[PATCH 2/2] dma-coherent: remove the DMA_MEMORY_MAP and DMA_MEMORY_IO flags

Christoph Hellwig
2017-08-26T07:27:08Z

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>
---
Documentation/DMA-API.txt | 21 +---------
arch/arm/mach-imx/mach-imx27_visstrim_m10.c | 43 +++++++-------------
arch/arm/mach-imx/mach-mx31moboard.c | 12 +++---
arch/sh/drivers/pci/fixups-dreamcast.c | 3 +-
drivers/base/dma-coherent.c | 46 +++++++---------------
drivers/base/dma-mapping.c | 7 +---
.../platform/soc_camera/sh_mobile_ceu_camera.c | 5 +--
drivers/scsi/NCR_Q720.c | 3 +-
drivers/usb/host/ohci-sm501.c | 7 ++--
drivers/usb/host/ohci-tmio.c | 9 ++---
include/linux/dma-mapping.h | 6 +--
11 files changed, 50 insertions(+), 112 deletions(-)

diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt
index ded50aed1cd8..da58585c7b3a 100644
--- a/Documentation/DMA-API.txt
+++ b/Documentation/DMA-API.txt
@@ -590,30 +590,11 @@ 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..c2818af18c55 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 +459,20 @@ 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;

pdev = imx27_add_mx2_emmaprp();
if (IS_ERR(pdev))
@@ -493,12 +482,10 @@ 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,
+ 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))
- pr_err("Failed to declare memory for emmaprp\n");
+ DMA_MEMORY_EXCLUSIVE);
}

/* Audio */
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 9b12cb255063..92f7d84e51f5 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -708,9 +708,7 @@ 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,
@@ -723,7 +721,7 @@ 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 -EINVAL;
}

static inline void
--
2.11.0