microblaze: Preliminary support for dma drivers

I found several problems for ll_temac driver and on system with WB.
This early fix should fix it. I will clean this patch before I will add
it to mainline
Signed-off-by: Michal Simek <monstr@monstr.eu>

arch/microblaze/include/asm/io.h

@@ -140,9 +140,6 @@ static inline void writel(unsigned int v, volatile void __iomem *addr)
 #define virt_to_phys(addr)	((unsigned long)__virt_to_phys(addr))
 #define virt_to_bus(addr)	((unsigned long)__virt_to_phys(addr))
 
-#define __page_address(page) \
-		(PAGE_OFFSET + (((page) - mem_map) << PAGE_SHIFT))
-#define page_to_phys(page)	virt_to_phys((void *)__page_address(page))
 #define page_to_bus(page)	(page_to_phys(page))
 #define bus_to_virt(addr)	(phys_to_virt(addr))
 

arch/microblaze/include/asm/page.h

@@ -61,12 +61,6 @@ extern unsigned int __page_offset;
  */
 #define PAGE_OFFSET	CONFIG_KERNEL_START
 
-/*
- * MAP_NR -- given an address, calculate the index of the page struct which
- * points to the address's page.
- */
-#define MAP_NR(addr) (((unsigned long)(addr) - PAGE_OFFSET) >> PAGE_SHIFT)
-
 /*
  * The basic type of a PTE - 32 bit physical addressing.
  */
@@ -154,7 +148,11 @@ extern int page_is_ram(unsigned long pfn);
 # define pfn_to_virt(pfn)	__va(pfn_to_phys((pfn)))
 
 #  ifdef CONFIG_MMU
-#  define virt_to_page(kaddr) 	(mem_map +  MAP_NR(kaddr))
+
+#  define virt_to_page(kaddr)	(pfn_to_page(__pa(kaddr) >> PAGE_SHIFT))
+#  define page_to_virt(page)   __va(page_to_pfn(page) << PAGE_SHIFT)
+#  define page_to_phys(page)     (page_to_pfn(page) << PAGE_SHIFT)
+
 #  else /* CONFIG_MMU */
 #  define virt_to_page(vaddr)	(pfn_to_page(virt_to_pfn(vaddr)))
 #  define page_to_virt(page)	(pfn_to_virt(page_to_pfn(page)))

arch/microblaze/kernel/dma.c

@@ -21,10 +21,10 @@
  * default the offset is PCI_DRAM_OFFSET.
  */
 
-static inline void __dma_sync_page(void *vaddr, unsigned long offset,
+static inline void __dma_sync_page(void *paddr, unsigned long offset,
 				size_t size, enum dma_data_direction direction)
 {
-	unsigned long start = virt_to_phys(vaddr);
+	unsigned long start = (unsigned long)paddr;
 
 	switch (direction) {
 	case DMA_TO_DEVICE:
@@ -79,10 +79,12 @@ static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
 	struct scatterlist *sg;
 	int i;
 
+	/* FIXME this part of code is untested */
 	for_each_sg(sgl, sg, nents, i) {
 		sg->dma_address = sg_phys(sg) + get_dma_direct_offset(dev);
 		sg->dma_length = sg->length;
-		__dma_sync_page(sg_page(sg), sg->offset, sg->length, direction);
+		__dma_sync_page(page_to_phys(sg_page(sg)), sg->offset,
+							sg->length, direction);
 	}
 
 	return nents;
@@ -107,7 +109,7 @@ static inline dma_addr_t dma_direct_map_page(struct device *dev,
 					     struct dma_attrs *attrs)
 {
 	BUG_ON(direction == DMA_NONE);
-	__dma_sync_page(page, offset, size, direction);
+	__dma_sync_page(page_to_phys(page), offset, size, direction);
 	return page_to_phys(page) + offset + get_dma_direct_offset(dev);
 }
 
@@ -117,8 +119,12 @@ static inline void dma_direct_unmap_page(struct device *dev,
 					 enum dma_data_direction direction,
 					 struct dma_attrs *attrs)
 {
-/* There is not necessary to do cache cleanup */
-	/* __dma_sync_page(dma_address, 0 , size, direction); */
+/* There is not necessary to do cache cleanup
+ *
+ * phys_to_virt is here because in __dma_sync_page is __virt_to_phys and
+ * dma_address is physical address
+ */
+	__dma_sync_page((void *)dma_address, 0 , size, direction);
 }
 
 struct dma_map_ops dma_direct_ops = {