X-Git-Url: http://git.cascardo.info/?a=blobdiff_plain;f=arch%2Farc%2Fmm%2Fdma.c;h=608c143e9d382e7737b0e317c68fdba1048fbf54;hb=f5db19e93f680160a0fb3e2b05ceb4832b24d486;hp=01eaf88bf821398fecb19dae6780e6702242ff64;hpb=f11aec0d7c835c3b83e74e3fd60d2e48a850c857;p=cascardo%2Flinux.git

diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c
index 01eaf88bf821..608c143e9d38 100644
--- a/arch/arc/mm/dma.c
+++ b/arch/arc/mm/dma.c
@@ -24,22 +24,22 @@
 static void *arc_dma_alloc(struct device *dev, size_t size,
 		dma_addr_t *dma_handle, gfp_t gfp, struct dma_attrs *attrs)
 {
-	void *paddr, *kvaddr;
-
-	/* This is linear addr (0x8000_0000 based) */
-	paddr = alloc_pages_exact(size, gfp);
-	if (!paddr)
+	unsigned long order = get_order(size);
+	struct page *page;
+	phys_addr_t paddr;
+	void *kvaddr;
+	int need_coh = 1, need_kvaddr = 0;
+
+	page = alloc_pages(gfp, order);
+	if (!page)
 		return NULL;
 
-	/* This is bus address, platform dependent */
-	*dma_handle = (dma_addr_t)paddr;
-
 	/*
 	 * IOC relies on all data (even coherent DMA data) being in cache
 	 * Thus allocate normal cached memory
 	 *
 	 * The gains with IOC are two pronged:
-	 *   -For streaming data, elides needs for cache maintenance, saving
+	 *   -For streaming data, elides need for cache maintenance, saving
 	 *    cycles in flush code, and bus bandwidth as all the lines of a
 	 *    buffer need to be flushed out to memory
 	 *   -For coherent data, Read/Write to buffers terminate early in cache
@@ -47,12 +47,32 @@ static void *arc_dma_alloc(struct device *dev, size_t size,
 	 */
 	if ((is_isa_arcv2() && ioc_exists) ||
 	    dma_get_attr(DMA_ATTR_NON_CONSISTENT, attrs))
-		return paddr;
+		need_coh = 0;
+
+	/*
+	 * - A coherent buffer needs MMU mapping to enforce non-cachability
+	 * - A highmem page needs a virtual handle (hence MMU mapping)
+	 *   independent of cachability
+	 */
+	if (PageHighMem(page) || need_coh)
+		need_kvaddr = 1;
+
+	/* This is linear addr (0x8000_0000 based) */
+	paddr = page_to_phys(page);
+
+	/* For now bus address is exactly same as paddr */
+	*dma_handle = paddr;
 
 	/* This is kernel Virtual address (0x7000_0000 based) */
-	kvaddr = ioremap_nocache((unsigned long)paddr, size);
-	if (kvaddr == NULL)
-		return NULL;
+	if (need_kvaddr) {
+		kvaddr = ioremap_nocache(paddr, size);
+		if (kvaddr == NULL) {
+			__free_pages(page, order);
+			return NULL;
+		}
+	} else {
+		kvaddr = (void *)(u32)paddr;
+	}
 
 	/*
 	 * Evict any existing L1 and/or L2 lines for the backing page
@@ -64,7 +84,8 @@ static void *arc_dma_alloc(struct device *dev, size_t size,
 	 * Currently flush_cache_vmap nukes the L1 cache completely which
 	 * will be optimized as a separate commit
 	 */
-	dma_cache_wback_inv((unsigned long)paddr, size);
+	if (need_coh)
+		dma_cache_wback_inv(paddr, size);
 
 	return kvaddr;
 }
@@ -72,11 +93,16 @@ static void *arc_dma_alloc(struct device *dev, size_t size,
 static void arc_dma_free(struct device *dev, size_t size, void *vaddr,
 		dma_addr_t dma_handle, struct dma_attrs *attrs)
 {
-	if (!dma_get_attr(DMA_ATTR_NON_CONSISTENT, attrs) &&
-	    !(is_isa_arcv2() && ioc_exists))
+	struct page *page = virt_to_page(dma_handle);
+	int is_non_coh = 1;
+
+	is_non_coh = dma_get_attr(DMA_ATTR_NON_CONSISTENT, attrs) ||
+			(is_isa_arcv2() && ioc_exists);
+
+	if (PageHighMem(page) || !is_non_coh)
 		iounmap((void __force __iomem *)vaddr);
 
-	free_pages_exact((void *)dma_handle, size);
+	__free_pages(page, get_order(size));
 }
 
 /*
@@ -84,7 +110,7 @@ static void arc_dma_free(struct device *dev, size_t size, void *vaddr,
  * CPU accesses page via normal paddr, thus needs to explicitly made
  * consistent before each use
  */
-static void _dma_cache_sync(unsigned long paddr, size_t size,
+static void _dma_cache_sync(phys_addr_t paddr, size_t size,
 		enum dma_data_direction dir)
 {
 	switch (dir) {
@@ -98,7 +124,7 @@ static void _dma_cache_sync(unsigned long paddr, size_t size,
 		dma_cache_wback_inv(paddr, size);
 		break;
 	default:
-		pr_err("Invalid DMA dir [%d] for OP @ %lx\n", dir, paddr);
+		pr_err("Invalid DMA dir [%d] for OP @ %pa[p]\n", dir, &paddr);
 	}
 }
 
@@ -106,7 +132,7 @@ static dma_addr_t arc_dma_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 paddr = page_to_phys(page) + offset;
+	phys_addr_t paddr = page_to_phys(page) + offset;
 	_dma_cache_sync(paddr, size, dir);
 	return (dma_addr_t)paddr;
 }
@@ -144,7 +170,7 @@ static void arc_dma_sync_sg_for_cpu(struct device *dev,
 	struct scatterlist *sg;
 
 	for_each_sg(sglist, sg, nelems, i)
-		_dma_cache_sync((unsigned int)sg_virt(sg), sg->length, dir);
+		_dma_cache_sync(sg_phys(sg), sg->length, dir);
 }
 
 static void arc_dma_sync_sg_for_device(struct device *dev,
@@ -155,7 +181,7 @@ static void arc_dma_sync_sg_for_device(struct device *dev,
 	struct scatterlist *sg;
 
 	for_each_sg(sglist, sg, nelems, i)
-		_dma_cache_sync((unsigned int)sg_virt(sg), sg->length, dir);
+		_dma_cache_sync(sg_phys(sg), sg->length, dir);
 }
 
 static int arc_dma_supported(struct device *dev, u64 dma_mask)