1 // SPDX-License-Identifier: MIT 2 3 #include <linux/export.h> 4 #include <linux/fb.h> 5 6 #include <drm/drm_drv.h> 7 #include <drm/drm_fbdev_shmem.h> 8 #include <drm/drm_fb_helper.h> 9 #include <drm/drm_framebuffer.h> 10 #include <drm/drm_gem_framebuffer_helper.h> 11 #include <drm/drm_gem_shmem_helper.h> 12 13 /* 14 * struct fb_ops 15 */ 16 17 static int drm_fbdev_shmem_fb_open(struct fb_info *info, int user) 18 { 19 struct drm_fb_helper *fb_helper = info->par; 20 21 /* No need to take a ref for fbcon because it unbinds on unregister */ 22 if (user && !try_module_get(fb_helper->dev->driver->fops->owner)) 23 return -ENODEV; 24 25 return 0; 26 } 27 28 static int drm_fbdev_shmem_fb_release(struct fb_info *info, int user) 29 { 30 struct drm_fb_helper *fb_helper = info->par; 31 32 if (user) 33 module_put(fb_helper->dev->driver->fops->owner); 34 35 return 0; 36 } 37 38 FB_GEN_DEFAULT_DEFERRED_SYSMEM_OPS(drm_fbdev_shmem, 39 drm_fb_helper_damage_range, 40 drm_fb_helper_damage_area); 41 42 static int drm_fbdev_shmem_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) 43 { 44 struct drm_fb_helper *fb_helper = info->par; 45 struct drm_framebuffer *fb = fb_helper->fb; 46 struct drm_gem_object *obj = drm_gem_fb_get_obj(fb, 0); 47 struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); 48 49 if (shmem->map_wc) 50 vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); 51 52 return fb_deferred_io_mmap(info, vma); 53 } 54 55 static void drm_fbdev_shmem_fb_destroy(struct fb_info *info) 56 { 57 struct drm_fb_helper *fb_helper = info->par; 58 59 if (!fb_helper->dev) 60 return; 61 62 fb_deferred_io_cleanup(info); 63 drm_fb_helper_fini(fb_helper); 64 65 drm_client_buffer_vunmap(fb_helper->buffer); 66 drm_client_framebuffer_delete(fb_helper->buffer); 67 drm_client_release(&fb_helper->client); 68 drm_fb_helper_unprepare(fb_helper); 69 kfree(fb_helper); 70 } 71 72 static const struct fb_ops drm_fbdev_shmem_fb_ops = { 73 .owner = THIS_MODULE, 74 .fb_open = drm_fbdev_shmem_fb_open, 75 .fb_release = drm_fbdev_shmem_fb_release, 76 __FB_DEFAULT_DEFERRED_OPS_RDWR(drm_fbdev_shmem), 77 DRM_FB_HELPER_DEFAULT_OPS, 78 __FB_DEFAULT_DEFERRED_OPS_DRAW(drm_fbdev_shmem), 79 .fb_mmap = drm_fbdev_shmem_fb_mmap, 80 .fb_destroy = drm_fbdev_shmem_fb_destroy, 81 }; 82 83 static struct page *drm_fbdev_shmem_get_page(struct fb_info *info, unsigned long offset) 84 { 85 struct drm_fb_helper *fb_helper = info->par; 86 struct drm_framebuffer *fb = fb_helper->fb; 87 struct drm_gem_object *obj = drm_gem_fb_get_obj(fb, 0); 88 struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); 89 unsigned int i = offset >> PAGE_SHIFT; 90 struct page *page; 91 92 if (fb_WARN_ON_ONCE(info, offset > obj->size)) 93 return NULL; 94 95 page = shmem->pages[i]; // protected by active vmap 96 if (page) 97 get_page(page); 98 fb_WARN_ON_ONCE(info, !page); 99 100 return page; 101 } 102 103 /* 104 * struct drm_fb_helper 105 */ 106 107 static int drm_fbdev_shmem_helper_fb_dirty(struct drm_fb_helper *helper, 108 struct drm_clip_rect *clip) 109 { 110 struct drm_device *dev = helper->dev; 111 int ret; 112 113 /* Call damage handlers only if necessary */ 114 if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2)) 115 return 0; 116 117 if (helper->fb->funcs->dirty) { 118 ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1); 119 if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret)) 120 return ret; 121 } 122 123 return 0; 124 } 125 126 static const struct drm_fb_helper_funcs drm_fbdev_shmem_helper_funcs = { 127 .fb_dirty = drm_fbdev_shmem_helper_fb_dirty, 128 }; 129 130 /* 131 * struct drm_driver 132 */ 133 134 int drm_fbdev_shmem_driver_fbdev_probe(struct drm_fb_helper *fb_helper, 135 struct drm_fb_helper_surface_size *sizes) 136 { 137 struct drm_client_dev *client = &fb_helper->client; 138 struct drm_device *dev = fb_helper->dev; 139 struct drm_client_buffer *buffer; 140 struct drm_gem_shmem_object *shmem; 141 struct drm_framebuffer *fb; 142 struct fb_info *info; 143 u32 format; 144 struct iosys_map map; 145 int ret; 146 147 drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n", 148 sizes->surface_width, sizes->surface_height, 149 sizes->surface_bpp); 150 151 format = drm_driver_legacy_fb_format(dev, sizes->surface_bpp, sizes->surface_depth); 152 buffer = drm_client_framebuffer_create(client, sizes->surface_width, 153 sizes->surface_height, format); 154 if (IS_ERR(buffer)) 155 return PTR_ERR(buffer); 156 shmem = to_drm_gem_shmem_obj(buffer->gem); 157 158 fb = buffer->fb; 159 160 ret = drm_client_buffer_vmap(buffer, &map); 161 if (ret) { 162 goto err_drm_client_buffer_delete; 163 } else if (drm_WARN_ON(dev, map.is_iomem)) { 164 ret = -ENODEV; /* I/O memory not supported; use generic emulation */ 165 goto err_drm_client_buffer_delete; 166 } 167 168 fb_helper->funcs = &drm_fbdev_shmem_helper_funcs; 169 fb_helper->buffer = buffer; 170 fb_helper->fb = fb; 171 172 info = drm_fb_helper_alloc_info(fb_helper); 173 if (IS_ERR(info)) { 174 ret = PTR_ERR(info); 175 goto err_drm_client_buffer_vunmap; 176 } 177 178 drm_fb_helper_fill_info(info, fb_helper, sizes); 179 180 info->fbops = &drm_fbdev_shmem_fb_ops; 181 182 /* screen */ 183 info->flags |= FBINFO_VIRTFB; /* system memory */ 184 if (!shmem->map_wc) 185 info->flags |= FBINFO_READS_FAST; /* signal caching */ 186 info->screen_size = sizes->surface_height * fb->pitches[0]; 187 info->screen_buffer = map.vaddr; 188 info->fix.smem_len = info->screen_size; 189 190 /* deferred I/O */ 191 fb_helper->fbdefio.delay = HZ / 20; 192 fb_helper->fbdefio.get_page = drm_fbdev_shmem_get_page; 193 fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io; 194 195 info->fbdefio = &fb_helper->fbdefio; 196 ret = fb_deferred_io_init(info); 197 if (ret) 198 goto err_drm_fb_helper_release_info; 199 200 return 0; 201 202 err_drm_fb_helper_release_info: 203 drm_fb_helper_release_info(fb_helper); 204 err_drm_client_buffer_vunmap: 205 fb_helper->fb = NULL; 206 fb_helper->buffer = NULL; 207 drm_client_buffer_vunmap(buffer); 208 err_drm_client_buffer_delete: 209 drm_client_framebuffer_delete(buffer); 210 return ret; 211 } 212 EXPORT_SYMBOL(drm_fbdev_shmem_driver_fbdev_probe); 213