| Message ID | 20201020122046.31167-11-tzimmermann@suse.de (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Support GEM object mappings from I/O memory | expand |
On Tue, Oct 20, 2020 at 02:20:46PM +0200, Thomas Zimmermann wrote: > At least sparc64 requires I/O-specific access to framebuffers. This > patch updates the fbdev console accordingly. > > For drivers with direct access to the framebuffer memory, the callback > functions in struct fb_ops test for the type of memory and call the rsp > fb_sys_ of fb_cfb_ functions. Read and write operations are implemented > internally by DRM's fbdev helper. > > For drivers that employ a shadow buffer, fbdev's blit function retrieves > the framebuffer address as struct dma_buf_map, and uses dma_buf_map > interfaces to access the buffer. > > The bochs driver on sparc64 uses a workaround to flag the framebuffer as > I/O memory and avoid a HW exception. With the introduction of struct > dma_buf_map, this is not required any longer. The patch removes the rsp > code from both, bochs and fbdev. > > v5: > * implement fb_read/fb_write internally (Daniel, Sam) > v4: > * move dma_buf_map changes into separate patch (Daniel) > * TODO list: comment on fbdev updates (Daniel) > > Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> > Tested-by: Sam Ravnborg <sam@ravnborg.org> > --- > Documentation/gpu/todo.rst | 19 ++- > drivers/gpu/drm/bochs/bochs_kms.c | 1 - > drivers/gpu/drm/drm_fb_helper.c | 227 ++++++++++++++++++++++++++++-- > include/drm/drm_mode_config.h | 12 -- > 4 files changed, 230 insertions(+), 29 deletions(-) > > diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst > index 7e6fc3c04add..638b7f704339 100644 > --- a/Documentation/gpu/todo.rst > +++ b/Documentation/gpu/todo.rst > @@ -197,13 +197,28 @@ Convert drivers to use drm_fbdev_generic_setup() > ------------------------------------------------ > > Most drivers can use drm_fbdev_generic_setup(). Driver have to implement > -atomic modesetting and GEM vmap support. Current generic fbdev emulation > -expects the framebuffer in system memory (or system-like memory). > +atomic modesetting and GEM vmap support. Historically, generic fbdev emulation > +expected the framebuffer in system memory or system-like memory. By employing > +struct dma_buf_map, drivers with frambuffers in I/O memory can be supported > +as well. > > Contact: Maintainer of the driver you plan to convert > > Level: Intermediate > > +Reimplement functions in drm_fbdev_fb_ops without fbdev > +------------------------------------------------------- > + > +A number of callback functions in drm_fbdev_fb_ops could benefit from > +being rewritten without dependencies on the fbdev module. Some of the > +helpers could further benefit from using struct dma_buf_map instead of > +raw pointers. > + > +Contact: Thomas Zimmermann <tzimmermann@suse.de>, Daniel Vetter > + > +Level: Advanced > + > + > drm_framebuffer_funcs and drm_mode_config_funcs.fb_create cleanup > ----------------------------------------------------------------- > > diff --git a/drivers/gpu/drm/bochs/bochs_kms.c b/drivers/gpu/drm/bochs/bochs_kms.c > index 13d0d04c4457..853081d186d5 100644 > --- a/drivers/gpu/drm/bochs/bochs_kms.c > +++ b/drivers/gpu/drm/bochs/bochs_kms.c > @@ -151,7 +151,6 @@ int bochs_kms_init(struct bochs_device *bochs) > bochs->dev->mode_config.preferred_depth = 24; > bochs->dev->mode_config.prefer_shadow = 0; > bochs->dev->mode_config.prefer_shadow_fbdev = 1; > - bochs->dev->mode_config.fbdev_use_iomem = true; > bochs->dev->mode_config.quirk_addfb_prefer_host_byte_order = true; > > bochs->dev->mode_config.funcs = &bochs_mode_funcs; > diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c > index 6212cd7cde1d..1d3180841778 100644 > --- a/drivers/gpu/drm/drm_fb_helper.c > +++ b/drivers/gpu/drm/drm_fb_helper.c > @@ -372,24 +372,22 @@ static void drm_fb_helper_resume_worker(struct work_struct *work) > } > > static void drm_fb_helper_dirty_blit_real(struct drm_fb_helper *fb_helper, > - struct drm_clip_rect *clip) > + struct drm_clip_rect *clip, > + struct dma_buf_map *dst) > { > struct drm_framebuffer *fb = fb_helper->fb; > unsigned int cpp = fb->format->cpp[0]; > size_t offset = clip->y1 * fb->pitches[0] + clip->x1 * cpp; > void *src = fb_helper->fbdev->screen_buffer + offset; > - void *dst = fb_helper->buffer->map.vaddr + offset; > size_t len = (clip->x2 - clip->x1) * cpp; > unsigned int y; > > - for (y = clip->y1; y < clip->y2; y++) { > - if (!fb_helper->dev->mode_config.fbdev_use_iomem) > - memcpy(dst, src, len); > - else > - memcpy_toio((void __iomem *)dst, src, len); > + dma_buf_map_incr(dst, offset); /* go to first pixel within clip rect */ > > + for (y = clip->y1; y < clip->y2; y++) { > + dma_buf_map_memcpy_to(dst, src, len); > + dma_buf_map_incr(dst, fb->pitches[0]); > src += fb->pitches[0]; > - dst += fb->pitches[0]; > } > } > > @@ -417,8 +415,9 @@ static void drm_fb_helper_dirty_work(struct work_struct *work) > ret = drm_client_buffer_vmap(helper->buffer, &map); > if (ret) > return; > - drm_fb_helper_dirty_blit_real(helper, &clip_copy); > + drm_fb_helper_dirty_blit_real(helper, &clip_copy, &map); > } > + > if (helper->fb->funcs->dirty) > helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, > &clip_copy, 1); > @@ -2027,6 +2026,206 @@ static int drm_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) > return -ENODEV; > } > > +static bool drm_fbdev_use_iomem(struct fb_info *info) > +{ > + struct drm_fb_helper *fb_helper = info->par; > + struct drm_client_buffer *buffer = fb_helper->buffer; > + > + return !drm_fbdev_use_shadow_fb(fb_helper) && buffer->map.is_iomem; > +} > + > +static ssize_t fb_read_screen_base(struct fb_info *info, char __user *buf, size_t count, > + loff_t pos) > +{ > + const char __iomem *src = info->screen_base + pos; Maybe a bit much a bikeshed, but I'd write this in terms of drm objects, like the dirty_blit function, using the dma_buf_map (instead of the fb_info parameter). And then instead of screen_base and screen_buffer suffixes give them _mem and _iomem suffixes. Same for write below. Or I'm not quite understanding why we do it like this here - I don't think this code will be used outside of the generic fbdev code, so we can always assume that drm_fb_helper->buffer is set up. The other thing I think we need is some minimal testcases to make sure. The fbtest tool used way back seems to have disappeared, I couldn't find a copy of the source anywhere anymore. With all that: Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Cheers, Daniel > + size_t alloc_size = min(count, PAGE_SIZE); > + ssize_t ret = 0; > + char *tmp; > + > + tmp = kmalloc(alloc_size, GFP_KERNEL); > + if (!tmp) > + return -ENOMEM; > + > + while (count) { > + size_t c = min(count, alloc_size); > + > + memcpy_fromio(tmp, src, c); > + if (copy_to_user(buf, tmp, c)) { > + ret = -EFAULT; > + break; > + } > + > + src += c; > + buf += c; > + ret += c; > + count -= c; > + } > + > + kfree(tmp); > + > + return ret; > +} > + > +static ssize_t fb_read_screen_buffer(struct fb_info *info, char __user *buf, size_t count, > + loff_t pos) > +{ > + const char *src = info->screen_buffer + pos; > + > + if (copy_to_user(buf, src, count)) > + return -EFAULT; > + > + return count; > +} > + > +static ssize_t drm_fbdev_fb_read(struct fb_info *info, char __user *buf, > + size_t count, loff_t *ppos) > +{ > + loff_t pos = *ppos; > + size_t total_size; > + ssize_t ret; > + > + if (info->state != FBINFO_STATE_RUNNING) > + return -EPERM; > + > + if (info->screen_size) > + total_size = info->screen_size; > + else > + total_size = info->fix.smem_len; > + > + if (pos >= total_size) > + return 0; > + if (count >= total_size) > + count = total_size; > + if (total_size - count < pos) > + count = total_size - pos; > + > + if (drm_fbdev_use_iomem(info)) > + ret = fb_read_screen_base(info, buf, count, pos); > + else > + ret = fb_read_screen_buffer(info, buf, count, pos); > + > + if (ret > 0) > + *ppos = ret; > + > + return ret; > +} > + > +static ssize_t fb_write_screen_base(struct fb_info *info, const char __user *buf, size_t count, > + loff_t pos) > +{ > + char __iomem *dst = info->screen_base + pos; > + size_t alloc_size = min(count, PAGE_SIZE); > + ssize_t ret = 0; > + u8 *tmp; > + > + tmp = kmalloc(alloc_size, GFP_KERNEL); > + if (!tmp) > + return -ENOMEM; > + > + while (count) { > + size_t c = min(count, alloc_size); > + > + if (copy_from_user(tmp, buf, c)) { > + ret = -EFAULT; > + break; > + } > + memcpy_toio(dst, tmp, c); > + > + dst += c; > + buf += c; > + ret += c; > + count -= c; > + } > + > + kfree(tmp); > + > + return ret; > +} > + > +static ssize_t fb_write_screen_buffer(struct fb_info *info, const char __user *buf, size_t count, > + loff_t pos) > +{ > + char *dst = info->screen_buffer + pos; > + > + if (copy_from_user(dst, buf, count)) > + return -EFAULT; > + > + return count; > +} > + > +static ssize_t drm_fbdev_fb_write(struct fb_info *info, const char __user *buf, > + size_t count, loff_t *ppos) > +{ > + loff_t pos = *ppos; > + size_t total_size; > + ssize_t ret; > + int err; > + > + if (info->state != FBINFO_STATE_RUNNING) > + return -EPERM; > + > + if (info->screen_size) > + total_size = info->screen_size; > + else > + total_size = info->fix.smem_len; > + > + if (pos > total_size) > + return -EFBIG; > + if (count > total_size) { > + err = -EFBIG; > + count = total_size; > + } > + if (total_size - count < pos) { > + if (!err) > + err = -ENOSPC; > + count = total_size - pos; > + } > + > + /* > + * Copy to framebuffer even if we already logged an error. Emulates > + * the behavior of the original fbdev implementation. > + */ > + if (drm_fbdev_use_iomem(info)) > + ret = fb_write_screen_base(info, buf, count, pos); > + else > + ret = fb_write_screen_buffer(info, buf, count, pos); > + > + if (ret > 0) > + *ppos = ret; > + > + if (err) > + return err; > + > + return ret; > +} > + > +static void drm_fbdev_fb_fillrect(struct fb_info *info, > + const struct fb_fillrect *rect) > +{ > + if (drm_fbdev_use_iomem(info)) > + drm_fb_helper_cfb_fillrect(info, rect); > + else > + drm_fb_helper_sys_fillrect(info, rect); > +} > + > +static void drm_fbdev_fb_copyarea(struct fb_info *info, > + const struct fb_copyarea *area) > +{ > + if (drm_fbdev_use_iomem(info)) > + drm_fb_helper_cfb_copyarea(info, area); > + else > + drm_fb_helper_sys_copyarea(info, area); > +} > + > +static void drm_fbdev_fb_imageblit(struct fb_info *info, > + const struct fb_image *image) > +{ > + if (drm_fbdev_use_iomem(info)) > + drm_fb_helper_cfb_imageblit(info, image); > + else > + drm_fb_helper_sys_imageblit(info, image); > +} > + > static const struct fb_ops drm_fbdev_fb_ops = { > .owner = THIS_MODULE, > DRM_FB_HELPER_DEFAULT_OPS, > @@ -2034,11 +2233,11 @@ static const struct fb_ops drm_fbdev_fb_ops = { > .fb_release = drm_fbdev_fb_release, > .fb_destroy = drm_fbdev_fb_destroy, > .fb_mmap = drm_fbdev_fb_mmap, > - .fb_read = drm_fb_helper_sys_read, > - .fb_write = drm_fb_helper_sys_write, > - .fb_fillrect = drm_fb_helper_sys_fillrect, > - .fb_copyarea = drm_fb_helper_sys_copyarea, > - .fb_imageblit = drm_fb_helper_sys_imageblit, > + .fb_read = drm_fbdev_fb_read, > + .fb_write = drm_fbdev_fb_write, > + .fb_fillrect = drm_fbdev_fb_fillrect, > + .fb_copyarea = drm_fbdev_fb_copyarea, > + .fb_imageblit = drm_fbdev_fb_imageblit, > }; > > static struct fb_deferred_io drm_fbdev_defio = { > diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h > index 5ffbb4ed5b35..ab424ddd7665 100644 > --- a/include/drm/drm_mode_config.h > +++ b/include/drm/drm_mode_config.h > @@ -877,18 +877,6 @@ struct drm_mode_config { > */ > bool prefer_shadow_fbdev; > > - /** > - * @fbdev_use_iomem: > - * > - * Set to true if framebuffer reside in iomem. > - * When set to true memcpy_toio() is used when copying the framebuffer in > - * drm_fb_helper.drm_fb_helper_dirty_blit_real(). > - * > - * FIXME: This should be replaced with a per-mapping is_iomem > - * flag (like ttm does), and then used everywhere in fbdev code. > - */ > - bool fbdev_use_iomem; > - > /** > * @quirk_addfb_prefer_xbgr_30bpp: > * > -- > 2.28.0 >
Hi On 22.10.20 10:05, Daniel Vetter wrote: > On Tue, Oct 20, 2020 at 02:20:46PM +0200, Thomas Zimmermann wrote: >> At least sparc64 requires I/O-specific access to framebuffers. This >> patch updates the fbdev console accordingly. >> >> For drivers with direct access to the framebuffer memory, the callback >> functions in struct fb_ops test for the type of memory and call the rsp >> fb_sys_ of fb_cfb_ functions. Read and write operations are implemented >> internally by DRM's fbdev helper. >> >> For drivers that employ a shadow buffer, fbdev's blit function retrieves >> the framebuffer address as struct dma_buf_map, and uses dma_buf_map >> interfaces to access the buffer. >> >> The bochs driver on sparc64 uses a workaround to flag the framebuffer as >> I/O memory and avoid a HW exception. With the introduction of struct >> dma_buf_map, this is not required any longer. The patch removes the rsp >> code from both, bochs and fbdev. >> >> v5: >> * implement fb_read/fb_write internally (Daniel, Sam) >> v4: >> * move dma_buf_map changes into separate patch (Daniel) >> * TODO list: comment on fbdev updates (Daniel) >> >> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> >> Tested-by: Sam Ravnborg <sam@ravnborg.org> >> --- >> Documentation/gpu/todo.rst | 19 ++- >> drivers/gpu/drm/bochs/bochs_kms.c | 1 - >> drivers/gpu/drm/drm_fb_helper.c | 227 ++++++++++++++++++++++++++++-- >> include/drm/drm_mode_config.h | 12 -- >> 4 files changed, 230 insertions(+), 29 deletions(-) >> >> diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst >> index 7e6fc3c04add..638b7f704339 100644 >> --- a/Documentation/gpu/todo.rst >> +++ b/Documentation/gpu/todo.rst >> @@ -197,13 +197,28 @@ Convert drivers to use drm_fbdev_generic_setup() >> ------------------------------------------------ >> >> Most drivers can use drm_fbdev_generic_setup(). Driver have to implement >> -atomic modesetting and GEM vmap support. Current generic fbdev emulation >> -expects the framebuffer in system memory (or system-like memory). >> +atomic modesetting and GEM vmap support. Historically, generic fbdev emulation >> +expected the framebuffer in system memory or system-like memory. By employing >> +struct dma_buf_map, drivers with frambuffers in I/O memory can be supported >> +as well. >> >> Contact: Maintainer of the driver you plan to convert >> >> Level: Intermediate >> >> +Reimplement functions in drm_fbdev_fb_ops without fbdev >> +------------------------------------------------------- >> + >> +A number of callback functions in drm_fbdev_fb_ops could benefit from >> +being rewritten without dependencies on the fbdev module. Some of the >> +helpers could further benefit from using struct dma_buf_map instead of >> +raw pointers. >> + >> +Contact: Thomas Zimmermann <tzimmermann@suse.de>, Daniel Vetter >> + >> +Level: Advanced >> + >> + >> drm_framebuffer_funcs and drm_mode_config_funcs.fb_create cleanup >> ----------------------------------------------------------------- >> >> diff --git a/drivers/gpu/drm/bochs/bochs_kms.c b/drivers/gpu/drm/bochs/bochs_kms.c >> index 13d0d04c4457..853081d186d5 100644 >> --- a/drivers/gpu/drm/bochs/bochs_kms.c >> +++ b/drivers/gpu/drm/bochs/bochs_kms.c >> @@ -151,7 +151,6 @@ int bochs_kms_init(struct bochs_device *bochs) >> bochs->dev->mode_config.preferred_depth = 24; >> bochs->dev->mode_config.prefer_shadow = 0; >> bochs->dev->mode_config.prefer_shadow_fbdev = 1; >> - bochs->dev->mode_config.fbdev_use_iomem = true; >> bochs->dev->mode_config.quirk_addfb_prefer_host_byte_order = true; >> >> bochs->dev->mode_config.funcs = &bochs_mode_funcs; >> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c >> index 6212cd7cde1d..1d3180841778 100644 >> --- a/drivers/gpu/drm/drm_fb_helper.c >> +++ b/drivers/gpu/drm/drm_fb_helper.c >> @@ -372,24 +372,22 @@ static void drm_fb_helper_resume_worker(struct work_struct *work) >> } >> >> static void drm_fb_helper_dirty_blit_real(struct drm_fb_helper *fb_helper, >> - struct drm_clip_rect *clip) >> + struct drm_clip_rect *clip, >> + struct dma_buf_map *dst) >> { >> struct drm_framebuffer *fb = fb_helper->fb; >> unsigned int cpp = fb->format->cpp[0]; >> size_t offset = clip->y1 * fb->pitches[0] + clip->x1 * cpp; >> void *src = fb_helper->fbdev->screen_buffer + offset; >> - void *dst = fb_helper->buffer->map.vaddr + offset; >> size_t len = (clip->x2 - clip->x1) * cpp; >> unsigned int y; >> >> - for (y = clip->y1; y < clip->y2; y++) { >> - if (!fb_helper->dev->mode_config.fbdev_use_iomem) >> - memcpy(dst, src, len); >> - else >> - memcpy_toio((void __iomem *)dst, src, len); >> + dma_buf_map_incr(dst, offset); /* go to first pixel within clip rect */ >> >> + for (y = clip->y1; y < clip->y2; y++) { >> + dma_buf_map_memcpy_to(dst, src, len); >> + dma_buf_map_incr(dst, fb->pitches[0]); >> src += fb->pitches[0]; >> - dst += fb->pitches[0]; >> } >> } >> >> @@ -417,8 +415,9 @@ static void drm_fb_helper_dirty_work(struct work_struct *work) >> ret = drm_client_buffer_vmap(helper->buffer, &map); >> if (ret) >> return; >> - drm_fb_helper_dirty_blit_real(helper, &clip_copy); >> + drm_fb_helper_dirty_blit_real(helper, &clip_copy, &map); >> } >> + >> if (helper->fb->funcs->dirty) >> helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, >> &clip_copy, 1); >> @@ -2027,6 +2026,206 @@ static int drm_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) >> return -ENODEV; >> } >> >> +static bool drm_fbdev_use_iomem(struct fb_info *info) >> +{ >> + struct drm_fb_helper *fb_helper = info->par; >> + struct drm_client_buffer *buffer = fb_helper->buffer; >> + >> + return !drm_fbdev_use_shadow_fb(fb_helper) && buffer->map.is_iomem; >> +} >> + >> +static ssize_t fb_read_screen_base(struct fb_info *info, char __user *buf, size_t count, >> + loff_t pos) >> +{ >> + const char __iomem *src = info->screen_base + pos; > > Maybe a bit much a bikeshed, but I'd write this in terms of drm objects, > like the dirty_blit function, using the dma_buf_map (instead of the > fb_info parameter). And then instead of > screen_base and screen_buffer suffixes give them _mem and _iomem suffixes. Screen_buffer can be a shadow buffer. Until the blit worker (see drm_fb_helper_dirty_work() ) completes, it might be more up to date than the real buffer that's stored in the client. The orignal fbdev code supported an fb_sync callback to synchronize with outstanding screen updates (e.g., HW blit ops), but fb_sync is just overhead here. Copying from screen_buffer or screen_base always returns the most up-to-date image. > > Same for write below. Or I'm not quite understanding why we do it like > this here - I don't think this code will be used outside of the generic > fbdev code, so we can always assume that drm_fb_helper->buffer is set up. It's similar as in the read case. If we write to the client's buffer, an outstanding blit worker could write the now-outdated shadow buffer over the user's newly written framebuffer data. Thinking about it, we might want to schedule the blit worker at the end of each fb_write, so that the data makes it into the HW buffer in time. > > The other thing I think we need is some minimal testcases to make sure. > The fbtest tool used way back seems to have disappeared, I couldn't find > a copy of the source anywhere anymore. As discussed on IRC, I'll add some testcase to the igt test. I'll share the link here when done. Best regards Thomas > > With all that: Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> > > Cheers, Daniel > >> + size_t alloc_size = min(count, PAGE_SIZE); >> + ssize_t ret = 0; >> + char *tmp; >> + >> + tmp = kmalloc(alloc_size, GFP_KERNEL); >> + if (!tmp) >> + return -ENOMEM; >> + >> + while (count) { >> + size_t c = min(count, alloc_size); >> + >> + memcpy_fromio(tmp, src, c); >> + if (copy_to_user(buf, tmp, c)) { >> + ret = -EFAULT; >> + break; >> + } >> + >> + src += c; >> + buf += c; >> + ret += c; >> + count -= c; >> + } >> + >> + kfree(tmp); >> + >> + return ret; >> +} >> + >> +static ssize_t fb_read_screen_buffer(struct fb_info *info, char __user *buf, size_t count, >> + loff_t pos) >> +{ >> + const char *src = info->screen_buffer + pos; >> + >> + if (copy_to_user(buf, src, count)) >> + return -EFAULT; >> + >> + return count; >> +} >> + >> +static ssize_t drm_fbdev_fb_read(struct fb_info *info, char __user *buf, >> + size_t count, loff_t *ppos) >> +{ >> + loff_t pos = *ppos; >> + size_t total_size; >> + ssize_t ret; >> + >> + if (info->state != FBINFO_STATE_RUNNING) >> + return -EPERM; >> + >> + if (info->screen_size) >> + total_size = info->screen_size; >> + else >> + total_size = info->fix.smem_len; >> + >> + if (pos >= total_size) >> + return 0; >> + if (count >= total_size) >> + count = total_size; >> + if (total_size - count < pos) >> + count = total_size - pos; >> + >> + if (drm_fbdev_use_iomem(info)) >> + ret = fb_read_screen_base(info, buf, count, pos); >> + else >> + ret = fb_read_screen_buffer(info, buf, count, pos); >> + >> + if (ret > 0) >> + *ppos = ret; >> + >> + return ret; >> +} >> + >> +static ssize_t fb_write_screen_base(struct fb_info *info, const char __user *buf, size_t count, >> + loff_t pos) >> +{ >> + char __iomem *dst = info->screen_base + pos; >> + size_t alloc_size = min(count, PAGE_SIZE); >> + ssize_t ret = 0; >> + u8 *tmp; >> + >> + tmp = kmalloc(alloc_size, GFP_KERNEL); >> + if (!tmp) >> + return -ENOMEM; >> + >> + while (count) { >> + size_t c = min(count, alloc_size); >> + >> + if (copy_from_user(tmp, buf, c)) { >> + ret = -EFAULT; >> + break; >> + } >> + memcpy_toio(dst, tmp, c); >> + >> + dst += c; >> + buf += c; >> + ret += c; >> + count -= c; >> + } >> + >> + kfree(tmp); >> + >> + return ret; >> +} >> + >> +static ssize_t fb_write_screen_buffer(struct fb_info *info, const char __user *buf, size_t count, >> + loff_t pos) >> +{ >> + char *dst = info->screen_buffer + pos; >> + >> + if (copy_from_user(dst, buf, count)) >> + return -EFAULT; >> + >> + return count; >> +} >> + >> +static ssize_t drm_fbdev_fb_write(struct fb_info *info, const char __user *buf, >> + size_t count, loff_t *ppos) >> +{ >> + loff_t pos = *ppos; >> + size_t total_size; >> + ssize_t ret; >> + int err; >> + >> + if (info->state != FBINFO_STATE_RUNNING) >> + return -EPERM; >> + >> + if (info->screen_size) >> + total_size = info->screen_size; >> + else >> + total_size = info->fix.smem_len; >> + >> + if (pos > total_size) >> + return -EFBIG; >> + if (count > total_size) { >> + err = -EFBIG; >> + count = total_size; >> + } >> + if (total_size - count < pos) { >> + if (!err) >> + err = -ENOSPC; >> + count = total_size - pos; >> + } >> + >> + /* >> + * Copy to framebuffer even if we already logged an error. Emulates >> + * the behavior of the original fbdev implementation. >> + */ >> + if (drm_fbdev_use_iomem(info)) >> + ret = fb_write_screen_base(info, buf, count, pos); >> + else >> + ret = fb_write_screen_buffer(info, buf, count, pos); >> + >> + if (ret > 0) >> + *ppos = ret; >> + >> + if (err) >> + return err; >> + >> + return ret; >> +} >> + >> +static void drm_fbdev_fb_fillrect(struct fb_info *info, >> + const struct fb_fillrect *rect) >> +{ >> + if (drm_fbdev_use_iomem(info)) >> + drm_fb_helper_cfb_fillrect(info, rect); >> + else >> + drm_fb_helper_sys_fillrect(info, rect); >> +} >> + >> +static void drm_fbdev_fb_copyarea(struct fb_info *info, >> + const struct fb_copyarea *area) >> +{ >> + if (drm_fbdev_use_iomem(info)) >> + drm_fb_helper_cfb_copyarea(info, area); >> + else >> + drm_fb_helper_sys_copyarea(info, area); >> +} >> + >> +static void drm_fbdev_fb_imageblit(struct fb_info *info, >> + const struct fb_image *image) >> +{ >> + if (drm_fbdev_use_iomem(info)) >> + drm_fb_helper_cfb_imageblit(info, image); >> + else >> + drm_fb_helper_sys_imageblit(info, image); >> +} >> + >> static const struct fb_ops drm_fbdev_fb_ops = { >> .owner = THIS_MODULE, >> DRM_FB_HELPER_DEFAULT_OPS, >> @@ -2034,11 +2233,11 @@ static const struct fb_ops drm_fbdev_fb_ops = { >> .fb_release = drm_fbdev_fb_release, >> .fb_destroy = drm_fbdev_fb_destroy, >> .fb_mmap = drm_fbdev_fb_mmap, >> - .fb_read = drm_fb_helper_sys_read, >> - .fb_write = drm_fb_helper_sys_write, >> - .fb_fillrect = drm_fb_helper_sys_fillrect, >> - .fb_copyarea = drm_fb_helper_sys_copyarea, >> - .fb_imageblit = drm_fb_helper_sys_imageblit, >> + .fb_read = drm_fbdev_fb_read, >> + .fb_write = drm_fbdev_fb_write, >> + .fb_fillrect = drm_fbdev_fb_fillrect, >> + .fb_copyarea = drm_fbdev_fb_copyarea, >> + .fb_imageblit = drm_fbdev_fb_imageblit, >> }; >> >> static struct fb_deferred_io drm_fbdev_defio = { >> diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h >> index 5ffbb4ed5b35..ab424ddd7665 100644 >> --- a/include/drm/drm_mode_config.h >> +++ b/include/drm/drm_mode_config.h >> @@ -877,18 +877,6 @@ struct drm_mode_config { >> */ >> bool prefer_shadow_fbdev; >> >> - /** >> - * @fbdev_use_iomem: >> - * >> - * Set to true if framebuffer reside in iomem. >> - * When set to true memcpy_toio() is used when copying the framebuffer in >> - * drm_fb_helper.drm_fb_helper_dirty_blit_real(). >> - * >> - * FIXME: This should be replaced with a per-mapping is_iomem >> - * flag (like ttm does), and then used everywhere in fbdev code. >> - */ >> - bool fbdev_use_iomem; >> - >> /** >> * @quirk_addfb_prefer_xbgr_30bpp: >> * >> -- >> 2.28.0 >> >
On Thu, Oct 22, 2020 at 10:37:56AM +0200, Thomas Zimmermann wrote: > Hi > > On 22.10.20 10:05, Daniel Vetter wrote: > > On Tue, Oct 20, 2020 at 02:20:46PM +0200, Thomas Zimmermann wrote: > >> At least sparc64 requires I/O-specific access to framebuffers. This > >> patch updates the fbdev console accordingly. > >> > >> For drivers with direct access to the framebuffer memory, the callback > >> functions in struct fb_ops test for the type of memory and call the rsp > >> fb_sys_ of fb_cfb_ functions. Read and write operations are implemented > >> internally by DRM's fbdev helper. > >> > >> For drivers that employ a shadow buffer, fbdev's blit function retrieves > >> the framebuffer address as struct dma_buf_map, and uses dma_buf_map > >> interfaces to access the buffer. > >> > >> The bochs driver on sparc64 uses a workaround to flag the framebuffer as > >> I/O memory and avoid a HW exception. With the introduction of struct > >> dma_buf_map, this is not required any longer. The patch removes the rsp > >> code from both, bochs and fbdev. > >> > >> v5: > >> * implement fb_read/fb_write internally (Daniel, Sam) > >> v4: > >> * move dma_buf_map changes into separate patch (Daniel) > >> * TODO list: comment on fbdev updates (Daniel) > >> > >> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> > >> Tested-by: Sam Ravnborg <sam@ravnborg.org> > >> --- > >> Documentation/gpu/todo.rst | 19 ++- > >> drivers/gpu/drm/bochs/bochs_kms.c | 1 - > >> drivers/gpu/drm/drm_fb_helper.c | 227 ++++++++++++++++++++++++++++-- > >> include/drm/drm_mode_config.h | 12 -- > >> 4 files changed, 230 insertions(+), 29 deletions(-) > >> > >> diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst > >> index 7e6fc3c04add..638b7f704339 100644 > >> --- a/Documentation/gpu/todo.rst > >> +++ b/Documentation/gpu/todo.rst > >> @@ -197,13 +197,28 @@ Convert drivers to use drm_fbdev_generic_setup() > >> ------------------------------------------------ > >> > >> Most drivers can use drm_fbdev_generic_setup(). Driver have to implement > >> -atomic modesetting and GEM vmap support. Current generic fbdev emulation > >> -expects the framebuffer in system memory (or system-like memory). > >> +atomic modesetting and GEM vmap support. Historically, generic fbdev emulation > >> +expected the framebuffer in system memory or system-like memory. By employing > >> +struct dma_buf_map, drivers with frambuffers in I/O memory can be supported > >> +as well. > >> > >> Contact: Maintainer of the driver you plan to convert > >> > >> Level: Intermediate > >> > >> +Reimplement functions in drm_fbdev_fb_ops without fbdev > >> +------------------------------------------------------- > >> + > >> +A number of callback functions in drm_fbdev_fb_ops could benefit from > >> +being rewritten without dependencies on the fbdev module. Some of the > >> +helpers could further benefit from using struct dma_buf_map instead of > >> +raw pointers. > >> + > >> +Contact: Thomas Zimmermann <tzimmermann@suse.de>, Daniel Vetter > >> + > >> +Level: Advanced > >> + > >> + > >> drm_framebuffer_funcs and drm_mode_config_funcs.fb_create cleanup > >> ----------------------------------------------------------------- > >> > >> diff --git a/drivers/gpu/drm/bochs/bochs_kms.c b/drivers/gpu/drm/bochs/bochs_kms.c > >> index 13d0d04c4457..853081d186d5 100644 > >> --- a/drivers/gpu/drm/bochs/bochs_kms.c > >> +++ b/drivers/gpu/drm/bochs/bochs_kms.c > >> @@ -151,7 +151,6 @@ int bochs_kms_init(struct bochs_device *bochs) > >> bochs->dev->mode_config.preferred_depth = 24; > >> bochs->dev->mode_config.prefer_shadow = 0; > >> bochs->dev->mode_config.prefer_shadow_fbdev = 1; > >> - bochs->dev->mode_config.fbdev_use_iomem = true; > >> bochs->dev->mode_config.quirk_addfb_prefer_host_byte_order = true; > >> > >> bochs->dev->mode_config.funcs = &bochs_mode_funcs; > >> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c > >> index 6212cd7cde1d..1d3180841778 100644 > >> --- a/drivers/gpu/drm/drm_fb_helper.c > >> +++ b/drivers/gpu/drm/drm_fb_helper.c > >> @@ -372,24 +372,22 @@ static void drm_fb_helper_resume_worker(struct work_struct *work) > >> } > >> > >> static void drm_fb_helper_dirty_blit_real(struct drm_fb_helper *fb_helper, > >> - struct drm_clip_rect *clip) > >> + struct drm_clip_rect *clip, > >> + struct dma_buf_map *dst) > >> { > >> struct drm_framebuffer *fb = fb_helper->fb; > >> unsigned int cpp = fb->format->cpp[0]; > >> size_t offset = clip->y1 * fb->pitches[0] + clip->x1 * cpp; > >> void *src = fb_helper->fbdev->screen_buffer + offset; > >> - void *dst = fb_helper->buffer->map.vaddr + offset; > >> size_t len = (clip->x2 - clip->x1) * cpp; > >> unsigned int y; > >> > >> - for (y = clip->y1; y < clip->y2; y++) { > >> - if (!fb_helper->dev->mode_config.fbdev_use_iomem) > >> - memcpy(dst, src, len); > >> - else > >> - memcpy_toio((void __iomem *)dst, src, len); > >> + dma_buf_map_incr(dst, offset); /* go to first pixel within clip rect */ > >> > >> + for (y = clip->y1; y < clip->y2; y++) { > >> + dma_buf_map_memcpy_to(dst, src, len); > >> + dma_buf_map_incr(dst, fb->pitches[0]); > >> src += fb->pitches[0]; > >> - dst += fb->pitches[0]; > >> } > >> } > >> > >> @@ -417,8 +415,9 @@ static void drm_fb_helper_dirty_work(struct work_struct *work) > >> ret = drm_client_buffer_vmap(helper->buffer, &map); > >> if (ret) > >> return; > >> - drm_fb_helper_dirty_blit_real(helper, &clip_copy); > >> + drm_fb_helper_dirty_blit_real(helper, &clip_copy, &map); > >> } > >> + > >> if (helper->fb->funcs->dirty) > >> helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, > >> &clip_copy, 1); > >> @@ -2027,6 +2026,206 @@ static int drm_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) > >> return -ENODEV; > >> } > >> > >> +static bool drm_fbdev_use_iomem(struct fb_info *info) > >> +{ > >> + struct drm_fb_helper *fb_helper = info->par; > >> + struct drm_client_buffer *buffer = fb_helper->buffer; > >> + > >> + return !drm_fbdev_use_shadow_fb(fb_helper) && buffer->map.is_iomem; > >> +} > >> + > >> +static ssize_t fb_read_screen_base(struct fb_info *info, char __user *buf, size_t count, > >> + loff_t pos) > >> +{ > >> + const char __iomem *src = info->screen_base + pos; > > > > Maybe a bit much a bikeshed, but I'd write this in terms of drm objects, > > like the dirty_blit function, using the dma_buf_map (instead of the > > fb_info parameter). And then instead of > > screen_base and screen_buffer suffixes give them _mem and _iomem suffixes. > > Screen_buffer can be a shadow buffer. Until the blit worker (see > drm_fb_helper_dirty_work() ) completes, it might be more up to date than > the real buffer that's stored in the client. > > The orignal fbdev code supported an fb_sync callback to synchronize with > outstanding screen updates (e.g., HW blit ops), but fb_sync is just > overhead here. Copying from screen_buffer or screen_base always returns > the most up-to-date image. > > > > > Same for write below. Or I'm not quite understanding why we do it like > > this here - I don't think this code will be used outside of the generic > > fbdev code, so we can always assume that drm_fb_helper->buffer is set up. > > It's similar as in the read case. If we write to the client's buffer, an > outstanding blit worker could write the now-outdated shadow buffer over > the user's newly written framebuffer data. > > Thinking about it, we might want to schedule the blit worker at the end > of each fb_write, so that the data makes it into the HW buffer in time. Hm ok, makes some sense. I think there's some potential for cleanup if we add a dma_buf_map drm_fb_helper->uapi_map which points at the right thing always. That could then also the drm_fbdev_use_iomem() helper and make this all look really neat. But maybe a follow up clean up patch, if you're bored. As-is: Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> While looking at this I also noticed a potential small issue in an earlier patch. > > The other thing I think we need is some minimal testcases to make sure. > > The fbtest tool used way back seems to have disappeared, I couldn't find > > a copy of the source anywhere anymore. > > As discussed on IRC, I'll add some testcase to the igt test. I'll share > the link here when done. > > Best regards > Thomas > > > > > With all that: Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> > > > > Cheers, Daniel > > > >> + size_t alloc_size = min(count, PAGE_SIZE); > >> + ssize_t ret = 0; > >> + char *tmp; > >> + > >> + tmp = kmalloc(alloc_size, GFP_KERNEL); > >> + if (!tmp) > >> + return -ENOMEM; > >> + > >> + while (count) { > >> + size_t c = min(count, alloc_size); > >> + > >> + memcpy_fromio(tmp, src, c); > >> + if (copy_to_user(buf, tmp, c)) { > >> + ret = -EFAULT; > >> + break; > >> + } > >> + > >> + src += c; > >> + buf += c; > >> + ret += c; > >> + count -= c; > >> + } > >> + > >> + kfree(tmp); > >> + > >> + return ret; > >> +} > >> + > >> +static ssize_t fb_read_screen_buffer(struct fb_info *info, char __user *buf, size_t count, > >> + loff_t pos) > >> +{ > >> + const char *src = info->screen_buffer + pos; > >> + > >> + if (copy_to_user(buf, src, count)) > >> + return -EFAULT; > >> + > >> + return count; > >> +} > >> + > >> +static ssize_t drm_fbdev_fb_read(struct fb_info *info, char __user *buf, > >> + size_t count, loff_t *ppos) > >> +{ > >> + loff_t pos = *ppos; > >> + size_t total_size; > >> + ssize_t ret; > >> + > >> + if (info->state != FBINFO_STATE_RUNNING) > >> + return -EPERM; > >> + > >> + if (info->screen_size) > >> + total_size = info->screen_size; > >> + else > >> + total_size = info->fix.smem_len; > >> + > >> + if (pos >= total_size) > >> + return 0; > >> + if (count >= total_size) > >> + count = total_size; > >> + if (total_size - count < pos) > >> + count = total_size - pos; > >> + > >> + if (drm_fbdev_use_iomem(info)) > >> + ret = fb_read_screen_base(info, buf, count, pos); > >> + else > >> + ret = fb_read_screen_buffer(info, buf, count, pos); > >> + > >> + if (ret > 0) > >> + *ppos = ret; > >> + > >> + return ret; > >> +} > >> + > >> +static ssize_t fb_write_screen_base(struct fb_info *info, const char __user *buf, size_t count, > >> + loff_t pos) > >> +{ > >> + char __iomem *dst = info->screen_base + pos; > >> + size_t alloc_size = min(count, PAGE_SIZE); > >> + ssize_t ret = 0; > >> + u8 *tmp; > >> + > >> + tmp = kmalloc(alloc_size, GFP_KERNEL); > >> + if (!tmp) > >> + return -ENOMEM; > >> + > >> + while (count) { > >> + size_t c = min(count, alloc_size); > >> + > >> + if (copy_from_user(tmp, buf, c)) { > >> + ret = -EFAULT; > >> + break; > >> + } > >> + memcpy_toio(dst, tmp, c); > >> + > >> + dst += c; > >> + buf += c; > >> + ret += c; > >> + count -= c; > >> + } > >> + > >> + kfree(tmp); > >> + > >> + return ret; > >> +} > >> + > >> +static ssize_t fb_write_screen_buffer(struct fb_info *info, const char __user *buf, size_t count, > >> + loff_t pos) > >> +{ > >> + char *dst = info->screen_buffer + pos; > >> + > >> + if (copy_from_user(dst, buf, count)) > >> + return -EFAULT; > >> + > >> + return count; > >> +} > >> + > >> +static ssize_t drm_fbdev_fb_write(struct fb_info *info, const char __user *buf, > >> + size_t count, loff_t *ppos) > >> +{ > >> + loff_t pos = *ppos; > >> + size_t total_size; > >> + ssize_t ret; > >> + int err; > >> + > >> + if (info->state != FBINFO_STATE_RUNNING) > >> + return -EPERM; > >> + > >> + if (info->screen_size) > >> + total_size = info->screen_size; > >> + else > >> + total_size = info->fix.smem_len; > >> + > >> + if (pos > total_size) > >> + return -EFBIG; > >> + if (count > total_size) { > >> + err = -EFBIG; > >> + count = total_size; > >> + } > >> + if (total_size - count < pos) { > >> + if (!err) > >> + err = -ENOSPC; > >> + count = total_size - pos; > >> + } > >> + > >> + /* > >> + * Copy to framebuffer even if we already logged an error. Emulates > >> + * the behavior of the original fbdev implementation. > >> + */ > >> + if (drm_fbdev_use_iomem(info)) > >> + ret = fb_write_screen_base(info, buf, count, pos); > >> + else > >> + ret = fb_write_screen_buffer(info, buf, count, pos); > >> + > >> + if (ret > 0) > >> + *ppos = ret; > >> + > >> + if (err) > >> + return err; > >> + > >> + return ret; > >> +} > >> + > >> +static void drm_fbdev_fb_fillrect(struct fb_info *info, > >> + const struct fb_fillrect *rect) > >> +{ > >> + if (drm_fbdev_use_iomem(info)) > >> + drm_fb_helper_cfb_fillrect(info, rect); > >> + else > >> + drm_fb_helper_sys_fillrect(info, rect); > >> +} > >> + > >> +static void drm_fbdev_fb_copyarea(struct fb_info *info, > >> + const struct fb_copyarea *area) > >> +{ > >> + if (drm_fbdev_use_iomem(info)) > >> + drm_fb_helper_cfb_copyarea(info, area); > >> + else > >> + drm_fb_helper_sys_copyarea(info, area); > >> +} > >> + > >> +static void drm_fbdev_fb_imageblit(struct fb_info *info, > >> + const struct fb_image *image) > >> +{ > >> + if (drm_fbdev_use_iomem(info)) > >> + drm_fb_helper_cfb_imageblit(info, image); > >> + else > >> + drm_fb_helper_sys_imageblit(info, image); > >> +} > >> + > >> static const struct fb_ops drm_fbdev_fb_ops = { > >> .owner = THIS_MODULE, > >> DRM_FB_HELPER_DEFAULT_OPS, > >> @@ -2034,11 +2233,11 @@ static const struct fb_ops drm_fbdev_fb_ops = { > >> .fb_release = drm_fbdev_fb_release, > >> .fb_destroy = drm_fbdev_fb_destroy, > >> .fb_mmap = drm_fbdev_fb_mmap, > >> - .fb_read = drm_fb_helper_sys_read, > >> - .fb_write = drm_fb_helper_sys_write, > >> - .fb_fillrect = drm_fb_helper_sys_fillrect, > >> - .fb_copyarea = drm_fb_helper_sys_copyarea, > >> - .fb_imageblit = drm_fb_helper_sys_imageblit, > >> + .fb_read = drm_fbdev_fb_read, > >> + .fb_write = drm_fbdev_fb_write, > >> + .fb_fillrect = drm_fbdev_fb_fillrect, > >> + .fb_copyarea = drm_fbdev_fb_copyarea, > >> + .fb_imageblit = drm_fbdev_fb_imageblit, > >> }; > >> > >> static struct fb_deferred_io drm_fbdev_defio = { > >> diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h > >> index 5ffbb4ed5b35..ab424ddd7665 100644 > >> --- a/include/drm/drm_mode_config.h > >> +++ b/include/drm/drm_mode_config.h > >> @@ -877,18 +877,6 @@ struct drm_mode_config { > >> */ > >> bool prefer_shadow_fbdev; > >> > >> - /** > >> - * @fbdev_use_iomem: > >> - * > >> - * Set to true if framebuffer reside in iomem. > >> - * When set to true memcpy_toio() is used when copying the framebuffer in > >> - * drm_fb_helper.drm_fb_helper_dirty_blit_real(). > >> - * > >> - * FIXME: This should be replaced with a per-mapping is_iomem > >> - * flag (like ttm does), and then used everywhere in fbdev code. > >> - */ > >> - bool fbdev_use_iomem; > >> - > >> /** > >> * @quirk_addfb_prefer_xbgr_30bpp: > >> * > >> -- > >> 2.28.0 > >> > > > > -- > Thomas Zimmermann > Graphics Driver Developer > SUSE Software Solutions Germany GmbH > Maxfeldstr. 5, 90409 Nürnberg, Germany > (HRB 36809, AG Nürnberg) > Geschäftsführer: Felix Imendörffer
Hi Thomas. On Tue, Oct 20, 2020 at 02:20:46PM +0200, Thomas Zimmermann wrote: > At least sparc64 requires I/O-specific access to framebuffers. This > patch updates the fbdev console accordingly. > > For drivers with direct access to the framebuffer memory, the callback > functions in struct fb_ops test for the type of memory and call the rsp > fb_sys_ of fb_cfb_ functions. Read and write operations are implemented > internally by DRM's fbdev helper. > > For drivers that employ a shadow buffer, fbdev's blit function retrieves > the framebuffer address as struct dma_buf_map, and uses dma_buf_map > interfaces to access the buffer. > > The bochs driver on sparc64 uses a workaround to flag the framebuffer as > I/O memory and avoid a HW exception. With the introduction of struct > dma_buf_map, this is not required any longer. The patch removes the rsp > code from both, bochs and fbdev. > > v5: > * implement fb_read/fb_write internally (Daniel, Sam) > v4: > * move dma_buf_map changes into separate patch (Daniel) > * TODO list: comment on fbdev updates (Daniel) > > Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> > Tested-by: Sam Ravnborg <sam@ravnborg.org> Reviewed-by: Sam Ravnborg <sam@ravnborg.org> But see a few comments below on naming for you to consider. Sam > --- > Documentation/gpu/todo.rst | 19 ++- > drivers/gpu/drm/bochs/bochs_kms.c | 1 - > drivers/gpu/drm/drm_fb_helper.c | 227 ++++++++++++++++++++++++++++-- > include/drm/drm_mode_config.h | 12 -- > 4 files changed, 230 insertions(+), 29 deletions(-) > > diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst > index 7e6fc3c04add..638b7f704339 100644 > --- a/Documentation/gpu/todo.rst > +++ b/Documentation/gpu/todo.rst > @@ -197,13 +197,28 @@ Convert drivers to use drm_fbdev_generic_setup() > ------------------------------------------------ > > Most drivers can use drm_fbdev_generic_setup(). Driver have to implement > -atomic modesetting and GEM vmap support. Current generic fbdev emulation > -expects the framebuffer in system memory (or system-like memory). > +atomic modesetting and GEM vmap support. Historically, generic fbdev emulation > +expected the framebuffer in system memory or system-like memory. By employing > +struct dma_buf_map, drivers with frambuffers in I/O memory can be supported > +as well. > > Contact: Maintainer of the driver you plan to convert > > Level: Intermediate > > +Reimplement functions in drm_fbdev_fb_ops without fbdev > +------------------------------------------------------- > + > +A number of callback functions in drm_fbdev_fb_ops could benefit from > +being rewritten without dependencies on the fbdev module. Some of the > +helpers could further benefit from using struct dma_buf_map instead of > +raw pointers. > + > +Contact: Thomas Zimmermann <tzimmermann@suse.de>, Daniel Vetter > + > +Level: Advanced > + > + > drm_framebuffer_funcs and drm_mode_config_funcs.fb_create cleanup > ----------------------------------------------------------------- > > diff --git a/drivers/gpu/drm/bochs/bochs_kms.c b/drivers/gpu/drm/bochs/bochs_kms.c > index 13d0d04c4457..853081d186d5 100644 > --- a/drivers/gpu/drm/bochs/bochs_kms.c > +++ b/drivers/gpu/drm/bochs/bochs_kms.c > @@ -151,7 +151,6 @@ int bochs_kms_init(struct bochs_device *bochs) > bochs->dev->mode_config.preferred_depth = 24; > bochs->dev->mode_config.prefer_shadow = 0; > bochs->dev->mode_config.prefer_shadow_fbdev = 1; > - bochs->dev->mode_config.fbdev_use_iomem = true; > bochs->dev->mode_config.quirk_addfb_prefer_host_byte_order = true; > > bochs->dev->mode_config.funcs = &bochs_mode_funcs; > diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c > index 6212cd7cde1d..1d3180841778 100644 > --- a/drivers/gpu/drm/drm_fb_helper.c > +++ b/drivers/gpu/drm/drm_fb_helper.c > @@ -372,24 +372,22 @@ static void drm_fb_helper_resume_worker(struct work_struct *work) > } > > static void drm_fb_helper_dirty_blit_real(struct drm_fb_helper *fb_helper, > - struct drm_clip_rect *clip) > + struct drm_clip_rect *clip, > + struct dma_buf_map *dst) > { > struct drm_framebuffer *fb = fb_helper->fb; > unsigned int cpp = fb->format->cpp[0]; > size_t offset = clip->y1 * fb->pitches[0] + clip->x1 * cpp; > void *src = fb_helper->fbdev->screen_buffer + offset; > - void *dst = fb_helper->buffer->map.vaddr + offset; > size_t len = (clip->x2 - clip->x1) * cpp; > unsigned int y; > > - for (y = clip->y1; y < clip->y2; y++) { > - if (!fb_helper->dev->mode_config.fbdev_use_iomem) > - memcpy(dst, src, len); > - else > - memcpy_toio((void __iomem *)dst, src, len); > + dma_buf_map_incr(dst, offset); /* go to first pixel within clip rect */ > > + for (y = clip->y1; y < clip->y2; y++) { > + dma_buf_map_memcpy_to(dst, src, len); > + dma_buf_map_incr(dst, fb->pitches[0]); > src += fb->pitches[0]; > - dst += fb->pitches[0]; > } > } > > @@ -417,8 +415,9 @@ static void drm_fb_helper_dirty_work(struct work_struct *work) > ret = drm_client_buffer_vmap(helper->buffer, &map); > if (ret) > return; > - drm_fb_helper_dirty_blit_real(helper, &clip_copy); > + drm_fb_helper_dirty_blit_real(helper, &clip_copy, &map); > } > + > if (helper->fb->funcs->dirty) > helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, > &clip_copy, 1); > @@ -2027,6 +2026,206 @@ static int drm_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) > return -ENODEV; > } > > +static bool drm_fbdev_use_iomem(struct fb_info *info) > +{ > + struct drm_fb_helper *fb_helper = info->par; > + struct drm_client_buffer *buffer = fb_helper->buffer; > + > + return !drm_fbdev_use_shadow_fb(fb_helper) && buffer->map.is_iomem; > +} > + > +static ssize_t fb_read_screen_base(struct fb_info *info, char __user *buf, size_t count, > + loff_t pos) The naming here confused me - a name like: fb_read_iomem() would have helped me more. With the current naming I shall remember that the screen_base member is the iomem pointer. > +{ > + const char __iomem *src = info->screen_base + pos; > + size_t alloc_size = min(count, PAGE_SIZE); > + ssize_t ret = 0; > + char *tmp; > + > + tmp = kmalloc(alloc_size, GFP_KERNEL); > + if (!tmp) > + return -ENOMEM; > + I looked around and could not find other places where we copy from iomem to mem to usermem in chunks of PAGE_SIZE. > + while (count) { > + size_t c = min(count, alloc_size); > + > + memcpy_fromio(tmp, src, c); > + if (copy_to_user(buf, tmp, c)) { > + ret = -EFAULT; > + break; > + } > + > + src += c; > + buf += c; > + ret += c; > + count -= c; > + } > + > + kfree(tmp); > + > + return ret; > +} > + > +static ssize_t fb_read_screen_buffer(struct fb_info *info, char __user *buf, size_t count, > + loff_t pos) And fb_read_sysmem() here. > +{ > + const char *src = info->screen_buffer + pos; > + > + if (copy_to_user(buf, src, count)) > + return -EFAULT; > + > + return count; > +} > + > +static ssize_t drm_fbdev_fb_read(struct fb_info *info, char __user *buf, > + size_t count, loff_t *ppos) > +{ > + loff_t pos = *ppos; > + size_t total_size; > + ssize_t ret; > + > + if (info->state != FBINFO_STATE_RUNNING) > + return -EPERM; > + > + if (info->screen_size) > + total_size = info->screen_size; > + else > + total_size = info->fix.smem_len; > + > + if (pos >= total_size) > + return 0; > + if (count >= total_size) > + count = total_size; > + if (total_size - count < pos) > + count = total_size - pos; > + > + if (drm_fbdev_use_iomem(info)) > + ret = fb_read_screen_base(info, buf, count, pos); > + else > + ret = fb_read_screen_buffer(info, buf, count, pos); > + > + if (ret > 0) > + *ppos = ret; > + > + return ret; > +} > + > +static ssize_t fb_write_screen_base(struct fb_info *info, const char __user *buf, size_t count, > + loff_t pos) fb_write_iomem() > +{ > + char __iomem *dst = info->screen_base + pos; > + size_t alloc_size = min(count, PAGE_SIZE); > + ssize_t ret = 0; > + u8 *tmp; > + > + tmp = kmalloc(alloc_size, GFP_KERNEL); > + if (!tmp) > + return -ENOMEM; > + > + while (count) { > + size_t c = min(count, alloc_size); > + > + if (copy_from_user(tmp, buf, c)) { > + ret = -EFAULT; > + break; > + } > + memcpy_toio(dst, tmp, c); > + > + dst += c; > + buf += c; > + ret += c; > + count -= c; > + } > + > + kfree(tmp); > + > + return ret; > +} > + > +static ssize_t fb_write_screen_buffer(struct fb_info *info, const char __user *buf, size_t count, > + loff_t pos) fb_write_sysmem() > +{ > + char *dst = info->screen_buffer + pos; > + > + if (copy_from_user(dst, buf, count)) > + return -EFAULT; > + > + return count; > +} > + > +static ssize_t drm_fbdev_fb_write(struct fb_info *info, const char __user *buf, > + size_t count, loff_t *ppos) > +{ > + loff_t pos = *ppos; > + size_t total_size; > + ssize_t ret; > + int err; > + > + if (info->state != FBINFO_STATE_RUNNING) > + return -EPERM; > + > + if (info->screen_size) > + total_size = info->screen_size; > + else > + total_size = info->fix.smem_len; > + > + if (pos > total_size) > + return -EFBIG; > + if (count > total_size) { > + err = -EFBIG; > + count = total_size; > + } > + if (total_size - count < pos) { > + if (!err) > + err = -ENOSPC; > + count = total_size - pos; > + } > + > + /* > + * Copy to framebuffer even if we already logged an error. Emulates > + * the behavior of the original fbdev implementation. > + */ > + if (drm_fbdev_use_iomem(info)) > + ret = fb_write_screen_base(info, buf, count, pos); > + else > + ret = fb_write_screen_buffer(info, buf, count, pos); > + > + if (ret > 0) > + *ppos = ret; > + > + if (err) > + return err; > + > + return ret; > +} > + > +static void drm_fbdev_fb_fillrect(struct fb_info *info, > + const struct fb_fillrect *rect) > +{ > + if (drm_fbdev_use_iomem(info)) > + drm_fb_helper_cfb_fillrect(info, rect); > + else > + drm_fb_helper_sys_fillrect(info, rect); > +} > + > +static void drm_fbdev_fb_copyarea(struct fb_info *info, > + const struct fb_copyarea *area) > +{ > + if (drm_fbdev_use_iomem(info)) > + drm_fb_helper_cfb_copyarea(info, area); > + else > + drm_fb_helper_sys_copyarea(info, area); > +} > + > +static void drm_fbdev_fb_imageblit(struct fb_info *info, > + const struct fb_image *image) > +{ > + if (drm_fbdev_use_iomem(info)) > + drm_fb_helper_cfb_imageblit(info, image); > + else > + drm_fb_helper_sys_imageblit(info, image); > +} > + > static const struct fb_ops drm_fbdev_fb_ops = { > .owner = THIS_MODULE, > DRM_FB_HELPER_DEFAULT_OPS, > @@ -2034,11 +2233,11 @@ static const struct fb_ops drm_fbdev_fb_ops = { > .fb_release = drm_fbdev_fb_release, > .fb_destroy = drm_fbdev_fb_destroy, > .fb_mmap = drm_fbdev_fb_mmap, > - .fb_read = drm_fb_helper_sys_read, > - .fb_write = drm_fb_helper_sys_write, > - .fb_fillrect = drm_fb_helper_sys_fillrect, > - .fb_copyarea = drm_fb_helper_sys_copyarea, > - .fb_imageblit = drm_fb_helper_sys_imageblit, > + .fb_read = drm_fbdev_fb_read, > + .fb_write = drm_fbdev_fb_write, > + .fb_fillrect = drm_fbdev_fb_fillrect, > + .fb_copyarea = drm_fbdev_fb_copyarea, > + .fb_imageblit = drm_fbdev_fb_imageblit, > }; > > static struct fb_deferred_io drm_fbdev_defio = { > diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h > index 5ffbb4ed5b35..ab424ddd7665 100644 > --- a/include/drm/drm_mode_config.h > +++ b/include/drm/drm_mode_config.h > @@ -877,18 +877,6 @@ struct drm_mode_config { > */ > bool prefer_shadow_fbdev; > > - /** > - * @fbdev_use_iomem: > - * > - * Set to true if framebuffer reside in iomem. > - * When set to true memcpy_toio() is used when copying the framebuffer in > - * drm_fb_helper.drm_fb_helper_dirty_blit_real(). > - * > - * FIXME: This should be replaced with a per-mapping is_iomem > - * flag (like ttm does), and then used everywhere in fbdev code. > - */ > - bool fbdev_use_iomem; > - > /** > * @quirk_addfb_prefer_xbgr_30bpp: > * > -- > 2.28.0
Hi Am 24.10.20 um 22:38 schrieb Sam Ravnborg: > Hi Thomas. > > On Tue, Oct 20, 2020 at 02:20:46PM +0200, Thomas Zimmermann wrote: >> At least sparc64 requires I/O-specific access to framebuffers. This >> patch updates the fbdev console accordingly. >> >> For drivers with direct access to the framebuffer memory, the callback >> functions in struct fb_ops test for the type of memory and call the rsp >> fb_sys_ of fb_cfb_ functions. Read and write operations are implemented >> internally by DRM's fbdev helper. >> >> For drivers that employ a shadow buffer, fbdev's blit function retrieves >> the framebuffer address as struct dma_buf_map, and uses dma_buf_map >> interfaces to access the buffer. >> >> The bochs driver on sparc64 uses a workaround to flag the framebuffer as >> I/O memory and avoid a HW exception. With the introduction of struct >> dma_buf_map, this is not required any longer. The patch removes the rsp >> code from both, bochs and fbdev. >> >> v5: >> * implement fb_read/fb_write internally (Daniel, Sam) >> v4: >> * move dma_buf_map changes into separate patch (Daniel) >> * TODO list: comment on fbdev updates (Daniel) >> >> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> >> Tested-by: Sam Ravnborg <sam@ravnborg.org> > Reviewed-by: Sam Ravnborg <sam@ravnborg.org> > > But see a few comments below on naming for you to consider. > > Sam > >> --- >> Documentation/gpu/todo.rst | 19 ++- >> drivers/gpu/drm/bochs/bochs_kms.c | 1 - >> drivers/gpu/drm/drm_fb_helper.c | 227 ++++++++++++++++++++++++++++-- >> include/drm/drm_mode_config.h | 12 -- >> 4 files changed, 230 insertions(+), 29 deletions(-) >> >> diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst >> index 7e6fc3c04add..638b7f704339 100644 >> --- a/Documentation/gpu/todo.rst >> +++ b/Documentation/gpu/todo.rst >> @@ -197,13 +197,28 @@ Convert drivers to use drm_fbdev_generic_setup() >> ------------------------------------------------ >> >> Most drivers can use drm_fbdev_generic_setup(). Driver have to implement >> -atomic modesetting and GEM vmap support. Current generic fbdev emulation >> -expects the framebuffer in system memory (or system-like memory). >> +atomic modesetting and GEM vmap support. Historically, generic fbdev emulation >> +expected the framebuffer in system memory or system-like memory. By employing >> +struct dma_buf_map, drivers with frambuffers in I/O memory can be supported >> +as well. >> >> Contact: Maintainer of the driver you plan to convert >> >> Level: Intermediate >> >> +Reimplement functions in drm_fbdev_fb_ops without fbdev >> +------------------------------------------------------- >> + >> +A number of callback functions in drm_fbdev_fb_ops could benefit from >> +being rewritten without dependencies on the fbdev module. Some of the >> +helpers could further benefit from using struct dma_buf_map instead of >> +raw pointers. >> + >> +Contact: Thomas Zimmermann <tzimmermann@suse.de>, Daniel Vetter >> + >> +Level: Advanced >> + >> + >> drm_framebuffer_funcs and drm_mode_config_funcs.fb_create cleanup >> ----------------------------------------------------------------- >> >> diff --git a/drivers/gpu/drm/bochs/bochs_kms.c b/drivers/gpu/drm/bochs/bochs_kms.c >> index 13d0d04c4457..853081d186d5 100644 >> --- a/drivers/gpu/drm/bochs/bochs_kms.c >> +++ b/drivers/gpu/drm/bochs/bochs_kms.c >> @@ -151,7 +151,6 @@ int bochs_kms_init(struct bochs_device *bochs) >> bochs->dev->mode_config.preferred_depth = 24; >> bochs->dev->mode_config.prefer_shadow = 0; >> bochs->dev->mode_config.prefer_shadow_fbdev = 1; >> - bochs->dev->mode_config.fbdev_use_iomem = true; >> bochs->dev->mode_config.quirk_addfb_prefer_host_byte_order = true; >> >> bochs->dev->mode_config.funcs = &bochs_mode_funcs; >> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c >> index 6212cd7cde1d..1d3180841778 100644 >> --- a/drivers/gpu/drm/drm_fb_helper.c >> +++ b/drivers/gpu/drm/drm_fb_helper.c >> @@ -372,24 +372,22 @@ static void drm_fb_helper_resume_worker(struct work_struct *work) >> } >> >> static void drm_fb_helper_dirty_blit_real(struct drm_fb_helper *fb_helper, >> - struct drm_clip_rect *clip) >> + struct drm_clip_rect *clip, >> + struct dma_buf_map *dst) >> { >> struct drm_framebuffer *fb = fb_helper->fb; >> unsigned int cpp = fb->format->cpp[0]; >> size_t offset = clip->y1 * fb->pitches[0] + clip->x1 * cpp; >> void *src = fb_helper->fbdev->screen_buffer + offset; >> - void *dst = fb_helper->buffer->map.vaddr + offset; >> size_t len = (clip->x2 - clip->x1) * cpp; >> unsigned int y; >> >> - for (y = clip->y1; y < clip->y2; y++) { >> - if (!fb_helper->dev->mode_config.fbdev_use_iomem) >> - memcpy(dst, src, len); >> - else >> - memcpy_toio((void __iomem *)dst, src, len); >> + dma_buf_map_incr(dst, offset); /* go to first pixel within clip rect */ >> >> + for (y = clip->y1; y < clip->y2; y++) { >> + dma_buf_map_memcpy_to(dst, src, len); >> + dma_buf_map_incr(dst, fb->pitches[0]); >> src += fb->pitches[0]; >> - dst += fb->pitches[0]; >> } >> } >> >> @@ -417,8 +415,9 @@ static void drm_fb_helper_dirty_work(struct work_struct *work) >> ret = drm_client_buffer_vmap(helper->buffer, &map); >> if (ret) >> return; >> - drm_fb_helper_dirty_blit_real(helper, &clip_copy); >> + drm_fb_helper_dirty_blit_real(helper, &clip_copy, &map); >> } >> + >> if (helper->fb->funcs->dirty) >> helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, >> &clip_copy, 1); >> @@ -2027,6 +2026,206 @@ static int drm_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) >> return -ENODEV; >> } >> >> +static bool drm_fbdev_use_iomem(struct fb_info *info) >> +{ >> + struct drm_fb_helper *fb_helper = info->par; >> + struct drm_client_buffer *buffer = fb_helper->buffer; >> + >> + return !drm_fbdev_use_shadow_fb(fb_helper) && buffer->map.is_iomem; >> +} >> + >> +static ssize_t fb_read_screen_base(struct fb_info *info, char __user *buf, size_t count, >> + loff_t pos) > The naming here confused me - a name like: > fb_read_iomem() would have helped me more. > With the current naming I shall remember that the screen_base member is > the iomem pointer. Yeah, true. In terms of naming, I was undecided. I was thinking about adopting a naming similar to what you describe, but OTOH we don't use sysmem anywhere in the code. I thought about adopting fbdev's conention of using _sys_ and _cfb_. But that would make sensein the local context. > >> +{ >> + const char __iomem *src = info->screen_base + pos; >> + size_t alloc_size = min(count, PAGE_SIZE); >> + ssize_t ret = 0; >> + char *tmp; >> + >> + tmp = kmalloc(alloc_size, GFP_KERNEL); >> + if (!tmp) >> + return -ENOMEM; >> + > > I looked around and could not find other places where > we copy from iomem to mem to usermem in chunks of PAGE_SIZE. I took this pattern from fbdev's original implementation. I think it's done to work nicely with kmalloc. Best regards Thomas > >> + while (count) { >> + size_t c = min(count, alloc_size); >> + >> + memcpy_fromio(tmp, src, c); >> + if (copy_to_user(buf, tmp, c)) { >> + ret = -EFAULT; >> + break; >> + } >> + >> + src += c; >> + buf += c; >> + ret += c; >> + count -= c; >> + } >> + >> + kfree(tmp); >> + >> + return ret; >> +} >> + >> +static ssize_t fb_read_screen_buffer(struct fb_info *info, char __user *buf, size_t count, >> + loff_t pos) > And fb_read_sysmem() here. > >> +{ >> + const char *src = info->screen_buffer + pos; >> + >> + if (copy_to_user(buf, src, count)) >> + return -EFAULT; >> + >> + return count; >> +} >> + >> +static ssize_t drm_fbdev_fb_read(struct fb_info *info, char __user *buf, >> + size_t count, loff_t *ppos) >> +{ >> + loff_t pos = *ppos; >> + size_t total_size; >> + ssize_t ret; >> + >> + if (info->state != FBINFO_STATE_RUNNING) >> + return -EPERM; >> + >> + if (info->screen_size) >> + total_size = info->screen_size; >> + else >> + total_size = info->fix.smem_len; >> + >> + if (pos >= total_size) >> + return 0; >> + if (count >= total_size) >> + count = total_size; >> + if (total_size - count < pos) >> + count = total_size - pos; >> + >> + if (drm_fbdev_use_iomem(info)) >> + ret = fb_read_screen_base(info, buf, count, pos); >> + else >> + ret = fb_read_screen_buffer(info, buf, count, pos); >> + >> + if (ret > 0) >> + *ppos = ret; >> + >> + return ret; >> +} >> + >> +static ssize_t fb_write_screen_base(struct fb_info *info, const char __user *buf, size_t count, >> + loff_t pos) > > fb_write_iomem() > >> +{ >> + char __iomem *dst = info->screen_base + pos; >> + size_t alloc_size = min(count, PAGE_SIZE); >> + ssize_t ret = 0; >> + u8 *tmp; >> + >> + tmp = kmalloc(alloc_size, GFP_KERNEL); >> + if (!tmp) >> + return -ENOMEM; >> + >> + while (count) { >> + size_t c = min(count, alloc_size); >> + >> + if (copy_from_user(tmp, buf, c)) { >> + ret = -EFAULT; >> + break; >> + } >> + memcpy_toio(dst, tmp, c); >> + >> + dst += c; >> + buf += c; >> + ret += c; >> + count -= c; >> + } >> + >> + kfree(tmp); >> + >> + return ret; >> +} >> + >> +static ssize_t fb_write_screen_buffer(struct fb_info *info, const char __user *buf, size_t count, >> + loff_t pos) > fb_write_sysmem() > >> +{ >> + char *dst = info->screen_buffer + pos; >> + >> + if (copy_from_user(dst, buf, count)) >> + return -EFAULT; >> + >> + return count; >> +} >> + >> +static ssize_t drm_fbdev_fb_write(struct fb_info *info, const char __user *buf, >> + size_t count, loff_t *ppos) >> +{ >> + loff_t pos = *ppos; >> + size_t total_size; >> + ssize_t ret; >> + int err; >> + >> + if (info->state != FBINFO_STATE_RUNNING) >> + return -EPERM; >> + >> + if (info->screen_size) >> + total_size = info->screen_size; >> + else >> + total_size = info->fix.smem_len; >> + >> + if (pos > total_size) >> + return -EFBIG; >> + if (count > total_size) { >> + err = -EFBIG; >> + count = total_size; >> + } >> + if (total_size - count < pos) { >> + if (!err) >> + err = -ENOSPC; >> + count = total_size - pos; >> + } >> + >> + /* >> + * Copy to framebuffer even if we already logged an error. Emulates >> + * the behavior of the original fbdev implementation. >> + */ >> + if (drm_fbdev_use_iomem(info)) >> + ret = fb_write_screen_base(info, buf, count, pos); >> + else >> + ret = fb_write_screen_buffer(info, buf, count, pos); >> + >> + if (ret > 0) >> + *ppos = ret; >> + >> + if (err) >> + return err; >> + >> + return ret; >> +} >> + >> +static void drm_fbdev_fb_fillrect(struct fb_info *info, >> + const struct fb_fillrect *rect) >> +{ >> + if (drm_fbdev_use_iomem(info)) >> + drm_fb_helper_cfb_fillrect(info, rect); >> + else >> + drm_fb_helper_sys_fillrect(info, rect); >> +} >> + >> +static void drm_fbdev_fb_copyarea(struct fb_info *info, >> + const struct fb_copyarea *area) >> +{ >> + if (drm_fbdev_use_iomem(info)) >> + drm_fb_helper_cfb_copyarea(info, area); >> + else >> + drm_fb_helper_sys_copyarea(info, area); >> +} >> + >> +static void drm_fbdev_fb_imageblit(struct fb_info *info, >> + const struct fb_image *image) >> +{ >> + if (drm_fbdev_use_iomem(info)) >> + drm_fb_helper_cfb_imageblit(info, image); >> + else >> + drm_fb_helper_sys_imageblit(info, image); >> +} >> + >> static const struct fb_ops drm_fbdev_fb_ops = { >> .owner = THIS_MODULE, >> DRM_FB_HELPER_DEFAULT_OPS, >> @@ -2034,11 +2233,11 @@ static const struct fb_ops drm_fbdev_fb_ops = { >> .fb_release = drm_fbdev_fb_release, >> .fb_destroy = drm_fbdev_fb_destroy, >> .fb_mmap = drm_fbdev_fb_mmap, >> - .fb_read = drm_fb_helper_sys_read, >> - .fb_write = drm_fb_helper_sys_write, >> - .fb_fillrect = drm_fb_helper_sys_fillrect, >> - .fb_copyarea = drm_fb_helper_sys_copyarea, >> - .fb_imageblit = drm_fb_helper_sys_imageblit, >> + .fb_read = drm_fbdev_fb_read, >> + .fb_write = drm_fbdev_fb_write, >> + .fb_fillrect = drm_fbdev_fb_fillrect, >> + .fb_copyarea = drm_fbdev_fb_copyarea, >> + .fb_imageblit = drm_fbdev_fb_imageblit, >> }; >> >> static struct fb_deferred_io drm_fbdev_defio = { >> diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h >> index 5ffbb4ed5b35..ab424ddd7665 100644 >> --- a/include/drm/drm_mode_config.h >> +++ b/include/drm/drm_mode_config.h >> @@ -877,18 +877,6 @@ struct drm_mode_config { >> */ >> bool prefer_shadow_fbdev; >> >> - /** >> - * @fbdev_use_iomem: >> - * >> - * Set to true if framebuffer reside in iomem. >> - * When set to true memcpy_toio() is used when copying the framebuffer in >> - * drm_fb_helper.drm_fb_helper_dirty_blit_real(). >> - * >> - * FIXME: This should be replaced with a per-mapping is_iomem >> - * flag (like ttm does), and then used everywhere in fbdev code. >> - */ >> - bool fbdev_use_iomem; >> - >> /** >> * @quirk_addfb_prefer_xbgr_30bpp: >> * >> -- >> 2.28.0 > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel >
diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst index 7e6fc3c04add..638b7f704339 100644 --- a/Documentation/gpu/todo.rst +++ b/Documentation/gpu/todo.rst @@ -197,13 +197,28 @@ Convert drivers to use drm_fbdev_generic_setup() ------------------------------------------------ Most drivers can use drm_fbdev_generic_setup(). Driver have to implement -atomic modesetting and GEM vmap support. Current generic fbdev emulation -expects the framebuffer in system memory (or system-like memory). +atomic modesetting and GEM vmap support. Historically, generic fbdev emulation +expected the framebuffer in system memory or system-like memory. By employing +struct dma_buf_map, drivers with frambuffers in I/O memory can be supported +as well. Contact: Maintainer of the driver you plan to convert Level: Intermediate +Reimplement functions in drm_fbdev_fb_ops without fbdev +------------------------------------------------------- + +A number of callback functions in drm_fbdev_fb_ops could benefit from +being rewritten without dependencies on the fbdev module. Some of the +helpers could further benefit from using struct dma_buf_map instead of +raw pointers. + +Contact: Thomas Zimmermann <tzimmermann@suse.de>, Daniel Vetter + +Level: Advanced + + drm_framebuffer_funcs and drm_mode_config_funcs.fb_create cleanup ----------------------------------------------------------------- diff --git a/drivers/gpu/drm/bochs/bochs_kms.c b/drivers/gpu/drm/bochs/bochs_kms.c index 13d0d04c4457..853081d186d5 100644 --- a/drivers/gpu/drm/bochs/bochs_kms.c +++ b/drivers/gpu/drm/bochs/bochs_kms.c @@ -151,7 +151,6 @@ int bochs_kms_init(struct bochs_device *bochs) bochs->dev->mode_config.preferred_depth = 24; bochs->dev->mode_config.prefer_shadow = 0; bochs->dev->mode_config.prefer_shadow_fbdev = 1; - bochs->dev->mode_config.fbdev_use_iomem = true; bochs->dev->mode_config.quirk_addfb_prefer_host_byte_order = true; bochs->dev->mode_config.funcs = &bochs_mode_funcs; diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 6212cd7cde1d..1d3180841778 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -372,24 +372,22 @@ static void drm_fb_helper_resume_worker(struct work_struct *work) } static void drm_fb_helper_dirty_blit_real(struct drm_fb_helper *fb_helper, - struct drm_clip_rect *clip) + struct drm_clip_rect *clip, + struct dma_buf_map *dst) { struct drm_framebuffer *fb = fb_helper->fb; unsigned int cpp = fb->format->cpp[0]; size_t offset = clip->y1 * fb->pitches[0] + clip->x1 * cpp; void *src = fb_helper->fbdev->screen_buffer + offset; - void *dst = fb_helper->buffer->map.vaddr + offset; size_t len = (clip->x2 - clip->x1) * cpp; unsigned int y; - for (y = clip->y1; y < clip->y2; y++) { - if (!fb_helper->dev->mode_config.fbdev_use_iomem) - memcpy(dst, src, len); - else - memcpy_toio((void __iomem *)dst, src, len); + dma_buf_map_incr(dst, offset); /* go to first pixel within clip rect */ + for (y = clip->y1; y < clip->y2; y++) { + dma_buf_map_memcpy_to(dst, src, len); + dma_buf_map_incr(dst, fb->pitches[0]); src += fb->pitches[0]; - dst += fb->pitches[0]; } } @@ -417,8 +415,9 @@ static void drm_fb_helper_dirty_work(struct work_struct *work) ret = drm_client_buffer_vmap(helper->buffer, &map); if (ret) return; - drm_fb_helper_dirty_blit_real(helper, &clip_copy); + drm_fb_helper_dirty_blit_real(helper, &clip_copy, &map); } + if (helper->fb->funcs->dirty) helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1); @@ -2027,6 +2026,206 @@ static int drm_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) return -ENODEV; } +static bool drm_fbdev_use_iomem(struct fb_info *info) +{ + struct drm_fb_helper *fb_helper = info->par; + struct drm_client_buffer *buffer = fb_helper->buffer; + + return !drm_fbdev_use_shadow_fb(fb_helper) && buffer->map.is_iomem; +} + +static ssize_t fb_read_screen_base(struct fb_info *info, char __user *buf, size_t count, + loff_t pos) +{ + const char __iomem *src = info->screen_base + pos; + size_t alloc_size = min(count, PAGE_SIZE); + ssize_t ret = 0; + char *tmp; + + tmp = kmalloc(alloc_size, GFP_KERNEL); + if (!tmp) + return -ENOMEM; + + while (count) { + size_t c = min(count, alloc_size); + + memcpy_fromio(tmp, src, c); + if (copy_to_user(buf, tmp, c)) { + ret = -EFAULT; + break; + } + + src += c; + buf += c; + ret += c; + count -= c; + } + + kfree(tmp); + + return ret; +} + +static ssize_t fb_read_screen_buffer(struct fb_info *info, char __user *buf, size_t count, + loff_t pos) +{ + const char *src = info->screen_buffer + pos; + + if (copy_to_user(buf, src, count)) + return -EFAULT; + + return count; +} + +static ssize_t drm_fbdev_fb_read(struct fb_info *info, char __user *buf, + size_t count, loff_t *ppos) +{ + loff_t pos = *ppos; + size_t total_size; + ssize_t ret; + + if (info->state != FBINFO_STATE_RUNNING) + return -EPERM; + + if (info->screen_size) + total_size = info->screen_size; + else + total_size = info->fix.smem_len; + + if (pos >= total_size) + return 0; + if (count >= total_size) + count = total_size; + if (total_size - count < pos) + count = total_size - pos; + + if (drm_fbdev_use_iomem(info)) + ret = fb_read_screen_base(info, buf, count, pos); + else + ret = fb_read_screen_buffer(info, buf, count, pos); + + if (ret > 0) + *ppos = ret; + + return ret; +} + +static ssize_t fb_write_screen_base(struct fb_info *info, const char __user *buf, size_t count, + loff_t pos) +{ + char __iomem *dst = info->screen_base + pos; + size_t alloc_size = min(count, PAGE_SIZE); + ssize_t ret = 0; + u8 *tmp; + + tmp = kmalloc(alloc_size, GFP_KERNEL); + if (!tmp) + return -ENOMEM; + + while (count) { + size_t c = min(count, alloc_size); + + if (copy_from_user(tmp, buf, c)) { + ret = -EFAULT; + break; + } + memcpy_toio(dst, tmp, c); + + dst += c; + buf += c; + ret += c; + count -= c; + } + + kfree(tmp); + + return ret; +} + +static ssize_t fb_write_screen_buffer(struct fb_info *info, const char __user *buf, size_t count, + loff_t pos) +{ + char *dst = info->screen_buffer + pos; + + if (copy_from_user(dst, buf, count)) + return -EFAULT; + + return count; +} + +static ssize_t drm_fbdev_fb_write(struct fb_info *info, const char __user *buf, + size_t count, loff_t *ppos) +{ + loff_t pos = *ppos; + size_t total_size; + ssize_t ret; + int err; + + if (info->state != FBINFO_STATE_RUNNING) + return -EPERM; + + if (info->screen_size) + total_size = info->screen_size; + else + total_size = info->fix.smem_len; + + if (pos > total_size) + return -EFBIG; + if (count > total_size) { + err = -EFBIG; + count = total_size; + } + if (total_size - count < pos) { + if (!err) + err = -ENOSPC; + count = total_size - pos; + } + + /* + * Copy to framebuffer even if we already logged an error. Emulates + * the behavior of the original fbdev implementation. + */ + if (drm_fbdev_use_iomem(info)) + ret = fb_write_screen_base(info, buf, count, pos); + else + ret = fb_write_screen_buffer(info, buf, count, pos); + + if (ret > 0) + *ppos = ret; + + if (err) + return err; + + return ret; +} + +static void drm_fbdev_fb_fillrect(struct fb_info *info, + const struct fb_fillrect *rect) +{ + if (drm_fbdev_use_iomem(info)) + drm_fb_helper_cfb_fillrect(info, rect); + else + drm_fb_helper_sys_fillrect(info, rect); +} + +static void drm_fbdev_fb_copyarea(struct fb_info *info, + const struct fb_copyarea *area) +{ + if (drm_fbdev_use_iomem(info)) + drm_fb_helper_cfb_copyarea(info, area); + else + drm_fb_helper_sys_copyarea(info, area); +} + +static void drm_fbdev_fb_imageblit(struct fb_info *info, + const struct fb_image *image) +{ + if (drm_fbdev_use_iomem(info)) + drm_fb_helper_cfb_imageblit(info, image); + else + drm_fb_helper_sys_imageblit(info, image); +} + static const struct fb_ops drm_fbdev_fb_ops = { .owner = THIS_MODULE, DRM_FB_HELPER_DEFAULT_OPS, @@ -2034,11 +2233,11 @@ static const struct fb_ops drm_fbdev_fb_ops = { .fb_release = drm_fbdev_fb_release, .fb_destroy = drm_fbdev_fb_destroy, .fb_mmap = drm_fbdev_fb_mmap, - .fb_read = drm_fb_helper_sys_read, - .fb_write = drm_fb_helper_sys_write, - .fb_fillrect = drm_fb_helper_sys_fillrect, - .fb_copyarea = drm_fb_helper_sys_copyarea, - .fb_imageblit = drm_fb_helper_sys_imageblit, + .fb_read = drm_fbdev_fb_read, + .fb_write = drm_fbdev_fb_write, + .fb_fillrect = drm_fbdev_fb_fillrect, + .fb_copyarea = drm_fbdev_fb_copyarea, + .fb_imageblit = drm_fbdev_fb_imageblit, }; static struct fb_deferred_io drm_fbdev_defio = { diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h index 5ffbb4ed5b35..ab424ddd7665 100644 --- a/include/drm/drm_mode_config.h +++ b/include/drm/drm_mode_config.h @@ -877,18 +877,6 @@ struct drm_mode_config { */ bool prefer_shadow_fbdev; - /** - * @fbdev_use_iomem: - * - * Set to true if framebuffer reside in iomem. - * When set to true memcpy_toio() is used when copying the framebuffer in - * drm_fb_helper.drm_fb_helper_dirty_blit_real(). - * - * FIXME: This should be replaced with a per-mapping is_iomem - * flag (like ttm does), and then used everywhere in fbdev code. - */ - bool fbdev_use_iomem; - /** * @quirk_addfb_prefer_xbgr_30bpp: *