	__dma_free_coherent(size, vaddr);
-#else
 	free_pages((unsigned long)vaddr, get_order(size));
-#endif
 }
+#endif /* !CONFIG_NOT_COHERENT_CACHE */
 
 static void *dma_nommu_alloc_coherent(struct device *dev, size_t size,
 				       dma_addr_t *dma_handle, gfp_t flag,

arch/powerpc/mm/dma-noncoherent.c

@@ -29,7 +29,7 @@
 #include <linux/string.h>
 #include <linux/types.h>
 #include <linux/highmem.h>
-#include <linux/dma-mapping.h>
+#include <linux/dma-direct.h>
 #include <linux/export.h>
 
 #include <asm/tlbflush.h>
@@ -151,8 +151,8 @@ static struct ppc_vm_region *ppc_vm_region_find(struct ppc_vm_region *head, unsi
  * Allocate DMA-coherent memory space and return both the kernel remapped
  * virtual and bus address for that space.
  */
-void *
-__dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp)
+void *__dma_nommu_alloc_coherent(struct device *dev, size_t size,
+		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
 {
 	struct page *page;
 	struct ppc_vm_region *c;
@@ -223,7 +223,7 @@ __dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t
 		/*
 		 * Set the "dma handle"
 		 */
-		*handle = page_to_phys(page);
+		*dma_handle = phys_to_dma(dev, page_to_phys(page));
 
 		do {
 			SetPageReserved(page);
@@ -249,12 +249,12 @@ __dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t
  no_page:
 	return NULL;
 }
-EXPORT_SYMBOL(__dma_alloc_coherent);
 
 /*
  * free a page as defined by the above mapping.
  */
-void __dma_free_coherent(size_t size, void *vaddr)
+void __dma_nommu_free_coherent(struct device *dev, size_t size, void *vaddr,
+		dma_addr_t dma_handle, unsigned long attrs)
 {
 	struct ppc_vm_region *c;
 	unsigned long flags, addr;
@@ -309,7 +309,6 @@ void __dma_free_coherent(size_t size, void *vaddr)
 	       __func__, vaddr);
 	dump_stack();
 }
-EXPORT_SYMBOL(__dma_free_coherent);
 
 /*
  * make an area consistent.
@@ -401,7 +400,7 @@ EXPORT_SYMBOL(__dma_sync_page);
 
 /*
  * Return the PFN for a given cpu virtual address returned by
- * __dma_alloc_coherent. This is used by dma_mmap_coherent()
+ * __dma_nommu_alloc_coherent. This is used by dma_mmap_coherent()
  */
 unsigned long __dma_get_coherent_pfn(unsigned long cpu_addr)
 {

arch/powerpc/platforms/44x/warp.c

@@ -47,7 +47,7 @@ static int __init warp_probe(void)
 	if (!of_machine_is_compatible("pika,warp"))
 		return 0;
 
-	/* For __dma_alloc_coherent */
+	/* For __dma_nommu_alloc_coherent */
 	ISA_DMA_THRESHOLD = ~0L;
 
 	return 1;