drivers/gpu/host1x/cdma.c

   1 /*
   2  * Tegra host1x Command DMA
   3  *
   4  * Copyright (c) 2010-2013, NVIDIA Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms and conditions of the GNU General Public License,
   8  * version 2, as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19
  20 #include <asm/cacheflush.h>
  21 #include <linux/device.h>
  22 #include <linux/dma-mapping.h>
  23 #include <linux/host1x.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/kernel.h>
  26 #include <linux/kfifo.h>
  27 #include <linux/slab.h>
  28 #include <trace/events/host1x.h>
  29
  30 #include "cdma.h"
  31 #include "channel.h"
  32 #include "dev.h"
  33 #include "debug.h"
  34 #include "job.h"
  35
  36 /*
  37  * push_buffer
  38  *
  39  * The push buffer is a circular array of words to be fetched by command DMA.
  40  * Note that it works slightly differently to the sync queue; fence == pos
  41  * means that the push buffer is full, not empty.
  42  */
  43
  44 #define HOST1X_PUSHBUFFER_SLOTS 512
  45
  46 /*
  47  * Clean up push buffer resources
  48  */
  49 static void host1x_pushbuffer_destroy(struct push_buffer *pb)
  50 {
  51         struct host1x_cdma *cdma = pb_to_cdma(pb);
  52         struct host1x *host1x = cdma_to_host1x(cdma);
  53
  54         if (pb->phys != 0)
  55                 dma_free_wc(host1x->dev, pb->size_bytes + 4, pb->mapped,
  56                             pb->phys);
  57
  58         pb->mapped = NULL;
  59         pb->phys = 0;
  60 }
  61
  62 /*
  63  * Init push buffer resources
  64  */
  65 static int host1x_pushbuffer_init(struct push_buffer *pb)
  66 {
  67         struct host1x_cdma *cdma = pb_to_cdma(pb);
  68         struct host1x *host1x = cdma_to_host1x(cdma);
  69
  70         pb->mapped = NULL;
  71         pb->phys = 0;
  72         pb->size_bytes = HOST1X_PUSHBUFFER_SLOTS * 8;
  73
  74         /* initialize buffer pointers */
  75         pb->fence = pb->size_bytes - 8;
  76         pb->pos = 0;
  77
  78         /* allocate and map pushbuffer memory */
  79         pb->mapped = dma_alloc_wc(host1x->dev, pb->size_bytes + 4, &pb->phys,
  80                                   GFP_KERNEL);
  81         if (!pb->mapped)
  82                 goto fail;
  83
  84         host1x_hw_pushbuffer_init(host1x, pb);
  85
  86         return 0;
  87
  88 fail:
  89         host1x_pushbuffer_destroy(pb);
  90         return -ENOMEM;
  91 }
  92
  93 /*
  94  * Push two words to the push buffer
  95  * Caller must ensure push buffer is not full
  96  */
  97 static void host1x_pushbuffer_push(struct push_buffer *pb, u32 op1, u32 op2)
  98 {
  99         u32 *p = (u32 *)((void *)pb->mapped + pb->pos);
 100
 101         WARN_ON(pb->pos == pb->fence);
 102         *(p++) = op1;
 103         *(p++) = op2;
 104         pb->pos = (pb->pos + 8) & (pb->size_bytes - 1);
 105 }
 106
 107 /*
 108  * Pop a number of two word slots from the push buffer
 109  * Caller must ensure push buffer is not empty
 110  */
 111 static void host1x_pushbuffer_pop(struct push_buffer *pb, unsigned int slots)
 112 {
 113         /* Advance the next write position */
 114         pb->fence = (pb->fence + slots * 8) & (pb->size_bytes - 1);
 115 }
 116
 117 /*
 118  * Return the number of two word slots free in the push buffer
 119  */
 120 static u32 host1x_pushbuffer_space(struct push_buffer *pb)
 121 {
 122         return ((pb->fence - pb->pos) & (pb->size_bytes - 1)) / 8;
 123 }
 124
 125 /*
 126  * Sleep (if necessary) until the requested event happens
 127  *   - CDMA_EVENT_SYNC_QUEUE_EMPTY : sync queue is completely empty.
 128  *     - Returns 1
 129  *   - CDMA_EVENT_PUSH_BUFFER_SPACE : there is space in the push buffer
 130  *     - Return the amount of space (> 0)
 131  * Must be called with the cdma lock held.
 132  */
 133 unsigned int host1x_cdma_wait_locked(struct host1x_cdma *cdma,
 134                                      enum cdma_event event)
 135 {
 136         for (;;) {
 137                 unsigned int space;
 138
 139                 if (event == CDMA_EVENT_SYNC_QUEUE_EMPTY)
 140                         space = list_empty(&cdma->sync_queue) ? 1 : 0;
 141                 else if (event == CDMA_EVENT_PUSH_BUFFER_SPACE) {
 142                         struct push_buffer *pb = &cdma->push_buffer;
 143                         space = host1x_pushbuffer_space(pb);
 144                 } else {
 145                         WARN_ON(1);
 146                         return -EINVAL;
 147                 }
 148
 149                 if (space)
 150                         return space;
 151
 152                 trace_host1x_wait_cdma(dev_name(cdma_to_channel(cdma)->dev),
 153                                        event);
 154
 155                 /* If somebody has managed to already start waiting, yield */
 156                 if (cdma->event != CDMA_EVENT_NONE) {
 157                         mutex_unlock(&cdma->lock);
 158                         schedule();
 159                         mutex_lock(&cdma->lock);
 160                         continue;
 161                 }
 162                 cdma->event = event;
 163
 164                 mutex_unlock(&cdma->lock);
 165                 down(&cdma->sem);
 166                 mutex_lock(&cdma->lock);
 167         }
 168         return 0;
 169 }
 170
 171 /*
 172  * Start timer that tracks the time spent by the job.
 173  * Must be called with the cdma lock held.
 174  */
 175 static void cdma_start_timer_locked(struct host1x_cdma *cdma,
 176                                     struct host1x_job *job)
 177 {
 178         struct host1x *host = cdma_to_host1x(cdma);
 179
 180         if (cdma->timeout.client) {
 181                 /* timer already started */
 182                 return;
 183         }
 184
 185         cdma->timeout.client = job->client;
 186         cdma->timeout.syncpt = host1x_syncpt_get(host, job->syncpt_id);
 187         cdma->timeout.syncpt_val = job->syncpt_end;
 188         cdma->timeout.start_ktime = ktime_get();
 189
 190         schedule_delayed_work(&cdma->timeout.wq,
 191                               msecs_to_jiffies(job->timeout));
 192 }
 193
 194 /*
 195  * Stop timer when a buffer submission completes.
 196  * Must be called with the cdma lock held.
 197  */
 198 static void stop_cdma_timer_locked(struct host1x_cdma *cdma)
 199 {
 200         cancel_delayed_work(&cdma->timeout.wq);
 201         cdma->timeout.client = 0;
 202 }
 203
 204 /*
 205  * For all sync queue entries that have already finished according to the
 206  * current sync point registers:
 207  *  - unpin & unref their mems
 208  *  - pop their push buffer slots
 209  *  - remove them from the sync queue
 210  * This is normally called from the host code's worker thread, but can be
 211  * called manually if necessary.
 212  * Must be called with the cdma lock held.
 213  */
 214 static void update_cdma_locked(struct host1x_cdma *cdma)
 215 {
 216         bool signal = false;
 217         struct host1x *host1x = cdma_to_host1x(cdma);
 218         struct host1x_job *job, *n;
 219
 220         /* If CDMA is stopped, queue is cleared and we can return */
 221         if (!cdma->running)
 222                 return;
 223
 224         /*
 225          * Walk the sync queue, reading the sync point registers as necessary,
 226          * to consume as many sync queue entries as possible without blocking
 227          */
 228         list_for_each_entry_safe(job, n, &cdma->sync_queue, list) {
 229                 struct host1x_syncpt *sp =
 230                         host1x_syncpt_get(host1x, job->syncpt_id);
 231
 232                 /* Check whether this syncpt has completed, and bail if not */
 233                 if (!host1x_syncpt_is_expired(sp, job->syncpt_end)) {
 234                         /* Start timer on next pending syncpt */
 235                         if (job->timeout)
 236                                 cdma_start_timer_locked(cdma, job);
 237                         break;
 238                 }
 239
 240                 /* Cancel timeout, when a buffer completes */
 241                 if (cdma->timeout.client)
 242                         stop_cdma_timer_locked(cdma);
 243
 244                 /* Unpin the memory */
 245                 host1x_job_unpin(job);
 246
 247                 /* Pop push buffer slots */
 248                 if (job->num_slots) {
 249                         struct push_buffer *pb = &cdma->push_buffer;
 250
 251                         host1x_pushbuffer_pop(pb, job->num_slots);
 252                         if (cdma->event == CDMA_EVENT_PUSH_BUFFER_SPACE)
 253                                 signal = true;
 254                 }
 255
 256                 list_del(&job->list);
 257                 host1x_job_put(job);
 258         }
 259
 260         if (cdma->event == CDMA_EVENT_SYNC_QUEUE_EMPTY &&
 261             list_empty(&cdma->sync_queue))
 262                 signal = true;
 263
 264         if (signal) {
 265                 cdma->event = CDMA_EVENT_NONE;
 266                 up(&cdma->sem);
 267         }
 268 }
 269
 270 void host1x_cdma_update_sync_queue(struct host1x_cdma *cdma,
 271                                    struct device *dev)
 272 {
 273         u32 restart_addr;
 274         u32 syncpt_incrs;
 275         struct host1x_job *job = NULL;
 276         u32 syncpt_val;
 277         struct host1x *host1x = cdma_to_host1x(cdma);
 278
 279         syncpt_val = host1x_syncpt_load(cdma->timeout.syncpt);
 280
 281         dev_dbg(dev, "%s: starting cleanup (thresh %d)\n",
 282                 __func__, syncpt_val);
 283
 284         /*
 285          * Move the sync_queue read pointer to the first entry that hasn't
 286          * completed based on the current HW syncpt value. It's likely there
 287          * won't be any (i.e. we're still at the head), but covers the case
 288          * where a syncpt incr happens just prior/during the teardown.
 289          */
 290
 291         dev_dbg(dev, "%s: skip completed buffers still in sync_queue\n",
 292                 __func__);
 293
 294         list_for_each_entry(job, &cdma->sync_queue, list) {
 295                 if (syncpt_val < job->syncpt_end)
 296                         break;
 297
 298                 host1x_job_dump(dev, job);
 299         }
 300
 301         /*
 302          * Walk the sync_queue, first incrementing with the CPU syncpts that
 303          * are partially executed (the first buffer) or fully skipped while
 304          * still in the current context (slots are also NOP-ed).
 305          *
 306          * At the point contexts are interleaved, syncpt increments must be
 307          * done inline with the pushbuffer from a GATHER buffer to maintain
 308          * the order (slots are modified to be a GATHER of syncpt incrs).
 309          *
 310          * Note: save in restart_addr the location where the timed out buffer
 311          * started in the PB, so we can start the refetch from there (with the
 312          * modified NOP-ed PB slots). This lets things appear to have completed
 313          * properly for this buffer and resources are freed.
 314          */
 315
 316         dev_dbg(dev, "%s: perform CPU incr on pending same ctx buffers\n",
 317                 __func__);
 318
 319         if (!list_empty(&cdma->sync_queue))
 320                 restart_addr = job->first_get;
 321         else
 322                 restart_addr = cdma->last_pos;
 323
 324         /* do CPU increments as long as this context continues */
 325         list_for_each_entry_from(job, &cdma->sync_queue, list) {
 326                 /* different context, gets us out of this loop */
 327                 if (job->client != cdma->timeout.client)
 328                         break;
 329
 330                 /* won't need a timeout when replayed */
 331                 job->timeout = 0;
 332
 333                 syncpt_incrs = job->syncpt_end - syncpt_val;
 334                 dev_dbg(dev, "%s: CPU incr (%d)\n", __func__, syncpt_incrs);
 335
 336                 host1x_job_dump(dev, job);
 337
 338                 /* safe to use CPU to incr syncpts */
 339                 host1x_hw_cdma_timeout_cpu_incr(host1x, cdma, job->first_get,
 340                                                 syncpt_incrs, job->syncpt_end,
 341                                                 job->num_slots);
 342
 343                 syncpt_val += syncpt_incrs;
 344         }
 345
 346         /*
 347          * The following sumbits from the same client may be dependent on the
 348          * failed submit and therefore they may fail. Force a small timeout
 349          * to make the queue cleanup faster.
 350          */
 351
 352         list_for_each_entry_from(job, &cdma->sync_queue, list)
 353                 if (job->client == cdma->timeout.client)
 354                         job->timeout = min_t(unsigned int, job->timeout, 500);
 355
 356         dev_dbg(dev, "%s: finished sync_queue modification\n", __func__);
 357
 358         /* roll back DMAGET and start up channel again */
 359         host1x_hw_cdma_resume(host1x, cdma, restart_addr);
 360 }
 361
 362 /*
 363  * Create a cdma
 364  */
 365 int host1x_cdma_init(struct host1x_cdma *cdma)
 366 {
 367         int err;
 368
 369         mutex_init(&cdma->lock);
 370         sema_init(&cdma->sem, 0);
 371
 372         INIT_LIST_HEAD(&cdma->sync_queue);
 373
 374         cdma->event = CDMA_EVENT_NONE;
 375         cdma->running = false;
 376         cdma->torndown = false;
 377
 378         err = host1x_pushbuffer_init(&cdma->push_buffer);
 379         if (err)
 380                 return err;
 381         return 0;
 382 }
 383
 384 /*
 385  * Destroy a cdma
 386  */
 387 int host1x_cdma_deinit(struct host1x_cdma *cdma)
 388 {
 389         struct push_buffer *pb = &cdma->push_buffer;
 390         struct host1x *host1x = cdma_to_host1x(cdma);
 391
 392         if (cdma->running) {
 393                 pr_warn("%s: CDMA still running\n", __func__);
 394                 return -EBUSY;
 395         }
 396
 397         host1x_pushbuffer_destroy(pb);
 398         host1x_hw_cdma_timeout_destroy(host1x, cdma);
 399
 400         return 0;
 401 }
 402
 403 /*
 404  * Begin a cdma submit
 405  */
 406 int host1x_cdma_begin(struct host1x_cdma *cdma, struct host1x_job *job)
 407 {
 408         struct host1x *host1x = cdma_to_host1x(cdma);
 409
 410         mutex_lock(&cdma->lock);
 411
 412         if (job->timeout) {
 413                 /* init state on first submit with timeout value */
 414                 if (!cdma->timeout.initialized) {
 415                         int err;
 416
 417                         err = host1x_hw_cdma_timeout_init(host1x, cdma,
 418                                                           job->syncpt_id);
 419                         if (err) {
 420                                 mutex_unlock(&cdma->lock);
 421                                 return err;
 422                         }
 423                 }
 424         }
 425         if (!cdma->running)
 426                 host1x_hw_cdma_start(host1x, cdma);
 427
 428         cdma->slots_free = 0;
 429         cdma->slots_used = 0;
 430         cdma->first_get = cdma->push_buffer.pos;
 431
 432         trace_host1x_cdma_begin(dev_name(job->channel->dev));
 433         return 0;
 434 }
 435
 436 /*
 437  * Push two words into a push buffer slot
 438  * Blocks as necessary if the push buffer is full.
 439  */
 440 void host1x_cdma_push(struct host1x_cdma *cdma, u32 op1, u32 op2)
 441 {
 442         struct host1x *host1x = cdma_to_host1x(cdma);
 443         struct push_buffer *pb = &cdma->push_buffer;
 444         u32 slots_free = cdma->slots_free;
 445
 446         if (host1x_debug_trace_cmdbuf)
 447                 trace_host1x_cdma_push(dev_name(cdma_to_channel(cdma)->dev),
 448                                        op1, op2);
 449
 450         if (slots_free == 0) {
 451                 host1x_hw_cdma_flush(host1x, cdma);
 452                 slots_free = host1x_cdma_wait_locked(cdma,
 453                                                 CDMA_EVENT_PUSH_BUFFER_SPACE);
 454         }
 455         cdma->slots_free = slots_free - 1;
 456         cdma->slots_used++;
 457         host1x_pushbuffer_push(pb, op1, op2);
 458 }
 459
 460 /*
 461  * End a cdma submit
 462  * Kick off DMA, add job to the sync queue, and a number of slots to be freed
 463  * from the pushbuffer. The handles for a submit must all be pinned at the same
 464  * time, but they can be unpinned in smaller chunks.
 465  */
 466 void host1x_cdma_end(struct host1x_cdma *cdma,
 467                      struct host1x_job *job)
 468 {
 469         struct host1x *host1x = cdma_to_host1x(cdma);
 470         bool idle = list_empty(&cdma->sync_queue);
 471
 472         host1x_hw_cdma_flush(host1x, cdma);
 473
 474         job->first_get = cdma->first_get;
 475         job->num_slots = cdma->slots_used;
 476         host1x_job_get(job);
 477         list_add_tail(&job->list, &cdma->sync_queue);
 478
 479         /* start timer on idle -> active transitions */
 480         if (job->timeout && idle)
 481                 cdma_start_timer_locked(cdma, job);
 482
 483         trace_host1x_cdma_end(dev_name(job->channel->dev));
 484         mutex_unlock(&cdma->lock);
 485 }
 486
 487 /*
 488  * Update cdma state according to current sync point values
 489  */
 490 void host1x_cdma_update(struct host1x_cdma *cdma)
 491 {
 492         mutex_lock(&cdma->lock);
 493         update_cdma_locked(cdma);
 494         mutex_unlock(&cdma->lock);
 495 }