root/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c

DEFINITIONS

1. amdgpu_ring_alloc
2. amdgpu_ring_insert_nop
3. amdgpu_ring_generic_pad_ib
4. amdgpu_ring_commit
5. amdgpu_ring_undo
6. amdgpu_ring_priority_put
7. amdgpu_ring_priority_get
8. amdgpu_ring_init
9. amdgpu_ring_fini
10. amdgpu_ring_emit_reg_write_reg_wait_helper
11. amdgpu_ring_soft_recovery
12. amdgpu_debugfs_ring_read
13. amdgpu_debugfs_ring_init
14. amdgpu_debugfs_ring_fini
15. amdgpu_ring_test_helper

   1 /*
   2  * Copyright 2008 Advanced Micro Devices, Inc.
   3  * Copyright 2008 Red Hat Inc.
   4  * Copyright 2009 Jerome Glisse.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
  20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  22  * OTHER DEALINGS IN THE SOFTWARE.
  23  *
  24  * Authors: Dave Airlie
  25  *          Alex Deucher
  26  *          Jerome Glisse
  27  *          Christian König
  28  */
  29 #include <linux/seq_file.h>
  30 #include <linux/slab.h>
  31 #include <linux/uaccess.h>
  32 #include <linux/debugfs.h>
  33 
  34 #include <drm/amdgpu_drm.h>
  35 #include "amdgpu.h"
  36 #include "atom.h"
  37 
  38 /*
  39  * Rings
  40  * Most engines on the GPU are fed via ring buffers.  Ring
  41  * buffers are areas of GPU accessible memory that the host
  42  * writes commands into and the GPU reads commands out of.
  43  * There is a rptr (read pointer) that determines where the
  44  * GPU is currently reading, and a wptr (write pointer)
  45  * which determines where the host has written.  When the
  46  * pointers are equal, the ring is idle.  When the host
  47  * writes commands to the ring buffer, it increments the
  48  * wptr.  The GPU then starts fetching commands and executes
  49  * them until the pointers are equal again.
  50  */
  51 static int amdgpu_debugfs_ring_init(struct amdgpu_device *adev,
  52                                     struct amdgpu_ring *ring);
  53 static void amdgpu_debugfs_ring_fini(struct amdgpu_ring *ring);
  54 
  55 /**
  56  * amdgpu_ring_alloc - allocate space on the ring buffer
  57  *
  58  * @adev: amdgpu_device pointer
  59  * @ring: amdgpu_ring structure holding ring information
  60  * @ndw: number of dwords to allocate in the ring buffer
  61  *
  62  * Allocate @ndw dwords in the ring buffer (all asics).
  63  * Returns 0 on success, error on failure.
  64  */
  65 int amdgpu_ring_alloc(struct amdgpu_ring *ring, unsigned ndw)
  66 {
  67         /* Align requested size with padding so unlock_commit can
  68          * pad safely */
  69         ndw = (ndw + ring->funcs->align_mask) & ~ring->funcs->align_mask;
  70 
  71         /* Make sure we aren't trying to allocate more space
  72          * than the maximum for one submission
  73          */
  74         if (WARN_ON_ONCE(ndw > ring->max_dw))
  75                 return -ENOMEM;
  76 
  77         ring->count_dw = ndw;
  78         ring->wptr_old = ring->wptr;
  79 
  80         if (ring->funcs->begin_use)
  81                 ring->funcs->begin_use(ring);
  82 
  83         return 0;
  84 }
  85 
  86 /** amdgpu_ring_insert_nop - insert NOP packets
  87  *
  88  * @ring: amdgpu_ring structure holding ring information
  89  * @count: the number of NOP packets to insert
  90  *
  91  * This is the generic insert_nop function for rings except SDMA
  92  */
  93 void amdgpu_ring_insert_nop(struct amdgpu_ring *ring, uint32_t count)
  94 {
  95         int i;
  96 
  97         for (i = 0; i < count; i++)
  98                 amdgpu_ring_write(ring, ring->funcs->nop);
  99 }
 100 
 101 /** amdgpu_ring_generic_pad_ib - pad IB with NOP packets
 102  *
 103  * @ring: amdgpu_ring structure holding ring information
 104  * @ib: IB to add NOP packets to
 105  *
 106  * This is the generic pad_ib function for rings except SDMA
 107  */
 108 void amdgpu_ring_generic_pad_ib(struct amdgpu_ring *ring, struct amdgpu_ib *ib)
 109 {
 110         while (ib->length_dw & ring->funcs->align_mask)
 111                 ib->ptr[ib->length_dw++] = ring->funcs->nop;
 112 }
 113 
 114 /**
 115  * amdgpu_ring_commit - tell the GPU to execute the new
 116  * commands on the ring buffer
 117  *
 118  * @adev: amdgpu_device pointer
 119  * @ring: amdgpu_ring structure holding ring information
 120  *
 121  * Update the wptr (write pointer) to tell the GPU to
 122  * execute new commands on the ring buffer (all asics).
 123  */
 124 void amdgpu_ring_commit(struct amdgpu_ring *ring)
 125 {
 126         uint32_t count;
 127 
 128         /* We pad to match fetch size */
 129         count = ring->funcs->align_mask + 1 -
 130                 (ring->wptr & ring->funcs->align_mask);
 131         count %= ring->funcs->align_mask + 1;
 132         ring->funcs->insert_nop(ring, count);
 133 
 134         mb();
 135         amdgpu_ring_set_wptr(ring);
 136 
 137         if (ring->funcs->end_use)
 138                 ring->funcs->end_use(ring);
 139 }
 140 
 141 /**
 142  * amdgpu_ring_undo - reset the wptr
 143  *
 144  * @ring: amdgpu_ring structure holding ring information
 145  *
 146  * Reset the driver's copy of the wptr (all asics).
 147  */
 148 void amdgpu_ring_undo(struct amdgpu_ring *ring)
 149 {
 150         ring->wptr = ring->wptr_old;
 151 
 152         if (ring->funcs->end_use)
 153                 ring->funcs->end_use(ring);
 154 }
 155 
 156 /**
 157  * amdgpu_ring_priority_put - restore a ring's priority
 158  *
 159  * @ring: amdgpu_ring structure holding the information
 160  * @priority: target priority
 161  *
 162  * Release a request for executing at @priority
 163  */
 164 void amdgpu_ring_priority_put(struct amdgpu_ring *ring,
 165                               enum drm_sched_priority priority)
 166 {
 167         int i;
 168 
 169         if (!ring->funcs->set_priority)
 170                 return;
 171 
 172         if (atomic_dec_return(&ring->num_jobs[priority]) > 0)
 173                 return;
 174 
 175         /* no need to restore if the job is already at the lowest priority */
 176         if (priority == DRM_SCHED_PRIORITY_NORMAL)
 177                 return;
 178 
 179         mutex_lock(&ring->priority_mutex);
 180         /* something higher prio is executing, no need to decay */
 181         if (ring->priority > priority)
 182                 goto out_unlock;
 183 
 184         /* decay priority to the next level with a job available */
 185         for (i = priority; i >= DRM_SCHED_PRIORITY_MIN; i--) {
 186                 if (i == DRM_SCHED_PRIORITY_NORMAL
 187                                 || atomic_read(&ring->num_jobs[i])) {
 188                         ring->priority = i;
 189                         ring->funcs->set_priority(ring, i);
 190                         break;
 191                 }
 192         }
 193 
 194 out_unlock:
 195         mutex_unlock(&ring->priority_mutex);
 196 }
 197 
 198 /**
 199  * amdgpu_ring_priority_get - change the ring's priority
 200  *
 201  * @ring: amdgpu_ring structure holding the information
 202  * @priority: target priority
 203  *
 204  * Request a ring's priority to be raised to @priority (refcounted).
 205  */
 206 void amdgpu_ring_priority_get(struct amdgpu_ring *ring,
 207                               enum drm_sched_priority priority)
 208 {
 209         if (!ring->funcs->set_priority)
 210                 return;
 211 
 212         if (atomic_inc_return(&ring->num_jobs[priority]) <= 0)
 213                 return;
 214 
 215         mutex_lock(&ring->priority_mutex);
 216         if (priority <= ring->priority)
 217                 goto out_unlock;
 218 
 219         ring->priority = priority;
 220         ring->funcs->set_priority(ring, priority);
 221 
 222 out_unlock:
 223         mutex_unlock(&ring->priority_mutex);
 224 }
 225 
 226 /**
 227  * amdgpu_ring_init - init driver ring struct.
 228  *
 229  * @adev: amdgpu_device pointer
 230  * @ring: amdgpu_ring structure holding ring information
 231  * @max_ndw: maximum number of dw for ring alloc
 232  * @nop: nop packet for this ring
 233  *
 234  * Initialize the driver information for the selected ring (all asics).
 235  * Returns 0 on success, error on failure.
 236  */
 237 int amdgpu_ring_init(struct amdgpu_device *adev, struct amdgpu_ring *ring,
 238                      unsigned max_dw, struct amdgpu_irq_src *irq_src,
 239                      unsigned irq_type)
 240 {
 241         int r, i;
 242         int sched_hw_submission = amdgpu_sched_hw_submission;
 243 
 244         /* Set the hw submission limit higher for KIQ because
 245          * it's used for a number of gfx/compute tasks by both
 246          * KFD and KGD which may have outstanding fences and
 247          * it doesn't really use the gpu scheduler anyway;
 248          * KIQ tasks get submitted directly to the ring.
 249          */
 250         if (ring->funcs->type == AMDGPU_RING_TYPE_KIQ)
 251                 sched_hw_submission = max(sched_hw_submission, 256);
 252         else if (ring == &adev->sdma.instance[0].page)
 253                 sched_hw_submission = 256;
 254 
 255         if (ring->adev == NULL) {
 256                 if (adev->num_rings >= AMDGPU_MAX_RINGS)
 257                         return -EINVAL;
 258 
 259                 ring->adev = adev;
 260                 ring->idx = adev->num_rings++;
 261                 adev->rings[ring->idx] = ring;
 262                 r = amdgpu_fence_driver_init_ring(ring, sched_hw_submission);
 263                 if (r)
 264                         return r;
 265         }
 266 
 267         r = amdgpu_device_wb_get(adev, &ring->rptr_offs);
 268         if (r) {
 269                 dev_err(adev->dev, "(%d) ring rptr_offs wb alloc failed\n", r);
 270                 return r;
 271         }
 272 
 273         r = amdgpu_device_wb_get(adev, &ring->wptr_offs);
 274         if (r) {
 275                 dev_err(adev->dev, "(%d) ring wptr_offs wb alloc failed\n", r);
 276                 return r;
 277         }
 278 
 279         r = amdgpu_device_wb_get(adev, &ring->fence_offs);
 280         if (r) {
 281                 dev_err(adev->dev, "(%d) ring fence_offs wb alloc failed\n", r);
 282                 return r;
 283         }
 284 
 285         r = amdgpu_device_wb_get(adev, &ring->trail_fence_offs);
 286         if (r) {
 287                 dev_err(adev->dev,
 288                         "(%d) ring trail_fence_offs wb alloc failed\n", r);
 289                 return r;
 290         }
 291         ring->trail_fence_gpu_addr =
 292                 adev->wb.gpu_addr + (ring->trail_fence_offs * 4);
 293         ring->trail_fence_cpu_addr = &adev->wb.wb[ring->trail_fence_offs];
 294 
 295         r = amdgpu_device_wb_get(adev, &ring->cond_exe_offs);
 296         if (r) {
 297                 dev_err(adev->dev, "(%d) ring cond_exec_polling wb alloc failed\n", r);
 298                 return r;
 299         }
 300         ring->cond_exe_gpu_addr = adev->wb.gpu_addr + (ring->cond_exe_offs * 4);
 301         ring->cond_exe_cpu_addr = &adev->wb.wb[ring->cond_exe_offs];
 302         /* always set cond_exec_polling to CONTINUE */
 303         *ring->cond_exe_cpu_addr = 1;
 304 
 305         r = amdgpu_fence_driver_start_ring(ring, irq_src, irq_type);
 306         if (r) {
 307                 dev_err(adev->dev, "failed initializing fences (%d).\n", r);
 308                 return r;
 309         }
 310 
 311         ring->ring_size = roundup_pow_of_two(max_dw * 4 * sched_hw_submission);
 312 
 313         ring->buf_mask = (ring->ring_size / 4) - 1;
 314         ring->ptr_mask = ring->funcs->support_64bit_ptrs ?
 315                 0xffffffffffffffff : ring->buf_mask;
 316         /* Allocate ring buffer */
 317         if (ring->ring_obj == NULL) {
 318                 r = amdgpu_bo_create_kernel(adev, ring->ring_size + ring->funcs->extra_dw, PAGE_SIZE,
 319                                             AMDGPU_GEM_DOMAIN_GTT,
 320                                             &ring->ring_obj,
 321                                             &ring->gpu_addr,
 322                                             (void **)&ring->ring);
 323                 if (r) {
 324                         dev_err(adev->dev, "(%d) ring create failed\n", r);
 325                         return r;
 326                 }
 327                 amdgpu_ring_clear_ring(ring);
 328         }
 329 
 330         ring->max_dw = max_dw;
 331         ring->priority = DRM_SCHED_PRIORITY_NORMAL;
 332         mutex_init(&ring->priority_mutex);
 333 
 334         for (i = 0; i < DRM_SCHED_PRIORITY_MAX; ++i)
 335                 atomic_set(&ring->num_jobs[i], 0);
 336 
 337         if (amdgpu_debugfs_ring_init(adev, ring)) {
 338                 DRM_ERROR("Failed to register debugfs file for rings !\n");
 339         }
 340 
 341         return 0;
 342 }
 343 
 344 /**
 345  * amdgpu_ring_fini - tear down the driver ring struct.
 346  *
 347  * @adev: amdgpu_device pointer
 348  * @ring: amdgpu_ring structure holding ring information
 349  *
 350  * Tear down the driver information for the selected ring (all asics).
 351  */
 352 void amdgpu_ring_fini(struct amdgpu_ring *ring)
 353 {
 354         ring->sched.ready = false;
 355 
 356         /* Not to finish a ring which is not initialized */
 357         if (!(ring->adev) || !(ring->adev->rings[ring->idx]))
 358                 return;
 359 
 360         amdgpu_device_wb_free(ring->adev, ring->rptr_offs);
 361         amdgpu_device_wb_free(ring->adev, ring->wptr_offs);
 362 
 363         amdgpu_device_wb_free(ring->adev, ring->cond_exe_offs);
 364         amdgpu_device_wb_free(ring->adev, ring->fence_offs);
 365 
 366         amdgpu_bo_free_kernel(&ring->ring_obj,
 367                               &ring->gpu_addr,
 368                               (void **)&ring->ring);
 369 
 370         amdgpu_debugfs_ring_fini(ring);
 371 
 372         dma_fence_put(ring->vmid_wait);
 373         ring->vmid_wait = NULL;
 374         ring->me = 0;
 375 
 376         ring->adev->rings[ring->idx] = NULL;
 377 }
 378 
 379 /**
 380  * amdgpu_ring_emit_reg_write_reg_wait_helper - ring helper
 381  *
 382  * @adev: amdgpu_device pointer
 383  * @reg0: register to write
 384  * @reg1: register to wait on
 385  * @ref: reference value to write/wait on
 386  * @mask: mask to wait on
 387  *
 388  * Helper for rings that don't support write and wait in a
 389  * single oneshot packet.
 390  */
 391 void amdgpu_ring_emit_reg_write_reg_wait_helper(struct amdgpu_ring *ring,
 392                                                 uint32_t reg0, uint32_t reg1,
 393                                                 uint32_t ref, uint32_t mask)
 394 {
 395         amdgpu_ring_emit_wreg(ring, reg0, ref);
 396         amdgpu_ring_emit_reg_wait(ring, reg1, mask, mask);
 397 }
 398 
 399 /**
 400  * amdgpu_ring_soft_recovery - try to soft recover a ring lockup
 401  *
 402  * @ring: ring to try the recovery on
 403  * @vmid: VMID we try to get going again
 404  * @fence: timedout fence
 405  *
 406  * Tries to get a ring proceeding again when it is stuck.
 407  */
 408 bool amdgpu_ring_soft_recovery(struct amdgpu_ring *ring, unsigned int vmid,
 409                                struct dma_fence *fence)
 410 {
 411         ktime_t deadline = ktime_add_us(ktime_get(), 10000);
 412 
 413         if (amdgpu_sriov_vf(ring->adev) || !ring->funcs->soft_recovery || !fence)
 414                 return false;
 415 
 416         atomic_inc(&ring->adev->gpu_reset_counter);
 417         while (!dma_fence_is_signaled(fence) &&
 418                ktime_to_ns(ktime_sub(deadline, ktime_get())) > 0)
 419                 ring->funcs->soft_recovery(ring, vmid);
 420 
 421         return dma_fence_is_signaled(fence);
 422 }
 423 
 424 /*
 425  * Debugfs info
 426  */
 427 #if defined(CONFIG_DEBUG_FS)
 428 
 429 /* Layout of file is 12 bytes consisting of
 430  * - rptr
 431  * - wptr
 432  * - driver's copy of wptr
 433  *
 434  * followed by n-words of ring data
 435  */
 436 static ssize_t amdgpu_debugfs_ring_read(struct file *f, char __user *buf,
 437                                         size_t size, loff_t *pos)
 438 {
 439         struct amdgpu_ring *ring = file_inode(f)->i_private;
 440         int r, i;
 441         uint32_t value, result, early[3];
 442 
 443         if (*pos & 3 || size & 3)
 444                 return -EINVAL;
 445 
 446         result = 0;
 447 
 448         if (*pos < 12) {
 449                 early[0] = amdgpu_ring_get_rptr(ring) & ring->buf_mask;
 450                 early[1] = amdgpu_ring_get_wptr(ring) & ring->buf_mask;
 451                 early[2] = ring->wptr & ring->buf_mask;
 452                 for (i = *pos / 4; i < 3 && size; i++) {
 453                         r = put_user(early[i], (uint32_t *)buf);
 454                         if (r)
 455                                 return r;
 456                         buf += 4;
 457                         result += 4;
 458                         size -= 4;
 459                         *pos += 4;
 460                 }
 461         }
 462 
 463         while (size) {
 464                 if (*pos >= (ring->ring_size + 12))
 465                         return result;
 466 
 467                 value = ring->ring[(*pos - 12)/4];
 468                 r = put_user(value, (uint32_t*)buf);
 469                 if (r)
 470                         return r;
 471                 buf += 4;
 472                 result += 4;
 473                 size -= 4;
 474                 *pos += 4;
 475         }
 476 
 477         return result;
 478 }
 479 
 480 static const struct file_operations amdgpu_debugfs_ring_fops = {
 481         .owner = THIS_MODULE,
 482         .read = amdgpu_debugfs_ring_read,
 483         .llseek = default_llseek
 484 };
 485 
 486 #endif
 487 
 488 static int amdgpu_debugfs_ring_init(struct amdgpu_device *adev,
 489                                     struct amdgpu_ring *ring)
 490 {
 491 #if defined(CONFIG_DEBUG_FS)
 492         struct drm_minor *minor = adev->ddev->primary;
 493         struct dentry *ent, *root = minor->debugfs_root;
 494         char name[32];
 495 
 496         sprintf(name, "amdgpu_ring_%s", ring->name);
 497 
 498         ent = debugfs_create_file(name,
 499                                   S_IFREG | S_IRUGO, root,
 500                                   ring, &amdgpu_debugfs_ring_fops);
 501         if (!ent)
 502                 return -ENOMEM;
 503 
 504         i_size_write(ent->d_inode, ring->ring_size + 12);
 505         ring->ent = ent;
 506 #endif
 507         return 0;
 508 }
 509 
 510 static void amdgpu_debugfs_ring_fini(struct amdgpu_ring *ring)
 511 {
 512 #if defined(CONFIG_DEBUG_FS)
 513         debugfs_remove(ring->ent);
 514 #endif
 515 }
 516 
 517 /**
 518  * amdgpu_ring_test_helper - tests ring and set sched readiness status
 519  *
 520  * @ring: ring to try the recovery on
 521  *
 522  * Tests ring and set sched readiness status
 523  *
 524  * Returns 0 on success, error on failure.
 525  */
 526 int amdgpu_ring_test_helper(struct amdgpu_ring *ring)
 527 {
 528         struct amdgpu_device *adev = ring->adev;
 529         int r;
 530 
 531         r = amdgpu_ring_test_ring(ring);
 532         if (r)
 533                 DRM_DEV_ERROR(adev->dev, "ring %s test failed (%d)\n",
 534                               ring->name, r);
 535         else
 536                 DRM_DEV_DEBUG(adev->dev, "ring test on %s succeeded\n",
 537                               ring->name);
 538 
 539         ring->sched.ready = !r;
 540         return r;
 541 }