drivers/char/drm/drm_irq.c

   1 /**
   2  * \file drm_irq.c
   3  * IRQ support
   4  *
   5  * \author Rickard E. (Rik) Faith <faith@valinux.com>
   6  * \author Gareth Hughes <gareth@valinux.com>
   7  */
   8
   9 /*
  10  * Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
  11  *
  12  * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
  13  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
  14  * All Rights Reserved.
  15  *
  16  * Permission is hereby granted, free of charge, to any person obtaining a
  17  * copy of this software and associated documentation files (the "Software"),
  18  * to deal in the Software without restriction, including without limitation
  19  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  20  * and/or sell copies of the Software, and to permit persons to whom the
  21  * Software is furnished to do so, subject to the following conditions:
  22  *
  23  * The above copyright notice and this permission notice (including the next
  24  * paragraph) shall be included in all copies or substantial portions of the
  25  * Software.
  26  *
  27  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  28  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  29  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  30  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  31  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  32  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  33  * OTHER DEALINGS IN THE SOFTWARE.
  34  */
  35
  36 #include "drmP.h"
  37
  38 #include <linux/interrupt.h>    /* For task queue support */
  39
  40 /**
  41  * Get interrupt from bus id.
  42  *
  43  * \param inode device inode.
  44  * \param filp file pointer.
  45  * \param cmd command.
  46  * \param arg user argument, pointing to a drm_irq_busid structure.
  47  * \return zero on success or a negative number on failure.
  48  *
  49  * Finds the PCI device with the specified bus id and gets its IRQ number.
  50  * This IOCTL is deprecated, and will now return EINVAL for any busid not equal
  51  * to that of the device that this DRM instance attached to.
  52  */
  53 int drm_irq_by_busid(struct inode *inode, struct file *filp,
  54                      unsigned int cmd, unsigned long arg)
  55 {
  56         drm_file_t *priv = filp->private_data;
  57         drm_device_t *dev = priv->head->dev;
  58         drm_irq_busid_t __user *argp = (void __user *)arg;
  59         drm_irq_busid_t p;
  60
  61         if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
  62                 return -EINVAL;
  63
  64         if (copy_from_user(&p, argp, sizeof(p)))
  65                 return -EFAULT;
  66
  67         if ((p.busnum >> 8) != dev->pci_domain ||
  68             (p.busnum & 0xff) != dev->pci_bus ||
  69             p.devnum != dev->pci_slot || p.funcnum != dev->pci_func)
  70                 return -EINVAL;
  71
  72         p.irq = dev->irq;
  73
  74         DRM_DEBUG("%d:%d:%d => IRQ %d\n", p.busnum, p.devnum, p.funcnum, p.irq);
  75         if (copy_to_user(argp, &p, sizeof(p)))
  76                 return -EFAULT;
  77         return 0;
  78 }
  79
  80 /**
  81  * Install IRQ handler.
  82  *
  83  * \param dev DRM device.
  84  * \param irq IRQ number.
  85  *
  86  * Initializes the IRQ related data, and setups drm_device::vbl_queue. Installs the handler, calling the driver
  87  * \c drm_driver_irq_preinstall() and \c drm_driver_irq_postinstall() functions
  88  * before and after the installation.
  89  */
  90 static int drm_irq_install(drm_device_t * dev)
  91 {
  92         int ret;
  93         unsigned long sh_flags = 0;
  94
  95         if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
  96                 return -EINVAL;
  97
  98         if (dev->irq == 0)
  99                 return -EINVAL;
 100
 101         down(&dev->struct_sem);
 102
 103         /* Driver must have been initialized */
 104         if (!dev->dev_private) {
 105                 up(&dev->struct_sem);
 106                 return -EINVAL;
 107         }
 108
 109         if (dev->irq_enabled) {
 110                 up(&dev->struct_sem);
 111                 return -EBUSY;
 112         }
 113         dev->irq_enabled = 1;
 114         up(&dev->struct_sem);
 115
 116         DRM_DEBUG("%s: irq=%d\n", __FUNCTION__, dev->irq);
 117
 118         if (drm_core_check_feature(dev, DRIVER_IRQ_VBL)) {
 119                 init_waitqueue_head(&dev->vbl_queue);
 120
 121                 spin_lock_init(&dev->vbl_lock);
 122
 123                 INIT_LIST_HEAD(&dev->vbl_sigs.head);
 124
 125                 dev->vbl_pending = 0;
 126         }
 127
 128         /* Before installing handler */
 129         dev->driver->irq_preinstall(dev);
 130
 131         /* Install handler */
 132         if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
 133                 sh_flags = SA_SHIRQ;
 134
 135         ret = request_irq(dev->irq, dev->driver->irq_handler,
 136                           sh_flags, dev->devname, dev);
 137         if (ret < 0) {
 138                 down(&dev->struct_sem);
 139                 dev->irq_enabled = 0;
 140                 up(&dev->struct_sem);
 141                 return ret;
 142         }
 143
 144         /* After installing handler */
 145         dev->driver->irq_postinstall(dev);
 146
 147         return 0;
 148 }
 149
 150 /**
 151  * Uninstall the IRQ handler.
 152  *
 153  * \param dev DRM device.
 154  *
 155  * Calls the driver's \c drm_driver_irq_uninstall() function, and stops the irq.
 156  */
 157 int drm_irq_uninstall(drm_device_t * dev)
 158 {
 159         int irq_enabled;
 160
 161         if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
 162                 return -EINVAL;
 163
 164         down(&dev->struct_sem);
 165         irq_enabled = dev->irq_enabled;
 166         dev->irq_enabled = 0;
 167         up(&dev->struct_sem);
 168
 169         if (!irq_enabled)
 170                 return -EINVAL;
 171
 172         DRM_DEBUG("%s: irq=%d\n", __FUNCTION__, dev->irq);
 173
 174         dev->driver->irq_uninstall(dev);
 175
 176         free_irq(dev->irq, dev);
 177
 178         return 0;
 179 }
 180
 181 EXPORT_SYMBOL(drm_irq_uninstall);
 182
 183 /**
 184  * IRQ control ioctl.
 185  *
 186  * \param inode device inode.
 187  * \param filp file pointer.
 188  * \param cmd command.
 189  * \param arg user argument, pointing to a drm_control structure.
 190  * \return zero on success or a negative number on failure.
 191  *
 192  * Calls irq_install() or irq_uninstall() according to \p arg.
 193  */
 194 int drm_control(struct inode *inode, struct file *filp,
 195                 unsigned int cmd, unsigned long arg)
 196 {
 197         drm_file_t *priv = filp->private_data;
 198         drm_device_t *dev = priv->head->dev;
 199         drm_control_t ctl;
 200
 201         /* if we haven't irq we fallback for compatibility reasons - this used to be a separate function in drm_dma.h */
 202
 203         if (copy_from_user(&ctl, (drm_control_t __user *) arg, sizeof(ctl)))
 204                 return -EFAULT;
 205
 206         switch (ctl.func) {
 207         case DRM_INST_HANDLER:
 208                 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
 209                         return 0;
 210                 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
 211                     ctl.irq != dev->irq)
 212                         return -EINVAL;
 213                 return drm_irq_install(dev);
 214         case DRM_UNINST_HANDLER:
 215                 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
 216                         return 0;
 217                 return drm_irq_uninstall(dev);
 218         default:
 219                 return -EINVAL;
 220         }
 221 }
 222
 223 /**
 224  * Wait for VBLANK.
 225  *
 226  * \param inode device inode.
 227  * \param filp file pointer.
 228  * \param cmd command.
 229  * \param data user argument, pointing to a drm_wait_vblank structure.
 230  * \return zero on success or a negative number on failure.
 231  *
 232  * Verifies the IRQ is installed.
 233  *
 234  * If a signal is requested checks if this task has already scheduled the same signal
 235  * for the same vblank sequence number - nothing to be done in
 236  * that case. If the number of tasks waiting for the interrupt exceeds 100 the
 237  * function fails. Otherwise adds a new entry to drm_device::vbl_sigs for this
 238  * task.
 239  *
 240  * If a signal is not requested, then calls vblank_wait().
 241  */
 242 int drm_wait_vblank(DRM_IOCTL_ARGS)
 243 {
 244         drm_file_t *priv = filp->private_data;
 245         drm_device_t *dev = priv->head->dev;
 246         drm_wait_vblank_t __user *argp = (void __user *)data;
 247         drm_wait_vblank_t vblwait;
 248         struct timeval now;
 249         int ret = 0;
 250         unsigned int flags;
 251
 252         if (!drm_core_check_feature(dev, DRIVER_IRQ_VBL))
 253                 return -EINVAL;
 254
 255         if (!dev->irq)
 256                 return -EINVAL;
 257
 258         DRM_COPY_FROM_USER_IOCTL(vblwait, argp, sizeof(vblwait));
 259
 260         switch (vblwait.request.type & ~_DRM_VBLANK_FLAGS_MASK) {
 261         case _DRM_VBLANK_RELATIVE:
 262                 vblwait.request.sequence += atomic_read(&dev->vbl_received);
 263                 vblwait.request.type &= ~_DRM_VBLANK_RELATIVE;
 264         case _DRM_VBLANK_ABSOLUTE:
 265                 break;
 266         default:
 267                 return -EINVAL;
 268         }
 269
 270         flags = vblwait.request.type & _DRM_VBLANK_FLAGS_MASK;
 271
 272         if (flags & _DRM_VBLANK_SIGNAL) {
 273                 unsigned long irqflags;
 274                 drm_vbl_sig_t *vbl_sig;
 275
 276                 vblwait.reply.sequence = atomic_read(&dev->vbl_received);
 277
 278                 spin_lock_irqsave(&dev->vbl_lock, irqflags);
 279
 280                 /* Check if this task has already scheduled the same signal
 281                  * for the same vblank sequence number; nothing to be done in
 282                  * that case
 283                  */
 284                 list_for_each_entry(vbl_sig, &dev->vbl_sigs.head, head) {
 285                         if (vbl_sig->sequence == vblwait.request.sequence
 286                             && vbl_sig->info.si_signo == vblwait.request.signal
 287                             && vbl_sig->task == current) {
 288                                 spin_unlock_irqrestore(&dev->vbl_lock,
 289                                                        irqflags);
 290                                 goto done;
 291                         }
 292                 }
 293
 294                 if (dev->vbl_pending >= 100) {
 295                         spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
 296                         return -EBUSY;
 297                 }
 298
 299                 dev->vbl_pending++;
 300
 301                 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
 302
 303                 if (!
 304                     (vbl_sig =
 305                      drm_alloc(sizeof(drm_vbl_sig_t), DRM_MEM_DRIVER))) {
 306                         return -ENOMEM;
 307                 }
 308
 309                 memset((void *)vbl_sig, 0, sizeof(*vbl_sig));
 310
 311                 vbl_sig->sequence = vblwait.request.sequence;
 312                 vbl_sig->info.si_signo = vblwait.request.signal;
 313                 vbl_sig->task = current;
 314
 315                 spin_lock_irqsave(&dev->vbl_lock, irqflags);
 316
 317                 list_add_tail((struct list_head *)vbl_sig, &dev->vbl_sigs.head);
 318
 319                 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
 320         } else {
 321                 if (dev->driver->vblank_wait)
 322                         ret =
 323                             dev->driver->vblank_wait(dev,
 324                                                      &vblwait.request.sequence);
 325
 326                 do_gettimeofday(&now);
 327                 vblwait.reply.tval_sec = now.tv_sec;
 328                 vblwait.reply.tval_usec = now.tv_usec;
 329         }
 330
 331       done:
 332         DRM_COPY_TO_USER_IOCTL(argp, vblwait, sizeof(vblwait));
 333
 334         return ret;
 335 }
 336
 337 /**
 338  * Send the VBLANK signals.
 339  *
 340  * \param dev DRM device.
 341  *
 342  * Sends a signal for each task in drm_device::vbl_sigs and empties the list.
 343  *
 344  * If a signal is not requested, then calls vblank_wait().
 345  */
 346 void drm_vbl_send_signals(drm_device_t * dev)
 347 {
 348         struct list_head *list, *tmp;
 349         drm_vbl_sig_t *vbl_sig;
 350         unsigned int vbl_seq = atomic_read(&dev->vbl_received);
 351         unsigned long flags;
 352
 353         spin_lock_irqsave(&dev->vbl_lock, flags);
 354
 355         list_for_each_safe(list, tmp, &dev->vbl_sigs.head) {
 356                 vbl_sig = list_entry(list, drm_vbl_sig_t, head);
 357                 if ((vbl_seq - vbl_sig->sequence) <= (1 << 23)) {
 358                         vbl_sig->info.si_code = vbl_seq;
 359                         send_sig_info(vbl_sig->info.si_signo, &vbl_sig->info,
 360                                       vbl_sig->task);
 361
 362                         list_del(list);
 363
 364                         drm_free(vbl_sig, sizeof(*vbl_sig), DRM_MEM_DRIVER);
 365
 366                         dev->vbl_pending--;
 367                 }
 368         }
 369
 370         spin_unlock_irqrestore(&dev->vbl_lock, flags);
 371 }
 372
 373 EXPORT_SYMBOL(drm_vbl_send_signals);