Daniel Vetter
2020-Dec-11 10:18 UTC
[PATCH v3 2/8] drm/ast: Only map cursor BOs during updates
On Wed, Dec 09, 2020 at 03:25:21PM +0100, Thomas Zimmermann wrote:> The HW cursor's BO used to be mapped permanently into the kernel's > address space. GEM's vmap operation will be protected by locks, and > we don't want to lock the BO's for an indefinate period of time. > > Change the cursor code to map the HW BOs only during updates. The > vmap operation in VRAM helpers is cheap, as a once estabished mapping > is being reused until the BO actually moves. As the HW cursor BOs are > permanently pinned, they never move at all. > > v2: > * fix typos in commit description > > Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de> > Acked-by: Christian K?nig <christian.koenig at amd.com>Acked-by: Daniel Vetter <daniel.vetter at ffwll.ch> Now there's a pretty big issue here though: We can't take dma_resv_lock in commit_tail, because of possible deadlocks on at least gpus that do real async rendering because of the dma_fences. Unfortunately my annotations patches got stuck a bit, I need to refresh them. Rules are you can pin and unpin stuff in prepare/cleanup_plane, and also take dma_resv_lock there, but not in commit_tail in-between. So I think our vmap_local needs to loose the unconditional assert_locked and require either that or a pin count. -Daniel> --- > drivers/gpu/drm/ast/ast_cursor.c | 51 ++++++++++++++++++-------------- > drivers/gpu/drm/ast/ast_drv.h | 2 -- > 2 files changed, 28 insertions(+), 25 deletions(-) > > diff --git a/drivers/gpu/drm/ast/ast_cursor.c b/drivers/gpu/drm/ast/ast_cursor.c > index 68bf3d33f1ed..fac1ee79c372 100644 > --- a/drivers/gpu/drm/ast/ast_cursor.c > +++ b/drivers/gpu/drm/ast/ast_cursor.c > @@ -39,7 +39,6 @@ static void ast_cursor_fini(struct ast_private *ast) > > for (i = 0; i < ARRAY_SIZE(ast->cursor.gbo); ++i) { > gbo = ast->cursor.gbo[i]; > - drm_gem_vram_vunmap(gbo, &ast->cursor.map[i]); > drm_gem_vram_unpin(gbo); > drm_gem_vram_put(gbo); > } > @@ -53,14 +52,13 @@ static void ast_cursor_release(struct drm_device *dev, void *ptr) > } > > /* > - * Allocate cursor BOs and pins them at the end of VRAM. > + * Allocate cursor BOs and pin them at the end of VRAM. > */ > int ast_cursor_init(struct ast_private *ast) > { > struct drm_device *dev = &ast->base; > size_t size, i; > struct drm_gem_vram_object *gbo; > - struct dma_buf_map map; > int ret; > > size = roundup(AST_HWC_SIZE + AST_HWC_SIGNATURE_SIZE, PAGE_SIZE); > @@ -77,15 +75,7 @@ int ast_cursor_init(struct ast_private *ast) > drm_gem_vram_put(gbo); > goto err_drm_gem_vram_put; > } > - ret = drm_gem_vram_vmap(gbo, &map); > - if (ret) { > - drm_gem_vram_unpin(gbo); > - drm_gem_vram_put(gbo); > - goto err_drm_gem_vram_put; > - } > - > ast->cursor.gbo[i] = gbo; > - ast->cursor.map[i] = map; > } > > return drmm_add_action_or_reset(dev, ast_cursor_release, NULL); > @@ -94,7 +84,6 @@ int ast_cursor_init(struct ast_private *ast) > while (i) { > --i; > gbo = ast->cursor.gbo[i]; > - drm_gem_vram_vunmap(gbo, &ast->cursor.map[i]); > drm_gem_vram_unpin(gbo); > drm_gem_vram_put(gbo); > } > @@ -168,31 +157,38 @@ static void update_cursor_image(u8 __iomem *dst, const u8 *src, int width, int h > int ast_cursor_blit(struct ast_private *ast, struct drm_framebuffer *fb) > { > struct drm_device *dev = &ast->base; > - struct drm_gem_vram_object *gbo; > - struct dma_buf_map map; > - int ret; > - void *src; > + struct drm_gem_vram_object *dst_gbo = ast->cursor.gbo[ast->cursor.next_index]; > + struct drm_gem_vram_object *src_gbo = drm_gem_vram_of_gem(fb->obj[0]); > + struct dma_buf_map src_map, dst_map; > void __iomem *dst; > + void *src; > + int ret; > > if (drm_WARN_ON_ONCE(dev, fb->width > AST_MAX_HWC_WIDTH) || > drm_WARN_ON_ONCE(dev, fb->height > AST_MAX_HWC_HEIGHT)) > return -EINVAL; > > - gbo = drm_gem_vram_of_gem(fb->obj[0]); > - > - ret = drm_gem_vram_vmap(gbo, &map); > + ret = drm_gem_vram_vmap(src_gbo, &src_map); > if (ret) > return ret; > - src = map.vaddr; /* TODO: Use mapping abstraction properly */ > + src = src_map.vaddr; /* TODO: Use mapping abstraction properly */ > > - dst = ast->cursor.map[ast->cursor.next_index].vaddr_iomem; > + ret = drm_gem_vram_vmap(dst_gbo, &dst_map); > + if (ret) > + goto err_drm_gem_vram_vunmap; > + dst = dst_map.vaddr_iomem; /* TODO: Use mapping abstraction properly */ > > /* do data transfer to cursor BO */ > update_cursor_image(dst, src, fb->width, fb->height); > > - drm_gem_vram_vunmap(gbo, &map); > + drm_gem_vram_vunmap(dst_gbo, &dst_map); > + drm_gem_vram_vunmap(src_gbo, &src_map); > > return 0; > + > +err_drm_gem_vram_vunmap: > + drm_gem_vram_vunmap(src_gbo, &src_map); > + return ret; > } > > static void ast_cursor_set_base(struct ast_private *ast, u64 address) > @@ -243,17 +239,26 @@ static void ast_cursor_set_location(struct ast_private *ast, u16 x, u16 y, > void ast_cursor_show(struct ast_private *ast, int x, int y, > unsigned int offset_x, unsigned int offset_y) > { > + struct drm_device *dev = &ast->base; > + struct drm_gem_vram_object *gbo = ast->cursor.gbo[ast->cursor.next_index]; > + struct dma_buf_map map; > u8 x_offset, y_offset; > u8 __iomem *dst; > u8 __iomem *sig; > u8 jreg; > + int ret; > > - dst = ast->cursor.map[ast->cursor.next_index].vaddr; > + ret = drm_gem_vram_vmap(gbo, &map); > + if (drm_WARN_ONCE(dev, ret, "drm_gem_vram_vmap() failed, ret=%d\n", ret)) > + return; > + dst = map.vaddr_iomem; /* TODO: Use mapping abstraction properly */ > > sig = dst + AST_HWC_SIZE; > writel(x, sig + AST_HWC_SIGNATURE_X); > writel(y, sig + AST_HWC_SIGNATURE_Y); > > + drm_gem_vram_vunmap(gbo, &map); > + > if (x < 0) { > x_offset = (-x) + offset_x; > x = 0; > diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h > index ccaff81924ee..f871fc36c2f7 100644 > --- a/drivers/gpu/drm/ast/ast_drv.h > +++ b/drivers/gpu/drm/ast/ast_drv.h > @@ -28,7 +28,6 @@ > #ifndef __AST_DRV_H__ > #define __AST_DRV_H__ > > -#include <linux/dma-buf-map.h> > #include <linux/i2c.h> > #include <linux/i2c-algo-bit.h> > #include <linux/io.h> > @@ -133,7 +132,6 @@ struct ast_private { > > struct { > struct drm_gem_vram_object *gbo[AST_DEFAULT_HWC_NUM]; > - struct dma_buf_map map[AST_DEFAULT_HWC_NUM]; > unsigned int next_index; > } cursor; > > -- > 2.29.2 >-- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch
Thomas Zimmermann
2020-Dec-11 10:49 UTC
[PATCH v3 2/8] drm/ast: Only map cursor BOs during updates
Am 11.12.20 um 11:18 schrieb Daniel Vetter:> On Wed, Dec 09, 2020 at 03:25:21PM +0100, Thomas Zimmermann wrote: >> The HW cursor's BO used to be mapped permanently into the kernel's >> address space. GEM's vmap operation will be protected by locks, and >> we don't want to lock the BO's for an indefinate period of time. >> >> Change the cursor code to map the HW BOs only during updates. The >> vmap operation in VRAM helpers is cheap, as a once estabished mapping >> is being reused until the BO actually moves. As the HW cursor BOs are >> permanently pinned, they never move at all. >> >> v2: >> * fix typos in commit description >> >> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de> >> Acked-by: Christian K?nig <christian.koenig at amd.com> > > Acked-by: Daniel Vetter <daniel.vetter at ffwll.ch> > > Now there's a pretty big issue here though: We can't take dma_resv_lock in > commit_tail, because of possible deadlocks on at least gpus that do real > async rendering because of the dma_fences. Unfortunately my annotations > patches got stuck a bit, I need to refresh them. > > Rules are you can pin and unpin stuff in prepare/cleanup_plane, and also > take dma_resv_lock there, but not in commit_tail in-between. So I think > our vmap_local needs to loose the unconditional assert_locked and require > either that or a pin count.I guess my commit description is misleading when it speaks of updates. ast_cursor_blit() is actually called from the cursor plane's prepare_fb function. [1] The vmap code in ast_cursor_show() could be moved into blit() as well, I think. I guess the clean solution is to integrate the cursor code with the modesetting code in ast_mode. From there, locks and mappings can be established in prepare_fb and the HW state can be updated in atomic_commit. Best regards Thomas [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/gpu/drm/ast/ast_mode.c#n646> -Daniel > >> --- >> drivers/gpu/drm/ast/ast_cursor.c | 51 ++++++++++++++++++-------------- >> drivers/gpu/drm/ast/ast_drv.h | 2 -- >> 2 files changed, 28 insertions(+), 25 deletions(-) >> >> diff --git a/drivers/gpu/drm/ast/ast_cursor.c b/drivers/gpu/drm/ast/ast_cursor.c >> index 68bf3d33f1ed..fac1ee79c372 100644 >> --- a/drivers/gpu/drm/ast/ast_cursor.c >> +++ b/drivers/gpu/drm/ast/ast_cursor.c >> @@ -39,7 +39,6 @@ static void ast_cursor_fini(struct ast_private *ast) >> >> for (i = 0; i < ARRAY_SIZE(ast->cursor.gbo); ++i) { >> gbo = ast->cursor.gbo[i]; >> - drm_gem_vram_vunmap(gbo, &ast->cursor.map[i]); >> drm_gem_vram_unpin(gbo); >> drm_gem_vram_put(gbo); >> } >> @@ -53,14 +52,13 @@ static void ast_cursor_release(struct drm_device *dev, void *ptr) >> } >> >> /* >> - * Allocate cursor BOs and pins them at the end of VRAM. >> + * Allocate cursor BOs and pin them at the end of VRAM. >> */ >> int ast_cursor_init(struct ast_private *ast) >> { >> struct drm_device *dev = &ast->base; >> size_t size, i; >> struct drm_gem_vram_object *gbo; >> - struct dma_buf_map map; >> int ret; >> >> size = roundup(AST_HWC_SIZE + AST_HWC_SIGNATURE_SIZE, PAGE_SIZE); >> @@ -77,15 +75,7 @@ int ast_cursor_init(struct ast_private *ast) >> drm_gem_vram_put(gbo); >> goto err_drm_gem_vram_put; >> } >> - ret = drm_gem_vram_vmap(gbo, &map); >> - if (ret) { >> - drm_gem_vram_unpin(gbo); >> - drm_gem_vram_put(gbo); >> - goto err_drm_gem_vram_put; >> - } >> - >> ast->cursor.gbo[i] = gbo; >> - ast->cursor.map[i] = map; >> } >> >> return drmm_add_action_or_reset(dev, ast_cursor_release, NULL); >> @@ -94,7 +84,6 @@ int ast_cursor_init(struct ast_private *ast) >> while (i) { >> --i; >> gbo = ast->cursor.gbo[i]; >> - drm_gem_vram_vunmap(gbo, &ast->cursor.map[i]); >> drm_gem_vram_unpin(gbo); >> drm_gem_vram_put(gbo); >> } >> @@ -168,31 +157,38 @@ static void update_cursor_image(u8 __iomem *dst, const u8 *src, int width, int h >> int ast_cursor_blit(struct ast_private *ast, struct drm_framebuffer *fb) >> { >> struct drm_device *dev = &ast->base; >> - struct drm_gem_vram_object *gbo; >> - struct dma_buf_map map; >> - int ret; >> - void *src; >> + struct drm_gem_vram_object *dst_gbo = ast->cursor.gbo[ast->cursor.next_index]; >> + struct drm_gem_vram_object *src_gbo = drm_gem_vram_of_gem(fb->obj[0]); >> + struct dma_buf_map src_map, dst_map; >> void __iomem *dst; >> + void *src; >> + int ret; >> >> if (drm_WARN_ON_ONCE(dev, fb->width > AST_MAX_HWC_WIDTH) || >> drm_WARN_ON_ONCE(dev, fb->height > AST_MAX_HWC_HEIGHT)) >> return -EINVAL; >> >> - gbo = drm_gem_vram_of_gem(fb->obj[0]); >> - >> - ret = drm_gem_vram_vmap(gbo, &map); >> + ret = drm_gem_vram_vmap(src_gbo, &src_map); >> if (ret) >> return ret; >> - src = map.vaddr; /* TODO: Use mapping abstraction properly */ >> + src = src_map.vaddr; /* TODO: Use mapping abstraction properly */ >> >> - dst = ast->cursor.map[ast->cursor.next_index].vaddr_iomem; >> + ret = drm_gem_vram_vmap(dst_gbo, &dst_map); >> + if (ret) >> + goto err_drm_gem_vram_vunmap; >> + dst = dst_map.vaddr_iomem; /* TODO: Use mapping abstraction properly */ >> >> /* do data transfer to cursor BO */ >> update_cursor_image(dst, src, fb->width, fb->height); >> >> - drm_gem_vram_vunmap(gbo, &map); >> + drm_gem_vram_vunmap(dst_gbo, &dst_map); >> + drm_gem_vram_vunmap(src_gbo, &src_map); >> >> return 0; >> + >> +err_drm_gem_vram_vunmap: >> + drm_gem_vram_vunmap(src_gbo, &src_map); >> + return ret; >> } >> >> static void ast_cursor_set_base(struct ast_private *ast, u64 address) >> @@ -243,17 +239,26 @@ static void ast_cursor_set_location(struct ast_private *ast, u16 x, u16 y, >> void ast_cursor_show(struct ast_private *ast, int x, int y, >> unsigned int offset_x, unsigned int offset_y) >> { >> + struct drm_device *dev = &ast->base; >> + struct drm_gem_vram_object *gbo = ast->cursor.gbo[ast->cursor.next_index]; >> + struct dma_buf_map map; >> u8 x_offset, y_offset; >> u8 __iomem *dst; >> u8 __iomem *sig; >> u8 jreg; >> + int ret; >> >> - dst = ast->cursor.map[ast->cursor.next_index].vaddr; >> + ret = drm_gem_vram_vmap(gbo, &map); >> + if (drm_WARN_ONCE(dev, ret, "drm_gem_vram_vmap() failed, ret=%d\n", ret)) >> + return; >> + dst = map.vaddr_iomem; /* TODO: Use mapping abstraction properly */ >> >> sig = dst + AST_HWC_SIZE; >> writel(x, sig + AST_HWC_SIGNATURE_X); >> writel(y, sig + AST_HWC_SIGNATURE_Y); >> >> + drm_gem_vram_vunmap(gbo, &map); >> + >> if (x < 0) { >> x_offset = (-x) + offset_x; >> x = 0; >> diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h >> index ccaff81924ee..f871fc36c2f7 100644 >> --- a/drivers/gpu/drm/ast/ast_drv.h >> +++ b/drivers/gpu/drm/ast/ast_drv.h >> @@ -28,7 +28,6 @@ >> #ifndef __AST_DRV_H__ >> #define __AST_DRV_H__ >> >> -#include <linux/dma-buf-map.h> >> #include <linux/i2c.h> >> #include <linux/i2c-algo-bit.h> >> #include <linux/io.h> >> @@ -133,7 +132,6 @@ struct ast_private { >> >> struct { >> struct drm_gem_vram_object *gbo[AST_DEFAULT_HWC_NUM]; >> - struct dma_buf_map map[AST_DEFAULT_HWC_NUM]; >> unsigned int next_index; >> } cursor; >> >> -- >> 2.29.2 >> >-- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 N?rnberg, Germany (HRB 36809, AG N?rnberg) Gesch?ftsf?hrer: Felix Imend?rffer -------------- next part -------------- A non-text attachment was scrubbed... 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