drivers/char/drm/drm_irq.c

   1 /**
   2  * \file drm_irq.h
   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 ||
  70             p.funcnum != dev->pci_func)
  71                 return -EINVAL;
  72
  73         p.irq = dev->irq;
  74
  75         DRM_DEBUG("%d:%d:%d => IRQ %d\n",
  76                   p.busnum, p.devnum, p.funcnum, p.irq);
  77         if (copy_to_user(argp, &p, sizeof(p)))
  78                 return -EFAULT;
  79         return 0;
  80 }
  81
  82 /**
  83  * Install IRQ handler.
  84  *
  85  * \param dev DRM device.
  86  * \param irq IRQ number.
  87  *
  88  * Initializes the IRQ related data, and setups drm_device::vbl_queue. Installs the handler, calling the driver
  89  * \c drm_driver_irq_preinstall() and \c drm_driver_irq_postinstall() functions
  90  * before and after the installation.
  91  */
  92 int drm_irq_install( drm_device_t *dev )
  93 {
  94         int ret;
  95         unsigned long sh_flags=0;
  96
  97         if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
  98                 return -EINVAL;
  99
 100         if ( dev->irq == 0 )
 101                 return -EINVAL;
 102
 103         down( &dev->struct_sem );
 104
 105         /* Driver must have been initialized */
 106         if ( !dev->dev_private ) {
 107                 up( &dev->struct_sem );
 108                 return -EINVAL;
 109         }
 110
 111         if ( dev->irq_enabled ) {
 112                 up( &dev->struct_sem );
 113                 return -EBUSY;
 114         }
 115         dev->irq_enabled = 1;
 116         up( &dev->struct_sem );
 117
 118         DRM_DEBUG( "%s: irq=%d\n", __FUNCTION__, dev->irq );
 119
 120         if (drm_core_check_feature(dev, DRIVER_IRQ_VBL)) {
 121                 init_waitqueue_head(&dev->vbl_queue);
 122
 123                 spin_lock_init( &dev->vbl_lock );
 124
 125                 INIT_LIST_HEAD( &dev->vbl_sigs.head );
 126
 127                 dev->vbl_pending = 0;
 128         }
 129
 130                                 /* Before installing handler */
 131         dev->driver->irq_preinstall(dev);
 132
 133                                 /* Install handler */
 134         if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
 135                 sh_flags = SA_SHIRQ;
 136
 137         ret = request_irq( dev->irq, dev->driver->irq_handler,
 138                            sh_flags, dev->devname, dev );
 139         if ( ret < 0 ) {
 140                 down( &dev->struct_sem );
 141                 dev->irq_enabled = 0;
 142                 up( &dev->struct_sem );
 143                 return ret;
 144         }
 145
 146                                 /* After installing handler */
 147         dev->driver->irq_postinstall(dev);
 148
 149         return 0;
 150 }
 151
 152 /**
 153  * Uninstall the IRQ handler.
 154  *
 155  * \param dev DRM device.
 156  *
 157  * Calls the driver's \c drm_driver_irq_uninstall() function, and stops the irq.
 158  */
 159 int drm_irq_uninstall( drm_device_t *dev )
 160 {
 161         int irq_enabled;
 162
 163         if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
 164                 return -EINVAL;
 165
 166         down( &dev->struct_sem );
 167         irq_enabled = dev->irq_enabled;
 168         dev->irq_enabled = 0;
 169         up( &dev->struct_sem );
 170
 171         if ( !irq_enabled )
 172                 return -EINVAL;
 173
 174         DRM_DEBUG( "%s: irq=%d\n", __FUNCTION__, dev->irq );
 175
 176         dev->driver->irq_uninstall(dev);
 177
 178         free_irq( dev->irq, dev );
 179
 180         return 0;
 181 }
 182 EXPORT_SYMBOL(drm_irq_uninstall);
 183
 184 /**
 185  * IRQ control ioctl.
 186  *
 187  * \param inode device inode.
 188  * \param filp file pointer.
 189  * \param cmd command.
 190  * \param arg user argument, pointing to a drm_control structure.
 191  * \return zero on success or a negative number on failure.
 192  *
 193  * Calls irq_install() or irq_uninstall() according to \p arg.
 194  */
 195 int drm_control( struct inode *inode, struct file *filp,
 196                   unsigned int cmd, unsigned long arg )
 197 {
 198         drm_file_t *priv = filp->private_data;
 199         drm_device_t *dev = priv->head->dev;
 200         drm_control_t ctl;
 201
 202         /* if we haven't irq we fallback for compatibility reasons - this used to be a separate function in drm_dma.h */
 203
 204         if ( copy_from_user( &ctl, (drm_control_t __user *)arg, sizeof(ctl) ) )
 205                 return -EFAULT;
 206
 207         switch ( ctl.func ) {
 208         case DRM_INST_HANDLER:
 209                 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
 210                         return 0;
 211                 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
 212                     ctl.irq != dev->irq)
 213                         return -EINVAL;
 214                 return drm_irq_install( dev );
 215         case DRM_UNINST_HANDLER:
 216                 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
 217                         return 0;
 218                 return drm_irq_uninstall( dev );
 219         default:
 220                 return -EINVAL;
 221         }
 222 }
 223
 224 /**
 225  * Wait for VBLANK.
 226  *
 227  * \param inode device inode.
 228  * \param filp file pointer.
 229  * \param cmd command.
 230  * \param data user argument, pointing to a drm_wait_vblank structure.
 231  * \return zero on success or a negative number on failure.
 232  *
 233  * Verifies the IRQ is installed.
 234  *
 235  * If a signal is requested checks if this task has already scheduled the same signal
 236  * for the same vblank sequence number - nothing to be done in
 237  * that case. If the number of tasks waiting for the interrupt exceeds 100 the
 238  * function fails. Otherwise adds a new entry to drm_device::vbl_sigs for this
 239  * task.
 240  *
 241  * If a signal is not requested, then calls vblank_wait().
 242  */
 243 int drm_wait_vblank( DRM_IOCTL_ARGS )
 244 {
 245         drm_file_t *priv = filp->private_data;
 246         drm_device_t *dev = priv->head->dev;
 247         drm_wait_vblank_t __user *argp = (void __user *)data;
 248         drm_wait_vblank_t vblwait;
 249         struct timeval now;
 250         int ret = 0;
 251         unsigned int flags;
 252
 253         if (!drm_core_check_feature(dev, DRIVER_IRQ_VBL))
 254                 return -EINVAL;
 255
 256         if (!dev->irq)
 257                 return -EINVAL;
 258
 259         DRM_COPY_FROM_USER_IOCTL( vblwait, argp, sizeof(vblwait) );
 260
 261         switch ( vblwait.request.type & ~_DRM_VBLANK_FLAGS_MASK ) {
 262         case _DRM_VBLANK_RELATIVE:
 263                 vblwait.request.sequence += atomic_read( &dev->vbl_received );
 264                 vblwait.request.type &= ~_DRM_VBLANK_RELATIVE;
 265         case _DRM_VBLANK_ABSOLUTE:
 266                 break;
 267         default:
 268                 return -EINVAL;
 269         }
 270
 271         flags = vblwait.request.type & _DRM_VBLANK_FLAGS_MASK;
 272
 273         if ( flags & _DRM_VBLANK_SIGNAL ) {
 274                 unsigned long irqflags;
 275                 drm_vbl_sig_t *vbl_sig;
 276
 277                 vblwait.reply.sequence = atomic_read( &dev->vbl_received );
 278
 279                 spin_lock_irqsave( &dev->vbl_lock, irqflags );
 280
 281                 /* Check if this task has already scheduled the same signal
 282                  * for the same vblank sequence number; nothing to be done in
 283                  * that case
 284                  */
 285                 list_for_each_entry( vbl_sig, &dev->vbl_sigs.head, head ) {
 286                         if (vbl_sig->sequence == vblwait.request.sequence
 287                             && vbl_sig->info.si_signo == vblwait.request.signal
 288                             && vbl_sig->task == current)
 289                         {
 290                                 spin_unlock_irqrestore( &dev->vbl_lock, irqflags );
 291                                 goto done;
 292                         }
 293                 }
 294
 295                 if ( dev->vbl_pending >= 100 ) {
 296                         spin_unlock_irqrestore( &dev->vbl_lock, irqflags );
 297                         return -EBUSY;
 298                 }
 299
 300                 dev->vbl_pending++;
 301
 302                 spin_unlock_irqrestore( &dev->vbl_lock, irqflags );
 303
 304                 if ( !( vbl_sig = drm_alloc( sizeof( drm_vbl_sig_t ), DRM_MEM_DRIVER ) ) ) {
 305                         return -ENOMEM;
 306                 }
 307
 308                 memset( (void *)vbl_sig, 0, sizeof(*vbl_sig) );
 309
 310                 vbl_sig->sequence = vblwait.request.sequence;
 311                 vbl_sig->info.si_signo = vblwait.request.signal;
 312                 vbl_sig->task = current;
 313
 314                 spin_lock_irqsave( &dev->vbl_lock, irqflags );
 315
 316                 list_add_tail( (struct list_head *) vbl_sig, &dev->vbl_sigs.head );
 317
 318                 spin_unlock_irqrestore( &dev->vbl_lock, irqflags );
 319         } else {
 320                 if (dev->driver->vblank_wait)
 321                         ret = dev->driver->vblank_wait( dev, &vblwait.request.sequence );
 322
 323                 do_gettimeofday( &now );
 324                 vblwait.reply.tval_sec = now.tv_sec;
 325                 vblwait.reply.tval_usec = now.tv_usec;
 326         }
 327
 328 done:
 329         DRM_COPY_TO_USER_IOCTL( argp, vblwait, sizeof(vblwait) );
 330
 331         return ret;
 332 }
 333
 334 /**
 335  * Send the VBLANK signals.
 336  *
 337  * \param dev DRM device.
 338  *
 339  * Sends a signal for each task in drm_device::vbl_sigs and empties the list.
 340  *
 341  * If a signal is not requested, then calls vblank_wait().
 342  */
 343 void drm_vbl_send_signals( drm_device_t *dev )
 344 {
 345         struct list_head *list, *tmp;
 346         drm_vbl_sig_t *vbl_sig;
 347         unsigned int vbl_seq = atomic_read( &dev->vbl_received );
 348         unsigned long flags;
 349
 350         spin_lock_irqsave( &dev->vbl_lock, flags );
 351
 352         list_for_each_safe( list, tmp, &dev->vbl_sigs.head ) {
 353                 vbl_sig = list_entry( list, drm_vbl_sig_t, head );
 354                 if ( ( vbl_seq - vbl_sig->sequence ) <= (1<<23) ) {
 355                         vbl_sig->info.si_code = vbl_seq;
 356                         send_sig_info( vbl_sig->info.si_signo, &vbl_sig->info, vbl_sig->task );
 357
 358                         list_del( list );
 359
 360                         drm_free( vbl_sig, sizeof(*vbl_sig), DRM_MEM_DRIVER );
 361
 362                         dev->vbl_pending--;
 363                 }
 364         }
 365
 366         spin_unlock_irqrestore( &dev->vbl_lock, flags );
 367 }
 368 EXPORT_SYMBOL(drm_vbl_send_signals);
 369
 370