i810_drv.c

内核linux2.4.20,可跟rtlinux3.2打补丁 组成实时linux系统,编译内核

	dev->queue_count     = 0;
	if (dev->lock.hw_lock) {
		dev->lock.hw_lock    = NULL; /* SHM removed */
		dev->lock.pid	     = 0;
		wake_up_interruptible(&dev->lock.lock_queue);
	}
	up(&dev->struct_sem);

	return 0;
}

/* i810_init is called via init_module at module load time, or via
 * linux/init/main.c (this is not currently supported). */

static int __init i810_init(void)
{
	int		      retcode;
	drm_device_t	      *dev = &i810_device;

	DRM_DEBUG("\n");

	memset((void *)dev, 0, sizeof(*dev));
	dev->count_lock	  = SPIN_LOCK_UNLOCKED;
	sema_init(&dev->struct_sem, 1);

#ifdef MODULE
	drm_parse_options(i810);
#endif
	DRM_DEBUG("doing misc_register\n");
	if ((retcode = misc_register(&i810_misc))) {
		DRM_ERROR("Cannot register \"%s\"\n", I810_NAME);
		return retcode;
	}
	dev->device = MKDEV(MISC_MAJOR, i810_misc.minor);
	dev->name   = I810_NAME;

   	DRM_DEBUG("doing mem init\n");
	drm_mem_init();
	DRM_DEBUG("doing proc init\n");
	drm_proc_init(dev);
	DRM_DEBUG("doing agp init\n");
	dev->agp    = drm_agp_init();
   	if(dev->agp == NULL) {
	   	DRM_INFO("The i810 drm module requires the agpgart module"
			 " to function correctly\nPlease load the agpgart"
			 " module before you load the i810 module\n");
	   	drm_proc_cleanup();
	   	misc_deregister(&i810_misc);
	   	i810_takedown(dev);
	   	return -ENOMEM;
	}
	DRM_DEBUG("doing ctxbitmap init\n");
	if((retcode = drm_ctxbitmap_init(dev))) {
		DRM_ERROR("Cannot allocate memory for context bitmap.\n");
		drm_proc_cleanup();
		misc_deregister(&i810_misc);
		i810_takedown(dev);
		return retcode;
	}

	DRM_INFO("Initialized %s %d.%d.%d %s on minor %d\n",
		 I810_NAME,
		 I810_MAJOR,
		 I810_MINOR,
		 I810_PATCHLEVEL,
		 I810_DATE,
		 i810_misc.minor);

	return 0;
}

/* i810_cleanup is called via cleanup_module at module unload time. */

static void __exit i810_cleanup(void)
{
	drm_device_t	      *dev = &i810_device;

	DRM_DEBUG("\n");

	drm_proc_cleanup();
	if (misc_deregister(&i810_misc)) {
		DRM_ERROR("Cannot unload module\n");
	} else {
		DRM_INFO("Module unloaded\n");
	}
	drm_ctxbitmap_cleanup(dev);
	i810_takedown(dev);
	if (dev->agp) {
		drm_agp_uninit();
		drm_free(dev->agp, sizeof(*dev->agp), DRM_MEM_AGPLISTS);
		dev->agp = NULL;
	}
}

module_init(i810_init);
module_exit(i810_cleanup);


int i810_version(struct inode *inode, struct file *filp, unsigned int cmd,
		  unsigned long arg)
{
	drm_version_t version;
	int	      len;

	if (copy_from_user(&version,
			   (drm_version_t *)arg,
			   sizeof(version)))
		return -EFAULT;

#define DRM_COPY(name,value)				     \
	len = strlen(value);				     \
	if (len > name##_len) len = name##_len;		     \
	name##_len = strlen(value);			     \
	if (len && name) {				     \
		if (copy_to_user(name, value, len))          \
			return -EFAULT;			     \
	}

	version.version_major	   = I810_MAJOR;
	version.version_minor	   = I810_MINOR;
	version.version_patchlevel = I810_PATCHLEVEL;

	DRM_COPY(version.name, I810_NAME);
	DRM_COPY(version.date, I810_DATE);
	DRM_COPY(version.desc, I810_DESC);

	if (copy_to_user((drm_version_t *)arg,
			 &version,
			 sizeof(version)))
		return -EFAULT;
	return 0;
}

int i810_open(struct inode *inode, struct file *filp)
{
	drm_device_t  *dev    = &i810_device;
	int	      retcode = 0;

	DRM_DEBUG("open_count = %d\n", dev->open_count);
	if (!(retcode = drm_open_helper(inode, filp, dev))) {
#if LINUX_VERSION_CODE < 0x020333
		MOD_INC_USE_COUNT; /* Needed before Linux 2.3.51 */
#endif
		atomic_inc(&dev->total_open);
		spin_lock(&dev->count_lock);
		if (!dev->open_count++) {
			spin_unlock(&dev->count_lock);
			return i810_setup(dev);
		}
		spin_unlock(&dev->count_lock);
	}
	return retcode;
}

int i810_release(struct inode *inode, struct file *filp)
{
	drm_file_t    *priv   = filp->private_data;
	drm_device_t  *dev;
	int	      retcode = 0;

	lock_kernel();
	dev    = priv->dev;
	DRM_DEBUG("pid = %d, device = 0x%x, open_count = %d\n",
		  current->pid, dev->device, dev->open_count);

	if (dev->lock.hw_lock && _DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock)
	    && dev->lock.pid == current->pid) {
	      	i810_reclaim_buffers(dev, priv->pid);
		DRM_ERROR("Process %d dead, freeing lock for context %d\n",
			  current->pid,
			  _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
		drm_lock_free(dev,
			      &dev->lock.hw_lock->lock,
			      _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));

				/* FIXME: may require heavy-handed reset of
                                   hardware at this point, possibly
                                   processed via a callback to the X
                                   server. */
	} else if (dev->lock.hw_lock) {
	   	/* The lock is required to reclaim buffers */
	   	DECLARE_WAITQUEUE(entry, current);
	   	add_wait_queue(&dev->lock.lock_queue, &entry);
		for (;;) {
			current->state = TASK_INTERRUPTIBLE;
			if (!dev->lock.hw_lock) {
				/* Device has been unregistered */
				retcode = -EINTR;
				break;
			}
			if (drm_lock_take(&dev->lock.hw_lock->lock,
					  DRM_KERNEL_CONTEXT)) {
				dev->lock.pid	    = priv->pid;
				dev->lock.lock_time = jiffies;
				atomic_inc(&dev->total_locks);
				break;	/* Got lock */
			}
				/* Contention */
			atomic_inc(&dev->total_sleeps);
			schedule();
			if (signal_pending(current)) {
				retcode = -ERESTARTSYS;
				break;
			}
		}
		current->state = TASK_RUNNING;
		remove_wait_queue(&dev->lock.lock_queue, &entry);
	   	if(!retcode) {
		   	i810_reclaim_buffers(dev, priv->pid);
		   	drm_lock_free(dev, &dev->lock.hw_lock->lock,
				      DRM_KERNEL_CONTEXT);
		}
	}
	drm_fasync(-1, filp, 0);

	down(&dev->struct_sem);
	if (priv->prev) priv->prev->next = priv->next;
	else		dev->file_first	 = priv->next;
	if (priv->next) priv->next->prev = priv->prev;
	else		dev->file_last	 = priv->prev;
	up(&dev->struct_sem);

	drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
#if LINUX_VERSION_CODE < 0x020333
	MOD_DEC_USE_COUNT; /* Needed before Linux 2.3.51 */
#endif
   	atomic_inc(&dev->total_close);
   	spin_lock(&dev->count_lock);
   	if (!--dev->open_count) {
	   	if (atomic_read(&dev->ioctl_count) || dev->blocked) {
		   	DRM_ERROR("Device busy: %d %d\n",
				  atomic_read(&dev->ioctl_count),
				  dev->blocked);
		   	spin_unlock(&dev->count_lock);
			unlock_kernel();
		   	return -EBUSY;
		}
	   	spin_unlock(&dev->count_lock);
		unlock_kernel();
		return i810_takedown(dev);
	}
	spin_unlock(&dev->count_lock);
	unlock_kernel();
	return retcode;
}

/* drm_ioctl is called whenever a process performs an ioctl on /dev/drm. */

int i810_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
		unsigned long arg)
{
	int		 nr	 = DRM_IOCTL_NR(cmd);
	drm_file_t	 *priv	 = filp->private_data;
	drm_device_t	 *dev	 = priv->dev;
	int		 retcode = 0;
	drm_ioctl_desc_t *ioctl;
	drm_ioctl_t	 *func;

	atomic_inc(&dev->ioctl_count);
	atomic_inc(&dev->total_ioctl);
	++priv->ioctl_count;

	DRM_DEBUG("pid = %d, cmd = 0x%02x, nr = 0x%02x, dev 0x%x, auth = %d\n",
		  current->pid, cmd, nr, dev->device, priv->authenticated);

	if (nr >= I810_IOCTL_COUNT) {
		retcode = -EINVAL;
	} else {
		ioctl	  = &i810_ioctls[nr];
		func	  = ioctl->func;

		if (!func) {
			DRM_DEBUG("no function\n");
			retcode = -EINVAL;
		} else if ((ioctl->root_only && !capable(CAP_SYS_ADMIN))
			    || (ioctl->auth_needed && !priv->authenticated)) {
			retcode = -EACCES;
		} else {
			retcode = (func)(inode, filp, cmd, arg);
		}
	}

	atomic_dec(&dev->ioctl_count);
	return retcode;
}

int i810_unlock(struct inode *inode, struct file *filp, unsigned int cmd,
		 unsigned long arg)
{
	drm_file_t	  *priv	  = filp->private_data;
	drm_device_t	  *dev	  = priv->dev;
	drm_lock_t	  lock;

	if (copy_from_user(&lock, (drm_lock_t *)arg, sizeof(lock)))
		return -EFAULT;

	if (lock.context == DRM_KERNEL_CONTEXT) {
		DRM_ERROR("Process %d using kernel context %d\n",
			  current->pid, lock.context);
		return -EINVAL;
	}

	DRM_DEBUG("%d frees lock (%d holds)\n",
		  lock.context,
		  _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
	atomic_inc(&dev->total_unlocks);
	if (_DRM_LOCK_IS_CONT(dev->lock.hw_lock->lock))
		atomic_inc(&dev->total_contends);
   	drm_lock_transfer(dev, &dev->lock.hw_lock->lock, DRM_KERNEL_CONTEXT);
	if (!dev->context_flag) {
		if (drm_lock_free(dev, &dev->lock.hw_lock->lock,
				  DRM_KERNEL_CONTEXT)) {
			DRM_ERROR("\n");
		}
	}
#if DRM_DMA_HISTOGRAM
	atomic_inc(&dev->histo.lhld[drm_histogram_slot(get_cycles()
						       - dev->lck_start)]);
#endif

	unblock_all_signals();
	return 0;
}