Fix page_to_phys() and convert virt_to_bus()/virt_to_phys() to

page_to_bus()/page_to_phys() in consistent.c

arch/arm/mm/consistent.c

@@ -25,10 +25,12 @@
 
 /*
  * This allocates one page of cache-coherent memory space and returns
- * both the virtual and a "dma" address to that space.  It is not clear
- * whether this could be called from an interrupt context or not.  For
- * now, we expressly forbid it, especially as some of the stuff we do
- * here is not interrupt context safe.
+ * both the virtual and a "dma" address to that space.
+ *
+ * We should allow this function to be called from interrupt context.
+ * However, we call ioremap, which needs to fiddle around with various
+ * things (like the vmlist_lock, and allocating page tables).  These
+ * things aren't interrupt safe (yet).
  *
  * Note that this does *not* zero the allocated area!
  */
@@ -36,8 +38,9 @@ void *consistent_alloc(int gfp, size_t size, dma_addr_t *dma_handle)
 {
 	struct page *page, *end, *free;
 	unsigned long order;
-	void *ret, *virt;
+	void *ret;
 
+	/* FIXME */
 	if (in_interrupt())
 		BUG();
 
@@ -48,22 +51,22 @@ void *consistent_alloc(int gfp, size_t size, dma_addr_t *dma_handle)
 	if (!page)
 		goto no_page;
 
-	/*
-	 * We could do with a page_to_phys and page_to_bus here.
-	 */
-	virt = page_address(page);
-	*dma_handle = virt_to_bus(virt);
-	ret = __ioremap(virt_to_phys(virt), size, 0);
+	*dma_handle = page_to_bus(page);
+	ret = __ioremap(page_to_phys(page), size, 0);
 	if (!ret)
 		goto no_remap;
 
 #if 0 /* ioremap_does_flush_cache_all */
+	{
+		void *virt = page_address(page);
+
 		/*
 		 * we need to ensure that there are no cachelines in use, or
 		 * worse dirty in this area.  Really, we don't need to do
 		 * this since __ioremap does a flush_cache_all() anyway. --rmk
 		 */
 		invalidate_dcache_range(virt, virt + size);
+	}
 #endif
 
 	/*
@@ -72,7 +75,6 @@ void *consistent_alloc(int gfp, size_t size, dma_addr_t *dma_handle)
 	 * We also mark the pages in use as reserved so that
 	 * remap_page_range works.
 	 */
-	page = virt_to_page(virt);
 	free = page + (size >> PAGE_SHIFT);
 	end  = page + (1 << order);
 
@@ -93,18 +95,12 @@ void *consistent_alloc(int gfp, size_t size, dma_addr_t *dma_handle)
 
 void *pci_alloc_consistent(struct pci_dev *hwdev, size_t size, dma_addr_t *handle)
 {
-	void *__ret;
-	int __gfp = GFP_KERNEL;
+	int gfp = GFP_KERNEL;
 
-#ifdef CONFIG_PCI
-	if ((hwdev) == NULL ||
-	    (hwdev)->dma_mask != 0xffffffff)
-#endif
-		__gfp |= GFP_DMA;
+	if (hwdev == NULL || hwdev->dma_mask != 0xffffffff)
+		gfp |= GFP_DMA;
 
-	__ret = consistent_alloc(__gfp, (size),
-				 (handle));
-	return __ret;
+	return consistent_alloc(gfp, size, handle);
 }
 
 /*
@@ -114,19 +110,16 @@ void *pci_alloc_consistent(struct pci_dev *hwdev, size_t size, dma_addr_t *handl
 void consistent_free(void *vaddr, size_t size, dma_addr_t handle)
 {
 	struct page *page, *end;
-	void *virt;
 
 	if (in_interrupt())
 		BUG();
 
-	virt = bus_to_virt(handle);
-
 	/*
 	 * More messing around with the MM internals.  This is
 	 * sick, but then so is remap_page_range().
 	 */
 	size = PAGE_ALIGN(size);
-	page = virt_to_page(virt);
+	page = virt_to_page(bus_to_virt(handle));
 	end = page + (size >> PAGE_SHIFT);
 
 	for (; page < end; page++)

include/asm-arm/io.h

@@ -22,6 +22,7 @@
 
 #ifdef __KERNEL__
 
+#include <linux/config.h>
 #include <linux/types.h>
 #include <asm/byteorder.h>
 #include <asm/memory.h>
@@ -269,13 +270,22 @@ extern void consistent_free(void *vaddr, size_t size, dma_addr_t handle);
 extern void consistent_sync(void *vaddr, size_t size, int rw);
 
 /*
- * FIXME: I'm sure these will need to be changed for DISCONTIG
+ * Change "struct page" to physical address.
  */
+#ifdef CONFIG_DISCONTIG
+#define page_to_phys(page)					  \
+	((((page) - page_zone(page)->zone_mem_map) << PAGE_SHIFT) \
+		  + page_zone(page)->zone_start_paddr)
+#else
+#define page_to_phys(page)					  \
+	(PHYS_OFFSET + (((page) - mem_map) << PAGE_SHIFT))
+#endif
+
 /*
- * Change "struct page" to physical address.
+ * We should really eliminate virt_to_bus() here - it's depreciated.
  */
-#define page_to_phys(page)	(PHYS_OFFSET + ((page - mem_map) << PAGE_SHIFT))
-#define page_to_bus(page)	(PHYS_OFFSET + ((page - mem_map) << PAGE_SHIFT))
+#define page_to_bus(page)					  \
+	(virt_to_bus(page_address(page)))
 
 /*
  * can the hardware map this into one segment or not, given no other