[MIPS] Always use virt_to_phys() when translating kernel addresses

This patch fixes two places where we used plain 'x - PAGE_OFFSET' to
achieve virtual to physical address convertions. This type of convertion
is no more allowed since commit 6f284a2c.
Reported-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>

[Build fixes for machines that don't use the generic dma-coherence.h]
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/mm/dma-default.c

@@ -19,6 +19,13 @@
 
 #include <dma-coherence.h>
 
+static inline unsigned long dma_addr_to_virt(dma_addr_t dma_addr)
+{
+	unsigned long addr = plat_dma_addr_to_phys(dma_addr);
+
+	return (unsigned long)phys_to_virt(addr);
+}
+
 /*
  * Warning on the terminology - Linux calls an uncached area coherent;
  * MIPS terminology calls memory areas with hardware maintained coherency
@@ -140,7 +147,7 @@ void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
 	enum dma_data_direction direction)
 {
 	if (cpu_is_noncoherent_r10000(dev))
-		__dma_sync(plat_dma_addr_to_phys(dma_addr) + PAGE_OFFSET, size,
+		__dma_sync(dma_addr_to_virt(dma_addr), size,
 		           direction);
 
 	plat_unmap_dma_mem(dma_addr);
@@ -234,7 +241,7 @@ void dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
 	if (cpu_is_noncoherent_r10000(dev)) {
 		unsigned long addr;
 
-		addr = PAGE_OFFSET + plat_dma_addr_to_phys(dma_handle);
+		addr = dma_addr_to_virt(dma_handle);
 		__dma_sync(addr, size, direction);
 	}
 }
@@ -249,7 +256,7 @@ void dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle,
 	if (!plat_device_is_coherent(dev)) {
 		unsigned long addr;
 
-		addr = PAGE_OFFSET + plat_dma_addr_to_phys(dma_handle);
+		addr = dma_addr_to_virt(dma_handle);
 		__dma_sync(addr, size, direction);
 	}
 }
@@ -264,7 +271,7 @@ void dma_sync_single_range_for_cpu(struct device *dev, dma_addr_t dma_handle,
 	if (cpu_is_noncoherent_r10000(dev)) {
 		unsigned long addr;
 
-		addr = PAGE_OFFSET + plat_dma_addr_to_phys(dma_handle);
+		addr = dma_addr_to_virt(dma_handle);
 		__dma_sync(addr + offset, size, direction);
 	}
 }
@@ -279,7 +286,7 @@ void dma_sync_single_range_for_device(struct device *dev, dma_addr_t dma_handle,
 	if (!plat_device_is_coherent(dev)) {
 		unsigned long addr;
 
-		addr = PAGE_OFFSET + plat_dma_addr_to_phys(dma_handle);
+		addr = dma_addr_to_virt(dma_handle);
 		__dma_sync(addr + offset, size, direction);
 	}
 }

include/asm-mips/pgtable-64.h

@@ -199,7 +199,7 @@ static inline unsigned long pud_page_vaddr(pud_t pud)
 {
 	return pud_val(pud);
 }
-#define pud_phys(pud)		(pud_val(pud) - PAGE_OFFSET)
+#define pud_phys(pud)		virt_to_phys((void *)pud_val(pud))
 #define pud_page(pud)		(pfn_to_page(pud_phys(pud) >> PAGE_SHIFT))
 
 /* Find an entry in the second-level page table.. */

include/asm-mips/pgtable.h

@@ -75,7 +75,7 @@ extern void paging_init(void);
  * Conversion functions: convert a page and protection to a page entry,
  * and a page entry and page directory to the page they refer to.
  */
-#define pmd_phys(pmd)		(pmd_val(pmd) - PAGE_OFFSET)
+#define pmd_phys(pmd)		virt_to_phys((void *)pmd_val(pmd))
 #define pmd_page(pmd)		(pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
 #define pmd_page_vaddr(pmd)	pmd_val(pmd)