dma-coherent: remove the DMA_MEMORY_MAP and DMA_MEMORY_IO flags

DMA_MEMORY_IO was never used in the tree, so remove it.  That means there is
no need for the DMA_MEMORY_MAP flag either now, so remove it as well and
change dma_declare_coherent_memory to return a normal errno value.

Signed-off-by: Christoph Hellwig <hch@lst.de>
 Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>

Documentation/DMA-API.txt

@@ -592,30 +592,11 @@ size is the size of the area (must be multiples of PAGE_SIZE).
 
 flags can be ORed together and are:
 
-- DMA_MEMORY_MAP - request that the memory returned from
-  dma_alloc_coherent() be directly writable.
-
-- DMA_MEMORY_IO - request that the memory returned from
-  dma_alloc_coherent() be addressable using read()/write()/memcpy_toio() etc.
-
-One or both of these flags must be present.
-
 - DMA_MEMORY_EXCLUSIVE - only allocate memory from the declared regions.
   Do not allow dma_alloc_coherent() to fall back to system memory when
   it's out of memory in the declared region.
 
-The return value will be either DMA_MEMORY_MAP or DMA_MEMORY_IO and
-must correspond to a passed in flag (i.e. no returning DMA_MEMORY_IO
-if only DMA_MEMORY_MAP were passed in) for success or zero for
-failure.
-
-Note, for DMA_MEMORY_IO returns, all subsequent memory returned by
-dma_alloc_coherent() may no longer be accessed directly, but instead
-must be accessed using the correct bus functions.  If your driver
-isn't prepared to handle this contingency, it should not specify
-DMA_MEMORY_IO in the input flags.
-
-As a simplification for the platforms, only **one** such region of
+As a simplification for the platforms, only *one* such region of
 memory may be declared per device.
 
 For reasons of efficiency, most platforms choose to track the declared

arch/arm/mach-imx/mach-imx27_visstrim_m10.c

@@ -245,7 +245,6 @@ static phys_addr_t mx2_camera_base __initdata;
 static void __init visstrim_analog_camera_init(void)
 {
 	struct platform_device *pdev;
-	int dma;
 
 	gpio_set_value(TVP5150_PWDN, 1);
 	ndelay(1);
@@ -258,12 +257,9 @@ static void __init visstrim_analog_camera_init(void)
 	if (IS_ERR(pdev))
 		return;
 
-	dma = dma_declare_coherent_memory(&pdev->dev,
-				mx2_camera_base, mx2_camera_base,
-				MX2_CAMERA_BUF_SIZE,
-				DMA_MEMORY_MAP | DMA_MEMORY_EXCLUSIVE);
-	if (!(dma & DMA_MEMORY_MAP))
-		return;
+	dma_declare_coherent_memory(&pdev->dev, mx2_camera_base,
+				    mx2_camera_base, MX2_CAMERA_BUF_SIZE,
+				    DMA_MEMORY_EXCLUSIVE);
 }
 
 static void __init visstrim_reserve(void)
@@ -444,16 +440,13 @@ static const struct imx_ssi_platform_data visstrim_m10_ssi_pdata __initconst = {
 static void __init visstrim_coda_init(void)
 {
 	struct platform_device *pdev;
-	int dma;
 
 	pdev = imx27_add_coda();
-	dma = dma_declare_coherent_memory(&pdev->dev,
-					  mx2_camera_base + MX2_CAMERA_BUF_SIZE,
-					  mx2_camera_base + MX2_CAMERA_BUF_SIZE,
-					  MX2_CAMERA_BUF_SIZE,
-					  DMA_MEMORY_MAP | DMA_MEMORY_EXCLUSIVE);
-	if (!(dma & DMA_MEMORY_MAP))
-		return;
+	dma_declare_coherent_memory(&pdev->dev,
+				    mx2_camera_base + MX2_CAMERA_BUF_SIZE,
+				    mx2_camera_base + MX2_CAMERA_BUF_SIZE,
+				    MX2_CAMERA_BUF_SIZE,
+				    DMA_MEMORY_EXCLUSIVE);
 }
 
 /* DMA deinterlace */
@@ -466,24 +459,21 @@ static void __init visstrim_deinterlace_init(void)
 {
 	int ret = -ENOMEM;
 	struct platform_device *pdev = &visstrim_deinterlace;
-	int dma;
 
 	ret = platform_device_register(pdev);
 
-	dma = dma_declare_coherent_memory(&pdev->dev,
-					  mx2_camera_base + 2 * MX2_CAMERA_BUF_SIZE,
-					  mx2_camera_base + 2 * MX2_CAMERA_BUF_SIZE,
-					  MX2_CAMERA_BUF_SIZE,
-					  DMA_MEMORY_MAP | DMA_MEMORY_EXCLUSIVE);
-	if (!(dma & DMA_MEMORY_MAP))
-		return;
+	dma_declare_coherent_memory(&pdev->dev,
+				    mx2_camera_base + 2 * MX2_CAMERA_BUF_SIZE,
+				    mx2_camera_base + 2 * MX2_CAMERA_BUF_SIZE,
+				    MX2_CAMERA_BUF_SIZE,
+				    DMA_MEMORY_EXCLUSIVE);
 }
 
 /* Emma-PrP for format conversion */
 static void __init visstrim_emmaprp_init(void)
 {
 	struct platform_device *pdev;
-	int dma;
+	int ret;
 
 	pdev = imx27_add_mx2_emmaprp();
 	if (IS_ERR(pdev))
@@ -493,11 +483,11 @@ static void __init visstrim_emmaprp_init(void)
 	 * Use the same memory area as the analog camera since both
 	 * devices are, by nature, exclusive.
 	 */
-	dma = dma_declare_coherent_memory(&pdev->dev,
+	ret = dma_declare_coherent_memory(&pdev->dev,
 				mx2_camera_base, mx2_camera_base,
 				MX2_CAMERA_BUF_SIZE,
-				DMA_MEMORY_MAP | DMA_MEMORY_EXCLUSIVE);
-	if (!(dma & DMA_MEMORY_MAP))
+				DMA_MEMORY_EXCLUSIVE);
+	if (ret)
 		pr_err("Failed to declare memory for emmaprp\n");
 }
 

arch/arm/mach-imx/mach-mx31moboard.c

@@ -475,7 +475,7 @@ static phys_addr_t mx3_camera_base __initdata;
 
 static int __init mx31moboard_init_cam(void)
 {
-	int dma, ret = -ENOMEM;
+	int dma, ret;
 	struct platform_device *pdev;
 
 	imx31_add_ipu_core();
@@ -484,11 +484,11 @@ static int __init mx31moboard_init_cam(void)
 	if (IS_ERR(pdev))
 		return PTR_ERR(pdev);
 
-	dma = dma_declare_coherent_memory(&pdev->dev,
-					mx3_camera_base, mx3_camera_base,
-					MX3_CAMERA_BUF_SIZE,
-					DMA_MEMORY_MAP | DMA_MEMORY_EXCLUSIVE);
-	if (!(dma & DMA_MEMORY_MAP))
+	ret = dma_declare_coherent_memory(&pdev->dev,
+					  mx3_camera_base, mx3_camera_base,
+					  MX3_CAMERA_BUF_SIZE,
+					  DMA_MEMORY_EXCLUSIVE);
+	if (ret)
 		goto err;
 
 	ret = platform_device_add(pdev);

arch/sh/drivers/pci/fixups-dreamcast.c

@@ -63,11 +63,10 @@ static void gapspci_fixup_resources(struct pci_dev *dev)
 		res.end = GAPSPCI_DMA_BASE + GAPSPCI_DMA_SIZE - 1;
 		res.flags = IORESOURCE_MEM;
 		pcibios_resource_to_bus(dev->bus, &region, &res);
-		BUG_ON(!dma_declare_coherent_memory(&dev->dev,
+		BUG_ON(dma_declare_coherent_memory(&dev->dev,
 						res.start,
 						region.start,
 						resource_size(&res),
-						DMA_MEMORY_MAP |
 						DMA_MEMORY_EXCLUSIVE));
 		break;
 	default:

drivers/base/dma-coherent.c

@@ -46,15 +46,10 @@ static bool dma_init_coherent_memory(
 	int pages = size >> PAGE_SHIFT;
 	int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
 
-	if ((flags & (DMA_MEMORY_MAP | DMA_MEMORY_IO)) == 0)
-		goto out;
 	if (!size)
 		goto out;
 
-	if (flags & DMA_MEMORY_MAP)
-		mem_base = memremap(phys_addr, size, MEMREMAP_WC);
-	else
-		mem_base = ioremap(phys_addr, size);
+	mem_base = memremap(phys_addr, size, MEMREMAP_WC);
 	if (!mem_base)
 		goto out;
 
@@ -77,12 +72,8 @@ static bool dma_init_coherent_memory(
 
 out:
 	kfree(dma_mem);
-	if (mem_base) {
-		if (flags & DMA_MEMORY_MAP)
-			memunmap(mem_base);
-		else
-			iounmap(mem_base);
-	}
+	if (mem_base)
+		memunmap(mem_base);
 	return false;
 }
 
@@ -91,10 +82,7 @@ static void dma_release_coherent_memory(struct dma_coherent_mem *mem)
 	if (!mem)
 		return;
 
-	if (mem->flags & DMA_MEMORY_MAP)
-		memunmap(mem->virt_base);
-	else
-		iounmap(mem->virt_base);
+	memunmap(mem->virt_base);
 	kfree(mem->bitmap);
 	kfree(mem);
 }
@@ -116,16 +104,16 @@ int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
 				dma_addr_t device_addr, size_t size, int flags)
 {
 	struct dma_coherent_mem *mem;
+	int ret;
 
-	if (!dma_init_coherent_memory(phys_addr, device_addr, size, flags,
-				      &mem))
-		return 0;
-
-	if (dma_assign_coherent_memory(dev, mem) == 0)
-		return flags & DMA_MEMORY_MAP ? DMA_MEMORY_MAP : DMA_MEMORY_IO;
+	ret = dma_init_coherent_memory(phys_addr, device_addr, size, flags, &mem);
+	if (ret)
+		return ret;
 
-	dma_release_coherent_memory(mem);
-	return 0;
+	ret = dma_assign_coherent_memory(dev, mem);
+	if (ret)
+		dma_release_coherent_memory(mem);
+	return ret;
 }
 EXPORT_SYMBOL(dma_declare_coherent_memory);
 
@@ -186,15 +174,9 @@ static void *__dma_alloc_from_coherent(struct dma_coherent_mem *mem,
 	 */
 	*dma_handle = mem->device_base + (pageno << PAGE_SHIFT);
 	ret = mem->virt_base + (pageno << PAGE_SHIFT);
-	dma_memory_map = (mem->flags & DMA_MEMORY_MAP);
 	spin_unlock_irqrestore(&mem->spinlock, flags);
-	if (dma_memory_map)
-		memset(ret, 0, size);
-	else
-		memset_io(ret, 0, size);
-
+	memset(ret, 0, size);
 	return ret;
-
 err:
 	spin_unlock_irqrestore(&mem->spinlock, flags);
 	return NULL;
@@ -360,7 +342,7 @@ static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev)
 
 	if (!mem &&
 	    !dma_init_coherent_memory(rmem->base, rmem->base, rmem->size,
-				      DMA_MEMORY_MAP | DMA_MEMORY_EXCLUSIVE,
+				      DMA_MEMORY_EXCLUSIVE,
 				      &mem)) {
 		pr_err("Reserved memory: failed to init DMA memory pool at %pa, size %ld MiB\n",
 			&rmem->base, (unsigned long)rmem->size / SZ_1M);

drivers/base/dma-mapping.c

@@ -176,13 +176,10 @@ int dmam_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
 
 	rc = dma_declare_coherent_memory(dev, phys_addr, device_addr, size,
 					 flags);
-	if (rc) {
+	if (!rc)
 		devres_add(dev, res);
-		rc = 0;
-	} else {
+	else
 		devres_free(res);
-		rc = -ENOMEM;
-	}
 
 	return rc;
 }

drivers/media/platform/soc_camera/sh_mobile_ceu_camera.c

@@ -1708,11 +1708,10 @@ static int sh_mobile_ceu_probe(struct platform_device *pdev)
 		err = dma_declare_coherent_memory(&pdev->dev, res->start,
 						  res->start,
 						  resource_size(res),
-						  DMA_MEMORY_MAP |
 						  DMA_MEMORY_EXCLUSIVE);
-		if (!err) {
+		if (err) {
 			dev_err(&pdev->dev, "Unable to declare CEU memory.\n");
-			return -ENXIO;
+			return err;
 		}
 
 		pcdev->video_limit = resource_size(res);

drivers/scsi/NCR_Q720.c

@@ -217,8 +217,7 @@ NCR_Q720_probe(struct device *dev)
 	}
 
 	if (dma_declare_coherent_memory(dev, base_addr, base_addr,
-					mem_size, DMA_MEMORY_MAP)
-	    != DMA_MEMORY_MAP) {
+					mem_size, 0)) {
 		printk(KERN_ERR "NCR_Q720: DMA declare memory failed\n");
 		goto out_release_region;
 	}

drivers/usb/host/ohci-sm501.c

@@ -123,13 +123,12 @@ static int ohci_hcd_sm501_drv_probe(struct platform_device *pdev)
 	 * regular memory. The HCD_LOCAL_MEM flag does just that.
 	 */
 
-	if (!dma_declare_coherent_memory(dev, mem->start,
+	retval = dma_declare_coherent_memory(dev, mem->start,
 					 mem->start - mem->parent->start,
 					 resource_size(mem),
-					 DMA_MEMORY_MAP |
-					 DMA_MEMORY_EXCLUSIVE)) {
+					 DMA_MEMORY_EXCLUSIVE);
+	if (retval) {
 		dev_err(dev, "cannot declare coherent memory\n");
-		retval = -ENXIO;
 		goto err1;
 	}
 

drivers/usb/host/ohci-tmio.c

@@ -227,13 +227,10 @@ static int ohci_hcd_tmio_drv_probe(struct platform_device *dev)
 		goto err_ioremap_regs;
 	}
 
-	if (!dma_declare_coherent_memory(&dev->dev, sram->start,
-				sram->start,
-				resource_size(sram),
-				DMA_MEMORY_MAP | DMA_MEMORY_EXCLUSIVE)) {
-		ret = -EBUSY;
+	ret = dma_declare_coherent_memory(&dev->dev, sram->start, sram->start,
+				resource_size(sram), DMA_MEMORY_EXCLUSIVE);
+	if (ret)
 		goto err_dma_declare;
-	}
 
 	if (cell->enable) {
 		ret = cell->enable(dev);

include/linux/dma-mapping.h

@@ -694,9 +694,7 @@ static inline int dma_get_cache_alignment(void)
 #endif
 
 /* flags for the coherent memory api */
-#define	DMA_MEMORY_MAP			0x01
-#define DMA_MEMORY_IO			0x02
-#define DMA_MEMORY_EXCLUSIVE		0x04
+#define DMA_MEMORY_EXCLUSIVE		0x01
 
 #ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT
 int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
@@ -709,7 +707,7 @@ static inline int
 dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
 			    dma_addr_t device_addr, size_t size, int flags)
 {
-	return 0;
+	return -ENOSYS;
 }
 
 static inline void