drivers/gpu/drm/gud/gud_pipe.c

   1 // SPDX-License-Identifier: MIT
   2 /*
   3  * Copyright 2020 Noralf Trønnes
   4  */
   5
   6 #include <linux/lz4.h>
   7 #include <linux/usb.h>
   8 #include <linux/workqueue.h>
   9
  10 #include <drm/drm_atomic.h>
  11 #include <drm/drm_connector.h>
  12 #include <drm/drm_damage_helper.h>
  13 #include <drm/drm_drv.h>
  14 #include <drm/drm_format_helper.h>
  15 #include <drm/drm_fourcc.h>
  16 #include <drm/drm_framebuffer.h>
  17 #include <drm/drm_gem.h>
  18 #include <drm/drm_gem_framebuffer_helper.h>
  19 #include <drm/drm_print.h>
  20 #include <drm/drm_rect.h>
  21 #include <drm/drm_simple_kms_helper.h>
  22 #include <drm/gud.h>
  23
  24 #include "gud_internal.h"
  25
  26 /*
  27  * Some userspace rendering loops runs all displays in the same loop.
  28  * This means that a fast display will have to wait for a slow one.
  29  * For this reason gud does flushing asynchronous by default.
  30  * The down side is that in e.g. a single display setup userspace thinks
  31  * the display is insanely fast since the driver reports back immediately
  32  * that the flush/pageflip is done. This wastes CPU and power.
  33  * Such users might want to set this module parameter to false.
  34  */
  35 static bool gud_async_flush = true;
  36 module_param_named(async_flush, gud_async_flush, bool, 0644);
  37 MODULE_PARM_DESC(async_flush, "Enable asynchronous flushing [default=true]");
  38
  39 /*
  40  * FIXME: The driver is probably broken on Big Endian machines.
  41  * See discussion:
  42  * https://lore.kernel.org/dri-devel/CAKb7UvihLX0hgBOP3VBG7O+atwZcUVCPVuBdfmDMpg0NjXe-cQ@mail.gmail.com/
  43  */
  44
  45 static bool gud_is_big_endian(void)
  46 {
  47 #if defined(__BIG_ENDIAN)
  48         return true;
  49 #else
  50         return false;
  51 #endif
  52 }
  53
  54 static size_t gud_xrgb8888_to_r124(u8 *dst, const struct drm_format_info *format,
  55                                    void *src, struct drm_framebuffer *fb,
  56                                    struct drm_rect *rect)
  57 {
  58         unsigned int block_width = drm_format_info_block_width(format, 0);
  59         unsigned int bits_per_pixel = 8 / block_width;
  60         unsigned int x, y, width, height;
  61         u8 pix, *pix8, *block = dst; /* Assign to silence compiler warning */
  62         size_t len;
  63         void *buf;
  64
  65         WARN_ON_ONCE(format->char_per_block[0] != 1);
  66
  67         /* Start on a byte boundary */
  68         rect->x1 = ALIGN_DOWN(rect->x1, block_width);
  69         width = drm_rect_width(rect);
  70         height = drm_rect_height(rect);
  71         len = drm_format_info_min_pitch(format, 0, width) * height;
  72
  73         buf = kmalloc(width * height, GFP_KERNEL);
  74         if (!buf)
  75                 return 0;
  76
  77         drm_fb_xrgb8888_to_gray8(buf, src, fb, rect);
  78         pix8 = buf;
  79
  80         for (y = 0; y < height; y++) {
  81                 for (x = 0; x < width; x++) {
  82                         unsigned int pixpos = x % block_width; /* within byte from the left */
  83                         unsigned int pixshift = (block_width - pixpos - 1) * bits_per_pixel;
  84
  85                         if (!pixpos) {
  86                                 block = dst++;
  87                                 *block = 0;
  88                         }
  89
  90                         pix = (*pix8++) >> (8 - bits_per_pixel);
  91                         *block |= pix << pixshift;
  92                 }
  93         }
  94
  95         kfree(buf);
  96
  97         return len;
  98 }
  99
 100 static size_t gud_xrgb8888_to_color(u8 *dst, const struct drm_format_info *format,
 101                                     void *src, struct drm_framebuffer *fb,
 102                                     struct drm_rect *rect)
 103 {
 104         unsigned int block_width = drm_format_info_block_width(format, 0);
 105         unsigned int bits_per_pixel = 8 / block_width;
 106         u8 r, g, b, pix, *block = dst; /* Assign to silence compiler warning */
 107         unsigned int x, y, width;
 108         u32 *pix32;
 109         size_t len;
 110
 111         /* Start on a byte boundary */
 112         rect->x1 = ALIGN_DOWN(rect->x1, block_width);
 113         width = drm_rect_width(rect);
 114         len = drm_format_info_min_pitch(format, 0, width) * drm_rect_height(rect);
 115
 116         for (y = rect->y1; y < rect->y2; y++) {
 117                 pix32 = src + (y * fb->pitches[0]);
 118                 pix32 += rect->x1;
 119
 120                 for (x = 0; x < width; x++) {
 121                         unsigned int pixpos = x % block_width; /* within byte from the left */
 122                         unsigned int pixshift = (block_width - pixpos - 1) * bits_per_pixel;
 123
 124                         if (!pixpos) {
 125                                 block = dst++;
 126                                 *block = 0;
 127                         }
 128
 129                         r = *pix32 >> 16;
 130                         g = *pix32 >> 8;
 131                         b = *pix32++;
 132
 133                         switch (format->format) {
 134                         case GUD_DRM_FORMAT_XRGB1111:
 135                                 pix = ((r >> 7) << 2) | ((g >> 7) << 1) | (b >> 7);
 136                                 break;
 137                         default:
 138                                 WARN_ON_ONCE(1);
 139                                 return len;
 140                         }
 141
 142                         *block |= pix << pixshift;
 143                 }
 144         }
 145
 146         return len;
 147 }
 148
 149 static int gud_prep_flush(struct gud_device *gdrm, struct drm_framebuffer *fb,
 150                           const struct drm_format_info *format, struct drm_rect *rect,
 151                           struct gud_set_buffer_req *req)
 152 {
 153         struct dma_buf_attachment *import_attach = fb->obj[0]->import_attach;
 154         u8 compression = gdrm->compression;
 155         struct dma_buf_map map[DRM_FORMAT_MAX_PLANES];
 156         struct dma_buf_map map_data[DRM_FORMAT_MAX_PLANES];
 157         void *vaddr, *buf;
 158         size_t pitch, len;
 159         int ret = 0;
 160
 161         pitch = drm_format_info_min_pitch(format, 0, drm_rect_width(rect));
 162         len = pitch * drm_rect_height(rect);
 163         if (len > gdrm->bulk_len)
 164                 return -E2BIG;
 165
 166         ret = drm_gem_fb_vmap(fb, map, map_data);
 167         if (ret)
 168                 return ret;
 169
 170         vaddr = map_data[0].vaddr;
 171
 172         ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
 173         if (ret)
 174                 goto vunmap;
 175 retry:
 176         if (compression)
 177                 buf = gdrm->compress_buf;
 178         else
 179                 buf = gdrm->bulk_buf;
 180
 181         /*
 182          * Imported buffers are assumed to be write-combined and thus uncached
 183          * with slow reads (at least on ARM).
 184          */
 185         if (format != fb->format) {
 186                 if (format->format == GUD_DRM_FORMAT_R1) {
 187                         len = gud_xrgb8888_to_r124(buf, format, vaddr, fb, rect);
 188                         if (!len) {
 189                                 ret = -ENOMEM;
 190                                 goto end_cpu_access;
 191                         }
 192                 } else if (format->format == DRM_FORMAT_R8) {
 193                         drm_fb_xrgb8888_to_gray8(buf, vaddr, fb, rect);
 194                 } else if (format->format == DRM_FORMAT_RGB565) {
 195                         drm_fb_xrgb8888_to_rgb565(buf, vaddr, fb, rect, gud_is_big_endian());
 196                 } else {
 197                         len = gud_xrgb8888_to_color(buf, format, vaddr, fb, rect);
 198                 }
 199         } else if (gud_is_big_endian() && format->cpp[0] > 1) {
 200                 drm_fb_swab(buf, vaddr, fb, rect, !import_attach);
 201         } else if (compression && !import_attach && pitch == fb->pitches[0]) {
 202                 /* can compress directly from the framebuffer */
 203                 buf = vaddr + rect->y1 * pitch;
 204         } else {
 205                 drm_fb_memcpy(buf, vaddr, fb, rect);
 206         }
 207
 208         memset(req, 0, sizeof(*req));
 209         req->x = cpu_to_le32(rect->x1);
 210         req->y = cpu_to_le32(rect->y1);
 211         req->width = cpu_to_le32(drm_rect_width(rect));
 212         req->height = cpu_to_le32(drm_rect_height(rect));
 213         req->length = cpu_to_le32(len);
 214
 215         if (compression & GUD_COMPRESSION_LZ4) {
 216                 int complen;
 217
 218                 complen = LZ4_compress_default(buf, gdrm->bulk_buf, len, len, gdrm->lz4_comp_mem);
 219                 if (complen <= 0) {
 220                         compression = 0;
 221                         goto retry;
 222                 }
 223
 224                 req->compression = GUD_COMPRESSION_LZ4;
 225                 req->compressed_length = cpu_to_le32(complen);
 226         }
 227
 228 end_cpu_access:
 229         drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
 230 vunmap:
 231         drm_gem_fb_vunmap(fb, map);
 232
 233         return ret;
 234 }
 235
 236 struct gud_usb_bulk_context {
 237         struct timer_list timer;
 238         struct usb_sg_request sgr;
 239 };
 240
 241 static void gud_usb_bulk_timeout(struct timer_list *t)
 242 {
 243         struct gud_usb_bulk_context *ctx = from_timer(ctx, t, timer);
 244
 245         usb_sg_cancel(&ctx->sgr);
 246 }
 247
 248 static int gud_usb_bulk(struct gud_device *gdrm, size_t len)
 249 {
 250         struct gud_usb_bulk_context ctx;
 251         int ret;
 252
 253         ret = usb_sg_init(&ctx.sgr, gud_to_usb_device(gdrm), gdrm->bulk_pipe, 0,
 254                           gdrm->bulk_sgt.sgl, gdrm->bulk_sgt.nents, len, GFP_KERNEL);
 255         if (ret)
 256                 return ret;
 257
 258         timer_setup_on_stack(&ctx.timer, gud_usb_bulk_timeout, 0);
 259         mod_timer(&ctx.timer, jiffies + msecs_to_jiffies(3000));
 260
 261         usb_sg_wait(&ctx.sgr);
 262
 263         if (!del_timer_sync(&ctx.timer))
 264                 ret = -ETIMEDOUT;
 265         else if (ctx.sgr.status < 0)
 266                 ret = ctx.sgr.status;
 267         else if (ctx.sgr.bytes != len)
 268                 ret = -EIO;
 269
 270         destroy_timer_on_stack(&ctx.timer);
 271
 272         return ret;
 273 }
 274
 275 static int gud_flush_rect(struct gud_device *gdrm, struct drm_framebuffer *fb,
 276                           const struct drm_format_info *format, struct drm_rect *rect)
 277 {
 278         struct gud_set_buffer_req req;
 279         size_t len, trlen;
 280         int ret;
 281
 282         drm_dbg(&gdrm->drm, "Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));
 283
 284         ret = gud_prep_flush(gdrm, fb, format, rect, &req);
 285         if (ret)
 286                 return ret;
 287
 288         len = le32_to_cpu(req.length);
 289
 290         if (req.compression)
 291                 trlen = le32_to_cpu(req.compressed_length);
 292         else
 293                 trlen = len;
 294
 295         gdrm->stats_length += len;
 296         /* Did it wrap around? */
 297         if (gdrm->stats_length <= len && gdrm->stats_actual_length) {
 298                 gdrm->stats_length = len;
 299                 gdrm->stats_actual_length = 0;
 300         }
 301         gdrm->stats_actual_length += trlen;
 302
 303         if (!(gdrm->flags & GUD_DISPLAY_FLAG_FULL_UPDATE) || gdrm->prev_flush_failed) {
 304                 ret = gud_usb_set(gdrm, GUD_REQ_SET_BUFFER, 0, &req, sizeof(req));
 305                 if (ret)
 306                         return ret;
 307         }
 308
 309         ret = gud_usb_bulk(gdrm, trlen);
 310         if (ret)
 311                 gdrm->stats_num_errors++;
 312
 313         return ret;
 314 }
 315
 316 void gud_clear_damage(struct gud_device *gdrm)
 317 {
 318         gdrm->damage.x1 = INT_MAX;
 319         gdrm->damage.y1 = INT_MAX;
 320         gdrm->damage.x2 = 0;
 321         gdrm->damage.y2 = 0;
 322 }
 323
 324 static void gud_add_damage(struct gud_device *gdrm, struct drm_rect *damage)
 325 {
 326         gdrm->damage.x1 = min(gdrm->damage.x1, damage->x1);
 327         gdrm->damage.y1 = min(gdrm->damage.y1, damage->y1);
 328         gdrm->damage.x2 = max(gdrm->damage.x2, damage->x2);
 329         gdrm->damage.y2 = max(gdrm->damage.y2, damage->y2);
 330 }
 331
 332 static void gud_retry_failed_flush(struct gud_device *gdrm, struct drm_framebuffer *fb,
 333                                    struct drm_rect *damage)
 334 {
 335         /*
 336          * pipe_update waits for the worker when the display mode is going to change.
 337          * This ensures that the width and height is still the same making it safe to
 338          * add back the damage.
 339          */
 340
 341         mutex_lock(&gdrm->damage_lock);
 342         if (!gdrm->fb) {
 343                 drm_framebuffer_get(fb);
 344                 gdrm->fb = fb;
 345         }
 346         gud_add_damage(gdrm, damage);
 347         mutex_unlock(&gdrm->damage_lock);
 348
 349         /* Retry only once to avoid a possible storm in case of continues errors. */
 350         if (!gdrm->prev_flush_failed)
 351                 queue_work(system_long_wq, &gdrm->work);
 352         gdrm->prev_flush_failed = true;
 353 }
 354
 355 void gud_flush_work(struct work_struct *work)
 356 {
 357         struct gud_device *gdrm = container_of(work, struct gud_device, work);
 358         const struct drm_format_info *format;
 359         struct drm_framebuffer *fb;
 360         struct drm_rect damage;
 361         unsigned int i, lines;
 362         int idx, ret = 0;
 363         size_t pitch;
 364
 365         if (!drm_dev_enter(&gdrm->drm, &idx))
 366                 return;
 367
 368         mutex_lock(&gdrm->damage_lock);
 369         fb = gdrm->fb;
 370         gdrm->fb = NULL;
 371         damage = gdrm->damage;
 372         gud_clear_damage(gdrm);
 373         mutex_unlock(&gdrm->damage_lock);
 374
 375         if (!fb)
 376                 goto out;
 377
 378         format = fb->format;
 379         if (format->format == DRM_FORMAT_XRGB8888 && gdrm->xrgb8888_emulation_format)
 380                 format = gdrm->xrgb8888_emulation_format;
 381
 382         /* Split update if it's too big */
 383         pitch = drm_format_info_min_pitch(format, 0, drm_rect_width(&damage));
 384         lines = drm_rect_height(&damage);
 385
 386         if (gdrm->bulk_len < lines * pitch)
 387                 lines = gdrm->bulk_len / pitch;
 388
 389         for (i = 0; i < DIV_ROUND_UP(drm_rect_height(&damage), lines); i++) {
 390                 struct drm_rect rect = damage;
 391
 392                 rect.y1 += i * lines;
 393                 rect.y2 = min_t(u32, rect.y1 + lines, damage.y2);
 394
 395                 ret = gud_flush_rect(gdrm, fb, format, &rect);
 396                 if (ret) {
 397                         if (ret != -ENODEV && ret != -ECONNRESET &&
 398                             ret != -ESHUTDOWN && ret != -EPROTO) {
 399                                 bool prev_flush_failed = gdrm->prev_flush_failed;
 400
 401                                 gud_retry_failed_flush(gdrm, fb, &damage);
 402                                 if (!prev_flush_failed)
 403                                         dev_err_ratelimited(fb->dev->dev,
 404                                                             "Failed to flush framebuffer: error=%d\n", ret);
 405                         }
 406                         break;
 407                 }
 408
 409                 gdrm->prev_flush_failed = false;
 410         }
 411
 412         drm_framebuffer_put(fb);
 413 out:
 414         drm_dev_exit(idx);
 415 }
 416
 417 static void gud_fb_queue_damage(struct gud_device *gdrm, struct drm_framebuffer *fb,
 418                                 struct drm_rect *damage)
 419 {
 420         struct drm_framebuffer *old_fb = NULL;
 421
 422         mutex_lock(&gdrm->damage_lock);
 423
 424         if (fb != gdrm->fb) {
 425                 old_fb = gdrm->fb;
 426                 drm_framebuffer_get(fb);
 427                 gdrm->fb = fb;
 428         }
 429
 430         gud_add_damage(gdrm, damage);
 431
 432         mutex_unlock(&gdrm->damage_lock);
 433
 434         queue_work(system_long_wq, &gdrm->work);
 435
 436         if (old_fb)
 437                 drm_framebuffer_put(old_fb);
 438 }
 439
 440 int gud_pipe_check(struct drm_simple_display_pipe *pipe,
 441                    struct drm_plane_state *new_plane_state,
 442                    struct drm_crtc_state *new_crtc_state)
 443 {
 444         struct gud_device *gdrm = to_gud_device(pipe->crtc.dev);
 445         struct drm_plane_state *old_plane_state = pipe->plane.state;
 446         const struct drm_display_mode *mode = &new_crtc_state->mode;
 447         struct drm_atomic_state *state = new_plane_state->state;
 448         struct drm_framebuffer *old_fb = old_plane_state->fb;
 449         struct drm_connector_state *connector_state = NULL;
 450         struct drm_framebuffer *fb = new_plane_state->fb;
 451         const struct drm_format_info *format = fb->format;
 452         struct drm_connector *connector;
 453         unsigned int i, num_properties;
 454         struct gud_state_req *req;
 455         int idx, ret;
 456         size_t len;
 457
 458         if (WARN_ON_ONCE(!fb))
 459                 return -EINVAL;
 460
 461         if (old_plane_state->rotation != new_plane_state->rotation)
 462                 new_crtc_state->mode_changed = true;
 463
 464         if (old_fb && old_fb->format != format)
 465                 new_crtc_state->mode_changed = true;
 466
 467         if (!new_crtc_state->mode_changed && !new_crtc_state->connectors_changed)
 468                 return 0;
 469
 470         /* Only one connector is supported */
 471         if (hweight32(new_crtc_state->connector_mask) != 1)
 472                 return -EINVAL;
 473
 474         if (format->format == DRM_FORMAT_XRGB8888 && gdrm->xrgb8888_emulation_format)
 475                 format = gdrm->xrgb8888_emulation_format;
 476
 477         for_each_new_connector_in_state(state, connector, connector_state, i) {
 478                 if (connector_state->crtc)
 479                         break;
 480         }
 481
 482         /*
 483          * DRM_IOCTL_MODE_OBJ_SETPROPERTY on the rotation property will not have
 484          * the connector included in the state.
 485          */
 486         if (!connector_state) {
 487                 struct drm_connector_list_iter conn_iter;
 488
 489                 drm_connector_list_iter_begin(pipe->crtc.dev, &conn_iter);
 490                 drm_for_each_connector_iter(connector, &conn_iter) {
 491                         if (connector->state->crtc) {
 492                                 connector_state = connector->state;
 493                                 break;
 494                         }
 495                 }
 496                 drm_connector_list_iter_end(&conn_iter);
 497         }
 498
 499         if (WARN_ON_ONCE(!connector_state))
 500                 return -ENOENT;
 501
 502         len = struct_size(req, properties,
 503                           GUD_PROPERTIES_MAX_NUM + GUD_CONNECTOR_PROPERTIES_MAX_NUM);
 504         req = kzalloc(len, GFP_KERNEL);
 505         if (!req)
 506                 return -ENOMEM;
 507
 508         gud_from_display_mode(&req->mode, mode);
 509
 510         req->format = gud_from_fourcc(format->format);
 511         if (WARN_ON_ONCE(!req->format)) {
 512                 ret = -EINVAL;
 513                 goto out;
 514         }
 515
 516         req->connector = drm_connector_index(connector_state->connector);
 517
 518         ret = gud_connector_fill_properties(connector_state, req->properties);
 519         if (ret < 0)
 520                 goto out;
 521
 522         num_properties = ret;
 523         for (i = 0; i < gdrm->num_properties; i++) {
 524                 u16 prop = gdrm->properties[i];
 525                 u64 val;
 526
 527                 switch (prop) {
 528                 case GUD_PROPERTY_ROTATION:
 529                         /* DRM UAPI matches the protocol so use value directly */
 530                         val = new_plane_state->rotation;
 531                         break;
 532                 default:
 533                         WARN_ON_ONCE(1);
 534                         ret = -EINVAL;
 535                         goto out;
 536                 }
 537
 538                 req->properties[num_properties + i].prop = cpu_to_le16(prop);
 539                 req->properties[num_properties + i].val = cpu_to_le64(val);
 540                 num_properties++;
 541         }
 542
 543         if (drm_dev_enter(fb->dev, &idx)) {
 544                 len = struct_size(req, properties, num_properties);
 545                 ret = gud_usb_set(gdrm, GUD_REQ_SET_STATE_CHECK, 0, req, len);
 546                 drm_dev_exit(idx);
 547         }  else {
 548                 ret = -ENODEV;
 549         }
 550 out:
 551         kfree(req);
 552
 553         return ret;
 554 }
 555
 556 void gud_pipe_update(struct drm_simple_display_pipe *pipe,
 557                      struct drm_plane_state *old_state)
 558 {
 559         struct drm_device *drm = pipe->crtc.dev;
 560         struct gud_device *gdrm = to_gud_device(drm);
 561         struct drm_plane_state *state = pipe->plane.state;
 562         struct drm_framebuffer *fb = state->fb;
 563         struct drm_crtc *crtc = &pipe->crtc;
 564         struct drm_rect damage;
 565         int idx;
 566
 567         if (crtc->state->mode_changed || !crtc->state->enable) {
 568                 cancel_work_sync(&gdrm->work);
 569                 mutex_lock(&gdrm->damage_lock);
 570                 if (gdrm->fb) {
 571                         drm_framebuffer_put(gdrm->fb);
 572                         gdrm->fb = NULL;
 573                 }
 574                 gud_clear_damage(gdrm);
 575                 mutex_unlock(&gdrm->damage_lock);
 576         }
 577
 578         if (!drm_dev_enter(drm, &idx))
 579                 return;
 580
 581         if (!old_state->fb)
 582                 gud_usb_set_u8(gdrm, GUD_REQ_SET_CONTROLLER_ENABLE, 1);
 583
 584         if (fb && (crtc->state->mode_changed || crtc->state->connectors_changed))
 585                 gud_usb_set(gdrm, GUD_REQ_SET_STATE_COMMIT, 0, NULL, 0);
 586
 587         if (crtc->state->active_changed)
 588                 gud_usb_set_u8(gdrm, GUD_REQ_SET_DISPLAY_ENABLE, crtc->state->active);
 589
 590         if (drm_atomic_helper_damage_merged(old_state, state, &damage)) {
 591                 if (gdrm->flags & GUD_DISPLAY_FLAG_FULL_UPDATE)
 592                         drm_rect_init(&damage, 0, 0, fb->width, fb->height);
 593                 gud_fb_queue_damage(gdrm, fb, &damage);
 594                 if (!gud_async_flush)
 595                         flush_work(&gdrm->work);
 596         }
 597
 598         if (!crtc->state->enable)
 599                 gud_usb_set_u8(gdrm, GUD_REQ_SET_CONTROLLER_ENABLE, 0);
 600
 601         drm_dev_exit(idx);
 602 }