Messages in this thread | | | Date | Mon, 29 Aug 2022 07:58:10 +0200 | Subject | Re: [PTACH v3] drm/ast: add dmabuf/prime buffer sharing support | From | Christian König <> |
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Am 27.08.22 um 11:10 schrieb oushixiong: > This patch adds ast specific codes for DRM prime feature, this is to > allow for offloading of rending in one direction and outputs in other. > > This patch is designed to solve the problem that the AST is not displayed > when the server plug in a discrete graphics graphics card at the same time. > We call the dirty callback function to copy the rendering results of the > discrete graphics card to the ast side by dma-buf. > > v1->v2: > - Fix the comment. > v2->v3: > - we remove the gem_prime_import_sg_table callback and use the gem_prime_import > callback, becuase it just map and access the buffer with the CPU. and do not > to pin the buffer. > > Signed-off-by: oushixiong <oushixiong@kylinos.cn>
Thomas should probably comment as well, I think at least the memcpy_toio usage can still be made cleaner.
But from the DMA-buf side I think that looks good now, feel free to add an Acked-by: Christian König <christian.koenig@amd.com>
Regards, Christian.
> --- > drivers/gpu/drm/ast/ast_drv.c | 27 +++++++ > drivers/gpu/drm/ast/ast_mode.c | 125 ++++++++++++++++++++++++++++++++- > 2 files changed, 151 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/ast/ast_drv.c b/drivers/gpu/drm/ast/ast_drv.c > index 7465c4f0156a..107383a56ca7 100644 > --- a/drivers/gpu/drm/ast/ast_drv.c > +++ b/drivers/gpu/drm/ast/ast_drv.c > @@ -28,6 +28,7 @@ > > #include <linux/module.h> > #include <linux/pci.h> > +#include <linux/dma-buf.h> > > #include <drm/drm_aperture.h> > #include <drm/drm_atomic_helper.h> > @@ -50,6 +51,29 @@ module_param_named(modeset, ast_modeset, int, 0400); > > DEFINE_DRM_GEM_FOPS(ast_fops); > > +struct drm_gem_object *ast_gem_prime_import(struct drm_device *dev, > + struct dma_buf *dma_buf) > +{ > + struct drm_gem_vram_object *gbo; > + > + gbo = drm_gem_vram_of_gem(dma_buf->priv); > + if (gbo->bo.base.dev == dev) { > + /* > + * Importing dmabuf exported from out own gem increases > + * refcount on gem itself instead of f_count of dmabuf. > + */ > + drm_gem_object_get(&gbo->bo.base); > + return &gbo->bo.base; > + } > + > + gbo = drm_gem_vram_create(dev, dma_buf->size, 0); > + if (IS_ERR(gbo)) > + return NULL; > + > + get_dma_buf(dma_buf); > + return &gbo->bo.base; > +} > + > static const struct drm_driver ast_driver = { > .driver_features = DRIVER_ATOMIC | > DRIVER_GEM | > @@ -63,6 +87,9 @@ static const struct drm_driver ast_driver = { > .minor = DRIVER_MINOR, > .patchlevel = DRIVER_PATCHLEVEL, > > + .prime_fd_to_handle = drm_gem_prime_fd_to_handle, > + .gem_prime_import = ast_gem_prime_import, > + > DRM_GEM_VRAM_DRIVER > }; > > diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c > index 45b56b39ad47..65a4342c5622 100644 > --- a/drivers/gpu/drm/ast/ast_mode.c > +++ b/drivers/gpu/drm/ast/ast_mode.c > @@ -48,6 +48,8 @@ > #include "ast_drv.h" > #include "ast_tables.h" > > +MODULE_IMPORT_NS(DMA_BUF); > + > static inline void ast_load_palette_index(struct ast_private *ast, > u8 index, u8 red, u8 green, > u8 blue) > @@ -1535,8 +1537,129 @@ static const struct drm_mode_config_helper_funcs ast_mode_config_helper_funcs = > .atomic_commit_tail = drm_atomic_helper_commit_tail_rpm, > }; > > +static int ast_handle_damage(struct drm_framebuffer *fb, int x, int y, > + int width, int height) > +{ > + struct drm_gem_vram_object *dst_bo = NULL; > + void *dst = NULL; > + int ret = 0, i; > + unsigned long offset = 0; > + bool unmap = false; > + unsigned int bytesPerPixel; > + struct iosys_map map; > + struct iosys_map dmabuf_map; > + > + bytesPerPixel = fb->format->cpp[0]; > + > + if (!fb->obj[0]->dma_buf) > + return -EINVAL; > + > + if (!fb->obj[0]->dma_buf->vmap_ptr.vaddr) { > + ret = dma_buf_vmap(fb->obj[0]->dma_buf, &dmabuf_map); > + if (ret) > + return ret; > + } else > + dmabuf_map.vaddr = fb->obj[0]->dma_buf->vmap_ptr.vaddr; > + > + dst_bo = drm_gem_vram_of_gem(fb->obj[0]); > + > + ret = drm_gem_vram_pin(dst_bo, 0); > + if (ret) { > + DRM_ERROR("ast_bo_pin failed\n"); > + return ret; > + } > + > + if (!dst_bo->map.vaddr) { > + ret = drm_gem_vram_vmap(dst_bo, &map); > + if (ret) { > + drm_gem_vram_unpin(dst_bo); > + DRM_ERROR("failed to vmap fbcon\n"); > + return ret; > + } > + unmap = true; > + } > + dst = dst_bo->map.vaddr; > + > + for (i = y; i < y + height; i++) { > + offset = i * fb->pitches[0] + (x * bytesPerPixel); > + memcpy_toio(dst + offset, dmabuf_map.vaddr + offset, > + width * bytesPerPixel); > + } > + > + if (unmap) > + drm_gem_vram_vunmap(dst_bo, &map); > + > + drm_gem_vram_unpin(dst_bo); > + > + return 0; > +} > + > + > +static int ast_user_framebuffer_dirty(struct drm_framebuffer *fb, > + struct drm_file *file, > + unsigned int flags, > + unsigned int color, > + struct drm_clip_rect *clips, > + unsigned int num_clips) > +{ > + int i, ret = 0; > + > + drm_modeset_lock_all(fb->dev); > + if (fb->obj[0]->dma_buf) { > + ret = dma_buf_begin_cpu_access(fb->obj[0]->dma_buf, > + DMA_FROM_DEVICE); > + if (ret) > + goto unlock; > + } > + > + for (i = 0; i < num_clips; i++) { > + ret = ast_handle_damage(fb, clips[i].x1, clips[i].y1, > + clips[i].x2 - clips[i].x1, clips[i].y2 - clips[i].y1); > + if (ret) > + break; > + } > + > + if (fb->obj[0]->dma_buf) { > + dma_buf_end_cpu_access(fb->obj[0]->dma_buf, > + DMA_FROM_DEVICE); > + } > + > +unlock: > + drm_modeset_unlock_all(fb->dev); > + > + return ret; > +} > + > +static void ast_user_framebuffer_destroy(struct drm_framebuffer *fb) > +{ > + struct iosys_map dmabuf_map; > + > + if (fb->obj[0]->dma_buf) { > + dmabuf_map.is_iomem = fb->obj[0]->dma_buf->vmap_ptr.is_iomem; > + dmabuf_map.vaddr = fb->obj[0]->dma_buf->vmap_ptr.vaddr; > + if (dmabuf_map.vaddr) > + dma_buf_vunmap(fb->obj[0]->dma_buf, &dmabuf_map); > + } > + > + drm_gem_fb_destroy(fb); > +} > + > +static const struct drm_framebuffer_funcs ast_gem_fb_funcs_dirtyfb = { > + .destroy = ast_user_framebuffer_destroy, > + .create_handle = drm_gem_fb_create_handle, > + .dirty = ast_user_framebuffer_dirty, > +}; > + > +static struct drm_framebuffer * > +ast_gem_fb_create_with_dirty(struct drm_device *dev, struct drm_file *file, > + const struct drm_mode_fb_cmd2 *mode_cmd) > +{ > + return drm_gem_fb_create_with_funcs(dev, file, mode_cmd, > + &ast_gem_fb_funcs_dirtyfb); > +} > + > static const struct drm_mode_config_funcs ast_mode_config_funcs = { > - .fb_create = drm_gem_fb_create, > + .fb_create = ast_gem_fb_create_with_dirty, > .mode_valid = drm_vram_helper_mode_valid, > .atomic_check = drm_atomic_helper_check, > .atomic_commit = drm_atomic_helper_commit,
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