20. 4. 7. 오후 10:42에 Marek Szyprowski 이(가) 쓴 글:
> Internal pages array and scatter-list for them is not really needed for
> anything. FBDev emulation can simply rely on the DMA-mapping framework
> to create a proper kernel mapping for the buffer, while all other buffer
> use cases don't really need that array at all.
Picked it up.
Thanks,
Inki Dae
>
> Suggested-by: Christian König <christian.koenig@xxxxxxx>
> Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> ---
> drivers/gpu/drm/exynos/exynos_drm_fbdev.c | 28 +----
> drivers/gpu/drm/exynos/exynos_drm_gem.c | 124 +++++++---------------
> drivers/gpu/drm/exynos/exynos_drm_gem.h | 13 +--
> 3 files changed, 42 insertions(+), 123 deletions(-)
>
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> index e6ceaf36fb04..56a2b47e1af7 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> @@ -76,7 +76,6 @@ static int exynos_drm_fbdev_update(struct drm_fb_helper *helper,
> struct fb_info *fbi;
> struct drm_framebuffer *fb = helper->fb;
> unsigned int size = fb->width * fb->height * fb->format->cpp[0];
> - unsigned int nr_pages;
> unsigned long offset;
>
> fbi = drm_fb_helper_alloc_fbi(helper);
> @@ -90,16 +89,6 @@ static int exynos_drm_fbdev_update(struct drm_fb_helper *helper,
>
> drm_fb_helper_fill_info(fbi, helper, sizes);
>
> - nr_pages = exynos_gem->size >> PAGE_SHIFT;
> -
> - exynos_gem->kvaddr = (void __iomem *) vmap(exynos_gem->pages, nr_pages,
> - VM_MAP, pgprot_writecombine(PAGE_KERNEL));
> - if (!exynos_gem->kvaddr) {
> - DRM_DEV_ERROR(to_dma_dev(helper->dev),
> - "failed to map pages to kernel space.\n");
> - return -EIO;
> - }
> -
> offset = fbi->var.xoffset * fb->format->cpp[0];
> offset += fbi->var.yoffset * fb->pitches[0];
>
> @@ -133,18 +122,7 @@ static int exynos_drm_fbdev_create(struct drm_fb_helper *helper,
>
> size = mode_cmd.pitches[0] * mode_cmd.height;
>
> - exynos_gem = exynos_drm_gem_create(dev, EXYNOS_BO_CONTIG, size);
> - /*
> - * If physically contiguous memory allocation fails and if IOMMU is
> - * supported then try to get buffer from non physically contiguous
> - * memory area.
> - */
> - if (IS_ERR(exynos_gem) && is_drm_iommu_supported(dev)) {
> - dev_warn(dev->dev, "contiguous FB allocation failed, falling back to non-contiguous\n");
> - exynos_gem = exynos_drm_gem_create(dev, EXYNOS_BO_NONCONTIG,
> - size);
> - }
> -
> + exynos_gem = exynos_drm_gem_create(dev, EXYNOS_BO_WC, size, true);
> if (IS_ERR(exynos_gem))
> return PTR_ERR(exynos_gem);
>
> @@ -229,12 +207,8 @@ int exynos_drm_fbdev_init(struct drm_device *dev)
> static void exynos_drm_fbdev_destroy(struct drm_device *dev,
> struct drm_fb_helper *fb_helper)
> {
> - struct exynos_drm_fbdev *exynos_fbd = to_exynos_fbdev(fb_helper);
> - struct exynos_drm_gem *exynos_gem = exynos_fbd->exynos_gem;
> struct drm_framebuffer *fb;
>
> - vunmap(exynos_gem->kvaddr);
> -
> /* release drm framebuffer and real buffer */
> if (fb_helper->fb && fb_helper->fb->funcs) {
> fb = fb_helper->fb;
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c
> index 9d4e4d321bda..3c2732380517 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
> @@ -17,28 +17,23 @@
> #include "exynos_drm_drv.h"
> #include "exynos_drm_gem.h"
>
> -static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem)
> +static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem, bool kvmap)
> {
> struct drm_device *dev = exynos_gem->base.dev;
> - unsigned long attr;
> - unsigned int nr_pages;
> - struct sg_table sgt;
> - int ret = -ENOMEM;
> + unsigned long attr = 0;
>
> if (exynos_gem->dma_addr) {
> DRM_DEV_DEBUG_KMS(to_dma_dev(dev), "already allocated.\n");
> return 0;
> }
>
> - exynos_gem->dma_attrs = 0;
> -
> /*
> * if EXYNOS_BO_CONTIG, fully physically contiguous memory
> * region will be allocated else physically contiguous
> * as possible.
> */
> if (!(exynos_gem->flags & EXYNOS_BO_NONCONTIG))
> - exynos_gem->dma_attrs |= DMA_ATTR_FORCE_CONTIGUOUS;
> + attr |= DMA_ATTR_FORCE_CONTIGUOUS;
>
> /*
> * if EXYNOS_BO_WC or EXYNOS_BO_NONCACHABLE, writecombine mapping
> @@ -46,61 +41,29 @@ static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem)
> */
> if (exynos_gem->flags & EXYNOS_BO_WC ||
> !(exynos_gem->flags & EXYNOS_BO_CACHABLE))
> - attr = DMA_ATTR_WRITE_COMBINE;
> + attr |= DMA_ATTR_WRITE_COMBINE;
> else
> - attr = DMA_ATTR_NON_CONSISTENT;
> -
> - exynos_gem->dma_attrs |= attr;
> - exynos_gem->dma_attrs |= DMA_ATTR_NO_KERNEL_MAPPING;
> -
> - nr_pages = exynos_gem->size >> PAGE_SHIFT;
> + attr |= DMA_ATTR_NON_CONSISTENT;
>
> - exynos_gem->pages = kvmalloc_array(nr_pages, sizeof(struct page *),
> - GFP_KERNEL | __GFP_ZERO);
> - if (!exynos_gem->pages) {
> - DRM_DEV_ERROR(to_dma_dev(dev), "failed to allocate pages.\n");
> - return -ENOMEM;
> - }
> + /* FBDev emulation requires kernel mapping */
> + if (!kvmap)
> + attr |= DMA_ATTR_NO_KERNEL_MAPPING;
>
> + exynos_gem->dma_attrs = attr;
> exynos_gem->cookie = dma_alloc_attrs(to_dma_dev(dev), exynos_gem->size,
> &exynos_gem->dma_addr, GFP_KERNEL,
> exynos_gem->dma_attrs);
> if (!exynos_gem->cookie) {
> DRM_DEV_ERROR(to_dma_dev(dev), "failed to allocate buffer.\n");
> - goto err_free;
> - }
> -
> - ret = dma_get_sgtable_attrs(to_dma_dev(dev), &sgt, exynos_gem->cookie,
> - exynos_gem->dma_addr, exynos_gem->size,
> - exynos_gem->dma_attrs);
> - if (ret < 0) {
> - DRM_DEV_ERROR(to_dma_dev(dev), "failed to get sgtable.\n");
> - goto err_dma_free;
> - }
> -
> - if (drm_prime_sg_to_page_addr_arrays(&sgt, exynos_gem->pages, NULL,
> - nr_pages)) {
> - DRM_DEV_ERROR(to_dma_dev(dev), "invalid sgtable.\n");
> - ret = -EINVAL;
> - goto err_sgt_free;
> + return -ENOMEM;
> }
>
> - sg_free_table(&sgt);
> + if (kvmap)
> + exynos_gem->kvaddr = exynos_gem->cookie;
>
> DRM_DEV_DEBUG_KMS(to_dma_dev(dev), "dma_addr(0x%lx), size(0x%lx)\n",
> (unsigned long)exynos_gem->dma_addr, exynos_gem->size);
> -
> return 0;
> -
> -err_sgt_free:
> - sg_free_table(&sgt);
> -err_dma_free:
> - dma_free_attrs(to_dma_dev(dev), exynos_gem->size, exynos_gem->cookie,
> - exynos_gem->dma_addr, exynos_gem->dma_attrs);
> -err_free:
> - kvfree(exynos_gem->pages);
> -
> - return ret;
> }
>
> static void exynos_drm_free_buf(struct exynos_drm_gem *exynos_gem)
> @@ -118,8 +81,6 @@ static void exynos_drm_free_buf(struct exynos_drm_gem *exynos_gem)
> dma_free_attrs(to_dma_dev(dev), exynos_gem->size, exynos_gem->cookie,
> (dma_addr_t)exynos_gem->dma_addr,
> exynos_gem->dma_attrs);
> -
> - kvfree(exynos_gem->pages);
> }
>
> static int exynos_drm_gem_handle_create(struct drm_gem_object *obj,
> @@ -203,7 +164,8 @@ static struct exynos_drm_gem *exynos_drm_gem_init(struct drm_device *dev,
>
> struct exynos_drm_gem *exynos_drm_gem_create(struct drm_device *dev,
> unsigned int flags,
> - unsigned long size)
> + unsigned long size,
> + bool kvmap)
> {
> struct exynos_drm_gem *exynos_gem;
> int ret;
> @@ -237,7 +199,7 @@ struct exynos_drm_gem *exynos_drm_gem_create(struct drm_device *dev,
> /* set memory type and cache attribute from user side. */
> exynos_gem->flags = flags;
>
> - ret = exynos_drm_alloc_buf(exynos_gem);
> + ret = exynos_drm_alloc_buf(exynos_gem, kvmap);
> if (ret < 0) {
> drm_gem_object_release(&exynos_gem->base);
> kfree(exynos_gem);
> @@ -254,7 +216,7 @@ int exynos_drm_gem_create_ioctl(struct drm_device *dev, void *data,
> struct exynos_drm_gem *exynos_gem;
> int ret;
>
> - exynos_gem = exynos_drm_gem_create(dev, args->flags, args->size);
> + exynos_gem = exynos_drm_gem_create(dev, args->flags, args->size, false);
> if (IS_ERR(exynos_gem))
> return PTR_ERR(exynos_gem);
>
> @@ -365,7 +327,7 @@ int exynos_drm_gem_dumb_create(struct drm_file *file_priv,
> else
> flags = EXYNOS_BO_CONTIG | EXYNOS_BO_WC;
>
> - exynos_gem = exynos_drm_gem_create(dev, flags, args->size);
> + exynos_gem = exynos_drm_gem_create(dev, flags, args->size, false);
> if (IS_ERR(exynos_gem)) {
> dev_warn(dev->dev, "FB allocation failed.\n");
> return PTR_ERR(exynos_gem);
> @@ -442,11 +404,24 @@ struct drm_gem_object *exynos_drm_gem_prime_import(struct drm_device *dev,
> struct sg_table *exynos_drm_gem_prime_get_sg_table(struct drm_gem_object *obj)
> {
> struct exynos_drm_gem *exynos_gem = to_exynos_gem(obj);
> - int npages;
> + struct drm_device *drm_dev = obj->dev;
> + struct sg_table *sgt;
> + int ret;
> +
> + sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
> + if (!sgt)
> + return ERR_PTR(-ENOMEM);
>
> - npages = exynos_gem->size >> PAGE_SHIFT;
> + ret = dma_get_sgtable_attrs(to_dma_dev(drm_dev), sgt, exynos_gem->cookie,
> + exynos_gem->dma_addr, exynos_gem->size,
> + exynos_gem->dma_attrs);
> + if (ret) {
> + DRM_ERROR("failed to get sgtable, %d\n", ret);
> + kfree(sgt);
> + return ERR_PTR(ret);
> + }
>
> - return drm_prime_pages_to_sg(exynos_gem->pages, npages);
> + return sgt;
> }
>
> struct drm_gem_object *
> @@ -455,8 +430,6 @@ exynos_drm_gem_prime_import_sg_table(struct drm_device *dev,
> struct sg_table *sgt)
> {
> struct exynos_drm_gem *exynos_gem;
> - int npages;
> - int ret;
>
> if (sgt->nents != 1) {
> dma_addr_t next_addr = sg_dma_address(sgt->sgl);
> @@ -476,26 +449,8 @@ exynos_drm_gem_prime_import_sg_table(struct drm_device *dev,
> }
>
> exynos_gem = exynos_drm_gem_init(dev, attach->dmabuf->size);
> - if (IS_ERR(exynos_gem)) {
> - ret = PTR_ERR(exynos_gem);
> - return ERR_PTR(ret);
> - }
> -
> - exynos_gem->dma_addr = sg_dma_address(sgt->sgl);
> -
> - npages = exynos_gem->size >> PAGE_SHIFT;
> - exynos_gem->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
> - if (!exynos_gem->pages) {
> - ret = -ENOMEM;
> - goto err;
> - }
> -
> - ret = drm_prime_sg_to_page_addr_arrays(sgt, exynos_gem->pages, NULL,
> - npages);
> - if (ret < 0)
> - goto err_free_large;
> -
> - exynos_gem->sgt = sgt;
> + if (IS_ERR(exynos_gem))
> + return ERR_CAST(exynos_gem);
>
> /*
> * Buffer has been mapped as contiguous into DMA address space,
> @@ -507,14 +462,9 @@ exynos_drm_gem_prime_import_sg_table(struct drm_device *dev,
> else
> exynos_gem->flags |= EXYNOS_BO_CONTIG;
>
> + exynos_gem->dma_addr = sg_dma_address(sgt->sgl);
> + exynos_gem->sgt = sgt;
> return &exynos_gem->base;
> -
> -err_free_large:
> - kvfree(exynos_gem->pages);
> -err:
> - drm_gem_object_release(&exynos_gem->base);
> - kfree(exynos_gem);
> - return ERR_PTR(ret);
> }
>
> void *exynos_drm_gem_prime_vmap(struct drm_gem_object *obj)
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.h b/drivers/gpu/drm/exynos/exynos_drm_gem.h
> index f00044c0b688..6ef001f890aa 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_gem.h
> +++ b/drivers/gpu/drm/exynos/exynos_drm_gem.h
> @@ -21,20 +21,15 @@
> * @base: a gem object.
> * - a new handle to this gem object would be created
> * by drm_gem_handle_create().
> - * @buffer: a pointer to exynos_drm_gem_buffer object.
> - * - contain the information to memory region allocated
> - * by user request or at framebuffer creation.
> - * continuous memory region allocated by user request
> - * or at framebuffer creation.
> * @flags: indicate memory type to allocated buffer and cache attruibute.
> * @size: size requested from user, in bytes and this size is aligned
> * in page unit.
> * @cookie: cookie returned by dma_alloc_attrs
> - * @kvaddr: kernel virtual address to allocated memory region.
> + * @kvaddr: kernel virtual address to allocated memory region (for fbdev)
> * @dma_addr: bus address(accessed by dma) to allocated memory region.
> * - this address could be physical address without IOMMU and
> * device address with IOMMU.
> - * @pages: Array of backing pages.
> + * @dma_attrs: attrs passed dma mapping framework
> * @sgt: Imported sg_table.
> *
> * P.S. this object would be transferred to user as kms_bo.handle so
> @@ -48,7 +43,6 @@ struct exynos_drm_gem {
> void __iomem *kvaddr;
> dma_addr_t dma_addr;
> unsigned long dma_attrs;
> - struct page **pages;
> struct sg_table *sgt;
> };
>
> @@ -58,7 +52,8 @@ void exynos_drm_gem_destroy(struct exynos_drm_gem *exynos_gem);
> /* create a new buffer with gem object */
> struct exynos_drm_gem *exynos_drm_gem_create(struct drm_device *dev,
> unsigned int flags,
> - unsigned long size);
> + unsigned long size,
> + bool kvmap);
>
> /*
> * request gem object creation and buffer allocation as the size
>
