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 if (info->fbdefio) 52 fb_deferred_io_cleanup(info); 53 drm_fb_helper_fini(fb_helper); 54 55 drm_client_buffer_vunmap(fb_helper->buffer); 56 drm_client_framebuffer_delete(fb_helper->buffer); 57 drm_client_release(&fb_helper->client); 58 drm_fb_helper_unprepare(fb_helper); 59 kfree(fb_helper); 60 } 61 62 static const struct fb_ops drm_fbdev_dma_fb_ops = { 63 .owner = THIS_MODULE, 64 .fb_open = drm_fbdev_dma_fb_open, 65 .fb_release = drm_fbdev_dma_fb_release, 66 __FB_DEFAULT_DMAMEM_OPS_RDWR, 67 DRM_FB_HELPER_DEFAULT_OPS, 68 __FB_DEFAULT_DMAMEM_OPS_DRAW, 69 .fb_mmap = drm_fbdev_dma_fb_mmap, 70 .fb_destroy = drm_fbdev_dma_fb_destroy, 71 }; 72 73 FB_GEN_DEFAULT_DEFERRED_DMAMEM_OPS(drm_fbdev_dma, 74 drm_fb_helper_damage_range, 75 drm_fb_helper_damage_area); 76 77 static int drm_fbdev_dma_deferred_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) 78 { 79 struct drm_fb_helper *fb_helper = info->par; 80 struct drm_framebuffer *fb = fb_helper->fb; 81 struct drm_gem_dma_object *dma = drm_fb_dma_get_gem_obj(fb, 0); 82 83 if (!dma->map_noncoherent) 84 vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); 85 86 return fb_deferred_io_mmap(info, vma); 87 } 88 89 static const struct fb_ops drm_fbdev_dma_deferred_fb_ops = { 90 .owner = THIS_MODULE, 91 .fb_open = drm_fbdev_dma_fb_open, 92 .fb_release = drm_fbdev_dma_fb_release, 93 __FB_DEFAULT_DEFERRED_OPS_RDWR(drm_fbdev_dma), 94 DRM_FB_HELPER_DEFAULT_OPS, 95 __FB_DEFAULT_DEFERRED_OPS_DRAW(drm_fbdev_dma), 96 .fb_mmap = drm_fbdev_dma_deferred_fb_mmap, 97 .fb_destroy = drm_fbdev_dma_fb_destroy, 98 }; 99 100 /* 101 * struct drm_fb_helper 102 */ 103 104 static int drm_fbdev_dma_helper_fb_dirty(struct drm_fb_helper *helper, 105 struct drm_clip_rect *clip) 106 { 107 struct drm_device *dev = helper->dev; 108 int ret; 109 110 /* Call damage handlers only if necessary */ 111 if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2)) 112 return 0; 113 114 if (helper->fb->funcs->dirty) { 115 ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1); 116 if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret)) 117 return ret; 118 } 119 120 return 0; 121 } 122 123 static const struct drm_fb_helper_funcs drm_fbdev_dma_helper_funcs = { 124 .fb_dirty = drm_fbdev_dma_helper_fb_dirty, 125 }; 126 127 /* 128 * struct drm_fb_helper 129 */ 130 131 int drm_fbdev_dma_driver_fbdev_probe(struct drm_fb_helper *fb_helper, 132 struct drm_fb_helper_surface_size *sizes) 133 { 134 struct drm_client_dev *client = &fb_helper->client; 135 struct drm_device *dev = fb_helper->dev; 136 bool use_deferred_io = false; 137 struct drm_client_buffer *buffer; 138 struct drm_gem_dma_object *dma_obj; 139 struct drm_framebuffer *fb; 140 struct fb_info *info; 141 u32 format; 142 struct iosys_map map; 143 int ret; 144 145 drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n", 146 sizes->surface_width, sizes->surface_height, 147 sizes->surface_bpp); 148 149 format = drm_driver_legacy_fb_format(dev, sizes->surface_bpp, 150 sizes->surface_depth); 151 buffer = drm_client_framebuffer_create(client, sizes->surface_width, 152 sizes->surface_height, format); 153 if (IS_ERR(buffer)) 154 return PTR_ERR(buffer); 155 dma_obj = to_drm_gem_dma_obj(buffer->gem); 156 157 fb = buffer->fb; 158 159 /* 160 * Deferred I/O requires struct page for framebuffer memory, 161 * which is not guaranteed for all DMA ranges. We thus only 162 * install deferred I/O if we have a framebuffer that requires 163 * it. 164 */ 165 if (fb->funcs->dirty) 166 use_deferred_io = true; 167 168 ret = drm_client_buffer_vmap(buffer, &map); 169 if (ret) { 170 goto err_drm_client_buffer_delete; 171 } else if (drm_WARN_ON(dev, map.is_iomem)) { 172 ret = -ENODEV; /* I/O memory not supported; use generic emulation */ 173 goto err_drm_client_buffer_delete; 174 } 175 176 fb_helper->funcs = &drm_fbdev_dma_helper_funcs; 177 fb_helper->buffer = buffer; 178 fb_helper->fb = fb; 179 180 info = drm_fb_helper_alloc_info(fb_helper); 181 if (IS_ERR(info)) { 182 ret = PTR_ERR(info); 183 goto err_drm_client_buffer_vunmap; 184 } 185 186 drm_fb_helper_fill_info(info, fb_helper, sizes); 187 188 if (use_deferred_io) 189 info->fbops = &drm_fbdev_dma_deferred_fb_ops; 190 else 191 info->fbops = &drm_fbdev_dma_fb_ops; 192 193 /* screen */ 194 info->flags |= FBINFO_VIRTFB; /* system memory */ 195 if (dma_obj->map_noncoherent) 196 info->flags |= FBINFO_READS_FAST; /* signal caching */ 197 info->screen_size = sizes->surface_height * fb->pitches[0]; 198 info->screen_buffer = map.vaddr; 199 if (!(info->flags & FBINFO_HIDE_SMEM_START)) { 200 if (!drm_WARN_ON(dev, is_vmalloc_addr(info->screen_buffer))) 201 info->fix.smem_start = page_to_phys(virt_to_page(info->screen_buffer)); 202 } 203 info->fix.smem_len = info->screen_size; 204 205 /* 206 * Only set up deferred I/O if the screen buffer supports 207 * it. If this disagrees with the previous test for ->dirty, 208 * mmap on the /dev/fb file might not work correctly. 209 */ 210 if (!is_vmalloc_addr(info->screen_buffer) && info->fix.smem_start) { 211 unsigned long pfn = info->fix.smem_start >> PAGE_SHIFT; 212 213 if (drm_WARN_ON(dev, !pfn_to_page(pfn))) 214 use_deferred_io = false; 215 } 216 217 /* deferred I/O */ 218 if (use_deferred_io) { 219 fb_helper->fbdefio.delay = HZ / 20; 220 fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io; 221 222 info->fbdefio = &fb_helper->fbdefio; 223 ret = fb_deferred_io_init(info); 224 if (ret) 225 goto err_drm_fb_helper_release_info; 226 } 227 228 return 0; 229 230 err_drm_fb_helper_release_info: 231 drm_fb_helper_release_info(fb_helper); 232 err_drm_client_buffer_vunmap: 233 fb_helper->fb = NULL; 234 fb_helper->buffer = NULL; 235 drm_client_buffer_vunmap(buffer); 236 err_drm_client_buffer_delete: 237 drm_client_framebuffer_delete(buffer); 238 return ret; 239 } 240 EXPORT_SYMBOL(drm_fbdev_dma_driver_fbdev_probe); 241