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Code Issues Releases Wiki Activity

drm/exynos: fix DMA_ATTR_NO_KERNEL_MAPPING usage

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The Exynos DRM driver doesn't follow the correct API when dealing with
dma_{alloc, mmap, free}_attrs functions and the
DMA_ATTR_NO_KERNEL_MAPPING attribute.

When a IOMMU is not available and the DMA_ATTR_NO_KERNEL_MAPPING is
used, the driver should use the pointer returned by dma_alloc_attr() as
a cookie.

The Exynos DRM driver directly uses the non-requested virtual kernel
address returned by the DMA mapping subsystem. This just works now
because the non-IOMMU codepath doesn't obey DMA_ATTR_NO_KERNEL_MAPPING
but we need to fix it before fixing the DMA layer.

Signed-off-by: Carlo Caione <carlo@caione.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
This commit is contained in:
Carlo Caione 2015-02-04 10:23:19 +01:00 committed by Inki Dae
parent 129046c6ec
commit a5d7ac30fa
3 changed files with 14 additions and 23 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
drivers/gpu/drm/exynos/exynos_drm_buf.c
View file

@ -63,11 +63,11 @@ static int lowlevel_buffer_allocate(struct drm_device *dev,
return -ENOMEM;
}
buf->kvaddr = (void __iomem *)dma_alloc_attrs(dev->dev,
buf->cookie = dma_alloc_attrs(dev->dev,
buf->size,
&buf->dma_addr, GFP_KERNEL,
&buf->dma_attrs);
if (!buf->kvaddr) {
if (!buf->cookie) {
DRM_ERROR("failed to allocate buffer.\n");
ret = -ENOMEM;
goto err_free;
@ -132,7 +132,7 @@ static void lowlevel_buffer_deallocate(struct drm_device *dev,
buf->sgt = NULL;
if (!is_drm_iommu_supported(dev)) {
dma_free_attrs(dev->dev, buf->size, buf->kvaddr,
dma_free_attrs(dev->dev, buf->size, buf->cookie,
(dma_addr_t)buf->dma_addr, &buf->dma_attrs);
drm_free_large(buf->pages);
} else

29
drivers/gpu/drm/exynos/exynos_drm_fbdev.c
View file

@ -79,9 +79,9 @@ static int exynos_drm_fbdev_update(struct drm_fb_helper *helper,
struct drm_framebuffer *fb)
{
struct fb_info *fbi = helper->fbdev;
struct drm_device *dev = helper->dev;
struct exynos_drm_gem_buf *buffer;
unsigned int size = fb->width * fb->height * (fb->bits_per_pixel >> 3);
unsigned int nr_pages;
unsigned long offset;
drm_fb_helper_fill_fix(fbi, fb->pitches[0], fb->depth);
@ -94,25 +94,14 @@ static int exynos_drm_fbdev_update(struct drm_fb_helper *helper,
return -EFAULT;
}
/* map pages with kernel virtual space. */
if (!buffer->kvaddr) {
if (is_drm_iommu_supported(dev)) {
unsigned int nr_pages = buffer->size >> PAGE_SHIFT;
nr_pages = buffer->size >> PAGE_SHIFT;
buffer->kvaddr = (void __iomem *) vmap(buffer->pages,
nr_pages, VM_MAP,
pgprot_writecombine(PAGE_KERNEL));
} else {
phys_addr_t dma_addr = buffer->dma_addr;
if (dma_addr)
buffer->kvaddr = (void __iomem *)phys_to_virt(dma_addr);
else
buffer->kvaddr = (void __iomem *)NULL;
}
if (!buffer->kvaddr) {
DRM_ERROR("failed to map pages to kernel space.\n");
return -EIO;
}
buffer->kvaddr = (void __iomem *) vmap(buffer->pages,
nr_pages, VM_MAP,
pgprot_writecombine(PAGE_KERNEL));
if (!buffer->kvaddr) {
DRM_ERROR("failed to map pages to kernel space.\n");
return -EIO;
}
/* buffer count to framebuffer always is 1 at booting time. */
@ -313,7 +302,7 @@ static void exynos_drm_fbdev_destroy(struct drm_device *dev,
struct exynos_drm_gem_obj *exynos_gem_obj = exynos_fbd->exynos_gem_obj;
struct drm_framebuffer *fb;
if (is_drm_iommu_supported(dev) && exynos_gem_obj->buffer->kvaddr)
if (exynos_gem_obj->buffer->kvaddr)
vunmap(exynos_gem_obj->buffer->kvaddr);
/* release drm framebuffer and real buffer */

2
drivers/gpu/drm/exynos/exynos_drm_gem.h
View file

@ -22,6 +22,7 @@
/*
* exynos drm gem buffer structure.
*
* @cookie: cookie returned by dma_alloc_attrs
* @kvaddr: kernel virtual address to allocated memory region.
* *userptr: user space address.
* @dma_addr: bus address(accessed by dma) to allocated memory region.
@ -35,6 +36,7 @@
* VM_PFNMAP or not.
*/
struct exynos_drm_gem_buf {
void *cookie;
void __iomem *kvaddr;
unsigned long userptr;
dma_addr_t dma_addr;