1 // SPDX-License-Identifier: MIT 2 3 #include <linux/export.h> 4 #include <linux/moduleparam.h> 5 #include <linux/vmalloc.h> 6 7 #include <drm/drm_crtc_helper.h> 8 #include <drm/drm_drv.h> 9 #include <drm/drm_fb_helper.h> 10 #include <drm/drm_framebuffer.h> 11 #include <drm/drm_gem.h> 12 #include <drm/drm_print.h> 13 14 #include <drm/drm_fbdev_ttm.h> 15 16 /* @user: 1=userspace, 0=fbcon */ 17 static int drm_fbdev_ttm_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_ttm_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_ttm, 39 drm_fb_helper_damage_range, 40 drm_fb_helper_damage_area); 41 42 static void drm_fbdev_ttm_fb_destroy(struct fb_info *info) 43 { 44 struct drm_fb_helper *fb_helper = info->par; 45 void *shadow = info->screen_buffer; 46 47 if (!fb_helper->dev) 48 return; 49 50 fb_deferred_io_cleanup(info); 51 drm_fb_helper_fini(fb_helper); 52 vfree(shadow); 53 drm_client_framebuffer_delete(fb_helper->buffer); 54 55 drm_client_release(&fb_helper->client); 56 drm_fb_helper_unprepare(fb_helper); 57 kfree(fb_helper); 58 } 59 60 static const struct fb_ops drm_fbdev_ttm_fb_ops = { 61 .owner = THIS_MODULE, 62 .fb_open = drm_fbdev_ttm_fb_open, 63 .fb_release = drm_fbdev_ttm_fb_release, 64 FB_DEFAULT_DEFERRED_OPS(drm_fbdev_ttm), 65 DRM_FB_HELPER_DEFAULT_OPS, 66 .fb_destroy = drm_fbdev_ttm_fb_destroy, 67 }; 68 69 static void drm_fbdev_ttm_damage_blit_real(struct drm_fb_helper *fb_helper, 70 struct drm_clip_rect *clip, 71 struct iosys_map *dst) 72 { 73 struct drm_framebuffer *fb = fb_helper->fb; 74 size_t offset = clip->y1 * fb->pitches[0]; 75 size_t len = clip->x2 - clip->x1; 76 unsigned int y; 77 void *src; 78 79 switch (drm_format_info_bpp(fb->format, 0)) { 80 case 1: 81 offset += clip->x1 / 8; 82 len = DIV_ROUND_UP(len + clip->x1 % 8, 8); 83 break; 84 case 2: 85 offset += clip->x1 / 4; 86 len = DIV_ROUND_UP(len + clip->x1 % 4, 4); 87 break; 88 case 4: 89 offset += clip->x1 / 2; 90 len = DIV_ROUND_UP(len + clip->x1 % 2, 2); 91 break; 92 default: 93 offset += clip->x1 * fb->format->cpp[0]; 94 len *= fb->format->cpp[0]; 95 break; 96 } 97 98 src = fb_helper->info->screen_buffer + offset; 99 iosys_map_incr(dst, offset); /* go to first pixel within clip rect */ 100 101 for (y = clip->y1; y < clip->y2; y++) { 102 iosys_map_memcpy_to(dst, 0, src, len); 103 iosys_map_incr(dst, fb->pitches[0]); 104 src += fb->pitches[0]; 105 } 106 } 107 108 static int drm_fbdev_ttm_damage_blit(struct drm_fb_helper *fb_helper, 109 struct drm_clip_rect *clip) 110 { 111 struct drm_client_buffer *buffer = fb_helper->buffer; 112 struct iosys_map map, dst; 113 int ret; 114 115 /* 116 * We have to pin the client buffer to its current location while 117 * flushing the shadow buffer. In the general case, concurrent 118 * modesetting operations could try to move the buffer and would 119 * fail. The modeset has to be serialized by acquiring the reservation 120 * object of the underlying BO here. 121 * 122 * For fbdev emulation, we only have to protect against fbdev modeset 123 * operations. Nothing else will involve the client buffer's BO. So it 124 * is sufficient to acquire struct drm_fb_helper.lock here. 125 */ 126 mutex_lock(&fb_helper->lock); 127 128 ret = drm_client_buffer_vmap_local(buffer, &map); 129 if (ret) 130 goto out; 131 132 dst = map; 133 drm_fbdev_ttm_damage_blit_real(fb_helper, clip, &dst); 134 135 drm_client_buffer_vunmap_local(buffer); 136 137 out: 138 mutex_unlock(&fb_helper->lock); 139 140 return ret; 141 } 142 143 static int drm_fbdev_ttm_helper_fb_dirty(struct drm_fb_helper *helper, 144 struct drm_clip_rect *clip) 145 { 146 struct drm_device *dev = helper->dev; 147 int ret; 148 149 /* Call damage handlers only if necessary */ 150 if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2)) 151 return 0; 152 153 ret = drm_fbdev_ttm_damage_blit(helper, clip); 154 if (drm_WARN_ONCE(dev, ret, "Damage blitter failed: ret=%d\n", ret)) 155 return ret; 156 157 if (helper->fb->funcs->dirty) { 158 ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1); 159 if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret)) 160 return ret; 161 } 162 163 return 0; 164 } 165 166 static const struct drm_fb_helper_funcs drm_fbdev_ttm_helper_funcs = { 167 .fb_dirty = drm_fbdev_ttm_helper_fb_dirty, 168 }; 169 170 /* 171 * struct drm_driver 172 */ 173 174 int drm_fbdev_ttm_driver_fbdev_probe(struct drm_fb_helper *fb_helper, 175 struct drm_fb_helper_surface_size *sizes) 176 { 177 struct drm_client_dev *client = &fb_helper->client; 178 struct drm_device *dev = fb_helper->dev; 179 struct drm_client_buffer *buffer; 180 struct fb_info *info; 181 size_t screen_size; 182 void *screen_buffer; 183 u32 format; 184 int ret; 185 186 drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n", 187 sizes->surface_width, sizes->surface_height, 188 sizes->surface_bpp); 189 190 format = drm_driver_legacy_fb_format(dev, sizes->surface_bpp, 191 sizes->surface_depth); 192 buffer = drm_client_framebuffer_create(client, sizes->surface_width, 193 sizes->surface_height, format); 194 if (IS_ERR(buffer)) 195 return PTR_ERR(buffer); 196 197 fb_helper->funcs = &drm_fbdev_ttm_helper_funcs; 198 fb_helper->buffer = buffer; 199 fb_helper->fb = buffer->fb; 200 201 screen_size = buffer->gem->size; 202 screen_buffer = vzalloc(screen_size); 203 if (!screen_buffer) { 204 ret = -ENOMEM; 205 goto err_drm_client_framebuffer_delete; 206 } 207 208 info = drm_fb_helper_alloc_info(fb_helper); 209 if (IS_ERR(info)) { 210 ret = PTR_ERR(info); 211 goto err_vfree; 212 } 213 214 drm_fb_helper_fill_info(info, fb_helper, sizes); 215 216 info->fbops = &drm_fbdev_ttm_fb_ops; 217 218 /* screen */ 219 info->flags |= FBINFO_VIRTFB | FBINFO_READS_FAST; 220 info->screen_buffer = screen_buffer; 221 info->fix.smem_len = screen_size; 222 223 /* deferred I/O */ 224 fb_helper->fbdefio.delay = HZ / 20; 225 fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io; 226 227 info->fbdefio = &fb_helper->fbdefio; 228 ret = fb_deferred_io_init(info); 229 if (ret) 230 goto err_drm_fb_helper_release_info; 231 232 return 0; 233 234 err_drm_fb_helper_release_info: 235 drm_fb_helper_release_info(fb_helper); 236 err_vfree: 237 vfree(screen_buffer); 238 err_drm_client_framebuffer_delete: 239 fb_helper->fb = NULL; 240 fb_helper->buffer = NULL; 241 drm_client_framebuffer_delete(buffer); 242 return ret; 243 } 244 EXPORT_SYMBOL(drm_fbdev_ttm_driver_fbdev_probe); 245