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