The fbdev mmap function fb_mmap() unconditionally overrides the driver's implementation if deferred I/O has been activated. This makes it hard to implement mmap with anything but a vmalloc()'ed software buffer. That is specifically a problem for DRM, where video memory is maintained by a memory manager.
Leave the mmap handling to drivers and expect them to call the helper for deferred I/O by thmeselves.
v4: * unlock mm_lock in fb_mmap() error path (Dan) v3: * fix warning if fb_mmap is missing (kernel test robot) v2: * print a helpful error message if the defio setup is incorrect (Javier)
Signed-off-by: Thomas Zimmermann tzimmermann@suse.de Reviewed-by: Javier Martinez Canillas javierm@redhat.com --- drivers/gpu/drm/drm_fb_helper.c | 4 +++- drivers/gpu/drm/vmwgfx/vmwgfx_fb.c | 1 + drivers/hid/hid-picolcd_fb.c | 1 + drivers/staging/fbtft/fbtft-core.c | 1 + drivers/video/fbdev/broadsheetfb.c | 1 + drivers/video/fbdev/core/fb_defio.c | 1 + drivers/video/fbdev/core/fbmem.c | 22 ++++++++++++---------- drivers/video/fbdev/hecubafb.c | 1 + drivers/video/fbdev/hyperv_fb.c | 1 + drivers/video/fbdev/metronomefb.c | 1 + drivers/video/fbdev/sh_mobile_lcdcfb.c | 6 ++++++ drivers/video/fbdev/smscufx.c | 3 +++ drivers/video/fbdev/ssd1307fb.c | 1 + drivers/video/fbdev/udlfb.c | 3 +++ drivers/video/fbdev/xen-fbfront.c | 1 + 15 files changed, 37 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index d265a73313c9..d06ce0e92d66 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -2118,7 +2118,9 @@ static int drm_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) { struct drm_fb_helper *fb_helper = info->par;
- if (fb_helper->dev->driver->gem_prime_mmap) + if (drm_fbdev_use_shadow_fb(fb_helper)) + return fb_deferred_io_mmap(info, vma); + else if (fb_helper->dev->driver->gem_prime_mmap) return fb_helper->dev->driver->gem_prime_mmap(fb_helper->buffer->gem, vma); else return -ENODEV; diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c b/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c index adf17c740656..02a4a4fa3da3 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c @@ -619,6 +619,7 @@ static const struct fb_ops vmw_fb_ops = { .fb_imageblit = vmw_fb_imageblit, .fb_pan_display = vmw_fb_pan_display, .fb_blank = vmw_fb_blank, + .fb_mmap = fb_deferred_io_mmap, };
int vmw_fb_init(struct vmw_private *vmw_priv) diff --git a/drivers/hid/hid-picolcd_fb.c b/drivers/hid/hid-picolcd_fb.c index 33c102a60992..78515e6bacf0 100644 --- a/drivers/hid/hid-picolcd_fb.c +++ b/drivers/hid/hid-picolcd_fb.c @@ -428,6 +428,7 @@ static const struct fb_ops picolcdfb_ops = { .fb_imageblit = picolcd_fb_imageblit, .fb_check_var = picolcd_fb_check_var, .fb_set_par = picolcd_set_par, + .fb_mmap = fb_deferred_io_mmap, };
diff --git a/drivers/staging/fbtft/fbtft-core.c b/drivers/staging/fbtft/fbtft-core.c index 9c4d797e7ae4..d4e14f7c9d57 100644 --- a/drivers/staging/fbtft/fbtft-core.c +++ b/drivers/staging/fbtft/fbtft-core.c @@ -652,6 +652,7 @@ struct fb_info *fbtft_framebuffer_alloc(struct fbtft_display *display, fbops->fb_imageblit = fbtft_fb_imageblit; fbops->fb_setcolreg = fbtft_fb_setcolreg; fbops->fb_blank = fbtft_fb_blank; + fbops->fb_mmap = fb_deferred_io_mmap;
fbdefio->delay = HZ / fps; fbdefio->sort_pagelist = true; diff --git a/drivers/video/fbdev/broadsheetfb.c b/drivers/video/fbdev/broadsheetfb.c index b9054f658838..528bc0902338 100644 --- a/drivers/video/fbdev/broadsheetfb.c +++ b/drivers/video/fbdev/broadsheetfb.c @@ -1055,6 +1055,7 @@ static const struct fb_ops broadsheetfb_ops = { .fb_fillrect = broadsheetfb_fillrect, .fb_copyarea = broadsheetfb_copyarea, .fb_imageblit = broadsheetfb_imageblit, + .fb_mmap = fb_deferred_io_mmap, };
static struct fb_deferred_io broadsheetfb_defio = { diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c index 6aaf6d0abf39..6924d489a289 100644 --- a/drivers/video/fbdev/core/fb_defio.c +++ b/drivers/video/fbdev/core/fb_defio.c @@ -181,6 +181,7 @@ int fb_deferred_io_mmap(struct fb_info *info, struct vm_area_struct *vma) vma->vm_private_data = info; return 0; } +EXPORT_SYMBOL_GPL(fb_deferred_io_mmap);
/* workqueue callback */ static void fb_deferred_io_work(struct work_struct *work) diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 84427470367b..b445a7a00def 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -1334,7 +1334,6 @@ static int fb_mmap(struct file *file, struct vm_area_struct * vma) { struct fb_info *info = file_fb_info(file); - int (*fb_mmap_fn)(struct fb_info *info, struct vm_area_struct *vma); unsigned long mmio_pgoff; unsigned long start; u32 len; @@ -1343,14 +1342,7 @@ fb_mmap(struct file *file, struct vm_area_struct * vma) return -ENODEV; mutex_lock(&info->mm_lock);
- fb_mmap_fn = info->fbops->fb_mmap; - -#if IS_ENABLED(CONFIG_FB_DEFERRED_IO) - if (info->fbdefio) - fb_mmap_fn = fb_deferred_io_mmap; -#endif - - if (fb_mmap_fn) { + if (info->fbops->fb_mmap) { int res;
/* @@ -1358,9 +1350,19 @@ fb_mmap(struct file *file, struct vm_area_struct * vma) * SME protection is removed ahead of the call */ vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot); - res = fb_mmap_fn(info, vma); + res = info->fbops->fb_mmap(info, vma); mutex_unlock(&info->mm_lock); return res; +#if IS_ENABLED(CONFIG_FB_DEFERRED_IO) + } else if (info->fbdefio) { + /* + * FB deferred I/O wants you to handle mmap in your drivers. At a + * minimum, point struct fb_ops.fb_mmap to fb_deferred_io_mmap(). + */ + dev_warn_once(info->dev, "fbdev mmap not set up for deferred I/O.\n"); + mutex_unlock(&info->mm_lock); + return -ENODEV; +#endif }
/* diff --git a/drivers/video/fbdev/hecubafb.c b/drivers/video/fbdev/hecubafb.c index 00d77105161a..2c483e2cf9ec 100644 --- a/drivers/video/fbdev/hecubafb.c +++ b/drivers/video/fbdev/hecubafb.c @@ -204,6 +204,7 @@ static const struct fb_ops hecubafb_ops = { .fb_fillrect = hecubafb_fillrect, .fb_copyarea = hecubafb_copyarea, .fb_imageblit = hecubafb_imageblit, + .fb_mmap = fb_deferred_io_mmap, };
static struct fb_deferred_io hecubafb_defio = { diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c index c8e0ea27caf1..d7f6abf827b9 100644 --- a/drivers/video/fbdev/hyperv_fb.c +++ b/drivers/video/fbdev/hyperv_fb.c @@ -909,6 +909,7 @@ static const struct fb_ops hvfb_ops = { .fb_copyarea = hvfb_cfb_copyarea, .fb_imageblit = hvfb_cfb_imageblit, .fb_blank = hvfb_blank, + .fb_mmap = fb_deferred_io_mmap, };
diff --git a/drivers/video/fbdev/metronomefb.c b/drivers/video/fbdev/metronomefb.c index af858dd23ea6..2541f2fe065b 100644 --- a/drivers/video/fbdev/metronomefb.c +++ b/drivers/video/fbdev/metronomefb.c @@ -564,6 +564,7 @@ static const struct fb_ops metronomefb_ops = { .fb_fillrect = metronomefb_fillrect, .fb_copyarea = metronomefb_copyarea, .fb_imageblit = metronomefb_imageblit, + .fb_mmap = fb_deferred_io_mmap, };
static struct fb_deferred_io metronomefb_defio = { diff --git a/drivers/video/fbdev/sh_mobile_lcdcfb.c b/drivers/video/fbdev/sh_mobile_lcdcfb.c index aa4ebe3192ec..1dc5079e4518 100644 --- a/drivers/video/fbdev/sh_mobile_lcdcfb.c +++ b/drivers/video/fbdev/sh_mobile_lcdcfb.c @@ -1483,6 +1483,9 @@ sh_mobile_lcdc_overlay_mmap(struct fb_info *info, struct vm_area_struct *vma) { struct sh_mobile_lcdc_overlay *ovl = info->par;
+ if (info->fbdefio) + return fb_deferred_io_mmap(info, vma); + return dma_mmap_coherent(ovl->channel->lcdc->dev, vma, ovl->fb_mem, ovl->dma_handle, ovl->fb_size); } @@ -1957,6 +1960,9 @@ sh_mobile_lcdc_mmap(struct fb_info *info, struct vm_area_struct *vma) { struct sh_mobile_lcdc_chan *ch = info->par;
+ if (info->fbdefio) + return fb_deferred_io_mmap(info, vma); + return dma_mmap_coherent(ch->lcdc->dev, vma, ch->fb_mem, ch->dma_handle, ch->fb_size); } diff --git a/drivers/video/fbdev/smscufx.c b/drivers/video/fbdev/smscufx.c index 28768c272b73..9383f8d0914c 100644 --- a/drivers/video/fbdev/smscufx.c +++ b/drivers/video/fbdev/smscufx.c @@ -779,6 +779,9 @@ static int ufx_ops_mmap(struct fb_info *info, struct vm_area_struct *vma) unsigned long offset = vma->vm_pgoff << PAGE_SHIFT; unsigned long page, pos;
+ if (info->fbdefio) + return fb_deferred_io_mmap(info, vma); + if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT)) return -EINVAL; if (size > info->fix.smem_len) diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c index c6d5df31111d..7547b4628afc 100644 --- a/drivers/video/fbdev/ssd1307fb.c +++ b/drivers/video/fbdev/ssd1307fb.c @@ -368,6 +368,7 @@ static const struct fb_ops ssd1307fb_ops = { .fb_fillrect = ssd1307fb_fillrect, .fb_copyarea = ssd1307fb_copyarea, .fb_imageblit = ssd1307fb_imageblit, + .fb_mmap = fb_deferred_io_mmap, };
static void ssd1307fb_deferred_io(struct fb_info *info, diff --git a/drivers/video/fbdev/udlfb.c b/drivers/video/fbdev/udlfb.c index b6ec0b8e2b72..9e5a33396ef9 100644 --- a/drivers/video/fbdev/udlfb.c +++ b/drivers/video/fbdev/udlfb.c @@ -326,6 +326,9 @@ static int dlfb_ops_mmap(struct fb_info *info, struct vm_area_struct *vma) unsigned long offset = vma->vm_pgoff << PAGE_SHIFT; unsigned long page, pos;
+ if (info->fbdefio) + return fb_deferred_io_mmap(info, vma); + if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT)) return -EINVAL; if (size > info->fix.smem_len) diff --git a/drivers/video/fbdev/xen-fbfront.c b/drivers/video/fbdev/xen-fbfront.c index 6826f986da43..6c8846eba2fb 100644 --- a/drivers/video/fbdev/xen-fbfront.c +++ b/drivers/video/fbdev/xen-fbfront.c @@ -338,6 +338,7 @@ static const struct fb_ops xenfb_fb_ops = { .fb_imageblit = xenfb_imageblit, .fb_check_var = xenfb_check_var, .fb_set_par = xenfb_set_par, + .fb_mmap = fb_deferred_io_mmap, };
static irqreturn_t xenfb_event_handler(int rq, void *dev_id)