1 // SPDX-License-Identifier: GPL-2.0+ 2 3 #include <linux/crc32.h> 4 5 #include <drm/drm_atomic.h> 6 #include <drm/drm_atomic_helper.h> 7 #include <drm/drm_gem_framebuffer_helper.h> 8 #include <drm/drm_gem_shmem_helper.h> 9 #include <drm/drm_vblank.h> 10 11 #include "vkms_drv.h" 12 13 static u32 get_pixel_from_buffer(int x, int y, const u8 *buffer, 14 const struct vkms_composer *composer) 15 { 16 u32 pixel; 17 int src_offset = composer->offset + (y * composer->pitch) 18 + (x * composer->cpp); 19 20 pixel = *(u32 *)&buffer[src_offset]; 21 22 return pixel; 23 } 24 25 /** 26 * compute_crc - Compute CRC value on output frame 27 * 28 * @vaddr: address to final framebuffer 29 * @composer: framebuffer's metadata 30 * 31 * returns CRC value computed using crc32 on the visible portion of 32 * the final framebuffer at vaddr_out 33 */ 34 static uint32_t compute_crc(const u8 *vaddr, 35 const struct vkms_composer *composer) 36 { 37 int x, y; 38 u32 crc = 0, pixel = 0; 39 int x_src = composer->src.x1 >> 16; 40 int y_src = composer->src.y1 >> 16; 41 int h_src = drm_rect_height(&composer->src) >> 16; 42 int w_src = drm_rect_width(&composer->src) >> 16; 43 44 for (y = y_src; y < y_src + h_src; ++y) { 45 for (x = x_src; x < x_src + w_src; ++x) { 46 pixel = get_pixel_from_buffer(x, y, vaddr, composer); 47 crc = crc32_le(crc, (void *)&pixel, sizeof(u32)); 48 } 49 } 50 51 return crc; 52 } 53 54 static u8 blend_channel(u8 src, u8 dst, u8 alpha) 55 { 56 u32 pre_blend; 57 u8 new_color; 58 59 pre_blend = (src * 255 + dst * (255 - alpha)); 60 61 /* Faster div by 255 */ 62 new_color = ((pre_blend + ((pre_blend + 257) >> 8)) >> 8); 63 64 return new_color; 65 } 66 67 static void alpha_blending(const u8 *argb_src, u8 *argb_dst) 68 { 69 u8 alpha; 70 71 alpha = argb_src[3]; 72 argb_dst[0] = blend_channel(argb_src[0], argb_dst[0], alpha); 73 argb_dst[1] = blend_channel(argb_src[1], argb_dst[1], alpha); 74 argb_dst[2] = blend_channel(argb_src[2], argb_dst[2], alpha); 75 /* Opaque primary */ 76 argb_dst[3] = 0xFF; 77 } 78 79 /** 80 * blend - blend value at vaddr_src with value at vaddr_dst 81 * @vaddr_dst: destination address 82 * @vaddr_src: source address 83 * @dst_composer: destination framebuffer's metadata 84 * @src_composer: source framebuffer's metadata 85 * 86 * Blend the vaddr_src value with the vaddr_dst value using the pre-multiplied 87 * alpha blending equation, since DRM currently assumes that the pixel color 88 * values have already been pre-multiplied with the alpha channel values. See 89 * more drm_plane_create_blend_mode_property(). This function uses buffer's 90 * metadata to locate the new composite values at vaddr_dst. 91 */ 92 static void blend(void *vaddr_dst, void *vaddr_src, 93 struct vkms_composer *dst_composer, 94 struct vkms_composer *src_composer) 95 { 96 int i, j, j_dst, i_dst; 97 int offset_src, offset_dst; 98 u8 *pixel_dst, *pixel_src; 99 100 int x_src = src_composer->src.x1 >> 16; 101 int y_src = src_composer->src.y1 >> 16; 102 103 int x_dst = src_composer->dst.x1; 104 int y_dst = src_composer->dst.y1; 105 int h_dst = drm_rect_height(&src_composer->dst); 106 int w_dst = drm_rect_width(&src_composer->dst); 107 108 int y_limit = y_src + h_dst; 109 int x_limit = x_src + w_dst; 110 111 for (i = y_src, i_dst = y_dst; i < y_limit; ++i) { 112 for (j = x_src, j_dst = x_dst; j < x_limit; ++j) { 113 offset_dst = dst_composer->offset 114 + (i_dst * dst_composer->pitch) 115 + (j_dst++ * dst_composer->cpp); 116 offset_src = src_composer->offset 117 + (i * src_composer->pitch) 118 + (j * src_composer->cpp); 119 120 pixel_src = (u8 *)(vaddr_src + offset_src); 121 pixel_dst = (u8 *)(vaddr_dst + offset_dst); 122 alpha_blending(pixel_src, pixel_dst); 123 } 124 i_dst++; 125 } 126 } 127 128 static void compose_cursor(struct vkms_composer *cursor_composer, 129 struct vkms_composer *primary_composer, 130 void *vaddr_out) 131 { 132 struct drm_gem_object *cursor_obj; 133 struct drm_gem_shmem_object *cursor_shmem_obj; 134 135 cursor_obj = drm_gem_fb_get_obj(&cursor_composer->fb, 0); 136 cursor_shmem_obj = to_drm_gem_shmem_obj(cursor_obj); 137 138 if (WARN_ON(!cursor_shmem_obj->vaddr)) 139 return; 140 141 blend(vaddr_out, cursor_shmem_obj->vaddr, 142 primary_composer, cursor_composer); 143 } 144 145 static int compose_planes(void **vaddr_out, 146 struct vkms_composer *primary_composer, 147 struct vkms_composer *cursor_composer) 148 { 149 struct drm_framebuffer *fb = &primary_composer->fb; 150 struct drm_gem_object *gem_obj = drm_gem_fb_get_obj(fb, 0); 151 struct drm_gem_shmem_object *shmem_obj = to_drm_gem_shmem_obj(gem_obj); 152 153 if (!*vaddr_out) { 154 *vaddr_out = kzalloc(shmem_obj->base.size, GFP_KERNEL); 155 if (!*vaddr_out) { 156 DRM_ERROR("Cannot allocate memory for output frame."); 157 return -ENOMEM; 158 } 159 } 160 161 if (WARN_ON(!shmem_obj->vaddr)) 162 return -EINVAL; 163 164 memcpy(*vaddr_out, shmem_obj->vaddr, shmem_obj->base.size); 165 166 if (cursor_composer) 167 compose_cursor(cursor_composer, primary_composer, *vaddr_out); 168 169 return 0; 170 } 171 172 /** 173 * vkms_composer_worker - ordered work_struct to compute CRC 174 * 175 * @work: work_struct 176 * 177 * Work handler for composing and computing CRCs. work_struct scheduled in 178 * an ordered workqueue that's periodically scheduled to run by 179 * _vblank_handle() and flushed at vkms_atomic_crtc_destroy_state(). 180 */ 181 void vkms_composer_worker(struct work_struct *work) 182 { 183 struct vkms_crtc_state *crtc_state = container_of(work, 184 struct vkms_crtc_state, 185 composer_work); 186 struct drm_crtc *crtc = crtc_state->base.crtc; 187 struct vkms_output *out = drm_crtc_to_vkms_output(crtc); 188 struct vkms_composer *primary_composer = NULL; 189 struct vkms_composer *cursor_composer = NULL; 190 bool crc_pending, wb_pending; 191 void *vaddr_out = NULL; 192 u32 crc32 = 0; 193 u64 frame_start, frame_end; 194 int ret; 195 196 spin_lock_irq(&out->composer_lock); 197 frame_start = crtc_state->frame_start; 198 frame_end = crtc_state->frame_end; 199 crc_pending = crtc_state->crc_pending; 200 wb_pending = crtc_state->wb_pending; 201 crtc_state->frame_start = 0; 202 crtc_state->frame_end = 0; 203 crtc_state->crc_pending = false; 204 spin_unlock_irq(&out->composer_lock); 205 206 /* 207 * We raced with the vblank hrtimer and previous work already computed 208 * the crc, nothing to do. 209 */ 210 if (!crc_pending) 211 return; 212 213 if (crtc_state->num_active_planes >= 1) 214 primary_composer = crtc_state->active_planes[0]->composer; 215 216 if (crtc_state->num_active_planes == 2) 217 cursor_composer = crtc_state->active_planes[1]->composer; 218 219 if (!primary_composer) 220 return; 221 222 if (wb_pending) 223 vaddr_out = crtc_state->active_writeback; 224 225 ret = compose_planes(&vaddr_out, primary_composer, cursor_composer); 226 if (ret) { 227 if (ret == -EINVAL && !wb_pending) 228 kfree(vaddr_out); 229 return; 230 } 231 232 crc32 = compute_crc(vaddr_out, primary_composer); 233 234 if (wb_pending) { 235 drm_writeback_signal_completion(&out->wb_connector, 0); 236 spin_lock_irq(&out->composer_lock); 237 crtc_state->wb_pending = false; 238 spin_unlock_irq(&out->composer_lock); 239 } else { 240 kfree(vaddr_out); 241 } 242 243 /* 244 * The worker can fall behind the vblank hrtimer, make sure we catch up. 245 */ 246 while (frame_start <= frame_end) 247 drm_crtc_add_crc_entry(crtc, true, frame_start++, &crc32); 248 } 249 250 static const char * const pipe_crc_sources[] = {"auto"}; 251 252 const char *const *vkms_get_crc_sources(struct drm_crtc *crtc, 253 size_t *count) 254 { 255 *count = ARRAY_SIZE(pipe_crc_sources); 256 return pipe_crc_sources; 257 } 258 259 static int vkms_crc_parse_source(const char *src_name, bool *enabled) 260 { 261 int ret = 0; 262 263 if (!src_name) { 264 *enabled = false; 265 } else if (strcmp(src_name, "auto") == 0) { 266 *enabled = true; 267 } else { 268 *enabled = false; 269 ret = -EINVAL; 270 } 271 272 return ret; 273 } 274 275 int vkms_verify_crc_source(struct drm_crtc *crtc, const char *src_name, 276 size_t *values_cnt) 277 { 278 bool enabled; 279 280 if (vkms_crc_parse_source(src_name, &enabled) < 0) { 281 DRM_DEBUG_DRIVER("unknown source %s\n", src_name); 282 return -EINVAL; 283 } 284 285 *values_cnt = 1; 286 287 return 0; 288 } 289 290 void vkms_set_composer(struct vkms_output *out, bool enabled) 291 { 292 bool old_enabled; 293 294 if (enabled) 295 drm_crtc_vblank_get(&out->crtc); 296 297 spin_lock_irq(&out->lock); 298 old_enabled = out->composer_enabled; 299 out->composer_enabled = enabled; 300 spin_unlock_irq(&out->lock); 301 302 if (old_enabled) 303 drm_crtc_vblank_put(&out->crtc); 304 } 305 306 int vkms_set_crc_source(struct drm_crtc *crtc, const char *src_name) 307 { 308 struct vkms_output *out = drm_crtc_to_vkms_output(crtc); 309 bool enabled = false; 310 int ret = 0; 311 312 ret = vkms_crc_parse_source(src_name, &enabled); 313 314 vkms_set_composer(out, enabled); 315 316 return ret; 317 } 318