drivers/gpu/drm/i915/i915_irq.c

   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 /**
  37  * Interrupts that are always left unmasked.
  38  *
  39  * Since pipe events are edge-triggered from the PIPESTAT register to IIR,
  40  * we leave them always unmasked in IMR and then control enabling them through
  41  * PIPESTAT alone.
  42  */
  43 #define I915_INTERRUPT_ENABLE_FIX (I915_ASLE_INTERRUPT | \
  44                                    I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |  \
  45                                    I915_DISPLAY_PIPE_B_EVENT_INTERRUPT)
  46
  47 /** Interrupts that we mask and unmask at runtime. */
  48 #define I915_INTERRUPT_ENABLE_VAR (I915_USER_INTERRUPT)
  49
  50 /** These are all of the interrupts used by the driver */
  51 #define I915_INTERRUPT_ENABLE_MASK (I915_INTERRUPT_ENABLE_FIX | \
  52                                     I915_INTERRUPT_ENABLE_VAR)
  53
  54 void
  55 i915_enable_irq(drm_i915_private_t *dev_priv, u32 mask)
  56 {
  57         if ((dev_priv->irq_mask_reg & mask) != 0) {
  58                 dev_priv->irq_mask_reg &= ~mask;
  59                 I915_WRITE(IMR, dev_priv->irq_mask_reg);
  60                 (void) I915_READ(IMR);
  61         }
  62 }
  63
  64 static inline void
  65 i915_disable_irq(drm_i915_private_t *dev_priv, u32 mask)
  66 {
  67         if ((dev_priv->irq_mask_reg & mask) != mask) {
  68                 dev_priv->irq_mask_reg |= mask;
  69                 I915_WRITE(IMR, dev_priv->irq_mask_reg);
  70                 (void) I915_READ(IMR);
  71         }
  72 }
  73
  74 static inline u32
  75 i915_pipestat(int pipe)
  76 {
  77         if (pipe == 0)
  78                 return PIPEASTAT;
  79         if (pipe == 1)
  80                 return PIPEBSTAT;
  81         BUG_ON(1);
  82 }
  83
  84 void
  85 i915_enable_pipestat(drm_i915_private_t *dev_priv, int pipe, u32 mask)
  86 {
  87         if ((dev_priv->pipestat[pipe] & mask) != mask) {
  88                 u32 reg = i915_pipestat(pipe);
  89
  90                 dev_priv->pipestat[pipe] |= mask;
  91                 /* Enable the interrupt, clear any pending status */
  92                 I915_WRITE(reg, dev_priv->pipestat[pipe] | (mask >> 16));
  93                 (void) I915_READ(reg);
  94         }
  95 }
  96
  97 void
  98 i915_disable_pipestat(drm_i915_private_t *dev_priv, int pipe, u32 mask)
  99 {
 100         if ((dev_priv->pipestat[pipe] & mask) != 0) {
 101                 u32 reg = i915_pipestat(pipe);
 102
 103                 dev_priv->pipestat[pipe] &= ~mask;
 104                 I915_WRITE(reg, dev_priv->pipestat[pipe]);
 105                 (void) I915_READ(reg);
 106         }
 107 }
 108
 109 /**
 110  * i915_pipe_enabled - check if a pipe is enabled
 111  * @dev: DRM device
 112  * @pipe: pipe to check
 113  *
 114  * Reading certain registers when the pipe is disabled can hang the chip.
 115  * Use this routine to make sure the PLL is running and the pipe is active
 116  * before reading such registers if unsure.
 117  */
 118 static int
 119 i915_pipe_enabled(struct drm_device *dev, int pipe)
 120 {
 121         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 122         unsigned long pipeconf = pipe ? PIPEBCONF : PIPEACONF;
 123
 124         if (I915_READ(pipeconf) & PIPEACONF_ENABLE)
 125                 return 1;
 126
 127         return 0;
 128 }
 129
 130 /* Called from drm generic code, passed a 'crtc', which
 131  * we use as a pipe index
 132  */
 133 u32 i915_get_vblank_counter(struct drm_device *dev, int pipe)
 134 {
 135         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 136         unsigned long high_frame;
 137         unsigned long low_frame;
 138         u32 high1, high2, low, count;
 139
 140         high_frame = pipe ? PIPEBFRAMEHIGH : PIPEAFRAMEHIGH;
 141         low_frame = pipe ? PIPEBFRAMEPIXEL : PIPEAFRAMEPIXEL;
 142
 143         if (!i915_pipe_enabled(dev, pipe)) {
 144                 DRM_ERROR("trying to get vblank count for disabled pipe %d\n", pipe);
 145                 return 0;
 146         }
 147
 148         /*
 149          * High & low register fields aren't synchronized, so make sure
 150          * we get a low value that's stable across two reads of the high
 151          * register.
 152          */
 153         do {
 154                 high1 = ((I915_READ(high_frame) & PIPE_FRAME_HIGH_MASK) >>
 155                          PIPE_FRAME_HIGH_SHIFT);
 156                 low =  ((I915_READ(low_frame) & PIPE_FRAME_LOW_MASK) >>
 157                         PIPE_FRAME_LOW_SHIFT);
 158                 high2 = ((I915_READ(high_frame) & PIPE_FRAME_HIGH_MASK) >>
 159                          PIPE_FRAME_HIGH_SHIFT);
 160         } while (high1 != high2);
 161
 162         count = (high1 << 8) | low;
 163
 164         return count;
 165 }
 166
 167 irqreturn_t i915_driver_irq_handler(DRM_IRQ_ARGS)
 168 {
 169         struct drm_device *dev = (struct drm_device *) arg;
 170         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 171         u32 iir, new_iir;
 172         u32 pipea_stats, pipeb_stats;
 173         u32 vblank_status;
 174         u32 vblank_enable;
 175         int vblank = 0;
 176         unsigned long irqflags;
 177         int irq_received;
 178         int ret = IRQ_NONE;
 179
 180         atomic_inc(&dev_priv->irq_received);
 181
 182         iir = I915_READ(IIR);
 183
 184         if (IS_I965G(dev)) {
 185                 vblank_status = I915_START_VBLANK_INTERRUPT_STATUS;
 186                 vblank_enable = PIPE_START_VBLANK_INTERRUPT_ENABLE;
 187         } else {
 188                 vblank_status = I915_VBLANK_INTERRUPT_STATUS;
 189                 vblank_enable = I915_VBLANK_INTERRUPT_ENABLE;
 190         }
 191
 192         for (;;) {
 193                 irq_received = iir != 0;
 194
 195                 /* Can't rely on pipestat interrupt bit in iir as it might
 196                  * have been cleared after the pipestat interrupt was received.
 197                  * It doesn't set the bit in iir again, but it still produces
 198                  * interrupts (for non-MSI).
 199                  */
 200                 spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags);
 201                 pipea_stats = I915_READ(PIPEASTAT);
 202                 pipeb_stats = I915_READ(PIPEBSTAT);
 203                 /*
 204                  * Clear the PIPE(A|B)STAT regs before the IIR
 205                  */
 206                 if (pipea_stats & 0x8000ffff) {
 207                         I915_WRITE(PIPEASTAT, pipea_stats);
 208                         irq_received = 1;
 209                 }
 210
 211                 if (pipeb_stats & 0x8000ffff) {
 212                         I915_WRITE(PIPEBSTAT, pipeb_stats);
 213                         irq_received = 1;
 214                 }
 215                 spin_unlock_irqrestore(&dev_priv->user_irq_lock, irqflags);
 216
 217                 if (!irq_received)
 218                         break;
 219
 220                 ret = IRQ_HANDLED;
 221
 222                 I915_WRITE(IIR, iir);
 223                 new_iir = I915_READ(IIR); /* Flush posted writes */
 224
 225                 if (dev_priv->sarea_priv)
 226                         dev_priv->sarea_priv->last_dispatch =
 227                                 READ_BREADCRUMB(dev_priv);
 228
 229                 if (iir & I915_USER_INTERRUPT) {
 230                         dev_priv->mm.irq_gem_seqno = i915_get_gem_seqno(dev);
 231                         DRM_WAKEUP(&dev_priv->irq_queue);
 232                 }
 233
 234                 if (pipea_stats & vblank_status) {
 235                         vblank++;
 236                         drm_handle_vblank(dev, 0);
 237                 }
 238
 239                 if (pipeb_stats & vblank_status) {
 240                         vblank++;
 241                         drm_handle_vblank(dev, 1);
 242                 }
 243
 244                 if ((pipeb_stats & I915_LEGACY_BLC_EVENT_STATUS) ||
 245                     (iir & I915_ASLE_INTERRUPT))
 246                         opregion_asle_intr(dev);
 247
 248                 /* With MSI, interrupts are only generated when iir
 249                  * transitions from zero to nonzero.  If another bit got
 250                  * set while we were handling the existing iir bits, then
 251                  * we would never get another interrupt.
 252                  *
 253                  * This is fine on non-MSI as well, as if we hit this path
 254                  * we avoid exiting the interrupt handler only to generate
 255                  * another one.
 256                  *
 257                  * Note that for MSI this could cause a stray interrupt report
 258                  * if an interrupt landed in the time between writing IIR and
 259                  * the posting read.  This should be rare enough to never
 260                  * trigger the 99% of 100,000 interrupts test for disabling
 261                  * stray interrupts.
 262                  */
 263                 iir = new_iir;
 264         }
 265
 266         return ret;
 267 }
 268
 269 static int i915_emit_irq(struct drm_device * dev)
 270 {
 271         drm_i915_private_t *dev_priv = dev->dev_private;
 272         RING_LOCALS;
 273
 274         i915_kernel_lost_context(dev);
 275
 276         DRM_DEBUG("\n");
 277
 278         dev_priv->counter++;
 279         if (dev_priv->counter > 0x7FFFFFFFUL)
 280                 dev_priv->counter = 1;
 281         if (dev_priv->sarea_priv)
 282                 dev_priv->sarea_priv->last_enqueue = dev_priv->counter;
 283
 284         BEGIN_LP_RING(4);
 285         OUT_RING(MI_STORE_DWORD_INDEX);
 286         OUT_RING(I915_BREADCRUMB_INDEX << MI_STORE_DWORD_INDEX_SHIFT);
 287         OUT_RING(dev_priv->counter);
 288         OUT_RING(MI_USER_INTERRUPT);
 289         ADVANCE_LP_RING();
 290
 291         return dev_priv->counter;
 292 }
 293
 294 void i915_user_irq_get(struct drm_device *dev)
 295 {
 296         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 297         unsigned long irqflags;
 298
 299         spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags);
 300         if (dev->irq_enabled && (++dev_priv->user_irq_refcount == 1))
 301                 i915_enable_irq(dev_priv, I915_USER_INTERRUPT);
 302         spin_unlock_irqrestore(&dev_priv->user_irq_lock, irqflags);
 303 }
 304
 305 void i915_user_irq_put(struct drm_device *dev)
 306 {
 307         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 308         unsigned long irqflags;
 309
 310         spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags);
 311         BUG_ON(dev->irq_enabled && dev_priv->user_irq_refcount <= 0);
 312         if (dev->irq_enabled && (--dev_priv->user_irq_refcount == 0))
 313                 i915_disable_irq(dev_priv, I915_USER_INTERRUPT);
 314         spin_unlock_irqrestore(&dev_priv->user_irq_lock, irqflags);
 315 }
 316
 317 static int i915_wait_irq(struct drm_device * dev, int irq_nr)
 318 {
 319         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 320         int ret = 0;
 321
 322         DRM_DEBUG("irq_nr=%d breadcrumb=%d\n", irq_nr,
 323                   READ_BREADCRUMB(dev_priv));
 324
 325         if (READ_BREADCRUMB(dev_priv) >= irq_nr) {
 326                 if (dev_priv->sarea_priv) {
 327                         dev_priv->sarea_priv->last_dispatch =
 328                                 READ_BREADCRUMB(dev_priv);
 329                 }
 330                 return 0;
 331         }
 332
 333         if (dev_priv->sarea_priv)
 334                 dev_priv->sarea_priv->perf_boxes |= I915_BOX_WAIT;
 335
 336         i915_user_irq_get(dev);
 337         DRM_WAIT_ON(ret, dev_priv->irq_queue, 3 * DRM_HZ,
 338                     READ_BREADCRUMB(dev_priv) >= irq_nr);
 339         i915_user_irq_put(dev);
 340
 341         if (ret == -EBUSY) {
 342                 DRM_ERROR("EBUSY -- rec: %d emitted: %d\n",
 343                           READ_BREADCRUMB(dev_priv), (int)dev_priv->counter);
 344         }
 345
 346         if (dev_priv->sarea_priv)
 347                 dev_priv->sarea_priv->last_dispatch =
 348                         READ_BREADCRUMB(dev_priv);
 349
 350         return ret;
 351 }
 352
 353 /* Needs the lock as it touches the ring.
 354  */
 355 int i915_irq_emit(struct drm_device *dev, void *data,
 356                          struct drm_file *file_priv)
 357 {
 358         drm_i915_private_t *dev_priv = dev->dev_private;
 359         drm_i915_irq_emit_t *emit = data;
 360         int result;
 361
 362         RING_LOCK_TEST_WITH_RETURN(dev, file_priv);
 363
 364         if (!dev_priv) {
 365                 DRM_ERROR("called with no initialization\n");
 366                 return -EINVAL;
 367         }
 368         mutex_lock(&dev->struct_mutex);
 369         result = i915_emit_irq(dev);
 370         mutex_unlock(&dev->struct_mutex);
 371
 372         if (DRM_COPY_TO_USER(emit->irq_seq, &result, sizeof(int))) {
 373                 DRM_ERROR("copy_to_user\n");
 374                 return -EFAULT;
 375         }
 376
 377         return 0;
 378 }
 379
 380 /* Doesn't need the hardware lock.
 381  */
 382 int i915_irq_wait(struct drm_device *dev, void *data,
 383                          struct drm_file *file_priv)
 384 {
 385         drm_i915_private_t *dev_priv = dev->dev_private;
 386         drm_i915_irq_wait_t *irqwait = data;
 387
 388         if (!dev_priv) {
 389                 DRM_ERROR("called with no initialization\n");
 390                 return -EINVAL;
 391         }
 392
 393         return i915_wait_irq(dev, irqwait->irq_seq);
 394 }
 395
 396 /* Called from drm generic code, passed 'crtc' which
 397  * we use as a pipe index
 398  */
 399 int i915_enable_vblank(struct drm_device *dev, int pipe)
 400 {
 401         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 402         unsigned long irqflags;
 403
 404         spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags);
 405         if (IS_I965G(dev))
 406                 i915_enable_pipestat(dev_priv, pipe,
 407                                      PIPE_START_VBLANK_INTERRUPT_ENABLE);
 408         else
 409                 i915_enable_pipestat(dev_priv, pipe,
 410                                      PIPE_VBLANK_INTERRUPT_ENABLE);
 411         spin_unlock_irqrestore(&dev_priv->user_irq_lock, irqflags);
 412         return 0;
 413 }
 414
 415 /* Called from drm generic code, passed 'crtc' which
 416  * we use as a pipe index
 417  */
 418 void i915_disable_vblank(struct drm_device *dev, int pipe)
 419 {
 420         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 421         unsigned long irqflags;
 422
 423         spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags);
 424         i915_disable_pipestat(dev_priv, pipe,
 425                               PIPE_VBLANK_INTERRUPT_ENABLE |
 426                               PIPE_START_VBLANK_INTERRUPT_ENABLE);
 427         spin_unlock_irqrestore(&dev_priv->user_irq_lock, irqflags);
 428 }
 429
 430 /* Set the vblank monitor pipe
 431  */
 432 int i915_vblank_pipe_set(struct drm_device *dev, void *data,
 433                          struct drm_file *file_priv)
 434 {
 435         drm_i915_private_t *dev_priv = dev->dev_private;
 436
 437         if (!dev_priv) {
 438                 DRM_ERROR("called with no initialization\n");
 439                 return -EINVAL;
 440         }
 441
 442         return 0;
 443 }
 444
 445 int i915_vblank_pipe_get(struct drm_device *dev, void *data,
 446                          struct drm_file *file_priv)
 447 {
 448         drm_i915_private_t *dev_priv = dev->dev_private;
 449         drm_i915_vblank_pipe_t *pipe = data;
 450
 451         if (!dev_priv) {
 452                 DRM_ERROR("called with no initialization\n");
 453                 return -EINVAL;
 454         }
 455
 456         pipe->pipe = DRM_I915_VBLANK_PIPE_A | DRM_I915_VBLANK_PIPE_B;
 457
 458         return 0;
 459 }
 460
 461 /**
 462  * Schedule buffer swap at given vertical blank.
 463  */
 464 int i915_vblank_swap(struct drm_device *dev, void *data,
 465                      struct drm_file *file_priv)
 466 {
 467         /* The delayed swap mechanism was fundamentally racy, and has been
 468          * removed.  The model was that the client requested a delayed flip/swap
 469          * from the kernel, then waited for vblank before continuing to perform
 470          * rendering.  The problem was that the kernel might wake the client
 471          * up before it dispatched the vblank swap (since the lock has to be
 472          * held while touching the ringbuffer), in which case the client would
 473          * clear and start the next frame before the swap occurred, and
 474          * flicker would occur in addition to likely missing the vblank.
 475          *
 476          * In the absence of this ioctl, userland falls back to a correct path
 477          * of waiting for a vblank, then dispatching the swap on its own.
 478          * Context switching to userland and back is plenty fast enough for
 479          * meeting the requirements of vblank swapping.
 480          */
 481         return -EINVAL;
 482 }
 483
 484 /* drm_dma.h hooks
 485 */
 486 void i915_driver_irq_preinstall(struct drm_device * dev)
 487 {
 488         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 489
 490         I915_WRITE(HWSTAM, 0xeffe);
 491         I915_WRITE(PIPEASTAT, 0);
 492         I915_WRITE(PIPEBSTAT, 0);
 493         I915_WRITE(IMR, 0xffffffff);
 494         I915_WRITE(IER, 0x0);
 495         (void) I915_READ(IER);
 496 }
 497
 498 int i915_driver_irq_postinstall(struct drm_device *dev)
 499 {
 500         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 501
 502         dev_priv->vblank_pipe = DRM_I915_VBLANK_PIPE_A | DRM_I915_VBLANK_PIPE_B;
 503
 504         dev->max_vblank_count = 0xffffff; /* only 24 bits of frame count */
 505
 506         /* Unmask the interrupts that we always want on. */
 507         dev_priv->irq_mask_reg = ~I915_INTERRUPT_ENABLE_FIX;
 508
 509         dev_priv->pipestat[0] = 0;
 510         dev_priv->pipestat[1] = 0;
 511
 512         /* Disable pipe interrupt enables, clear pending pipe status */
 513         I915_WRITE(PIPEASTAT, I915_READ(PIPEASTAT) & 0x8000ffff);
 514         I915_WRITE(PIPEBSTAT, I915_READ(PIPEBSTAT) & 0x8000ffff);
 515         /* Clear pending interrupt status */
 516         I915_WRITE(IIR, I915_READ(IIR));
 517
 518         I915_WRITE(IER, I915_INTERRUPT_ENABLE_MASK);
 519         I915_WRITE(IMR, dev_priv->irq_mask_reg);
 520         (void) I915_READ(IER);
 521
 522         opregion_enable_asle(dev);
 523         DRM_INIT_WAITQUEUE(&dev_priv->irq_queue);
 524
 525         return 0;
 526 }
 527
 528 void i915_driver_irq_uninstall(struct drm_device * dev)
 529 {
 530         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 531
 532         if (!dev_priv)
 533                 return;
 534
 535         dev_priv->vblank_pipe = 0;
 536
 537         I915_WRITE(HWSTAM, 0xffffffff);
 538         I915_WRITE(PIPEASTAT, 0);
 539         I915_WRITE(PIPEBSTAT, 0);
 540         I915_WRITE(IMR, 0xffffffff);
 541         I915_WRITE(IER, 0x0);
 542
 543         I915_WRITE(PIPEASTAT, I915_READ(PIPEASTAT) & 0x8000ffff);
 544         I915_WRITE(PIPEBSTAT, I915_READ(PIPEBSTAT) & 0x8000ffff);
 545         I915_WRITE(IIR, I915_READ(IIR));
 546 }