From a5d7ac30fa9ffa923e3603309692a36e3b3b3ae1 Mon Sep 17 00:00:00 2001 From: Carlo Caione Date: Wed, 4 Feb 2015 10:23:19 +0100 Subject: [PATCH] drm/exynos: fix DMA_ATTR_NO_KERNEL_MAPPING usage 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 Acked-by: Marek Szyprowski Acked-by: Joonyoung Shim Signed-off-by: Inki Dae --- drivers/gpu/drm/exynos/exynos_drm_buf.c | 6 ++--- drivers/gpu/drm/exynos/exynos_drm_fbdev.c | 29 +++++++---------------- drivers/gpu/drm/exynos/exynos_drm_gem.h | 2 ++ 3 files changed, 14 insertions(+), 23 deletions(-) diff --git a/drivers/gpu/drm/exynos/exynos_drm_buf.c b/drivers/gpu/drm/exynos/exynos_drm_buf.c index 9c8088462c26..24994ba10e28 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_buf.c +++ b/drivers/gpu/drm/exynos/exynos_drm_buf.c @@ -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 diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c index e12ea90c6237..84f8dfe1c5ec 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c +++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c @@ -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. */ + nr_pages = buffer->size >> PAGE_SHIFT; + + buffer->kvaddr = (void __iomem *) vmap(buffer->pages, + nr_pages, VM_MAP, + pgprot_writecombine(PAGE_KERNEL)); if (!buffer->kvaddr) { - if (is_drm_iommu_supported(dev)) { - unsigned int 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; - } + 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 */ diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.h b/drivers/gpu/drm/exynos/exynos_drm_gem.h index ec58fe9c40df..308173cb4f0a 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_gem.h +++ b/drivers/gpu/drm/exynos/exynos_drm_gem.h @@ -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; -- 2.39.2