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>

11 files changed, 52 insertions, 111 deletions

diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt
index dddf52e768d6..ac66ae2509a9 100644
--- a/Documentation/DMA-API.txt
+++ b/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
diff --git a/arch/arm/mach-imx/mach-imx27_visstrim_m10.c b/arch/arm/mach-imx/mach-imx27_visstrim_m10.c
index dd75a4756761..5169dfba9718 100644
--- a/arch/arm/mach-imx/mach-imx27_visstrim_m10.c
+++ b/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");
 }
 
diff --git a/arch/arm/mach-imx/mach-mx31moboard.c b/arch/arm/mach-imx/mach-mx31moboard.c
index bde9a9af6714..3cd030960c98 100644
--- a/arch/arm/mach-imx/mach-mx31moboard.c
+++ b/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);
diff --git a/arch/sh/drivers/pci/fixups-dreamcast.c b/arch/sh/drivers/pci/fixups-dreamcast.c
index 1d1c5a227e50..c931d5872ffe 100644
--- a/arch/sh/drivers/pci/fixups-dreamcast.c
+++ b/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:
diff --git a/drivers/base/dma-coherent.c b/drivers/base/dma-coherent.c
index 6f6dc4d41788..b275eeb739f1 100644
--- a/drivers/base/dma-coherent.c
+++ b/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);
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index b555ff9dd8fc..e584eddef0a7 100644
--- a/drivers/base/dma-mapping.c
+++ b/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;
 }
diff --git a/drivers/media/platform/soc_camera/sh_mobile_ceu_camera.c b/drivers/media/platform/soc_camera/sh_mobile_ceu_camera.c
index 96dc01750bc0..36762ec954e7 100644
--- a/drivers/media/platform/soc_camera/sh_mobile_ceu_camera.c
+++ b/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);
diff --git a/drivers/scsi/NCR_Q720.c b/drivers/scsi/NCR_Q720.c
index 05835bf1bf9c..54e7d26908ee 100644
--- a/drivers/scsi/NCR_Q720.c
+++ b/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;
         }
diff --git a/drivers/usb/host/ohci-sm501.c b/drivers/usb/host/ohci-sm501.c
index a8b8d8b8d9f3..d4e0f7cd96fa 100644
--- a/drivers/usb/host/ohci-sm501.c
+++ b/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;
         }
 
diff --git a/drivers/usb/host/ohci-tmio.c b/drivers/usb/host/ohci-tmio.c
index cfcfadfc94fc..16d081a093bb 100644
--- a/drivers/usb/host/ohci-tmio.c
+++ b/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);
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index abf369b11f54..b7dd11c02a45 100644
--- a/include/linux/dma-mapping.h
+++ b/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