mga_drv.c

Linux内核源代码 为压缩文件 是<<Linux内核>>一书中的源代码

	return 0;
}

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

static int __init mga_init(void)
{
	int		      retcode;
	drm_device_t	      *dev = &mga_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(mga);
#endif
	if ((retcode = misc_register(&mga_misc))) {
		DRM_ERROR("Cannot register \"%s\"\n", MGA_NAME);
		return retcode;
	}
	dev->device = MKDEV(MISC_MAJOR, mga_misc.minor);
	dev->name   = MGA_NAME;

	drm_mem_init();
	drm_proc_init(dev);
	dev->agp    = drm_agp_init();
      	if(dev->agp == NULL) {
	   	DRM_INFO("The mga drm module requires the agpgart module"
		         " to function correctly\nPlease load the agpgart"
		         " module before you load the mga module\n");
	   	drm_proc_cleanup();
	   	misc_deregister(&mga_misc);
	   	mga_takedown(dev);
	   	return -ENOMEM;
	}
#ifdef CONFIG_MTRR
   	dev->agp->agp_mtrr = mtrr_add(dev->agp->agp_info.aper_base,
				      dev->agp->agp_info.aper_size * 1024 * 1024,
				      MTRR_TYPE_WRCOMB,
				      1);
#endif
	if((retcode = drm_ctxbitmap_init(dev))) {
		DRM_ERROR("Cannot allocate memory for context bitmap.\n");
		drm_proc_cleanup();
		misc_deregister(&mga_misc);
		mga_takedown(dev);
		return retcode;
	}

	DRM_INFO("Initialized %s %d.%d.%d %s on minor %d\n",
		 MGA_NAME,
		 MGA_MAJOR,
		 MGA_MINOR,
		 MGA_PATCHLEVEL,
		 MGA_DATE,
		 mga_misc.minor);

	return 0;
}

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

static void __exit mga_cleanup(void)
{
	drm_device_t	      *dev = &mga_device;

	DRM_DEBUG("\n");

	drm_proc_cleanup();
	if (misc_deregister(&mga_misc)) {
		DRM_ERROR("Cannot unload module\n");
	} else {
		DRM_INFO("Module unloaded\n");
	}
	drm_ctxbitmap_cleanup(dev);
#ifdef CONFIG_MTRR
   	if(dev->agp && dev->agp->agp_mtrr) {
	   	int retval;
	   	retval = mtrr_del(dev->agp->agp_mtrr,
				  dev->agp->agp_info.aper_base,
				  dev->agp->agp_info.aper_size * 1024*1024);
	   	DRM_DEBUG("mtrr_del = %d\n", retval);
	}
#endif

	mga_takedown(dev);
	if (dev->agp) {
		drm_agp_uninit();
		drm_free(dev->agp, sizeof(*dev->agp), DRM_MEM_AGPLISTS);
		dev->agp = NULL;
	}
}

module_init(mga_init);
module_exit(mga_cleanup);


int mga_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	   = MGA_MAJOR;
	version.version_minor	   = MGA_MINOR;
	version.version_patchlevel = MGA_PATCHLEVEL;

	DRM_COPY(version.name, MGA_NAME);
	DRM_COPY(version.date, MGA_DATE);
	DRM_COPY(version.desc, MGA_DESC);

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

int mga_open(struct inode *inode, struct file *filp)
{
	drm_device_t  *dev    = &mga_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 mga_setup(dev);
		}
		spin_unlock(&dev->count_lock);
	}
	return retcode;
}

int mga_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) {
	      	mga_reclaim_buffers(dev, priv->pid);
		DRM_INFO("Process %d dead (ctx %d, d_s = 0x%02lx)\n",
			 current->pid,
			 _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock),
			 dev->dev_private ?
			 ((drm_mga_private_t *)dev->dev_private)
			 ->dispatch_status
			 : 0);

		if (dev->dev_private)
			((drm_mga_private_t *)dev->dev_private)
				->dispatch_status &= MGA_IN_DISPATCH;
		
		drm_lock_free(dev,
			      &dev->lock.hw_lock->lock,
			      _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
	} 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) {
		   	mga_reclaim_buffers(dev, priv->pid);
			if (dev->dev_private)
				((drm_mga_private_t *)dev->dev_private)
					->dispatch_status &= MGA_IN_DISPATCH;
		   	drm_lock_free(dev, &dev->lock.hw_lock->lock,
				      DRM_KERNEL_CONTEXT);
		}
	}
	drm_fasync(-1, filp, 0);

	down(&dev->struct_sem);
	if (priv->remove_auth_on_close == 1) {
		drm_file_t *temp = dev->file_first;
		while(temp) {
			temp->authenticated = 0;
			temp = temp->next;
		}
	}
	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 mga_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 mga_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;

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

		if (!func) {
			DRM_DEBUG("no function: pid = %d, cmd = 0x%02x,"
				  " nr = 0x%02x, dev 0x%x, auth = %d\n",
				  current->pid, cmd, nr, dev->device,
				  priv->authenticated);
			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 mga_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;
	}

	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);
	mga_dma_schedule(dev, 1);

	if (drm_lock_free(dev, &dev->lock.hw_lock->lock,
			  DRM_KERNEL_CONTEXT)) DRM_ERROR("\n");

	unblock_all_signals();
	return 0;
}