drivers/char/drm/gamma_context.h

   1 /* drm_context.h -- IOCTLs for generic contexts -*- linux-c -*-
   2  * Created: Fri Nov 24 18:31:37 2000 by gareth@valinux.com
   3  *
   4  * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
   5  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
   6  * All Rights Reserved.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice (including the next
  16  * paragraph) shall be included in all copies or substantial portions of the
  17  * Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  22  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  23  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  24  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  25  * OTHER DEALINGS IN THE SOFTWARE.
  26  *
  27  * Authors:
  28  *    Rickard E. (Rik) Faith <faith@valinux.com>
  29  *    Gareth Hughes <gareth@valinux.com>
  30  * ChangeLog:
  31  *  2001-11-16  Torsten Duwe <duwe@caldera.de>
  32  *              added context constructor/destructor hooks,
  33  *              needed by SiS driver's memory management.
  34  */
  35
  36 /* ================================================================
  37  * Old-style context support -- only used by gamma.
  38  */
  39
  40
  41 /* The drm_read and drm_write_string code (especially that which manages
  42    the circular buffer), is based on Alessandro Rubini's LINUX DEVICE
  43    DRIVERS (Cambridge: O'Reilly, 1998), pages 111-113. */
  44
  45 ssize_t gamma_fops_read(struct file *filp, char __user *buf, size_t count, loff_t *off)
  46 {
  47         drm_file_t    *priv   = filp->private_data;
  48         drm_device_t  *dev    = priv->dev;
  49         int           left;
  50         int           avail;
  51         int           send;
  52         int           cur;
  53
  54         DRM_DEBUG("%p, %p\n", dev->buf_rp, dev->buf_wp);
  55
  56         while (dev->buf_rp == dev->buf_wp) {
  57                 DRM_DEBUG("  sleeping\n");
  58                 if (filp->f_flags & O_NONBLOCK) {
  59                         return -EAGAIN;
  60                 }
  61                 interruptible_sleep_on(&dev->buf_readers);
  62                 if (signal_pending(current)) {
  63                         DRM_DEBUG("  interrupted\n");
  64                         return -ERESTARTSYS;
  65                 }
  66                 DRM_DEBUG("  awake\n");
  67         }
  68
  69         left  = (dev->buf_rp + DRM_BSZ - dev->buf_wp) % DRM_BSZ;
  70         avail = DRM_BSZ - left;
  71         send  = DRM_MIN(avail, count);
  72
  73         while (send) {
  74                 if (dev->buf_wp > dev->buf_rp) {
  75                         cur = DRM_MIN(send, dev->buf_wp - dev->buf_rp);
  76                 } else {
  77                         cur = DRM_MIN(send, dev->buf_end - dev->buf_rp);
  78                 }
  79                 if (copy_to_user(buf, dev->buf_rp, cur))
  80                         return -EFAULT;
  81                 dev->buf_rp += cur;
  82                 if (dev->buf_rp == dev->buf_end) dev->buf_rp = dev->buf;
  83                 send -= cur;
  84         }
  85
  86         wake_up_interruptible(&dev->buf_writers);
  87         return DRM_MIN(avail, count);
  88 }
  89
  90
  91 /* In an incredibly convoluted setup, the kernel module actually calls
  92  * back into the X server to perform context switches on behalf of the
  93  * 3d clients.
  94  */
  95 int DRM(write_string)(drm_device_t *dev, const char *s)
  96 {
  97         int left   = (dev->buf_rp + DRM_BSZ - dev->buf_wp) % DRM_BSZ;
  98         int send   = strlen(s);
  99         int count;
 100
 101         DRM_DEBUG("%d left, %d to send (%p, %p)\n",
 102                   left, send, dev->buf_rp, dev->buf_wp);
 103
 104         if (left == 1 || dev->buf_wp != dev->buf_rp) {
 105                 DRM_ERROR("Buffer not empty (%d left, wp = %p, rp = %p)\n",
 106                           left,
 107                           dev->buf_wp,
 108                           dev->buf_rp);
 109         }
 110
 111         while (send) {
 112                 if (dev->buf_wp >= dev->buf_rp) {
 113                         count = DRM_MIN(send, dev->buf_end - dev->buf_wp);
 114                         if (count == left) --count; /* Leave a hole */
 115                 } else {
 116                         count = DRM_MIN(send, dev->buf_rp - dev->buf_wp - 1);
 117                 }
 118                 strncpy(dev->buf_wp, s, count);
 119                 dev->buf_wp += count;
 120                 if (dev->buf_wp == dev->buf_end) dev->buf_wp = dev->buf;
 121                 send -= count;
 122         }
 123
 124         if (dev->buf_async) kill_fasync(&dev->buf_async, SIGIO, POLL_IN);
 125
 126         DRM_DEBUG("waking\n");
 127         wake_up_interruptible(&dev->buf_readers);
 128         return 0;
 129 }
 130
 131 unsigned int gamma_fops_poll(struct file *filp, struct poll_table_struct *wait)
 132 {
 133         drm_file_t   *priv = filp->private_data;
 134         drm_device_t *dev  = priv->dev;
 135
 136         poll_wait(filp, &dev->buf_readers, wait);
 137         if (dev->buf_wp != dev->buf_rp) return POLLIN | POLLRDNORM;
 138         return 0;
 139 }
 140
 141 int DRM(context_switch)(drm_device_t *dev, int old, int new)
 142 {
 143         char        buf[64];
 144         drm_queue_t *q;
 145
 146         if (test_and_set_bit(0, &dev->context_flag)) {
 147                 DRM_ERROR("Reentering -- FIXME\n");
 148                 return -EBUSY;
 149         }
 150
 151         DRM_DEBUG("Context switch from %d to %d\n", old, new);
 152
 153         if (new >= dev->queue_count) {
 154                 clear_bit(0, &dev->context_flag);
 155                 return -EINVAL;
 156         }
 157
 158         if (new == dev->last_context) {
 159                 clear_bit(0, &dev->context_flag);
 160                 return 0;
 161         }
 162
 163         q = dev->queuelist[new];
 164         atomic_inc(&q->use_count);
 165         if (atomic_read(&q->use_count) == 1) {
 166                 atomic_dec(&q->use_count);
 167                 clear_bit(0, &dev->context_flag);
 168                 return -EINVAL;
 169         }
 170
 171         /* This causes the X server to wake up & do a bunch of hardware
 172          * interaction to actually effect the context switch.
 173          */
 174         sprintf(buf, "C %d %d\n", old, new);
 175         DRM(write_string)(dev, buf);
 176
 177         atomic_dec(&q->use_count);
 178
 179         return 0;
 180 }
 181
 182 int DRM(context_switch_complete)(drm_device_t *dev, int new)
 183 {
 184         drm_device_dma_t *dma = dev->dma;
 185
 186         dev->last_context = new;  /* PRE/POST: This is the _only_ writer. */
 187         dev->last_switch  = jiffies;
 188
 189         if (!_DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock)) {
 190                 DRM_ERROR("Lock isn't held after context switch\n");
 191         }
 192
 193         if (!dma || !(dma->next_buffer && dma->next_buffer->while_locked)) {
 194                 if (DRM(lock_free)(dev, &dev->lock.hw_lock->lock,
 195                                   DRM_KERNEL_CONTEXT)) {
 196                         DRM_ERROR("Cannot free lock\n");
 197                 }
 198         }
 199
 200         clear_bit(0, &dev->context_flag);
 201         wake_up_interruptible(&dev->context_wait);
 202
 203         return 0;
 204 }
 205
 206 static int DRM(init_queue)(drm_device_t *dev, drm_queue_t *q, drm_ctx_t *ctx)
 207 {
 208         DRM_DEBUG("\n");
 209
 210         if (atomic_read(&q->use_count) != 1
 211             || atomic_read(&q->finalization)
 212             || atomic_read(&q->block_count)) {
 213                 DRM_ERROR("New queue is already in use: u%d f%d b%d\n",
 214                           atomic_read(&q->use_count),
 215                           atomic_read(&q->finalization),
 216                           atomic_read(&q->block_count));
 217         }
 218
 219         atomic_set(&q->finalization,  0);
 220         atomic_set(&q->block_count,   0);
 221         atomic_set(&q->block_read,    0);
 222         atomic_set(&q->block_write,   0);
 223         atomic_set(&q->total_queued,  0);
 224         atomic_set(&q->total_flushed, 0);
 225         atomic_set(&q->total_locks,   0);
 226
 227         init_waitqueue_head(&q->write_queue);
 228         init_waitqueue_head(&q->read_queue);
 229         init_waitqueue_head(&q->flush_queue);
 230
 231         q->flags = ctx->flags;
 232
 233         DRM(waitlist_create)(&q->waitlist, dev->dma->buf_count);
 234
 235         return 0;
 236 }
 237
 238
 239 /* drm_alloc_queue:
 240 PRE: 1) dev->queuelist[0..dev->queue_count] is allocated and will not
 241         disappear (so all deallocation must be done after IOCTLs are off)
 242      2) dev->queue_count < dev->queue_slots
 243      3) dev->queuelist[i].use_count == 0 and
 244         dev->queuelist[i].finalization == 0 if i not in use
 245 POST: 1) dev->queuelist[i].use_count == 1
 246       2) dev->queue_count < dev->queue_slots */
 247
 248 static int DRM(alloc_queue)(drm_device_t *dev)
 249 {
 250         int         i;
 251         drm_queue_t *queue;
 252         int         oldslots;
 253         int         newslots;
 254                                 /* Check for a free queue */
 255         for (i = 0; i < dev->queue_count; i++) {
 256                 atomic_inc(&dev->queuelist[i]->use_count);
 257                 if (atomic_read(&dev->queuelist[i]->use_count) == 1
 258                     && !atomic_read(&dev->queuelist[i]->finalization)) {
 259                         DRM_DEBUG("%d (free)\n", i);
 260                         return i;
 261                 }
 262                 atomic_dec(&dev->queuelist[i]->use_count);
 263         }
 264                                 /* Allocate a new queue */
 265         down(&dev->struct_sem);
 266
 267         queue = DRM(alloc)(sizeof(*queue), DRM_MEM_QUEUES);
 268         memset(queue, 0, sizeof(*queue));
 269         atomic_set(&queue->use_count, 1);
 270
 271         ++dev->queue_count;
 272         if (dev->queue_count >= dev->queue_slots) {
 273                 oldslots = dev->queue_slots * sizeof(*dev->queuelist);
 274                 if (!dev->queue_slots) dev->queue_slots = 1;
 275                 dev->queue_slots *= 2;
 276                 newslots = dev->queue_slots * sizeof(*dev->queuelist);
 277
 278                 dev->queuelist = DRM(realloc)(dev->queuelist,
 279                                               oldslots,
 280                                               newslots,
 281                                               DRM_MEM_QUEUES);
 282                 if (!dev->queuelist) {
 283                         up(&dev->struct_sem);
 284                         DRM_DEBUG("out of memory\n");
 285                         return -ENOMEM;
 286                 }
 287         }
 288         dev->queuelist[dev->queue_count-1] = queue;
 289
 290         up(&dev->struct_sem);
 291         DRM_DEBUG("%d (new)\n", dev->queue_count - 1);
 292         return dev->queue_count - 1;
 293 }
 294
 295 int DRM(resctx)(struct inode *inode, struct file *filp,
 296                 unsigned int cmd, unsigned long arg)
 297 {
 298         drm_ctx_res_t __user *argp = (void __user *)arg;
 299         drm_ctx_res_t   res;
 300         drm_ctx_t       ctx;
 301         int             i;
 302
 303         DRM_DEBUG("%d\n", DRM_RESERVED_CONTEXTS);
 304         if (copy_from_user(&res, argp, sizeof(res)))
 305                 return -EFAULT;
 306         if (res.count >= DRM_RESERVED_CONTEXTS) {
 307                 memset(&ctx, 0, sizeof(ctx));
 308                 for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
 309                         ctx.handle = i;
 310                         if (copy_to_user(&res.contexts[i],
 311                                          &i,
 312                                          sizeof(i)))
 313                                 return -EFAULT;
 314                 }
 315         }
 316         res.count = DRM_RESERVED_CONTEXTS;
 317         if (copy_to_user(argp, &res, sizeof(res)))
 318                 return -EFAULT;
 319         return 0;
 320 }
 321
 322 int DRM(addctx)(struct inode *inode, struct file *filp,
 323                 unsigned int cmd, unsigned long arg)
 324 {
 325         drm_file_t      *priv   = filp->private_data;
 326         drm_device_t    *dev    = priv->dev;
 327         drm_ctx_t       ctx;
 328         drm_ctx_t       __user *argp = (void __user *)arg;
 329
 330         if (copy_from_user(&ctx, argp, sizeof(ctx)))
 331                 return -EFAULT;
 332         if ((ctx.handle = DRM(alloc_queue)(dev)) == DRM_KERNEL_CONTEXT) {
 333                                 /* Init kernel's context and get a new one. */
 334                 DRM(init_queue)(dev, dev->queuelist[ctx.handle], &ctx);
 335                 ctx.handle = DRM(alloc_queue)(dev);
 336         }
 337         DRM(init_queue)(dev, dev->queuelist[ctx.handle], &ctx);
 338         DRM_DEBUG("%d\n", ctx.handle);
 339         if (copy_to_user(argp, &ctx, sizeof(ctx)))
 340                 return -EFAULT;
 341         return 0;
 342 }
 343
 344 int DRM(modctx)(struct inode *inode, struct file *filp,
 345                 unsigned int cmd, unsigned long arg)
 346 {
 347         drm_file_t      *priv   = filp->private_data;
 348         drm_device_t    *dev    = priv->dev;
 349         drm_ctx_t       ctx;
 350         drm_queue_t     *q;
 351
 352         if (copy_from_user(&ctx, (drm_ctx_t __user *)arg, sizeof(ctx)))
 353                 return -EFAULT;
 354
 355         DRM_DEBUG("%d\n", ctx.handle);
 356
 357         if (ctx.handle < 0 || ctx.handle >= dev->queue_count) return -EINVAL;
 358         q = dev->queuelist[ctx.handle];
 359
 360         atomic_inc(&q->use_count);
 361         if (atomic_read(&q->use_count) == 1) {
 362                                 /* No longer in use */
 363                 atomic_dec(&q->use_count);
 364                 return -EINVAL;
 365         }
 366
 367         if (DRM_BUFCOUNT(&q->waitlist)) {
 368                 atomic_dec(&q->use_count);
 369                 return -EBUSY;
 370         }
 371
 372         q->flags = ctx.flags;
 373
 374         atomic_dec(&q->use_count);
 375         return 0;
 376 }
 377
 378 int DRM(getctx)(struct inode *inode, struct file *filp,
 379                 unsigned int cmd, unsigned long arg)
 380 {
 381         drm_file_t      *priv   = filp->private_data;
 382         drm_device_t    *dev    = priv->dev;
 383         drm_ctx_t       __user *argp = (void __user *)arg;
 384         drm_ctx_t       ctx;
 385         drm_queue_t     *q;
 386
 387         if (copy_from_user(&ctx, argp, sizeof(ctx)))
 388                 return -EFAULT;
 389
 390         DRM_DEBUG("%d\n", ctx.handle);
 391
 392         if (ctx.handle >= dev->queue_count) return -EINVAL;
 393         q = dev->queuelist[ctx.handle];
 394
 395         atomic_inc(&q->use_count);
 396         if (atomic_read(&q->use_count) == 1) {
 397                                 /* No longer in use */
 398                 atomic_dec(&q->use_count);
 399                 return -EINVAL;
 400         }
 401
 402         ctx.flags = q->flags;
 403         atomic_dec(&q->use_count);
 404
 405         if (copy_to_user(argp, &ctx, sizeof(ctx)))
 406                 return -EFAULT;
 407
 408         return 0;
 409 }
 410
 411 int DRM(switchctx)(struct inode *inode, struct file *filp,
 412                    unsigned int cmd, unsigned long arg)
 413 {
 414         drm_file_t      *priv   = filp->private_data;
 415         drm_device_t    *dev    = priv->dev;
 416         drm_ctx_t       ctx;
 417
 418         if (copy_from_user(&ctx, (drm_ctx_t __user *)arg, sizeof(ctx)))
 419                 return -EFAULT;
 420         DRM_DEBUG("%d\n", ctx.handle);
 421         return DRM(context_switch)(dev, dev->last_context, ctx.handle);
 422 }
 423
 424 int DRM(newctx)(struct inode *inode, struct file *filp,
 425                 unsigned int cmd, unsigned long arg)
 426 {
 427         drm_file_t      *priv   = filp->private_data;
 428         drm_device_t    *dev    = priv->dev;
 429         drm_ctx_t       ctx;
 430
 431         if (copy_from_user(&ctx, (drm_ctx_t __user *)arg, sizeof(ctx)))
 432                 return -EFAULT;
 433         DRM_DEBUG("%d\n", ctx.handle);
 434         DRM(context_switch_complete)(dev, ctx.handle);
 435
 436         return 0;
 437 }
 438
 439 int DRM(rmctx)(struct inode *inode, struct file *filp,
 440                unsigned int cmd, unsigned long arg)
 441 {
 442         drm_file_t      *priv   = filp->private_data;
 443         drm_device_t    *dev    = priv->dev;
 444         drm_ctx_t       ctx;
 445         drm_queue_t     *q;
 446         drm_buf_t       *buf;
 447
 448         if (copy_from_user(&ctx, (drm_ctx_t __user *)arg, sizeof(ctx)))
 449                 return -EFAULT;
 450         DRM_DEBUG("%d\n", ctx.handle);
 451
 452         if (ctx.handle >= dev->queue_count) return -EINVAL;
 453         q = dev->queuelist[ctx.handle];
 454
 455         atomic_inc(&q->use_count);
 456         if (atomic_read(&q->use_count) == 1) {
 457                                 /* No longer in use */
 458                 atomic_dec(&q->use_count);
 459                 return -EINVAL;
 460         }
 461
 462         atomic_inc(&q->finalization); /* Mark queue in finalization state */
 463         atomic_sub(2, &q->use_count); /* Mark queue as unused (pending
 464                                          finalization) */
 465
 466         while (test_and_set_bit(0, &dev->interrupt_flag)) {
 467                 schedule();
 468                 if (signal_pending(current)) {
 469                         clear_bit(0, &dev->interrupt_flag);
 470                         return -EINTR;
 471                 }
 472         }
 473                                 /* Remove queued buffers */
 474         while ((buf = DRM(waitlist_get)(&q->waitlist))) {
 475                 DRM(free_buffer)(dev, buf);
 476         }
 477         clear_bit(0, &dev->interrupt_flag);
 478
 479                                 /* Wakeup blocked processes */
 480         wake_up_interruptible(&q->read_queue);
 481         wake_up_interruptible(&q->write_queue);
 482         wake_up_interruptible(&q->flush_queue);
 483
 484                                 /* Finalization over.  Queue is made
 485                                    available when both use_count and
 486                                    finalization become 0, which won't
 487                                    happen until all the waiting processes
 488                                    stop waiting. */
 489         atomic_dec(&q->finalization);
 490         return 0;
 491 }
 492