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   1 /* i915_irq.c -- IRQ support for the I915 -*- linux-c -*-
   2  */
   3 /*
   4  * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
   5  * All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the
   9  * "Software"), to deal in the Software without restriction, including
  10  * without limitation the rights to use, copy, modify, merge, publish,
  11  * distribute, sub license, and/or sell copies of the Software, and to
  12  * permit persons to whom the Software is furnished to do so, subject to
  13  * the following conditions:
  14  *
  15  * The above copyright notice and this permission notice (including the
  16  * next paragraph) shall be included in all copies or substantial portions
  17  * of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  21  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  22  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
  23  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  24  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  25  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  26  *
  27  */
  28
  29 #include "drmP.h"
  30 #include "drm.h"
  31 #include "i915_drm.h"
  32 #include "i915_drv.h"
  33
  34 #define MAX_NOPID ((u32)~0)
  35
  36 /** These are the interrupts used by the driver */
  37 #define I915_INTERRUPT_ENABLE_MASK (I915_USER_INTERRUPT |               \
  38                                     I915_ASLE_INTERRUPT |               \
  39                                     I915_DISPLAY_PIPE_A_EVENT_INTERRUPT | \
  40                                     I915_DISPLAY_PIPE_B_EVENT_INTERRUPT)
  41
  42 void
  43 i915_enable_irq(drm_i915_private_t *dev_priv, u32 mask)
  44 {
  45         if ((dev_priv->irq_mask_reg & mask) != 0) {
  46                 dev_priv->irq_mask_reg &= ~mask;
  47                 I915_WRITE(IMR, dev_priv->irq_mask_reg);
  48                 (void) I915_READ(IMR);
  49         }
  50 }
  51
  52 static inline void
  53 i915_disable_irq(drm_i915_private_t *dev_priv, u32 mask)
  54 {
  55         if ((dev_priv->irq_mask_reg & mask) != mask) {
  56                 dev_priv->irq_mask_reg |= mask;
  57                 I915_WRITE(IMR, dev_priv->irq_mask_reg);
  58                 (void) I915_READ(IMR);
  59         }
  60 }
  61
  62 /**
  63  * i915_pipe_enabled - check if a pipe is enabled
  64  * @dev: DRM device
  65  * @pipe: pipe to check
  66  *
  67  * Reading certain registers when the pipe is disabled can hang the chip.
  68  * Use this routine to make sure the PLL is running and the pipe is active
  69  * before reading such registers if unsure.
  70  */
  71 static int
  72 i915_pipe_enabled(struct drm_device *dev, int pipe)
  73 {
  74         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
  75         unsigned long pipeconf = pipe ? PIPEBCONF : PIPEACONF;
  76
  77         if (I915_READ(pipeconf) & PIPEACONF_ENABLE)
  78                 return 1;
  79
  80         return 0;
  81 }
  82
  83 /* Called from drm generic code, passed a 'crtc', which
  84  * we use as a pipe index
  85  */
  86 u32 i915_get_vblank_counter(struct drm_device *dev, int pipe)
  87 {
  88         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
  89         unsigned long high_frame;
  90         unsigned long low_frame;
  91         u32 high1, high2, low, count;
  92
  93         high_frame = pipe ? PIPEBFRAMEHIGH : PIPEAFRAMEHIGH;
  94         low_frame = pipe ? PIPEBFRAMEPIXEL : PIPEAFRAMEPIXEL;
  95
  96         if (!i915_pipe_enabled(dev, pipe)) {
  97                 DRM_ERROR("trying to get vblank count for disabled pipe %d\n", pipe);
  98                 return 0;
  99         }
 100
 101         /*
 102          * High & low register fields aren't synchronized, so make sure
 103          * we get a low value that's stable across two reads of the high
 104          * register.
 105          */
 106         do {
 107                 high1 = ((I915_READ(high_frame) & PIPE_FRAME_HIGH_MASK) >>
 108                          PIPE_FRAME_HIGH_SHIFT);
 109                 low =  ((I915_READ(low_frame) & PIPE_FRAME_LOW_MASK) >>
 110                         PIPE_FRAME_LOW_SHIFT);
 111                 high2 = ((I915_READ(high_frame) & PIPE_FRAME_HIGH_MASK) >>
 112                          PIPE_FRAME_HIGH_SHIFT);
 113         } while (high1 != high2);
 114
 115         count = (high1 << 8) | low;
 116
 117         return count;
 118 }
 119
 120 irqreturn_t i915_driver_irq_handler(DRM_IRQ_ARGS)
 121 {
 122         struct drm_device *dev = (struct drm_device *) arg;
 123         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 124         u32 iir;
 125         u32 pipea_stats, pipeb_stats;
 126         int vblank = 0;
 127
 128         atomic_inc(&dev_priv->irq_received);
 129
 130         if (dev->pdev->msi_enabled)
 131                 I915_WRITE(IMR, ~0);
 132         iir = I915_READ(IIR);
 133
 134         if (iir == 0) {
 135                 if (dev->pdev->msi_enabled) {
 136                         I915_WRITE(IMR, dev_priv->irq_mask_reg);
 137                         (void) I915_READ(IMR);
 138                 }
 139                 return IRQ_NONE;
 140         }
 141
 142         /*
 143          * Clear the PIPE(A|B)STAT regs before the IIR otherwise
 144          * we may get extra interrupts.
 145          */
 146         if (iir & I915_DISPLAY_PIPE_A_EVENT_INTERRUPT) {
 147                 pipea_stats = I915_READ(PIPEASTAT);
 148                 if (!(dev_priv->vblank_pipe & DRM_I915_VBLANK_PIPE_A))
 149                         pipea_stats &= ~(PIPE_START_VBLANK_INTERRUPT_ENABLE |
 150                                          PIPE_VBLANK_INTERRUPT_ENABLE);
 151                 else if (pipea_stats & (PIPE_START_VBLANK_INTERRUPT_STATUS|
 152                                         PIPE_VBLANK_INTERRUPT_STATUS)) {
 153                         vblank++;
 154                         drm_handle_vblank(dev, 0);
 155                 }
 156
 157                 I915_WRITE(PIPEASTAT, pipea_stats);
 158         }
 159         if (iir & I915_DISPLAY_PIPE_B_EVENT_INTERRUPT) {
 160                 pipeb_stats = I915_READ(PIPEBSTAT);
 161                 /* Ack the event */
 162                 I915_WRITE(PIPEBSTAT, pipeb_stats);
 163
 164                 /* The vblank interrupt gets enabled even if we didn't ask for
 165                    it, so make sure it's shut down again */
 166                 if (!(dev_priv->vblank_pipe & DRM_I915_VBLANK_PIPE_B))
 167                         pipeb_stats &= ~(PIPE_START_VBLANK_INTERRUPT_ENABLE |
 168                                          PIPE_VBLANK_INTERRUPT_ENABLE);
 169                 else if (pipeb_stats & (PIPE_START_VBLANK_INTERRUPT_STATUS|
 170                                         PIPE_VBLANK_INTERRUPT_STATUS)) {
 171                         vblank++;
 172                         drm_handle_vblank(dev, 1);
 173                 }
 174
 175                 if (pipeb_stats & I915_LEGACY_BLC_EVENT_STATUS)
 176                         opregion_asle_intr(dev);
 177                 I915_WRITE(PIPEBSTAT, pipeb_stats);
 178         }
 179
 180         I915_WRITE(IIR, iir);
 181         if (dev->pdev->msi_enabled)
 182                 I915_WRITE(IMR, dev_priv->irq_mask_reg);
 183         (void) I915_READ(IIR); /* Flush posted writes */
 184
 185         if (dev_priv->sarea_priv)
 186                 dev_priv->sarea_priv->last_dispatch =
 187                         READ_BREADCRUMB(dev_priv);
 188
 189         if (iir & I915_USER_INTERRUPT) {
 190                 dev_priv->mm.irq_gem_seqno = i915_get_gem_seqno(dev);
 191                 DRM_WAKEUP(&dev_priv->irq_queue);
 192         }
 193
 194         if (iir & I915_ASLE_INTERRUPT)
 195                 opregion_asle_intr(dev);
 196
 197         return IRQ_HANDLED;
 198 }
 199
 200 static int i915_emit_irq(struct drm_device * dev)
 201 {
 202         drm_i915_private_t *dev_priv = dev->dev_private;
 203         RING_LOCALS;
 204
 205         i915_kernel_lost_context(dev);
 206
 207         DRM_DEBUG("\n");
 208
 209         dev_priv->counter++;
 210         if (dev_priv->counter > 0x7FFFFFFFUL)
 211                 dev_priv->counter = 1;
 212         if (dev_priv->sarea_priv)
 213                 dev_priv->sarea_priv->last_enqueue = dev_priv->counter;
 214
 215         BEGIN_LP_RING(4);
 216         OUT_RING(MI_STORE_DWORD_INDEX);
 217         OUT_RING(I915_BREADCRUMB_INDEX << MI_STORE_DWORD_INDEX_SHIFT);
 218         OUT_RING(dev_priv->counter);
 219         OUT_RING(MI_USER_INTERRUPT);
 220         ADVANCE_LP_RING();
 221
 222         return dev_priv->counter;
 223 }
 224
 225 void i915_user_irq_get(struct drm_device *dev)
 226 {
 227         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 228         unsigned long irqflags;
 229
 230         spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags);
 231         if (dev->irq_enabled && (++dev_priv->user_irq_refcount == 1))
 232                 i915_enable_irq(dev_priv, I915_USER_INTERRUPT);
 233         spin_unlock_irqrestore(&dev_priv->user_irq_lock, irqflags);
 234 }
 235
 236 void i915_user_irq_put(struct drm_device *dev)
 237 {
 238         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 239         unsigned long irqflags;
 240
 241         spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags);
 242         BUG_ON(dev->irq_enabled && dev_priv->user_irq_refcount <= 0);
 243         if (dev->irq_enabled && (--dev_priv->user_irq_refcount == 0))
 244                 i915_disable_irq(dev_priv, I915_USER_INTERRUPT);
 245         spin_unlock_irqrestore(&dev_priv->user_irq_lock, irqflags);
 246 }
 247
 248 static int i915_wait_irq(struct drm_device * dev, int irq_nr)
 249 {
 250         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 251         int ret = 0;
 252
 253         DRM_DEBUG("irq_nr=%d breadcrumb=%d\n", irq_nr,
 254                   READ_BREADCRUMB(dev_priv));
 255
 256         if (READ_BREADCRUMB(dev_priv) >= irq_nr) {
 257                 if (dev_priv->sarea_priv) {
 258                         dev_priv->sarea_priv->last_dispatch =
 259                                 READ_BREADCRUMB(dev_priv);
 260                 }
 261                 return 0;
 262         }
 263
 264         if (dev_priv->sarea_priv)
 265                 dev_priv->sarea_priv->perf_boxes |= I915_BOX_WAIT;
 266
 267         i915_user_irq_get(dev);
 268         DRM_WAIT_ON(ret, dev_priv->irq_queue, 3 * DRM_HZ,
 269                     READ_BREADCRUMB(dev_priv) >= irq_nr);
 270         i915_user_irq_put(dev);
 271
 272         if (ret == -EBUSY) {
 273                 DRM_ERROR("EBUSY -- rec: %d emitted: %d\n",
 274                           READ_BREADCRUMB(dev_priv), (int)dev_priv->counter);
 275         }
 276
 277         if (dev_priv->sarea_priv)
 278                 dev_priv->sarea_priv->last_dispatch =
 279                         READ_BREADCRUMB(dev_priv);
 280
 281         return ret;
 282 }
 283
 284 /* Needs the lock as it touches the ring.
 285  */
 286 int i915_irq_emit(struct drm_device *dev, void *data,
 287                          struct drm_file *file_priv)
 288 {
 289         drm_i915_private_t *dev_priv = dev->dev_private;
 290         drm_i915_irq_emit_t *emit = data;
 291         int result;
 292
 293         RING_LOCK_TEST_WITH_RETURN(dev, file_priv);
 294
 295         if (!dev_priv) {
 296                 DRM_ERROR("called with no initialization\n");
 297                 return -EINVAL;
 298         }
 299         mutex_lock(&dev->struct_mutex);
 300         result = i915_emit_irq(dev);
 301         mutex_unlock(&dev->struct_mutex);
 302
 303         if (DRM_COPY_TO_USER(emit->irq_seq, &result, sizeof(int))) {
 304                 DRM_ERROR("copy_to_user\n");
 305                 return -EFAULT;
 306         }
 307
 308         return 0;
 309 }
 310
 311 /* Doesn't need the hardware lock.
 312  */
 313 int i915_irq_wait(struct drm_device *dev, void *data,
 314                          struct drm_file *file_priv)
 315 {
 316         drm_i915_private_t *dev_priv = dev->dev_private;
 317         drm_i915_irq_wait_t *irqwait = data;
 318
 319         if (!dev_priv) {
 320                 DRM_ERROR("called with no initialization\n");
 321                 return -EINVAL;
 322         }
 323
 324         return i915_wait_irq(dev, irqwait->irq_seq);
 325 }
 326
 327 /* Called from drm generic code, passed 'crtc' which
 328  * we use as a pipe index
 329  */
 330 int i915_enable_vblank(struct drm_device *dev, int pipe)
 331 {
 332         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 333         u32     pipestat_reg = 0;
 334         u32     pipestat;
 335         u32     interrupt = 0;
 336         unsigned long irqflags;
 337
 338         switch (pipe) {
 339         case 0:
 340                 pipestat_reg = PIPEASTAT;
 341                 interrupt = I915_DISPLAY_PIPE_A_EVENT_INTERRUPT;
 342                 break;
 343         case 1:
 344                 pipestat_reg = PIPEBSTAT;
 345                 interrupt = I915_DISPLAY_PIPE_B_EVENT_INTERRUPT;
 346                 break;
 347         default:
 348                 DRM_ERROR("tried to enable vblank on non-existent pipe %d\n",
 349                           pipe);
 350                 return 0;
 351         }
 352
 353         spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags);
 354         /* Enabling vblank events in IMR comes before PIPESTAT write, or
 355          * there's a race where the PIPESTAT vblank bit gets set to 1, so
 356          * the OR of enabled PIPESTAT bits goes to 1, so the PIPExEVENT in
 357          * ISR flashes to 1, but the IIR bit doesn't get set to 1 because
 358          * IMR masks it.  It doesn't ever get set after we clear the masking
 359          * in IMR because the ISR bit is edge, not level-triggered, on the
 360          * OR of PIPESTAT bits.
 361          */
 362         i915_enable_irq(dev_priv, interrupt);
 363         pipestat = I915_READ(pipestat_reg);
 364         if (IS_I965G(dev))
 365                 pipestat |= PIPE_START_VBLANK_INTERRUPT_ENABLE;
 366         else
 367                 pipestat |= PIPE_VBLANK_INTERRUPT_ENABLE;
 368         /* Clear any stale interrupt status */
 369         pipestat |= (PIPE_START_VBLANK_INTERRUPT_STATUS |
 370                      PIPE_VBLANK_INTERRUPT_STATUS);
 371         I915_WRITE(pipestat_reg, pipestat);
 372         (void) I915_READ(pipestat_reg); /* Posting read */
 373         spin_unlock_irqrestore(&dev_priv->user_irq_lock, irqflags);
 374
 375         return 0;
 376 }
 377
 378 /* Called from drm generic code, passed 'crtc' which
 379  * we use as a pipe index
 380  */
 381 void i915_disable_vblank(struct drm_device *dev, int pipe)
 382 {
 383         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 384         u32     pipestat_reg = 0;
 385         u32     pipestat;
 386         u32     interrupt = 0;
 387         unsigned long irqflags;
 388
 389         switch (pipe) {
 390         case 0:
 391                 pipestat_reg = PIPEASTAT;
 392                 interrupt = I915_DISPLAY_PIPE_A_EVENT_INTERRUPT;
 393                 break;
 394         case 1:
 395                 pipestat_reg = PIPEBSTAT;
 396                 interrupt = I915_DISPLAY_PIPE_B_EVENT_INTERRUPT;
 397                 break;
 398         default:
 399                 DRM_ERROR("tried to disable vblank on non-existent pipe %d\n",
 400                           pipe);
 401                 return;
 402                 break;
 403         }
 404
 405         spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags);
 406         i915_disable_irq(dev_priv, interrupt);
 407         pipestat = I915_READ(pipestat_reg);
 408         pipestat &= ~(PIPE_START_VBLANK_INTERRUPT_ENABLE |
 409                       PIPE_VBLANK_INTERRUPT_ENABLE);
 410         /* Clear any stale interrupt status */
 411         pipestat |= (PIPE_START_VBLANK_INTERRUPT_STATUS |
 412                      PIPE_VBLANK_INTERRUPT_STATUS);
 413         I915_WRITE(pipestat_reg, pipestat);
 414         (void) I915_READ(pipestat_reg); /* Posting read */
 415         spin_unlock_irqrestore(&dev_priv->user_irq_lock, irqflags);
 416 }
 417
 418 /* Set the vblank monitor pipe
 419  */
 420 int i915_vblank_pipe_set(struct drm_device *dev, void *data,
 421                          struct drm_file *file_priv)
 422 {
 423         drm_i915_private_t *dev_priv = dev->dev_private;
 424
 425         if (!dev_priv) {
 426                 DRM_ERROR("called with no initialization\n");
 427                 return -EINVAL;
 428         }
 429
 430         return 0;
 431 }
 432
 433 int i915_vblank_pipe_get(struct drm_device *dev, void *data,
 434                          struct drm_file *file_priv)
 435 {
 436         drm_i915_private_t *dev_priv = dev->dev_private;
 437         drm_i915_vblank_pipe_t *pipe = data;
 438
 439         if (!dev_priv) {
 440                 DRM_ERROR("called with no initialization\n");
 441                 return -EINVAL;
 442         }
 443
 444         pipe->pipe = DRM_I915_VBLANK_PIPE_A | DRM_I915_VBLANK_PIPE_B;
 445
 446         return 0;
 447 }
 448
 449 /**
 450  * Schedule buffer swap at given vertical blank.
 451  */
 452 int i915_vblank_swap(struct drm_device *dev, void *data,
 453                      struct drm_file *file_priv)
 454 {
 455         /* The delayed swap mechanism was fundamentally racy, and has been
 456          * removed.  The model was that the client requested a delayed flip/swap
 457          * from the kernel, then waited for vblank before continuing to perform
 458          * rendering.  The problem was that the kernel might wake the client
 459          * up before it dispatched the vblank swap (since the lock has to be
 460          * held while touching the ringbuffer), in which case the client would
 461          * clear and start the next frame before the swap occurred, and
 462          * flicker would occur in addition to likely missing the vblank.
 463          *
 464          * In the absence of this ioctl, userland falls back to a correct path
 465          * of waiting for a vblank, then dispatching the swap on its own.
 466          * Context switching to userland and back is plenty fast enough for
 467          * meeting the requirements of vblank swapping.
 468          */
 469         return -EINVAL;
 470 }
 471
 472 /* drm_dma.h hooks
 473 */
 474 void i915_driver_irq_preinstall(struct drm_device * dev)
 475 {
 476         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 477
 478         I915_WRITE(HWSTAM, 0xeffe);
 479         I915_WRITE(IMR, 0xffffffff);
 480         I915_WRITE(IER, 0x0);
 481 }
 482
 483 int i915_driver_irq_postinstall(struct drm_device *dev)
 484 {
 485         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 486         int ret, num_pipes = 2;
 487
 488         /* Set initial unmasked IRQs to just the selected vblank pipes. */
 489         dev_priv->irq_mask_reg = ~0;
 490
 491         ret = drm_vblank_init(dev, num_pipes);
 492         if (ret)
 493                 return ret;
 494
 495         dev_priv->vblank_pipe = DRM_I915_VBLANK_PIPE_A | DRM_I915_VBLANK_PIPE_B;
 496         dev_priv->irq_mask_reg &= ~I915_DISPLAY_PIPE_A_VBLANK_INTERRUPT;
 497         dev_priv->irq_mask_reg &= ~I915_DISPLAY_PIPE_B_VBLANK_INTERRUPT;
 498
 499         dev->max_vblank_count = 0xffffff; /* only 24 bits of frame count */
 500
 501         dev_priv->irq_mask_reg &= I915_INTERRUPT_ENABLE_MASK;
 502
 503         I915_WRITE(IMR, dev_priv->irq_mask_reg);
 504         I915_WRITE(IER, I915_INTERRUPT_ENABLE_MASK);
 505         (void) I915_READ(IER);
 506
 507         opregion_enable_asle(dev);
 508         DRM_INIT_WAITQUEUE(&dev_priv->irq_queue);
 509
 510         return 0;
 511 }
 512
 513 void i915_driver_irq_uninstall(struct drm_device * dev)
 514 {
 515         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 516         u32 temp;
 517
 518         if (!dev_priv)
 519                 return;
 520
 521         dev_priv->vblank_pipe = 0;
 522
 523         I915_WRITE(HWSTAM, 0xffffffff);
 524         I915_WRITE(IMR, 0xffffffff);
 525         I915_WRITE(IER, 0x0);
 526
 527         temp = I915_READ(PIPEASTAT);
 528         I915_WRITE(PIPEASTAT, temp);
 529         temp = I915_READ(PIPEBSTAT);
 530         I915_WRITE(PIPEBSTAT, temp);
 531         temp = I915_READ(IIR);
 532         I915_WRITE(IIR, temp);
 533 }