1 // SPDX-License-Identifier: MIT 2 3 #include <linux/fb.h> 4 5 #include <drm/drm_drv.h> 6 #include <drm/drm_fbdev_dma.h> 7 #include <drm/drm_fb_dma_helper.h> 8 #include <drm/drm_fb_helper.h> 9 #include <drm/drm_framebuffer.h> 10 #include <drm/drm_gem_dma_helper.h> 11 12 /* 13 * struct fb_ops 14 */ 15 16 static int drm_fbdev_dma_fb_open(struct fb_info *info, int user) 17 { 18 struct drm_fb_helper *fb_helper = info->par; 19 20 /* No need to take a ref for fbcon because it unbinds on unregister */ 21 if (user && !try_module_get(fb_helper->dev->driver->fops->owner)) 22 return -ENODEV; 23 24 return 0; 25 } 26 27 static int drm_fbdev_dma_fb_release(struct fb_info *info, int user) 28 { 29 struct drm_fb_helper *fb_helper = info->par; 30 31 if (user) 32 module_put(fb_helper->dev->driver->fops->owner); 33 34 return 0; 35 } 36 37 static int drm_fbdev_dma_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) 38 { 39 struct drm_fb_helper *fb_helper = info->par; 40 41 return drm_gem_prime_mmap(fb_helper->buffer->gem, vma); 42 } 43 44 static void drm_fbdev_dma_fb_destroy(struct fb_info *info) 45 { 46 struct drm_fb_helper *fb_helper = info->par; 47 48 if (!fb_helper->dev) 49 return; 50 51 fb_deferred_io_cleanup(info); 52 drm_fb_helper_fini(fb_helper); 53 54 drm_client_buffer_vunmap(fb_helper->buffer); 55 drm_client_framebuffer_delete(fb_helper->buffer); 56 drm_client_release(&fb_helper->client); 57 drm_fb_helper_unprepare(fb_helper); 58 kfree(fb_helper); 59 } 60 61 static const struct fb_ops drm_fbdev_dma_fb_ops = { 62 .owner = THIS_MODULE, 63 .fb_open = drm_fbdev_dma_fb_open, 64 .fb_release = drm_fbdev_dma_fb_release, 65 __FB_DEFAULT_DMAMEM_OPS_RDWR, 66 DRM_FB_HELPER_DEFAULT_OPS, 67 __FB_DEFAULT_DMAMEM_OPS_DRAW, 68 .fb_mmap = drm_fbdev_dma_fb_mmap, 69 .fb_destroy = drm_fbdev_dma_fb_destroy, 70 }; 71 72 FB_GEN_DEFAULT_DEFERRED_DMAMEM_OPS(drm_fbdev_dma, 73 drm_fb_helper_damage_range, 74 drm_fb_helper_damage_area); 75 76 static int drm_fbdev_dma_deferred_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) 77 { 78 struct drm_fb_helper *fb_helper = info->par; 79 struct drm_framebuffer *fb = fb_helper->fb; 80 struct drm_gem_dma_object *dma = drm_fb_dma_get_gem_obj(fb, 0); 81 82 if (!dma->map_noncoherent) 83 vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); 84 85 return fb_deferred_io_mmap(info, vma); 86 } 87 88 static const struct fb_ops drm_fbdev_dma_deferred_fb_ops = { 89 .owner = THIS_MODULE, 90 .fb_open = drm_fbdev_dma_fb_open, 91 .fb_release = drm_fbdev_dma_fb_release, 92 __FB_DEFAULT_DEFERRED_OPS_RDWR(drm_fbdev_dma), 93 DRM_FB_HELPER_DEFAULT_OPS, 94 __FB_DEFAULT_DEFERRED_OPS_DRAW(drm_fbdev_dma), 95 .fb_mmap = drm_fbdev_dma_deferred_fb_mmap, 96 .fb_destroy = drm_fbdev_dma_fb_destroy, 97 }; 98 99 /* 100 * struct drm_fb_helper 101 */ 102 103 static int drm_fbdev_dma_helper_fb_dirty(struct drm_fb_helper *helper, 104 struct drm_clip_rect *clip) 105 { 106 struct drm_device *dev = helper->dev; 107 int ret; 108 109 /* Call damage handlers only if necessary */ 110 if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2)) 111 return 0; 112 113 if (helper->fb->funcs->dirty) { 114 ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1); 115 if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret)) 116 return ret; 117 } 118 119 return 0; 120 } 121 122 static const struct drm_fb_helper_funcs drm_fbdev_dma_helper_funcs = { 123 .fb_dirty = drm_fbdev_dma_helper_fb_dirty, 124 }; 125 126 /* 127 * struct drm_fb_helper 128 */ 129 130 int drm_fbdev_dma_driver_fbdev_probe(struct drm_fb_helper *fb_helper, 131 struct drm_fb_helper_surface_size *sizes) 132 { 133 struct drm_client_dev *client = &fb_helper->client; 134 struct drm_device *dev = fb_helper->dev; 135 bool use_deferred_io = false; 136 struct drm_client_buffer *buffer; 137 struct drm_gem_dma_object *dma_obj; 138 struct drm_framebuffer *fb; 139 struct fb_info *info; 140 u32 format; 141 struct iosys_map map; 142 int ret; 143 144 drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n", 145 sizes->surface_width, sizes->surface_height, 146 sizes->surface_bpp); 147 148 format = drm_driver_legacy_fb_format(dev, sizes->surface_bpp, 149 sizes->surface_depth); 150 buffer = drm_client_framebuffer_create(client, sizes->surface_width, 151 sizes->surface_height, format); 152 if (IS_ERR(buffer)) 153 return PTR_ERR(buffer); 154 dma_obj = to_drm_gem_dma_obj(buffer->gem); 155 156 fb = buffer->fb; 157 158 /* 159 * Deferred I/O requires struct page for framebuffer memory, 160 * which is not guaranteed for all DMA ranges. We thus only 161 * install deferred I/O if we have a framebuffer that requires 162 * it. 163 */ 164 if (fb->funcs->dirty) 165 use_deferred_io = true; 166 167 ret = drm_client_buffer_vmap(buffer, &map); 168 if (ret) { 169 goto err_drm_client_buffer_delete; 170 } else if (drm_WARN_ON(dev, map.is_iomem)) { 171 ret = -ENODEV; /* I/O memory not supported; use generic emulation */ 172 goto err_drm_client_buffer_delete; 173 } 174 175 fb_helper->funcs = &drm_fbdev_dma_helper_funcs; 176 fb_helper->buffer = buffer; 177 fb_helper->fb = fb; 178 179 info = drm_fb_helper_alloc_info(fb_helper); 180 if (IS_ERR(info)) { 181 ret = PTR_ERR(info); 182 goto err_drm_client_buffer_vunmap; 183 } 184 185 drm_fb_helper_fill_info(info, fb_helper, sizes); 186 187 if (use_deferred_io) 188 info->fbops = &drm_fbdev_dma_deferred_fb_ops; 189 else 190 info->fbops = &drm_fbdev_dma_fb_ops; 191 192 /* screen */ 193 info->flags |= FBINFO_VIRTFB; /* system memory */ 194 if (dma_obj->map_noncoherent) 195 info->flags |= FBINFO_READS_FAST; /* signal caching */ 196 info->screen_size = sizes->surface_height * fb->pitches[0]; 197 info->screen_buffer = map.vaddr; 198 if (!(info->flags & FBINFO_HIDE_SMEM_START)) { 199 if (!drm_WARN_ON(dev, is_vmalloc_addr(info->screen_buffer))) 200 info->fix.smem_start = page_to_phys(virt_to_page(info->screen_buffer)); 201 } 202 info->fix.smem_len = info->screen_size; 203 204 /* 205 * Only set up deferred I/O if the screen buffer supports 206 * it. If this disagrees with the previous test for ->dirty, 207 * mmap on the /dev/fb file might not work correctly. 208 */ 209 if (!is_vmalloc_addr(info->screen_buffer) && info->fix.smem_start) { 210 unsigned long pfn = info->fix.smem_start >> PAGE_SHIFT; 211 212 if (drm_WARN_ON(dev, !pfn_to_page(pfn))) 213 use_deferred_io = false; 214 } 215 216 /* deferred I/O */ 217 if (use_deferred_io) { 218 fb_helper->fbdefio.delay = HZ / 20; 219 fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io; 220 221 info->fbdefio = &fb_helper->fbdefio; 222 ret = fb_deferred_io_init(info); 223 if (ret) 224 goto err_drm_fb_helper_release_info; 225 } 226 227 return 0; 228 229 err_drm_fb_helper_release_info: 230 drm_fb_helper_release_info(fb_helper); 231 err_drm_client_buffer_vunmap: 232 fb_helper->fb = NULL; 233 fb_helper->buffer = NULL; 234 drm_client_buffer_vunmap(buffer); 235 err_drm_client_buffer_delete: 236 drm_client_framebuffer_delete(buffer); 237 return ret; 238 } 239 EXPORT_SYMBOL(drm_fbdev_dma_driver_fbdev_probe); 240