From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?Q?Noralf_Tr=c3=b8nnes?= Date: Wed, 27 Apr 2016 19:24:52 +0000 Subject: Re: [PATCH v3 3/7] drm/fb-helper: Add fb_deferred_io support Message-Id: <57211204.7080703@tronnes.org> List-Id: References: <1461780996-8612-1-git-send-email-noralf@tronnes.org> <1461780996-8612-4-git-send-email-noralf@tronnes.org> <20160427192052.GG2558@phenom.ffwll.local> In-Reply-To: <20160427192052.GG2558@phenom.ffwll.local> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, laurent.pinchart@ideasonboard.com, tomi.valkeinen@ti.com, linux-kernel@vger.kernel.org Den 27.04.2016 21:20, skrev Daniel Vetter: > On Wed, Apr 27, 2016 at 08:16:32PM +0200, Noralf Tr=F8nnes wrote: >> This adds deferred io support to drm_fb_helper. >> The fbdev framebuffer changes are flushed using the callback >> (struct drm_framebuffer *)->funcs->dirty() by a dedicated worker >> ensuring that it always runs in process context. >> >> Signed-off-by: Noralf Tr=F8nnes >> --- >> >> Changes since v2: >> - FB_DEFERRED_IO is now always selected by DRM_KMS_FB_HELPER, ifdef remo= ved >> - The drm_clip_rect utility functions are dropped, so open code it >> - docs: use & to denote structs >> >> Changes since v1: >> - Use a dedicated worker to run the framebuffer flushing like qxl does >> - Add parameter descriptions to drm_fb_helper_deferred_io >> >> drivers/gpu/drm/Kconfig | 1 + >> drivers/gpu/drm/drm_fb_helper.c | 109 ++++++++++++++++++++++++++++++++= +++++++- >> include/drm/drm_fb_helper.h | 15 ++++++ >> 3 files changed, 124 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig >> index 9e4f2f1..8e6f34b 100644 >> --- a/drivers/gpu/drm/Kconfig >> +++ b/drivers/gpu/drm/Kconfig >> @@ -52,6 +52,7 @@ config DRM_KMS_FB_HELPER >> select FB_CFB_FILLRECT >> select FB_CFB_COPYAREA >> select FB_CFB_IMAGEBLIT >> + select FB_DEFERRED_IO >> help >> FBDEV helpers for KMS drivers. >> >> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_he= lper.c >> index 855108e..5112b5d 100644 >> --- a/drivers/gpu/drm/drm_fb_helper.c >> +++ b/drivers/gpu/drm/drm_fb_helper.c >> @@ -48,6 +48,8 @@ MODULE_PARM_DESC(fbdev_emulation, >> >> static LIST_HEAD(kernel_fb_helper_list); >> >> +static void drm_fb_helper_dirty_init(struct drm_fb_helper *helper); > Instead of this forward decl just inline the few setup commands into > drm_fb_helper_prepare. That would mean that I have to forward declare drm_fb_helper_dirty_work() instead. Is that better? Or should I relocate the functions? >> + >> /** >> * DOC: fbdev helpers >> * >> @@ -84,6 +86,15 @@ static LIST_HEAD(kernel_fb_helper_list); >> * and set up an initial configuration using the detected hardware, dr= ivers >> * should call drm_fb_helper_single_add_all_connectors() followed by >> * drm_fb_helper_initial_config(). >> + * >> + * If CONFIG_FB_DEFERRED_IO is enabled and &drm_framebuffer_funcs ->dir= ty is >> + * set, the drm_fb_helper_{cfb,sys}_{write,fillrect,copyarea,imageblit} >> + * functions will accumulate changes and schedule &fb_helper .dirty_wor= k to run >> + * right away. This worker then calls the dirty() function ensuring tha= t it >> + * will always run in process context since the fb_*() function could be >> + * running in atomic context. If drm_fb_helper_deferred_io() is used as= the >> + * deferred_io callback it will also schedule dirty_work with the damage >> + * collected from the mmap page writes. >> */ >> >> /** >> @@ -650,6 +661,7 @@ void drm_fb_helper_prepare(struct drm_device *dev, s= truct drm_fb_helper *helper, >> const struct drm_fb_helper_funcs *funcs) >> { >> INIT_LIST_HEAD(&helper->kernel_fb_list); >> + drm_fb_helper_dirty_init(helper); >> helper->funcs =3D funcs; >> helper->dev =3D dev; >> } >> @@ -834,6 +846,82 @@ void drm_fb_helper_unlink_fbi(struct drm_fb_helper = *fb_helper) >> } >> EXPORT_SYMBOL(drm_fb_helper_unlink_fbi); >> >> +static void drm_fb_helper_dirty_work(struct work_struct *work) >> +{ >> + struct drm_fb_helper *helper =3D container_of(work, struct drm_fb_help= er, >> + dirty_work); >> + struct drm_clip_rect *clip =3D &helper->dirty_clip; >> + struct drm_clip_rect clip_copy; >> + unsigned long flags; >> + >> + spin_lock_irqsave(&helper->dirty_lock, flags); >> + clip_copy =3D *clip; >> + clip->x1 =3D clip->y1 =3D ~0; >> + clip->x2 =3D clip->y2 =3D 0; >> + spin_unlock_irqrestore(&helper->dirty_lock, flags); >> + >> + helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1); >> +} >> + >> +static void drm_fb_helper_dirty_init(struct drm_fb_helper *helper) >> +{ >> + spin_lock_init(&helper->dirty_lock); >> + INIT_WORK(&helper->dirty_work, drm_fb_helper_dirty_work); >> + helper->dirty_clip.x1 =3D helper->dirty_clip.y1 =3D ~0; >> +} >> + >> +static void drm_fb_helper_dirty(struct fb_info *info, u32 x, u32 y, >> + u32 width, u32 height) >> +{ >> + struct drm_fb_helper *helper =3D info->par; >> + struct drm_clip_rect *clip =3D &helper->dirty_clip; >> + unsigned long flags; >> + >> + if (!helper->fb->funcs->dirty) >> + return; >> + >> + spin_lock_irqsave(&helper->dirty_lock, flags); >> + clip->x1 =3D min_t(u32, clip->x1, x); >> + clip->y1 =3D min_t(u32, clip->y1, y); >> + clip->x2 =3D max_t(u32, clip->x2, x + width); >> + clip->y2 =3D max_t(u32, clip->y2, y + height); >> + spin_unlock_irqrestore(&helper->dirty_lock, flags); >> + >> + schedule_work(&helper->dirty_work); >> +} >> + >> +/** >> + * drm_fb_helper_deferred_io() - fbdev deferred_io callback function >> + * @info: fb_info struct pointer >> + * @pagelist: list of dirty mmap framebuffer pages >> + * >> + * This function is used as the &fb_deferred_io ->deferred_io >> + * callback function for flushing the fbdev mmap writes. >> + */ >> +void drm_fb_helper_deferred_io(struct fb_info *info, >> + struct list_head *pagelist) >> +{ >> + unsigned long start, end, min, max; >> + struct page *page; >> + u32 y1, y2; >> + >> + min =3D ULONG_MAX; >> + max =3D 0; >> + list_for_each_entry(page, pagelist, lru) { >> + start =3D page->index << PAGE_SHIFT; >> + end =3D start + PAGE_SIZE - 1; >> + min =3D min(min, start); >> + max =3D max(max, end); >> + } >> + >> + if (min < max) { >> + y1 =3D min / info->fix.line_length; >> + y2 =3D min_t(u32, max / info->fix.line_length, info->var.yres); > Needs a DIV_ROUND_UP here I think. > > Besides these two nits nothing else I've spotted. > > Reviewed-by: Daniel Vetter > > >> + drm_fb_helper_dirty(info, 0, y1, info->var.xres, y2 - y1); >> + } >> +} >> +EXPORT_SYMBOL(drm_fb_helper_deferred_io); >> + >> /** >> * drm_fb_helper_sys_read - wrapper around fb_sys_read >> * @info: fb_info struct pointer >> @@ -862,7 +950,14 @@ EXPORT_SYMBOL(drm_fb_helper_sys_read); >> ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __use= r *buf, >> size_t count, loff_t *ppos) >> { >> - return fb_sys_write(info, buf, count, ppos); >> + ssize_t ret; >> + >> + ret =3D fb_sys_write(info, buf, count, ppos); >> + if (ret > 0) >> + drm_fb_helper_dirty(info, 0, 0, info->var.xres, >> + info->var.yres); >> + >> + return ret; >> } >> EXPORT_SYMBOL(drm_fb_helper_sys_write); >> >> @@ -877,6 +972,8 @@ void drm_fb_helper_sys_fillrect(struct fb_info *info, >> const struct fb_fillrect *rect) >> { >> sys_fillrect(info, rect); >> + drm_fb_helper_dirty(info, rect->dx, rect->dy, >> + rect->width, rect->height); >> } >> EXPORT_SYMBOL(drm_fb_helper_sys_fillrect); >> >> @@ -891,6 +988,8 @@ void drm_fb_helper_sys_copyarea(struct fb_info *info, >> const struct fb_copyarea *area) >> { >> sys_copyarea(info, area); >> + drm_fb_helper_dirty(info, area->dx, area->dy, >> + area->width, area->height); >> } >> EXPORT_SYMBOL(drm_fb_helper_sys_copyarea); >> >> @@ -905,6 +1004,8 @@ void drm_fb_helper_sys_imageblit(struct fb_info *in= fo, >> const struct fb_image *image) >> { >> sys_imageblit(info, image); >> + drm_fb_helper_dirty(info, image->dx, image->dy, >> + image->width, image->height); >> } >> EXPORT_SYMBOL(drm_fb_helper_sys_imageblit); >> >> @@ -919,6 +1020,8 @@ void drm_fb_helper_cfb_fillrect(struct fb_info *inf= o, >> const struct fb_fillrect *rect) >> { >> cfb_fillrect(info, rect); >> + drm_fb_helper_dirty(info, rect->dx, rect->dy, >> + rect->width, rect->height); >> } >> EXPORT_SYMBOL(drm_fb_helper_cfb_fillrect); >> >> @@ -933,6 +1036,8 @@ void drm_fb_helper_cfb_copyarea(struct fb_info *inf= o, >> const struct fb_copyarea *area) >> { >> cfb_copyarea(info, area); >> + drm_fb_helper_dirty(info, area->dx, area->dy, >> + area->width, area->height); >> } >> EXPORT_SYMBOL(drm_fb_helper_cfb_copyarea); >> >> @@ -947,6 +1052,8 @@ void drm_fb_helper_cfb_imageblit(struct fb_info *in= fo, >> const struct fb_image *image) >> { >> cfb_imageblit(info, image); >> + drm_fb_helper_dirty(info, image->dx, image->dy, >> + image->width, image->height); >> } >> EXPORT_SYMBOL(drm_fb_helper_cfb_imageblit); >> >> diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h >> index 062723b..5b4aa35 100644 >> --- a/include/drm/drm_fb_helper.h >> +++ b/include/drm/drm_fb_helper.h >> @@ -172,6 +172,10 @@ struct drm_fb_helper_connector { >> * @funcs: driver callbacks for fb helper >> * @fbdev: emulated fbdev device info struct >> * @pseudo_palette: fake palette of 16 colors >> + * @dirty_clip: clip rectangle used with deferred_io to accumulate dama= ge to >> + * the screen buffer >> + * @dirty_lock: spinlock protecting @dirty_clip >> + * @dirty_work: worker used to flush the framebuffer >> * >> * This is the main structure used by the fbdev helpers. Drivers suppo= rting >> * fbdev emulation should embedded this into their overall driver stru= cture. >> @@ -189,6 +193,9 @@ struct drm_fb_helper { >> const struct drm_fb_helper_funcs *funcs; >> struct fb_info *fbdev; >> u32 pseudo_palette[17]; >> + struct drm_clip_rect dirty_clip; >> + spinlock_t dirty_lock; >> + struct work_struct dirty_work; >> >> /** >> * @kernel_fb_list: >> @@ -245,6 +252,9 @@ void drm_fb_helper_fill_fix(struct fb_info *info, ui= nt32_t pitch, >> >> void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper); >> >> +void drm_fb_helper_deferred_io(struct fb_info *info, >> + struct list_head *pagelist); >> + >> ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf, >> size_t count, loff_t *ppos); >> ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __use= r *buf, >> @@ -368,6 +378,11 @@ static inline void drm_fb_helper_unlink_fbi(struct = drm_fb_helper *fb_helper) >> { >> } >> >> +static inline void drm_fb_helper_deferred_io(struct fb_info *info, >> + struct list_head *pagelist) >> +{ >> +} >> + >> static inline ssize_t drm_fb_helper_sys_read(struct fb_info *info, >> char __user *buf, size_t count, >> loff_t *ppos) >> -- >> 2.2.2 >>