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_RGB565) {
 193                         drm_fb_xrgb8888_to_rgb565(buf, vaddr, fb, rect, gud_is_big_endian());
 194                 } else {
 195                         len = gud_xrgb8888_to_color(buf, format, vaddr, fb, rect);
 196                 }
 197         } else if (gud_is_big_endian() && format->cpp[0] > 1) {
 198                 drm_fb_swab(buf, vaddr, fb, rect, !import_attach);
 199         } else if (compression && !import_attach && pitch == fb->pitches[0]) {
 200                 /* can compress directly from the framebuffer */
 201                 buf = vaddr + rect->y1 * pitch;
 202         } else {
 203                 drm_fb_memcpy(buf, vaddr, fb, rect);
 204         }
 205
 206         memset(req, 0, sizeof(*req));
 207         req->x = cpu_to_le32(rect->x1);
 208         req->y = cpu_to_le32(rect->y1);
 209         req->width = cpu_to_le32(drm_rect_width(rect));
 210         req->height = cpu_to_le32(drm_rect_height(rect));
 211         req->length = cpu_to_le32(len);
 212
 213         if (compression & GUD_COMPRESSION_LZ4) {
 214                 int complen;
 215
 216                 complen = LZ4_compress_default(buf, gdrm->bulk_buf, len, len, gdrm->lz4_comp_mem);
 217                 if (complen <= 0) {
 218                         compression = 0;
 219                         goto retry;
 220                 }
 221
 222                 req->compression = GUD_COMPRESSION_LZ4;
 223                 req->compressed_length = cpu_to_le32(complen);
 224         }
 225
 226 end_cpu_access:
 227         drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
 228 vunmap:
 229         drm_gem_fb_vunmap(fb, map);
 230
 231         return ret;
 232 }
 233
 234 struct gud_usb_bulk_context {
 235         struct timer_list timer;
 236         struct usb_sg_request sgr;
 237 };
 238
 239 static void gud_usb_bulk_timeout(struct timer_list *t)
 240 {
 241         struct gud_usb_bulk_context *ctx = from_timer(ctx, t, timer);
 242
 243         usb_sg_cancel(&ctx->sgr);
 244 }
 245
 246 static int gud_usb_bulk(struct gud_device *gdrm, size_t len)
 247 {
 248         struct gud_usb_bulk_context ctx;
 249         int ret;
 250
 251         ret = usb_sg_init(&ctx.sgr, gud_to_usb_device(gdrm), gdrm->bulk_pipe, 0,
 252                           gdrm->bulk_sgt.sgl, gdrm->bulk_sgt.nents, len, GFP_KERNEL);
 253         if (ret)
 254                 return ret;
 255
 256         timer_setup_on_stack(&ctx.timer, gud_usb_bulk_timeout, 0);
 257         mod_timer(&ctx.timer, jiffies + msecs_to_jiffies(3000));
 258
 259         usb_sg_wait(&ctx.sgr);
 260
 261         if (!del_timer_sync(&ctx.timer))
 262                 ret = -ETIMEDOUT;
 263         else if (ctx.sgr.status < 0)
 264                 ret = ctx.sgr.status;
 265         else if (ctx.sgr.bytes != len)
 266                 ret = -EIO;
 267
 268         destroy_timer_on_stack(&ctx.timer);
 269
 270         return ret;
 271 }
 272
 273 static int gud_flush_rect(struct gud_device *gdrm, struct drm_framebuffer *fb,
 274                           const struct drm_format_info *format, struct drm_rect *rect)
 275 {
 276         struct gud_set_buffer_req req;
 277         size_t len, trlen;
 278         int ret;
 279
 280         drm_dbg(&gdrm->drm, "Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));
 281
 282         ret = gud_prep_flush(gdrm, fb, format, rect, &req);
 283         if (ret)
 284                 return ret;
 285
 286         len = le32_to_cpu(req.length);
 287
 288         if (req.compression)
 289                 trlen = le32_to_cpu(req.compressed_length);
 290         else
 291                 trlen = len;
 292
 293         gdrm->stats_length += len;
 294         /* Did it wrap around? */
 295         if (gdrm->stats_length <= len && gdrm->stats_actual_length) {
 296                 gdrm->stats_length = len;
 297                 gdrm->stats_actual_length = 0;
 298         }
 299         gdrm->stats_actual_length += trlen;
 300
 301         if (!(gdrm->flags & GUD_DISPLAY_FLAG_FULL_UPDATE) || gdrm->prev_flush_failed) {
 302                 ret = gud_usb_set(gdrm, GUD_REQ_SET_BUFFER, 0, &req, sizeof(req));
 303                 if (ret)
 304                         return ret;
 305         }
 306
 307         ret = gud_usb_bulk(gdrm, trlen);
 308         if (ret)
 309                 gdrm->stats_num_errors++;
 310
 311         return ret;
 312 }
 313
 314 void gud_clear_damage(struct gud_device *gdrm)
 315 {
 316         gdrm->damage.x1 = INT_MAX;
 317         gdrm->damage.y1 = INT_MAX;
 318         gdrm->damage.x2 = 0;
 319         gdrm->damage.y2 = 0;
 320 }
 321
 322 static void gud_add_damage(struct gud_device *gdrm, struct drm_rect *damage)
 323 {
 324         gdrm->damage.x1 = min(gdrm->damage.x1, damage->x1);
 325         gdrm->damage.y1 = min(gdrm->damage.y1, damage->y1);
 326         gdrm->damage.x2 = max(gdrm->damage.x2, damage->x2);
 327         gdrm->damage.y2 = max(gdrm->damage.y2, damage->y2);
 328 }
 329
 330 static void gud_retry_failed_flush(struct gud_device *gdrm, struct drm_framebuffer *fb,
 331                                    struct drm_rect *damage)
 332 {
 333         /*
 334          * pipe_update waits for the worker when the display mode is going to change.
 335          * This ensures that the width and height is still the same making it safe to
 336          * add back the damage.
 337          */
 338
 339         mutex_lock(&gdrm->damage_lock);
 340         if (!gdrm->fb) {
 341                 drm_framebuffer_get(fb);
 342                 gdrm->fb = fb;
 343         }
 344         gud_add_damage(gdrm, damage);
 345         mutex_unlock(&gdrm->damage_lock);
 346
 347         /* Retry only once to avoid a possible storm in case of continues errors. */
 348         if (!gdrm->prev_flush_failed)
 349                 queue_work(system_long_wq, &gdrm->work);
 350         gdrm->prev_flush_failed = true;
 351 }
 352
 353 void gud_flush_work(struct work_struct *work)
 354 {
 355         struct gud_device *gdrm = container_of(work, struct gud_device, work);
 356         const struct drm_format_info *format;
 357         struct drm_framebuffer *fb;
 358         struct drm_rect damage;
 359         unsigned int i, lines;
 360         int idx, ret = 0;
 361         size_t pitch;
 362
 363         if (!drm_dev_enter(&gdrm->drm, &idx))
 364                 return;
 365
 366         mutex_lock(&gdrm->damage_lock);
 367         fb = gdrm->fb;
 368         gdrm->fb = NULL;
 369         damage = gdrm->damage;
 370         gud_clear_damage(gdrm);
 371         mutex_unlock(&gdrm->damage_lock);
 372
 373         if (!fb)
 374                 goto out;
 375
 376         format = fb->format;
 377         if (format->format == DRM_FORMAT_XRGB8888 && gdrm->xrgb8888_emulation_format)
 378                 format = gdrm->xrgb8888_emulation_format;
 379
 380         /* Split update if it's too big */
 381         pitch = drm_format_info_min_pitch(format, 0, drm_rect_width(&damage));
 382         lines = drm_rect_height(&damage);
 383
 384         if (gdrm->bulk_len < lines * pitch)
 385                 lines = gdrm->bulk_len / pitch;
 386
 387         for (i = 0; i < DIV_ROUND_UP(drm_rect_height(&damage), lines); i++) {
 388                 struct drm_rect rect = damage;
 389
 390                 rect.y1 += i * lines;
 391                 rect.y2 = min_t(u32, rect.y1 + lines, damage.y2);
 392
 393                 ret = gud_flush_rect(gdrm, fb, format, &rect);
 394                 if (ret) {
 395                         if (ret != -ENODEV && ret != -ECONNRESET &&
 396                             ret != -ESHUTDOWN && ret != -EPROTO) {
 397                                 bool prev_flush_failed = gdrm->prev_flush_failed;
 398
 399                                 gud_retry_failed_flush(gdrm, fb, &damage);
 400                                 if (!prev_flush_failed)
 401                                         dev_err_ratelimited(fb->dev->dev,
 402                                                             "Failed to flush framebuffer: error=%d\n", ret);
 403                         }
 404                         break;
 405                 }
 406
 407                 gdrm->prev_flush_failed = false;
 408         }
 409
 410         drm_framebuffer_put(fb);
 411 out:
 412         drm_dev_exit(idx);
 413 }
 414
 415 static void gud_fb_queue_damage(struct gud_device *gdrm, struct drm_framebuffer *fb,
 416                                 struct drm_rect *damage)
 417 {
 418         struct drm_framebuffer *old_fb = NULL;
 419
 420         mutex_lock(&gdrm->damage_lock);
 421
 422         if (fb != gdrm->fb) {
 423                 old_fb = gdrm->fb;
 424                 drm_framebuffer_get(fb);
 425                 gdrm->fb = fb;
 426         }
 427
 428         gud_add_damage(gdrm, damage);
 429
 430         mutex_unlock(&gdrm->damage_lock);
 431
 432         queue_work(system_long_wq, &gdrm->work);
 433
 434         if (old_fb)
 435                 drm_framebuffer_put(old_fb);
 436 }
 437
 438 int gud_pipe_check(struct drm_simple_display_pipe *pipe,
 439                    struct drm_plane_state *new_plane_state,
 440                    struct drm_crtc_state *new_crtc_state)
 441 {
 442         struct gud_device *gdrm = to_gud_device(pipe->crtc.dev);
 443         struct drm_plane_state *old_plane_state = pipe->plane.state;
 444         const struct drm_display_mode *mode = &new_crtc_state->mode;
 445         struct drm_atomic_state *state = new_plane_state->state;
 446         struct drm_framebuffer *old_fb = old_plane_state->fb;
 447         struct drm_connector_state *connector_state = NULL;
 448         struct drm_framebuffer *fb = new_plane_state->fb;
 449         const struct drm_format_info *format = fb->format;
 450         struct drm_connector *connector;
 451         unsigned int i, num_properties;
 452         struct gud_state_req *req;
 453         int idx, ret;
 454         size_t len;
 455
 456         if (WARN_ON_ONCE(!fb))
 457                 return -EINVAL;
 458
 459         if (old_plane_state->rotation != new_plane_state->rotation)
 460                 new_crtc_state->mode_changed = true;
 461
 462         if (old_fb && old_fb->format != format)
 463                 new_crtc_state->mode_changed = true;
 464
 465         if (!new_crtc_state->mode_changed && !new_crtc_state->connectors_changed)
 466                 return 0;
 467
 468         /* Only one connector is supported */
 469         if (hweight32(new_crtc_state->connector_mask) != 1)
 470                 return -EINVAL;
 471
 472         if (format->format == DRM_FORMAT_XRGB8888 && gdrm->xrgb8888_emulation_format)
 473                 format = gdrm->xrgb8888_emulation_format;
 474
 475         for_each_new_connector_in_state(state, connector, connector_state, i) {
 476                 if (connector_state->crtc)
 477                         break;
 478         }
 479
 480         /*
 481          * DRM_IOCTL_MODE_OBJ_SETPROPERTY on the rotation property will not have
 482          * the connector included in the state.
 483          */
 484         if (!connector_state) {
 485                 struct drm_connector_list_iter conn_iter;
 486
 487                 drm_connector_list_iter_begin(pipe->crtc.dev, &conn_iter);
 488                 drm_for_each_connector_iter(connector, &conn_iter) {
 489                         if (connector->state->crtc) {
 490                                 connector_state = connector->state;
 491                                 break;
 492                         }
 493                 }
 494                 drm_connector_list_iter_end(&conn_iter);
 495         }
 496
 497         if (WARN_ON_ONCE(!connector_state))
 498                 return -ENOENT;
 499
 500         len = struct_size(req, properties,
 501                           GUD_PROPERTIES_MAX_NUM + GUD_CONNECTOR_PROPERTIES_MAX_NUM);
 502         req = kzalloc(len, GFP_KERNEL);
 503         if (!req)
 504                 return -ENOMEM;
 505
 506         gud_from_display_mode(&req->mode, mode);
 507
 508         req->format = gud_from_fourcc(format->format);
 509         if (WARN_ON_ONCE(!req->format)) {
 510                 ret = -EINVAL;
 511                 goto out;
 512         }
 513
 514         req->connector = drm_connector_index(connector_state->connector);
 515
 516         ret = gud_connector_fill_properties(connector_state, req->properties);
 517         if (ret < 0)
 518                 goto out;
 519
 520         num_properties = ret;
 521         for (i = 0; i < gdrm->num_properties; i++) {
 522                 u16 prop = gdrm->properties[i];
 523                 u64 val;
 524
 525                 switch (prop) {
 526                 case GUD_PROPERTY_ROTATION:
 527                         /* DRM UAPI matches the protocol so use value directly */
 528                         val = new_plane_state->rotation;
 529                         break;
 530                 default:
 531                         WARN_ON_ONCE(1);
 532                         ret = -EINVAL;
 533                         goto out;
 534                 }
 535
 536                 req->properties[num_properties + i].prop = cpu_to_le16(prop);
 537                 req->properties[num_properties + i].val = cpu_to_le64(val);
 538                 num_properties++;
 539         }
 540
 541         if (drm_dev_enter(fb->dev, &idx)) {
 542                 len = struct_size(req, properties, num_properties);
 543                 ret = gud_usb_set(gdrm, GUD_REQ_SET_STATE_CHECK, 0, req, len);
 544                 drm_dev_exit(idx);
 545         }  else {
 546                 ret = -ENODEV;
 547         }
 548 out:
 549         kfree(req);
 550
 551         return ret;
 552 }
 553
 554 void gud_pipe_update(struct drm_simple_display_pipe *pipe,
 555                      struct drm_plane_state *old_state)
 556 {
 557         struct drm_device *drm = pipe->crtc.dev;
 558         struct gud_device *gdrm = to_gud_device(drm);
 559         struct drm_plane_state *state = pipe->plane.state;
 560         struct drm_framebuffer *fb = state->fb;
 561         struct drm_crtc *crtc = &pipe->crtc;
 562         struct drm_rect damage;
 563         int idx;
 564
 565         if (crtc->state->mode_changed || !crtc->state->enable) {
 566                 cancel_work_sync(&gdrm->work);
 567                 mutex_lock(&gdrm->damage_lock);
 568                 if (gdrm->fb) {
 569                         drm_framebuffer_put(gdrm->fb);
 570                         gdrm->fb = NULL;
 571                 }
 572                 gud_clear_damage(gdrm);
 573                 mutex_unlock(&gdrm->damage_lock);
 574         }
 575
 576         if (!drm_dev_enter(drm, &idx))
 577                 return;
 578
 579         if (!old_state->fb)
 580                 gud_usb_set_u8(gdrm, GUD_REQ_SET_CONTROLLER_ENABLE, 1);
 581
 582         if (fb && (crtc->state->mode_changed || crtc->state->connectors_changed))
 583                 gud_usb_set(gdrm, GUD_REQ_SET_STATE_COMMIT, 0, NULL, 0);
 584
 585         if (crtc->state->active_changed)
 586                 gud_usb_set_u8(gdrm, GUD_REQ_SET_DISPLAY_ENABLE, crtc->state->active);
 587
 588         if (drm_atomic_helper_damage_merged(old_state, state, &damage)) {
 589                 if (gdrm->flags & GUD_DISPLAY_FLAG_FULL_UPDATE)
 590                         drm_rect_init(&damage, 0, 0, fb->width, fb->height);
 591                 gud_fb_queue_damage(gdrm, fb, &damage);
 592                 if (!gud_async_flush)
 593                         flush_work(&gdrm->work);
 594         }
 595
 596         if (!crtc->state->enable)
 597                 gud_usb_set_u8(gdrm, GUD_REQ_SET_CONTROLLER_ENABLE, 0);
 598
 599         drm_dev_exit(idx);
 600 }