drm_bufs.c

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/**
 * \file drm_bufs.c
 * Generic buffer template
 *
 * \author Rickard E. (Rik) Faith <[e-mail]>
 * \author Gareth Hughes <[e-mail]>
 */

/*
 * Created: Thu Nov 23 03:10:50 2000 by [e-mail]
 *
 * 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 <linux/vmalloc.h>
#include "drmP.h"

unsigned long drm_get_resource_start(struct drm_device *dev, unsigned int resource)
{
	return pci_resource_start(dev->pdev, resource);
}
EXPORT_SYMBOL(drm_get_resource_start);

unsigned long drm_get_resource_len(struct drm_device *dev, unsigned int resource)
{
	return pci_resource_len(dev->pdev, resource);
}

EXPORT_SYMBOL(drm_get_resource_len);

static struct drm_map_list *drm_find_matching_map(struct drm_device *dev,
					     drm_local_map_t *map)
{
	struct drm_map_list *entry;
	list_for_each_entry(entry, &dev->maplist, head) {
		if (entry->map && map->type == entry->map->type &&
		    ((entry->map->offset == map->offset) ||
		     (map->type == _DRM_SHM && map->flags==_DRM_CONTAINS_LOCK))) {
			return entry;
		}
	}

	return NULL;
}

static int drm_map_handle(struct drm_device *dev, struct drm_hash_item *hash,
			  unsigned long user_token, int hashed_handle)
{
	int use_hashed_handle;
#if (BITS_PER_LONG == 64)
	use_hashed_handle = ((user_token & 0xFFFFFFFF00000000UL) || hashed_handle);
#elif (BITS_PER_LONG == 32)
	use_hashed_handle = hashed_handle;
#else
#error Unsupported long size. Neither 64 nor 32 bits.
#endif

	if (!use_hashed_handle) {
		int ret;
		hash->key = user_token >> PAGE_SHIFT;
		ret = drm_ht_insert_item(&dev->map_hash, hash);
		if (ret != -EINVAL)
			return ret;
	}
	return drm_ht_just_insert_please(&dev->map_hash, hash,
					 user_token, 32 - PAGE_SHIFT - 3,
					 0, DRM_MAP_HASH_OFFSET >> PAGE_SHIFT);
}

/**
 * Ioctl to specify a range of memory that is available for mapping by a non-root process.
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg pointer to a drm_map structure.
 * \return zero on success or a negative value on error.
 *
 * Adjusts the memory offset to its absolute value according to the mapping
 * type.  Adds the map to the map list drm_device::maplist. Adds MTRR's where
 * applicable and if supported by the kernel.
 */
static int drm_addmap_core(struct drm_device * dev, unsigned int offset,
			   unsigned int size, enum drm_map_type type,
			   enum drm_map_flags flags,
			   struct drm_map_list ** maplist)
{
	struct drm_map *map;
	struct drm_map_list *list;
	drm_dma_handle_t *dmah;
	unsigned long user_token;
	int ret;

	map = drm_alloc(sizeof(*map), DRM_MEM_MAPS);
	if (!map)
		return -ENOMEM;

	map->offset = offset;
	map->size = size;
	map->flags = flags;
	map->type = type;

	/* Only allow shared memory to be removable since we only keep enough
	 * book keeping information about shared memory to allow for removal
	 * when processes fork.
	 */
	if ((map->flags & _DRM_REMOVABLE) && map->type != _DRM_SHM) {
		drm_free(map, sizeof(*map), DRM_MEM_MAPS);
		return -EINVAL;
	}
	DRM_DEBUG("offset = 0x%08lx, size = 0x%08lx, type = %d\n",
		  map->offset, map->size, map->type);
	if ((map->offset & (~PAGE_MASK)) || (map->size & (~PAGE_MASK))) {
		drm_free(map, sizeof(*map), DRM_MEM_MAPS);
		return -EINVAL;
	}
	map->mtrr = -1;
	map->handle = NULL;

	switch (map->type) {
	case _DRM_REGISTERS:
	case _DRM_FRAME_BUFFER:
#if !defined(__sparc__) && !defined(__alpha__) && !defined(__ia64__) && !defined(__powerpc64__) && !defined(__x86_64__)
		if (map->offset + (map->size-1) < map->offset ||
		    map->offset < virt_to_phys(high_memory)) {
			drm_free(map, sizeof(*map), DRM_MEM_MAPS);
			return -EINVAL;
		}
#endif
#ifdef __alpha__
		map->offset += dev->hose->mem_space->start;
#endif
		/* Some drivers preinitialize some maps, without the X Server
		 * needing to be aware of it.  Therefore, we just return success
		 * when the server tries to create a duplicate map.
		 */
		list = drm_find_matching_map(dev, map);
		if (list != NULL) {
			if (list->map->size != map->size) {
				DRM_DEBUG("Matching maps of type %d with "
					  "mismatched sizes, (%ld vs %ld)\n",
					  map->type, map->size,
					  list->map->size);
				list->map->size = map->size;
			}

			drm_free(map, sizeof(*map), DRM_MEM_MAPS);
			*maplist = list;
			return 0;
		}

		if (drm_core_has_MTRR(dev)) {
			if (map->type == _DRM_FRAME_BUFFER ||
			    (map->flags & _DRM_WRITE_COMBINING)) {
				map->mtrr = mtrr_add(map->offset, map->size,
						     MTRR_TYPE_WRCOMB, 1);
			}
		}
		if (map->type == _DRM_REGISTERS) {
			map->handle = ioremap(map->offset, map->size);
			if (!map->handle) {
				drm_free(map, sizeof(*map), DRM_MEM_MAPS);
				return -ENOMEM;
			}
		}
				
		break;
	case _DRM_SHM:
		list = drm_find_matching_map(dev, map);
		if (list != NULL) {
			if(list->map->size != map->size) {
				DRM_DEBUG("Matching maps of type %d with "
					  "mismatched sizes, (%ld vs %ld)\n",
					  map->type, map->size, list->map->size);
				list->map->size = map->size;
			}

			drm_free(map, sizeof(*map), DRM_MEM_MAPS);
			*maplist = list;
			return 0;
		}
		map->handle = vmalloc_user(map->size);
		DRM_DEBUG("%lu %d %p\n",
			  map->size, drm_order(map->size), map->handle);
		if (!map->handle) {
			drm_free(map, sizeof(*map), DRM_MEM_MAPS);
			return -ENOMEM;
		}
		map->offset = (unsigned long)map->handle;
		if (map->flags & _DRM_CONTAINS_LOCK) {
			/* Prevent a 2nd X Server from creating a 2nd lock */
			if (dev->lock.hw_lock != NULL) {
				vfree(map->handle);
				drm_free(map, sizeof(*map), DRM_MEM_MAPS);
				return -EBUSY;
			}
			dev->sigdata.lock = dev->lock.hw_lock = map->handle;	/* Pointer to lock */
		}
		break;
	case _DRM_AGP: {
		struct drm_agp_mem *entry;
		int valid = 0;

		if (!drm_core_has_AGP(dev)) {
			drm_free(map, sizeof(*map), DRM_MEM_MAPS);
			return -EINVAL;
		}
#ifdef __alpha__
		map->offset += dev->hose->mem_space->start;
#endif
		/* Note: dev->agp->base may actually be 0 when the DRM
		 * is not in control of AGP space. But if user space is
		 * it should already have added the AGP base itself.
		 */
		map->offset += dev->agp->base;
		map->mtrr = dev->agp->agp_mtrr;	/* for getmap */

		/* This assumes the DRM is in total control of AGP space.
		 * It's not always the case as AGP can be in the control
		 * of user space (i.e. i810 driver). So this loop will get
		 * skipped and we double check that dev->agp->memory is
		 * actually set as well as being invalid before EPERM'ing
		 */
		list_for_each_entry(entry, &dev->agp->memory, head) {
			if ((map->offset >= entry->bound) &&
			    (map->offset + map->size <= entry->bound + entry->pages * PAGE_SIZE)) {
				valid = 1;
				break;
			}
		}
		if (!list_empty(&dev->agp->memory) && !valid) {
			drm_free(map, sizeof(*map), DRM_MEM_MAPS);
			return -EPERM;
		}
		DRM_DEBUG("AGP offset = 0x%08lx, size = 0x%08lx\n", map->offset, map->size);

		break;
	}
	case _DRM_SCATTER_GATHER:
		if (!dev->sg) {
			drm_free(map, sizeof(*map), DRM_MEM_MAPS);
			return -EINVAL;
		}
		map->offset += (unsigned long)dev->sg->virtual;
		break;
	case _DRM_CONSISTENT:
		/* dma_addr_t is 64bit on i386 with CONFIG_HIGHMEM64G,
		 * As we're limiting the address to 2^32-1 (or less),
		 * casting it down to 32 bits is no problem, but we
		 * need to point to a 64bit variable first. */
		dmah = drm_pci_alloc(dev, map->size, map->size, 0xffffffffUL);
		if (!dmah) {
			drm_free(map, sizeof(*map), DRM_MEM_MAPS);
			return -ENOMEM;
		}
		map->handle = dmah->vaddr;
		map->offset = (unsigned long)dmah->busaddr;
		kfree(dmah);
		break;
	default:
		drm_free(map, sizeof(*map), DRM_MEM_MAPS);
		return -EINVAL;
	}

	list = drm_alloc(sizeof(*list), DRM_MEM_MAPS);
	if (!list) {
		if (map->type == _DRM_REGISTERS)
			iounmap(map->handle);
		drm_free(map, sizeof(*map), DRM_MEM_MAPS);
		return -EINVAL;
	}
	memset(list, 0, sizeof(*list));
	list->map = map;

	mutex_lock(&dev->struct_mutex);
	list_add(&list->head, &dev->maplist);

	/* Assign a 32-bit handle */
	/* We do it here so that dev->struct_mutex protects the increment */
	user_token = (map->type == _DRM_SHM) ? (unsigned long)map->handle :
		map->offset;
	ret = drm_map_handle(dev, &list->hash, user_token, 0);
	if (ret) {
		if (map->type == _DRM_REGISTERS)
			iounmap(map->handle);
		drm_free(map, sizeof(*map), DRM_MEM_MAPS);
		drm_free(list, sizeof(*list), DRM_MEM_MAPS);
		mutex_unlock(&dev->struct_mutex);
		return ret;
	}

	list->user_token = list->hash.key << PAGE_SHIFT;
	mutex_unlock(&dev->struct_mutex);

	*maplist = list;
	return 0;
	}

int drm_addmap(struct drm_device * dev, unsigned int offset,
	       unsigned int size, enum drm_map_type type,
	       enum drm_map_flags flags, drm_local_map_t ** map_ptr)
{
	struct drm_map_list *list;
	int rc;

	rc = drm_addmap_core(dev, offset, size, type, flags, &list);
	if (!rc)
		*map_ptr = list->map;
	return rc;
}

EXPORT_SYMBOL(drm_addmap);

int drm_addmap_ioctl(struct drm_device *dev, void *data,
		     struct drm_file *file_priv)
{
	struct drm_map *map = data;
	struct drm_map_list *maplist;
	int err;

	if (!(capable(CAP_SYS_ADMIN) || map->type == _DRM_AGP))
		return -EPERM;

	err = drm_addmap_core(dev, map->offset, map->size, map->type,
			      map->flags, &maplist);

	if (err)
		return err;

	/* avoid a warning on 64-bit, this casting isn't very nice, but the API is set so too late */
	map->handle = (void *)(unsigned long)maplist->user_token;
	return 0;
}

/**
 * Remove a map private from list and deallocate resources if the mapping
 * isn't in use.
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg pointer to a struct drm_map structure.
 * \return zero on success or a negative value on error.
 *
 * Searches the map on drm_device::maplist, removes it from the list, see if
 * its being used, and free any associate resource (such as MTRR's) if it's not
 * being on use.
 *
 * \sa drm_addmap
 */
int drm_rmmap_locked(struct drm_device *dev, drm_local_map_t *map)
{
	struct drm_map_list *r_list = NULL, *list_t;
	drm_dma_handle_t dmah;
	int found = 0;

	/* Find the list entry for the map and remove it */
	list_for_each_entry_safe(r_list, list_t, &dev->maplist, head) {
		if (r_list->map == map) {
			list_del(&r_list->head);
			drm_ht_remove_key(&dev->map_hash,
					  r_list->user_token >> PAGE_SHIFT);
			drm_free(r_list, sizeof(*r_list), DRM_MEM_MAPS);
			found = 1;
			break;
		}
	}

	if (!found)
		return -EINVAL;

	switch (map->type) {
	case _DRM_REGISTERS:
		iounmap(map->handle);
		/* FALLTHROUGH */
	case _DRM_FRAME_BUFFER:
		if (drm_core_has_MTRR(dev) && map->mtrr >= 0) {
			int retcode;
			retcode = mtrr_del(map->mtrr, map->offset, map->size);
			DRM_DEBUG("mtrr_del=%d\n", retcode);
		}
		break;
	case _DRM_SHM:
		vfree(map->handle);
		break;
	case _DRM_AGP:
	case _DRM_SCATTER_GATHER:
		break;
	case _DRM_CONSISTENT:
		dmah.vaddr = map->handle;
		dmah.busaddr = map->offset;
		dmah.size = map->size;
		__drm_pci_free(dev, &dmah);
		break;
	}
	drm_free(map, sizeof(*map), DRM_MEM_MAPS);

	return 0;
}

int drm_rmmap(struct drm_device *dev, drm_local_map_t *map)
{
	int ret;

	mutex_lock(&dev->struct_mutex);
	ret = drm_rmmap_locked(dev, map);
	mutex_unlock(&dev->struct_mutex);

	return ret;
}

/* The rmmap ioctl appears to be unnecessary.  All mappings are torn down on
 * the last close of the device, and this is necessary for cleanup when things
 * exit uncleanly.  Therefore, having userland manually remove mappings seems
 * like a pointless exercise since they're going away anyway.
 *
 * One use case might be after addmap is allowed for normal users for SHM and
 * gets used by drivers that the server doesn't need to care about.  This seems
 * unlikely.
 */
int drm_rmmap_ioctl(struct drm_device *dev, void *data,
		    struct drm_file *file_priv)
{
	struct drm_map *request = data;
	drm_local_map_t *map = NULL;
	struct drm_map_list *r_list;
	int ret;

	mutex_lock(&dev->struct_mutex);
	list_for_each_entry(r_list, &dev->maplist, head) {
		if (r_list->map &&
		    r_list->user_token == (unsigned long)request->handle &&
		    r_list->map->flags & _DRM_REMOVABLE) {
			map = r_list->map;
			break;
		}
	}

	/* List has wrapped around to the head pointer, or its empty we didn't
	 * find anything.
	 */
	if (list_empty(&dev->maplist) || !map) {
		mutex_unlock(&dev->struct_mutex);
		return -EINVAL;
	}

	/* Register and framebuffer maps are permanent */
	if ((map->type == _DRM_REGISTERS) || (map->type == _DRM_FRAME_BUFFER)) {
		mutex_unlock(&dev->struct_mutex);
		return 0;
	}

	ret = drm_rmmap_locked(dev, map);

	mutex_unlock(&dev->struct_mutex);

	return ret;
}

/**
 * Cleanup after an error on one of the addbufs() functions.
 *
 * \param dev DRM device.
 * \param entry buffer entry where the error occurred.
 *
 * Frees any pages and buffers associated with the given entry.
 */
static void drm_cleanup_buf_error(struct drm_device * dev,
				  struct drm_buf_entry * entry)
{
	int i;

	if (entry->seg_count) {
		for (i = 0; i < entry->seg_count; i++) {
			if (entry->seglist[i]) {
				drm_pci_free(dev, entry->seglist[i]);
			}
		}
		drm_free(entry->seglist,
			 entry->seg_count *
			 sizeof(*entry->seglist), DRM_MEM_SEGS);

		entry->seg_count = 0;
	}

	if (entry->buf_count) {
		for (i = 0; i < entry->buf_count; i++) {
			if (entry->buflist[i].dev_private) {
				drm_free(entry->buflist[i].dev_private,
					 entry->buflist[i].dev_priv_size,
					 DRM_MEM_BUFS);
			}
		}
		drm_free(entry->buflist,
			 entry->buf_count *
			 sizeof(*entry->buflist), DRM_MEM_BUFS);

		entry->buf_count = 0;
	}
}

#if __OS_HAS_AGP
/**
 * Add AGP buffers for DMA transfers.
 *
 * \param dev struct drm_device to which the buffers are to be added.
 * \param request pointer to a struct drm_buf_desc describing the request.
 * \return zero on success or a negative number on failure.
 *
 * After some sanity checks creates a drm_buf structure for each buffer and
 * reallocates the buffer list of the same size order to accommodate the new
 * buffers.