path: root/linux-core/drm_drv.c

/**
 * \file drm_drv.c
 * Generic driver template
 *
 * \author Rickard E. (Rik) Faith <faith@valinux.com>
 * \author Gareth Hughes <gareth@valinux.com>
 *
 * To use this template, you must at least define the following (samples
 * given for the MGA driver):
 *
 * \code
 * #define DRIVER_AUTHOR	"VA Linux Systems, Inc."
 *
 * #define DRIVER_NAME		"mga"
 * #define DRIVER_DESC		"Matrox G200/G400"
 * #define DRIVER_DATE		"20001127"
 *
 * #define drm_x		mga_##x
 * \endcode
 */

/*
 * Created: Thu Nov 23 03:10:50 2000 by gareth@valinux.com
 *
 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */
#include "drmP.h"
#include "drm_core.h"

static void drm_cleanup(drm_device_t * dev);
int drm_fb_loaded = 0;

static int drm_version(struct inode *inode, struct file *filp,
		unsigned int cmd, unsigned long arg);

/** Ioctl table */
static drm_ioctl_desc_t drm_ioctls[] = {
	[DRM_IOCTL_NR(DRM_IOCTL_VERSION)] = {drm_version, 0},
	[DRM_IOCTL_NR(DRM_IOCTL_GET_UNIQUE)] = {drm_getunique, 0},
	[DRM_IOCTL_NR(DRM_IOCTL_GET_MAGIC)] = {drm_getmagic, 0},
	[DRM_IOCTL_NR(DRM_IOCTL_IRQ_BUSID)] = {drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_GET_MAP)] = {drm_getmap, 0},
	[DRM_IOCTL_NR(DRM_IOCTL_GET_CLIENT)] = {drm_getclient, 0},
	[DRM_IOCTL_NR(DRM_IOCTL_GET_STATS)] = {drm_getstats, 0},
	[DRM_IOCTL_NR(DRM_IOCTL_SET_VERSION)] = {drm_setversion, DRM_MASTER|DRM_ROOT_ONLY},

	[DRM_IOCTL_NR(DRM_IOCTL_SET_UNIQUE)] = {drm_setunique, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_BLOCK)] = {drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_UNBLOCK)] = {drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_AUTH_MAGIC)] = {drm_authmagic, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},

	[DRM_IOCTL_NR(DRM_IOCTL_ADD_MAP)] = {drm_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_RM_MAP)] = {drm_rmmap_ioctl, DRM_AUTH},

	[DRM_IOCTL_NR(DRM_IOCTL_SET_SAREA_CTX)] = {drm_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_GET_SAREA_CTX)] = {drm_getsareactx, DRM_AUTH},

	[DRM_IOCTL_NR(DRM_IOCTL_ADD_CTX)] = {drm_addctx, DRM_AUTH|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_RM_CTX)] = {drm_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_MOD_CTX)] = {drm_modctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_GET_CTX)] = {drm_getctx, DRM_AUTH},
	[DRM_IOCTL_NR(DRM_IOCTL_SWITCH_CTX)] = {drm_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_NEW_CTX)] = {drm_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_RES_CTX)] = {drm_resctx, DRM_AUTH},

	[DRM_IOCTL_NR(DRM_IOCTL_ADD_DRAW)] = {drm_adddraw, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_RM_DRAW)] = {drm_rmdraw, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},

	[DRM_IOCTL_NR(DRM_IOCTL_LOCK)] = {drm_lock, DRM_AUTH},
	[DRM_IOCTL_NR(DRM_IOCTL_UNLOCK)] = {drm_unlock, DRM_AUTH},

	[DRM_IOCTL_NR(DRM_IOCTL_FINISH)] = {drm_noop, DRM_AUTH},

	[DRM_IOCTL_NR(DRM_IOCTL_ADD_BUFS)] = {drm_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_MARK_BUFS)] = {drm_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_INFO_BUFS)] = {drm_infobufs, DRM_AUTH},
	[DRM_IOCTL_NR(DRM_IOCTL_MAP_BUFS)] = {drm_mapbufs, DRM_AUTH},
	[DRM_IOCTL_NR(DRM_IOCTL_FREE_BUFS)] = {drm_freebufs, DRM_AUTH},
	/* The DRM_IOCTL_DMA ioctl should be defined by the driver. */
	[DRM_IOCTL_NR(DRM_IOCTL_DMA)] = {NULL, DRM_AUTH},

	[DRM_IOCTL_NR(DRM_IOCTL_CONTROL)] = {drm_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},

#if __OS_HAS_AGP
	[DRM_IOCTL_NR(DRM_IOCTL_AGP_ACQUIRE)] = {drm_agp_acquire_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_AGP_RELEASE)] = {drm_agp_release_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_AGP_ENABLE)] = {drm_agp_enable_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_AGP_INFO)] = {drm_agp_info_ioctl, DRM_AUTH},
	[DRM_IOCTL_NR(DRM_IOCTL_AGP_ALLOC)] = {drm_agp_alloc_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_AGP_FREE)] = {drm_agp_free_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_AGP_BIND)] = {drm_agp_bind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_AGP_UNBIND)] = {drm_agp_unbind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},
#endif

	[DRM_IOCTL_NR(DRM_IOCTL_SG_ALLOC)] = {drm_sg_alloc, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_SG_FREE)] = {drm_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},

	[DRM_IOCTL_NR(DRM_IOCTL_WAIT_VBLANK)] = {drm_wait_vblank, 0},
	[DRM_IOCTL_NR(DRM_IOCTL_FENCE)] = {drm_fence_ioctl, DRM_AUTH},
	[DRM_IOCTL_NR(DRM_IOCTL_BUFOBJ)] = {drm_bo_ioctl, DRM_AUTH},
	[DRM_IOCTL_NR(DRM_IOCTL_MM_INIT)] = {drm_mm_init_ioctl, 
					     DRM_AUTH },

	[DRM_IOCTL_NR(DRM_IOCTL_UPDATE_DRAW)] = {drm_update_drawable_info, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_MODE_GETRESOURCES)] = {drm_mode_getresources, DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_MODE_GETCRTC)] = {drm_mode_getcrtc, DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_MODE_GETOUTPUT)] = {drm_mode_getoutput, DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_MODE_SETCRTC)] = {drm_mode_setcrtc, DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_MODE_ADDFB)] = {drm_mode_addfb, DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_MODE_RMFB)] = {drm_mode_rmfb, DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_MODE_GETFB)] = {drm_mode_getfb, DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_MODE_ADDMODE)] = {drm_mode_addmode, DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_MODE_RMMODE)] = {drm_mode_rmmode, DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_MODE_ATTACHMODE)] = {drm_mode_attachmode, DRM_MASTER|DRM_ROOT_ONLY},
	[DRM_IOCTL_NR(DRM_IOCTL_MODE_DETACHMODE)] = {drm_mode_detachmode, DRM_MASTER|DRM_ROOT_ONLY},
};

#define DRM_CORE_IOCTL_COUNT	ARRAY_SIZE( drm_ioctls )


/**
 * Take down the DRM device.
 *
 * \param dev DRM device structure.
 *
 * Frees every resource in \p dev.
 *
 * \sa drm_device
 */
int drm_lastclose(drm_device_t * dev)
{
	drm_magic_entry_t *pt, *next;
	drm_map_list_t *r_list, *list_t;
	drm_vma_entry_t *vma, *vma_temp;
	int i;

	DRM_DEBUG("\n");

	/*
	 * We can't do much about this function failing.
	 */

	if (dev->driver->lastclose)
		dev->driver->lastclose(dev);
	DRM_DEBUG("driver lastclose completed\n");

	if (dev->unique) {
		drm_free(dev->unique, strlen(dev->unique) + 1, DRM_MEM_DRIVER);
		dev->unique=NULL;
		dev->unique_len=0;
	}

	if (dev->irq_enabled)
		drm_irq_uninstall(dev);

	/* Free drawable information memory */
	mutex_lock(&dev->struct_mutex);

	drm_drawable_free_all(dev);
	del_timer(&dev->timer);

	if (dev->unique) {
		drm_free(dev->unique, strlen(dev->unique) + 1, DRM_MEM_DRIVER);
		dev->unique = NULL;
		dev->unique_len = 0;
	}

	if (dev->magicfree.next) {
		list_for_each_entry_safe(pt, next, &dev->magicfree, head) {
			list_del(&pt->head);
			drm_ht_remove_item(&dev->magiclist, &pt->hash_item);
			drm_free(pt, sizeof(*pt), DRM_MEM_MAGIC);
		}
		drm_ht_remove(&dev->magiclist);
	}


	/* Clear AGP information */
	if (drm_core_has_AGP(dev) && dev->agp) {
		drm_agp_mem_t *entry, *tempe;

		/* Remove AGP resources, but leave dev->agp
		   intact until drv_cleanup is called. */
		list_for_each_entry_safe(entry, tempe, &dev->agp->memory, head) {
			if (entry->bound)
				drm_unbind_agp(entry->memory);
			drm_free_agp(entry->memory, entry->pages);
			drm_free(entry, sizeof(*entry), DRM_MEM_AGPLISTS);
		}
		INIT_LIST_HEAD(&dev->agp->memory);

		if (dev->agp->acquired)
			drm_agp_release(dev);

		dev->agp->acquired = 0;
		dev->agp->enabled = 0;
	}
	if (drm_core_check_feature(dev, DRIVER_SG) && dev->sg) {
		drm_sg_cleanup(dev->sg);
		dev->sg = NULL;
	}

	/* Clear vma list (only built for debugging) */
	list_for_each_entry_safe(vma, vma_temp, &dev->vmalist, head) {
		list_del(&vma->head);
		drm_ctl_free(vma, sizeof(*vma), DRM_MEM_VMAS);
	}
	
	list_for_each_entry_safe(r_list, list_t, &dev->maplist, head) {
		drm_rmmap_locked(dev, r_list->map);
		r_list = NULL;
	}

	if (drm_core_check_feature(dev, DRIVER_DMA_QUEUE) && dev->queuelist) {
		for (i = 0; i < dev->queue_count; i++) {

			if (dev->queuelist[i]) {
				drm_free(dev->queuelist[i],
					 sizeof(*dev->queuelist[0]),
					 DRM_MEM_QUEUES);
				dev->queuelist[i] = NULL;
			}
		}
		drm_free(dev->queuelist,
			 dev->queue_slots * sizeof(*dev->queuelist),
			 DRM_MEM_QUEUES);
		dev->queuelist = NULL;
	}
	dev->queue_count = 0;

	if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
		drm_dma_takedown(dev);

	if (dev->lock.filp) {
		dev->lock.filp = NULL;
		wake_up_interruptible(&dev->lock.lock_queue);
	}
	dev->dev_mapping = NULL;
	mutex_unlock(&dev->struct_mutex);

	DRM_DEBUG("lastclose completed\n");
	return 0;
}

void drm_cleanup_pci(struct pci_dev *pdev)
{
	drm_device_t *dev = pci_get_drvdata(pdev);

	pci_set_drvdata(pdev, NULL);
	pci_release_regions(pdev);
	if (dev)
		drm_cleanup(dev);
}
EXPORT_SYMBOL(drm_cleanup_pci);

/**
 * Module initialization. Called via init_module at module load time, or via
 * linux/init/main.c (this is not currently supported).
 *
 * \return zero on success or a negative number on failure.
 *
 * Initializes an array of drm_device structures, and attempts to
 * initialize all available devices, using consecutive minors, registering the
 * stubs and initializing the AGP device.
 *
 * Expands the \c DRIVER_PREINIT and \c DRIVER_POST_INIT macros before and
 * after the initialization for driver customization.
 */
int drm_init(struct drm_driver *driver,
		       struct pci_device_id *pciidlist)
{
	struct pci_dev *pdev;
	struct pci_device_id *pid;
	int rc, i;

	DRM_DEBUG("\n");

	for (i = 0; (pciidlist[i].vendor != 0) && !drm_fb_loaded; i++) {
		pid = &pciidlist[i];

		pdev = NULL;
		/* pass back in pdev to account for multiple identical cards */
		while ((pdev =
			pci_get_subsys(pid->vendor, pid->device, pid->subvendor,
				       pid->subdevice, pdev))) {
			/* is there already a driver loaded, or (short circuit saves work) */
			/* does something like VesaFB have control of the memory region? */
			if (pci_dev_driver(pdev)
			    || pci_request_regions(pdev, "DRM scan")) {
				/* go into stealth mode */
				drm_fb_loaded = 1;
				pci_dev_put(pdev);
				break;
			}
			/* no fbdev or vesadev, put things back and wait for normal probe */
			pci_release_regions(pdev);
		}
	}

	if (!drm_fb_loaded)
		pci_register_driver(&driver->pci_driver);
	else {
		for (i = 0; pciidlist[i].vendor != 0; i++) {
			pid = &pciidlist[i];

			pdev = NULL;
			/* pass back in pdev to account for multiple identical cards */
			while ((pdev =
				pci_get_subsys(pid->vendor, pid->device,
					       pid->subvendor, pid->subdevice,
					       pdev))) {
				/* stealth mode requires a manual probe */
				pci_dev_get(pdev);
				if ((rc = drm_get_dev(pdev, &pciidlist[i], driver))) {
					pci_dev_put(pdev);
					return rc;
				}
			}
		}
		DRM_INFO("Used old pci detect: framebuffer loaded\n");
	}
	return 0;
}
EXPORT_SYMBOL(drm_init);

/**
 * Called via cleanup_module() at module unload time.
 *
 * Cleans up all DRM device, calling drm_lastclose().
 *
 * \sa drm_init
 */
static void drm_cleanup(drm_device_t * dev)
{

	DRM_DEBUG("\n");
	if (!dev) {
		DRM_ERROR("cleanup called no dev\n");
		return;
	}

	drm_lastclose(dev);
	drm_fence_manager_takedown(dev);

	drm_ht_remove(&dev->map_hash);
	drm_mm_takedown(&dev->offset_manager);
	drm_ht_remove(&dev->object_hash);

	if (!drm_fb_loaded)
		pci_disable_device(dev->pdev);

	drm_ctxbitmap_cleanup(dev);

	if (drm_core_has_MTRR(dev) && drm_core_has_AGP(dev) && dev->agp
	    && dev->agp->agp_mtrr >= 0) {
		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);
	}

	if (dev->driver->unload)
		dev->driver->unload(dev);
        
	if (drm_core_has_AGP(dev) && dev->agp) {
		drm_free(dev->agp, sizeof(*dev->agp), DRM_MEM_AGPLISTS);
		dev->agp = NULL;
	}

	if (!drm_fb_loaded)
		pci_disable_device(dev->pdev);

	drm_put_head(&dev->primary);
	if (drm_put_dev(dev))
		DRM_ERROR("Cannot unload module\n");
}

void drm_exit(struct drm_driver *driver)
{
	int i;
	drm_device_t *dev = NULL;
	drm_head_t *head;

	DRM_DEBUG("\n");
	if (drm_fb_loaded) {
		for (i = 0; i < drm_cards_limit; i++) {
			head = drm_heads[i];
			if (!head)
				continue;
			if (!head->dev)
				continue;
			if (head->dev->driver != driver)
				continue;
			dev = head->dev;
			if (dev) {
				/* release the pci driver */
				if (dev->pdev)
					pci_dev_put(dev->pdev);
				drm_cleanup(dev);
			}
		}
	} else
		pci_unregister_driver(&driver->pci_driver);
#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15))
	free_nopage_retry();
#endif
	DRM_INFO("Module unloaded\n");
}
EXPORT_SYMBOL(drm_exit);

/** File operations structure */
static const struct file_operations drm_stub_fops = {
	.owner = THIS_MODULE,
	.open = drm_stub_open
};

static int __init drm_core_init(void)
{
	int ret;
	struct sysinfo si;
	unsigned long avail_memctl_mem;
	unsigned long max_memctl_mem;

	si_meminfo(&si);
	
	/*
	 * AGP only allows low / DMA32 memory ATM.
	 */

	avail_memctl_mem = si.totalram - si.totalhigh;

	/* 
	 * Avoid overflows 
	 */

	max_memctl_mem = 1UL << (32 - PAGE_SHIFT);
	max_memctl_mem = (max_memctl_mem / si.mem_unit) * PAGE_SIZE; 

	if (avail_memctl_mem >= max_memctl_mem)
		avail_memctl_mem = max_memctl_mem;

	drm_init_memctl(avail_memctl_mem/2, avail_memctl_mem*3/4, si.mem_unit);

	ret = -ENOMEM;
	drm_cards_limit =
	    (drm_cards_limit < DRM_MAX_MINOR + 1 ? drm_cards_limit : DRM_MAX_MINOR + 1);
	drm_heads = drm_calloc(drm_cards_limit, sizeof(*drm_heads), DRM_MEM_STUB);
	if (!drm_heads)
		goto err_p1;

	if (register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops))
		goto err_p1;

	drm_class = drm_sysfs_create(THIS_MODULE, "drm");
	if (IS_ERR(drm_class)) {
		printk(KERN_ERR "DRM: Error creating drm class.\n");
		ret = PTR_ERR(drm_class);
		goto err_p2;
	}

	drm_proc_root = proc_mkdir("dri", NULL);
	if (!drm_proc_root) {
		DRM_ERROR("Cannot create /proc/dri\n");
		ret = -1;
		goto err_p3;
	}

	drm_mem_init();

	DRM_INFO("Initialized %s %d.%d.%d %s\n",
		 CORE_NAME,
		 CORE_MAJOR, CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
	return 0;
err_p3:
	drm_sysfs_destroy(drm_class);
err_p2:
	unregister_chrdev(DRM_MAJOR, "drm");
	drm_free(drm_heads, sizeof(*drm_heads) * drm_cards_limit, DRM_MEM_STUB);
err_p1:
	return ret;
}

static void __exit drm_core_exit(void)
{
	remove_proc_entry("dri", NULL);
	drm_sysfs_destroy(drm_class);

	unregister_chrdev(DRM_MAJOR, "drm");

	drm_free(drm_heads, sizeof(*drm_heads) * drm_cards_limit, DRM_MEM_STUB);
}

module_init(drm_core_init);
module_exit(drm_core_exit);

/**
 * Get version information
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg user argument, pointing to a drm_version structure.
 * \return zero on success or negative number on failure.
 *
 * Fills in the version information in \p arg.
 */
static int drm_version(struct inode *inode, struct file *filp,
		unsigned int cmd, unsigned long arg)
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	drm_version_t __user *argp = (void __user *)arg;
	drm_version_t version;
	int len;

	if (copy_from_user(&version, argp, sizeof(version)))
		return -EFAULT;

	version.version_major = dev->driver->major;
	version.version_minor = dev->driver->minor;
	version.version_patchlevel = dev->driver->patchlevel;
	DRM_COPY(version.name, dev->driver->name);
	DRM_COPY(version.date, dev->driver->date);
	DRM_COPY(version.desc, dev->driver->desc);

	if (copy_to_user(argp, &version, sizeof(version)))
		return -EFAULT;
	return 0;
}

/**
 * Called whenever a process performs an ioctl on /dev/drm.
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg user argument.
 * \return zero on success or negative number on failure.
 *
 * Looks up the ioctl function in the ::ioctls table, checking for root
 * previleges if so required, and dispatches to the respective function.
 */
int drm_ioctl(struct inode *inode, struct file *filp,
	      unsigned int cmd, unsigned long arg)
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	drm_ioctl_desc_t *ioctl;
	drm_ioctl_t *func;
	unsigned int nr = DRM_IOCTL_NR(cmd);
	int retcode = -EINVAL;

	atomic_inc(&dev->ioctl_count);
	atomic_inc(&dev->counts[_DRM_STAT_IOCTLS]);
	++priv->ioctl_count;

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

	if ((nr >= DRM_CORE_IOCTL_COUNT) &&
	    ((nr < DRM_COMMAND_BASE) || (nr >= DRM_COMMAND_END)))
		goto err_i1;
	if ((nr >= DRM_COMMAND_BASE) && (nr < DRM_COMMAND_END)
		&& (nr < DRM_COMMAND_BASE + dev->driver->num_ioctls))
		ioctl = &dev->driver->ioctls[nr - DRM_COMMAND_BASE];
	else if ((nr >= DRM_COMMAND_END) || (nr < DRM_COMMAND_BASE))
		ioctl = &drm_ioctls[nr];
	else
		goto err_i1;

	func = ioctl->func;
	/* is there a local override? */
	if ((nr == DRM_IOCTL_NR(DRM_IOCTL_DMA)) && dev->driver->dma_ioctl)
		func = dev->driver->dma_ioctl;

	if (!func) {
		DRM_DEBUG("no function\n");
		retcode = -EINVAL;
	} else if (((ioctl->flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)) ||
		   ((ioctl->flags & DRM_AUTH) && !priv->authenticated) ||
		   ((ioctl->flags & DRM_MASTER) && !priv->master)) {
		retcode = -EACCES;
	} else {
		retcode = func(inode, filp, cmd, arg);
	}
err_i1:
	atomic_dec(&dev->ioctl_count);
	if (retcode)
		DRM_DEBUG("ret = %x\n", retcode);
	return retcode;
}
EXPORT_SYMBOL(drm_ioctl);

drm_local_map_t *drm_getsarea(struct drm_device *dev)
{
	drm_map_list_t *entry;

	list_for_each_entry(entry, &dev->maplist, head) {
		if (entry->map && entry->map->type == _DRM_SHM &&
		    (entry->map->flags & _DRM_CONTAINS_LOCK)) {
			return entry->map;
		}
	}
	return NULL;
}
EXPORT_SYMBOL(drm_getsarea);