drivers/gpu/drm/drm_vm.c - kernel/msm - Gitiles

 /**
  * \file drm_vm.c
  * Memory mapping for DRM
  *
  * \author Rickard E. (Rik) Faith <faith@valinux.com>
  * \author Gareth Hughes <gareth@valinux.com>
  */

 /*
  * Created: Mon Jan  4 08:58:31 1999 by faith@valinux.com
  *
  * Copyright 1999 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"
 #if defined(__ia64__)
 #include <linux/efi.h>
 #include <linux/slab.h>
 #endif

 static void drm_vm_open(struct vm_area_struct *vma);
 static void drm_vm_close(struct vm_area_struct *vma);

 static pgprot_t drm_io_prot(uint32_t map_type, struct vm_area_struct *vma)
 {
 	pgprot_t tmp = vm_get_page_prot(vma->vm_flags);

 #if defined(__i386__) || defined(__x86_64__)
 	if (boot_cpu_data.x86 > 3 && map_type != _DRM_AGP) {
 		pgprot_val(tmp) |= _PAGE_PCD;
 		pgprot_val(tmp) &= ~_PAGE_PWT;
 	}
 #elif defined(__powerpc__)
 	pgprot_val(tmp) |= _PAGE_NO_CACHE;
 	if (map_type == _DRM_REGISTERS)
 		pgprot_val(tmp) |= _PAGE_GUARDED;
 #elif defined(__ia64__)
 	if (efi_range_is_wc(vma->vm_start, vma->vm_end -
 				    vma->vm_start))
 		tmp = pgprot_writecombine(tmp);
 	else
 		tmp = pgprot_noncached(tmp);
 #elif defined(__sparc__) || defined(__arm__)
 	tmp = pgprot_noncached(tmp);
 #endif
 	return tmp;
 }

 static pgprot_t drm_dma_prot(uint32_t map_type, struct vm_area_struct *vma)
 {
 	pgprot_t tmp = vm_get_page_prot(vma->vm_flags);

 #if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE)
 	tmp |= _PAGE_NO_CACHE;
 #endif
 	return tmp;
 }

 /**
  * \c fault method for AGP virtual memory.
  *
  * \param vma virtual memory area.
  * \param address access address.
  * \return pointer to the page structure.
  *
  * Find the right map and if it's AGP memory find the real physical page to
  * map, get the page, increment the use count and return it.
  */
 #if __OS_HAS_AGP
 static int drm_do_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	struct drm_file *priv = vma->vm_file->private_data;
 	struct drm_device *dev = priv->minor->dev;
 	struct drm_local_map *map = NULL;
 	struct drm_map_list *r_list;
 	struct drm_hash_item *hash;

 	/*
 	 * Find the right map
 	 */
 	if (!drm_core_has_AGP(dev))
 		goto vm_fault_error;

 	if (!dev->agp || !dev->agp->cant_use_aperture)
 		goto vm_fault_error;

 	if (drm_ht_find_item(&dev->map_hash, vma->vm_pgoff, &hash))
 		goto vm_fault_error;

 	r_list = drm_hash_entry(hash, struct drm_map_list, hash);
 	map = r_list->map;

 	if (map && map->type == _DRM_AGP) {
 		/*
 		 * Using vm_pgoff as a selector forces us to use this unusual
 		 * addressing scheme.
 		 */
 		resource_size_t offset = (unsigned long)vmf->virtual_address -
 			vma->vm_start;
 		resource_size_t baddr = map->offset + offset;
 		struct drm_agp_mem *agpmem;
 		struct page *page;

 #ifdef __alpha__
 		/*
 		 * Adjust to a bus-relative address
 		 */
 		baddr -= dev->hose->mem_space->start;
 #endif

 		/*
 		 * It's AGP memory - find the real physical page to map
 		 */
 		list_for_each_entry(agpmem, &dev->agp->memory, head) {
 			if (agpmem->bound <= baddr &&
 			    agpmem->bound + agpmem->pages * PAGE_SIZE > baddr)
 				break;
 		}

 		if (!agpmem)
 			goto vm_fault_error;

 		/*
 		 * Get the page, inc the use count, and return it
 		 */
 		offset = (baddr - agpmem->bound) >> PAGE_SHIFT;
 		page = agpmem->memory->pages[offset];
 		get_page(page);
 		vmf->page = page;

 		DRM_DEBUG
 		    ("baddr = 0x%llx page = 0x%p, offset = 0x%llx, count=%d\n",
 		     (unsigned long long)baddr,
 		     agpmem->memory->pages[offset],
 		     (unsigned long long)offset,
 		     page_count(page));
 		return 0;
 	}
 vm_fault_error:
 	return VM_FAULT_SIGBUS;	/* Disallow mremap */
 }
 #else				/* __OS_HAS_AGP */
 static int drm_do_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	return VM_FAULT_SIGBUS;
 }
 #endif				/* __OS_HAS_AGP */

 /**
  * \c nopage method for shared virtual memory.
  *
  * \param vma virtual memory area.
  * \param address access address.
  * \return pointer to the page structure.
  *
  * Get the mapping, find the real physical page to map, get the page, and
  * return it.
  */
 static int drm_do_vm_shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	struct drm_local_map *map = vma->vm_private_data;
 	unsigned long offset;
 	unsigned long i;
 	struct page *page;

 	if (!map)
 		return VM_FAULT_SIGBUS;	/* Nothing allocated */

 	offset = (unsigned long)vmf->virtual_address - vma->vm_start;
 	i = (unsigned long)map->handle + offset;
 	page = vmalloc_to_page((void *)i);
 	if (!page)
 		return VM_FAULT_SIGBUS;
 	get_page(page);
 	vmf->page = page;

 	DRM_DEBUG("shm_fault 0x%lx\n", offset);
 	return 0;
 }

 /**
  * \c close method for shared virtual memory.
  *
  * \param vma virtual memory area.
  *
  * Deletes map information if we are the last
  * person to close a mapping and it's not in the global maplist.
  */
 static void drm_vm_shm_close(struct vm_area_struct *vma)
 {
 	struct drm_file *priv = vma->vm_file->private_data;
 	struct drm_device *dev = priv->minor->dev;
 	struct drm_vma_entry *pt, *temp;
 	struct drm_local_map *map;
 	struct drm_map_list *r_list;
 	int found_maps = 0;

 	DRM_DEBUG("0x%08lx,0x%08lx\n",
 		  vma->vm_start, vma->vm_end - vma->vm_start);
 	atomic_dec(&dev->vma_count);

 	map = vma->vm_private_data;

 	mutex_lock(&dev->struct_mutex);
 	list_for_each_entry_safe(pt, temp, &dev->vmalist, head) {
 		if (pt->vma->vm_private_data == map)
 			found_maps++;
 		if (pt->vma == vma) {
 			list_del(&pt->head);
 			kfree(pt);
 		}
 	}

 	/* We were the only map that was found */
 	if (found_maps == 1 && map->flags & _DRM_REMOVABLE) {
 		/* Check to see if we are in the maplist, if we are not, then
 		 * we delete this mappings information.
 		 */
 		found_maps = 0;
 		list_for_each_entry(r_list, &dev->maplist, head) {
 			if (r_list->map == map)
 				found_maps++;
 		}

 		if (!found_maps) {
 			drm_dma_handle_t dmah;

 			switch (map->type) {
 			case _DRM_REGISTERS:
 			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);
 				}
 				iounmap(map->handle);
 				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;
 			case _DRM_GEM:
 				DRM_ERROR("tried to rmmap GEM object\n");
 				break;
 			}
 			kfree(map);
 		}
 	}
 	mutex_unlock(&dev->struct_mutex);
 }

 /**
  * \c fault method for DMA virtual memory.
  *
  * \param vma virtual memory area.
  * \param address access address.
  * \return pointer to the page structure.
  *
  * Determine the page number from the page offset and get it from drm_device_dma::pagelist.
  */
 static int drm_do_vm_dma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	struct drm_file *priv = vma->vm_file->private_data;
 	struct drm_device *dev = priv->minor->dev;
 	struct drm_device_dma *dma = dev->dma;
 	unsigned long offset;
 	unsigned long page_nr;
 	struct page *page;

 	if (!dma)
 		return VM_FAULT_SIGBUS;	/* Error */
 	if (!dma->pagelist)
 		return VM_FAULT_SIGBUS;	/* Nothing allocated */

 	offset = (unsigned long)vmf->virtual_address - vma->vm_start;	/* vm_[pg]off[set] should be 0 */
 	page_nr = offset >> PAGE_SHIFT; /* page_nr could just be vmf->pgoff */
 	page = virt_to_page((dma->pagelist[page_nr] + (offset & (~PAGE_MASK))));

 	get_page(page);
 	vmf->page = page;

 	DRM_DEBUG("dma_fault 0x%lx (page %lu)\n", offset, page_nr);
 	return 0;
 }

 /**
  * \c fault method for scatter-gather virtual memory.
  *
  * \param vma virtual memory area.
  * \param address access address.
  * \return pointer to the page structure.
  *
  * Determine the map offset from the page offset and get it from drm_sg_mem::pagelist.
  */
 static int drm_do_vm_sg_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	struct drm_local_map *map = vma->vm_private_data;
 	struct drm_file *priv = vma->vm_file->private_data;
 	struct drm_device *dev = priv->minor->dev;
 	struct drm_sg_mem *entry = dev->sg;
 	unsigned long offset;
 	unsigned long map_offset;
 	unsigned long page_offset;
 	struct page *page;

 	if (!entry)
 		return VM_FAULT_SIGBUS;	/* Error */
 	if (!entry->pagelist)
 		return VM_FAULT_SIGBUS;	/* Nothing allocated */

 	offset = (unsigned long)vmf->virtual_address - vma->vm_start;
 	map_offset = map->offset - (unsigned long)dev->sg->virtual;
 	page_offset = (offset >> PAGE_SHIFT) + (map_offset >> PAGE_SHIFT);
 	page = entry->pagelist[page_offset];
 	get_page(page);
 	vmf->page = page;

 	return 0;
 }

 static int drm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	return drm_do_vm_fault(vma, vmf);
 }

 static int drm_vm_shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	return drm_do_vm_shm_fault(vma, vmf);
 }

 static int drm_vm_dma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	return drm_do_vm_dma_fault(vma, vmf);
 }

 static int drm_vm_sg_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	return drm_do_vm_sg_fault(vma, vmf);
 }

 /** AGP virtual memory operations */
 static const struct vm_operations_struct drm_vm_ops = {
 	.fault = drm_vm_fault,
 	.open = drm_vm_open,
 	.close = drm_vm_close,
 };

 /** Shared virtual memory operations */
 static const struct vm_operations_struct drm_vm_shm_ops = {
 	.fault = drm_vm_shm_fault,
 	.open = drm_vm_open,
 	.close = drm_vm_shm_close,
 };

 /** DMA virtual memory operations */
 static const struct vm_operations_struct drm_vm_dma_ops = {
 	.fault = drm_vm_dma_fault,
 	.open = drm_vm_open,
 	.close = drm_vm_close,
 };

 /** Scatter-gather virtual memory operations */
 static const struct vm_operations_struct drm_vm_sg_ops = {
 	.fault = drm_vm_sg_fault,
 	.open = drm_vm_open,
 	.close = drm_vm_close,
 };

 /**
  * \c open method for shared virtual memory.
  *
  * \param vma virtual memory area.
  *
  * Create a new drm_vma_entry structure as the \p vma private data entry and
  * add it to drm_device::vmalist.
  */
 void drm_vm_open_locked(struct vm_area_struct *vma)
 {
 	struct drm_file *priv = vma->vm_file->private_data;
 	struct drm_device *dev = priv->minor->dev;
 	struct drm_vma_entry *vma_entry;

 	DRM_DEBUG("0x%08lx,0x%08lx\n",
 		  vma->vm_start, vma->vm_end - vma->vm_start);
 	atomic_inc(&dev->vma_count);

 	vma_entry = kmalloc(sizeof(*vma_entry), GFP_KERNEL);
 	if (vma_entry) {
 		vma_entry->vma = vma;
 		vma_entry->pid = current->pid;
 		list_add(&vma_entry->head, &dev->vmalist);
 	}
 }

 static void drm_vm_open(struct vm_area_struct *vma)
 {
 	struct drm_file *priv = vma->vm_file->private_data;
 	struct drm_device *dev = priv->minor->dev;

 	mutex_lock(&dev->struct_mutex);
 	drm_vm_open_locked(vma);
 	mutex_unlock(&dev->struct_mutex);
 }

 /**
  * \c close method for all virtual memory types.
  *
  * \param vma virtual memory area.
  *
  * Search the \p vma private data entry in drm_device::vmalist, unlink it, and
  * free it.
  */
 static void drm_vm_close(struct vm_area_struct *vma)
 {
 	struct drm_file *priv = vma->vm_file->private_data;
 	struct drm_device *dev = priv->minor->dev;
 	struct drm_vma_entry *pt, *temp;

 	DRM_DEBUG("0x%08lx,0x%08lx\n",
 		  vma->vm_start, vma->vm_end - vma->vm_start);
 	atomic_dec(&dev->vma_count);

 	mutex_lock(&dev->struct_mutex);
 	list_for_each_entry_safe(pt, temp, &dev->vmalist, head) {
 		if (pt->vma == vma) {
 			list_del(&pt->head);
 			kfree(pt);
 			break;
 		}
 	}
 	mutex_unlock(&dev->struct_mutex);
 }

 /**
  * mmap DMA memory.
  *
  * \param file_priv DRM file private.
  * \param vma virtual memory area.
  * \return zero on success or a negative number on failure.
  *
  * Sets the virtual memory area operations structure to vm_dma_ops, the file
  * pointer, and calls vm_open().
  */
 static int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma)
 {
 	struct drm_file *priv = filp->private_data;
 	struct drm_device *dev;
 	struct drm_device_dma *dma;
 	unsigned long length = vma->vm_end - vma->vm_start;

 	dev = priv->minor->dev;
 	dma = dev->dma;
 	DRM_DEBUG("start = 0x%lx, end = 0x%lx, page offset = 0x%lx\n",
 		  vma->vm_start, vma->vm_end, vma->vm_pgoff);

 	/* Length must match exact page count */
 	if (!dma || (length >> PAGE_SHIFT) != dma->page_count) {
 		return -EINVAL;
 	}

 	if (!capable(CAP_SYS_ADMIN) &&
 	    (dma->flags & _DRM_DMA_USE_PCI_RO)) {
 		vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE);
 #if defined(__i386__) || defined(__x86_64__)
 		pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
 #else
 		/* Ye gads this is ugly.  With more thought
 		   we could move this up higher and use
 		   `protection_map' instead.  */
 		vma->vm_page_prot =
 		    __pgprot(pte_val
 			     (pte_wrprotect
 			      (__pte(pgprot_val(vma->vm_page_prot)))));
 #endif
 	}

 	vma->vm_ops = &drm_vm_dma_ops;

 	vma->vm_flags |= VM_RESERVED;	/* Don't swap */
 	vma->vm_flags |= VM_DONTEXPAND;

 	vma->vm_file = filp;	/* Needed for drm_vm_open() */
 	drm_vm_open_locked(vma);
 	return 0;
 }

 resource_size_t drm_core_get_map_ofs(struct drm_local_map * map)
 {
 	return map->offset;
 }

 EXPORT_SYMBOL(drm_core_get_map_ofs);

 resource_size_t drm_core_get_reg_ofs(struct drm_device *dev)
 {
 #ifdef __alpha__
 	return dev->hose->dense_mem_base - dev->hose->mem_space->start;
 #else
 	return 0;
 #endif
 }

 EXPORT_SYMBOL(drm_core_get_reg_ofs);

 /**
  * mmap DMA memory.
  *
  * \param file_priv DRM file private.
  * \param vma virtual memory area.
  * \return zero on success or a negative number on failure.
  *
  * If the virtual memory area has no offset associated with it then it's a DMA
  * area, so calls mmap_dma(). Otherwise searches the map in drm_device::maplist,
  * checks that the restricted flag is not set, sets the virtual memory operations
  * according to the mapping type and remaps the pages. Finally sets the file
  * pointer and calls vm_open().
  */
 int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma)
 {
 	struct drm_file *priv = filp->private_data;
 	struct drm_device *dev = priv->minor->dev;
 	struct drm_local_map *map = NULL;
 	resource_size_t offset = 0;
 	struct drm_hash_item *hash;

 	DRM_DEBUG("start = 0x%lx, end = 0x%lx, page offset = 0x%lx\n",
 		  vma->vm_start, vma->vm_end, vma->vm_pgoff);

 	if (!priv->authenticated)
 		return -EACCES;

 	/* We check for "dma". On Apple's UniNorth, it's valid to have
 	 * the AGP mapped at physical address 0
 	 * --BenH.
 	 */
 	if (!vma->vm_pgoff
 #if __OS_HAS_AGP
 	    && (!dev->agp
 		|| dev->agp->agp_info.device->vendor != PCI_VENDOR_ID_APPLE)
 #endif
 	    )
 		return drm_mmap_dma(filp, vma);

 	if (drm_ht_find_item(&dev->map_hash, vma->vm_pgoff, &hash)) {
 		DRM_ERROR("Could not find map\n");
 		return -EINVAL;
 	}

 	map = drm_hash_entry(hash, struct drm_map_list, hash)->map;
 	if (!map || ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN)))
 		return -EPERM;

 	/* Check for valid size. */
 	if (map->size < vma->vm_end - vma->vm_start)
 		return -EINVAL;

 	if (!capable(CAP_SYS_ADMIN) && (map->flags & _DRM_READ_ONLY)) {
 		vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE);
 #if defined(__i386__) || defined(__x86_64__)
 		pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
 #else
 		/* Ye gads this is ugly.  With more thought
 		   we could move this up higher and use
 		   `protection_map' instead.  */
 		vma->vm_page_prot =
 		    __pgprot(pte_val
 			     (pte_wrprotect
 			      (__pte(pgprot_val(vma->vm_page_prot)))));
 #endif
 	}

 	switch (map->type) {
 #if !defined(__arm__)
 	case _DRM_AGP:
 		if (drm_core_has_AGP(dev) && dev->agp->cant_use_aperture) {
 			/*
 			 * On some platforms we can't talk to bus dma address from the CPU, so for
 			 * memory of type DRM_AGP, we'll deal with sorting out the real physical
 			 * pages and mappings in fault()
 			 */
 #if defined(__powerpc__)
 			pgprot_val(vma->vm_page_prot) |= _PAGE_NO_CACHE;
 #endif
 			vma->vm_ops = &drm_vm_ops;
 			break;
 		}
 		/* fall through to _DRM_FRAME_BUFFER... */
 #endif
 	case _DRM_FRAME_BUFFER:
 	case _DRM_REGISTERS:
 		offset = dev->driver->get_reg_ofs(dev);
 		vma->vm_flags |= VM_IO;	/* not in core dump */
 		vma->vm_page_prot = drm_io_prot(map->type, vma);
 #if !defined(__arm__)
 		if (io_remap_pfn_range(vma, vma->vm_start,
 				       (map->offset + offset) >> PAGE_SHIFT,
 				       vma->vm_end - vma->vm_start,
 				       vma->vm_page_prot))
 			return -EAGAIN;
 #else
 		if (remap_pfn_range(vma, vma->vm_start,
 					(map->offset + offset) >> PAGE_SHIFT,
 					vma->vm_end - vma->vm_start,
 					vma->vm_page_prot))
 			return -EAGAIN;
 #endif

 		DRM_DEBUG("   Type = %d; start = 0x%lx, end = 0x%lx,"
 			  " offset = 0x%llx\n",
 			  map->type,
 			  vma->vm_start, vma->vm_end, (unsigned long long)(map->offset + offset));

 		vma->vm_ops = &drm_vm_ops;
 		break;
 	case _DRM_CONSISTENT:
 		/* Consistent memory is really like shared memory. But
 		 * it's allocated in a different way, so avoid fault */
 		if (remap_pfn_range(vma, vma->vm_start,
 		    page_to_pfn(virt_to_page(map->handle)),
 		    vma->vm_end - vma->vm_start, vma->vm_page_prot))
 			return -EAGAIN;
 		vma->vm_page_prot = drm_dma_prot(map->type, vma);
 	/* fall through to _DRM_SHM */
 	case _DRM_SHM:
 		vma->vm_ops = &drm_vm_shm_ops;
 		vma->vm_private_data = (void *)map;
 		/* Don't let this area swap.  Change when
 		   DRM_KERNEL advisory is supported. */
 		vma->vm_flags |= VM_RESERVED;
 		break;
 	case _DRM_SCATTER_GATHER:
 		vma->vm_ops = &drm_vm_sg_ops;
 		vma->vm_private_data = (void *)map;
 		vma->vm_flags |= VM_RESERVED;
 		vma->vm_page_prot = drm_dma_prot(map->type, vma);
 		break;
 	default:
 		return -EINVAL;	/* This should never happen. */
 	}
 	vma->vm_flags |= VM_RESERVED;	/* Don't swap */
 	vma->vm_flags |= VM_DONTEXPAND;

 	vma->vm_file = filp;	/* Needed for drm_vm_open() */
 	drm_vm_open_locked(vma);
 	return 0;
 }

 int drm_mmap(struct file *filp, struct vm_area_struct *vma)
 {
 	struct drm_file *priv = filp->private_data;
 	struct drm_device *dev = priv->minor->dev;
 	int ret;

 	mutex_lock(&dev->struct_mutex);
 	ret = drm_mmap_locked(filp, vma);
 	mutex_unlock(&dev->struct_mutex);

 	return ret;
 }
 EXPORT_SYMBOL(drm_mmap);
	/**
	* \file drm_vm.c
	* Memory mapping for DRM
	*
	* \author Rickard E. (Rik) Faith <faith@valinux.com>
	* \author Gareth Hughes <gareth@valinux.com>
	*/

	/*
	* Created: Mon Jan 4 08:58:31 1999 by faith@valinux.com
	*
	* Copyright 1999 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"
	#if defined(__ia64__)
	#include <linux/efi.h>
	#include <linux/slab.h>
	#endif

	static void drm_vm_open(struct vm_area_struct *vma);
	static void drm_vm_close(struct vm_area_struct *vma);

	static pgprot_t drm_io_prot(uint32_t map_type, struct vm_area_struct *vma)
	{
	pgprot_t tmp = vm_get_page_prot(vma->vm_flags);

	#if defined(__i386__) \|\| defined(__x86_64__)
	if (boot_cpu_data.x86 > 3 && map_type != _DRM_AGP) {
	pgprot_val(tmp) \|= _PAGE_PCD;
	pgprot_val(tmp) &= ~_PAGE_PWT;
	}
	#elif defined(__powerpc__)
	pgprot_val(tmp) \|= _PAGE_NO_CACHE;
	if (map_type == _DRM_REGISTERS)
	pgprot_val(tmp) \|= _PAGE_GUARDED;
	#elif defined(__ia64__)
	if (efi_range_is_wc(vma->vm_start, vma->vm_end -
	vma->vm_start))
	tmp = pgprot_writecombine(tmp);
	else
	tmp = pgprot_noncached(tmp);
	#elif defined(__sparc__) \|\| defined(__arm__)
	tmp = pgprot_noncached(tmp);
	#endif
	return tmp;
	}

	static pgprot_t drm_dma_prot(uint32_t map_type, struct vm_area_struct *vma)
	{
	pgprot_t tmp = vm_get_page_prot(vma->vm_flags);

	#if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE)
	tmp \|= _PAGE_NO_CACHE;
	#endif
	return tmp;
	}

	/**
	* \c fault method for AGP virtual memory.
	*
	* \param vma virtual memory area.
	* \param address access address.
	* \return pointer to the page structure.
	*
	* Find the right map and if it's AGP memory find the real physical page to
	* map, get the page, increment the use count and return it.
	*/
	#if __OS_HAS_AGP
	static int drm_do_vm_fault(struct vm_area_struct vma, struct vm_fault vmf)
	{
	struct drm_file *priv = vma->vm_file->private_data;
	struct drm_device *dev = priv->minor->dev;
	struct drm_local_map *map = NULL;
	struct drm_map_list *r_list;
	struct drm_hash_item *hash;

	/*
	* Find the right map
	*/
	if (!drm_core_has_AGP(dev))
	goto vm_fault_error;

	if (!dev->agp \|\| !dev->agp->cant_use_aperture)
	goto vm_fault_error;

	if (drm_ht_find_item(&dev->map_hash, vma->vm_pgoff, &hash))
	goto vm_fault_error;

	r_list = drm_hash_entry(hash, struct drm_map_list, hash);
	map = r_list->map;

	if (map && map->type == _DRM_AGP) {
	/*
	* Using vm_pgoff as a selector forces us to use this unusual
	* addressing scheme.
	*/
	resource_size_t offset = (unsigned long)vmf->virtual_address -
	vma->vm_start;
	resource_size_t baddr = map->offset + offset;
	struct drm_agp_mem *agpmem;
	struct page *page;

	#ifdef __alpha__
	/*
	* Adjust to a bus-relative address
	*/
	baddr -= dev->hose->mem_space->start;
	#endif

	/*
	* It's AGP memory - find the real physical page to map
	*/
	list_for_each_entry(agpmem, &dev->agp->memory, head) {
	if (agpmem->bound <= baddr &&
	agpmem->bound + agpmem->pages * PAGE_SIZE > baddr)
	break;
	}

	if (!agpmem)
	goto vm_fault_error;

	/*
	* Get the page, inc the use count, and return it
	*/
	offset = (baddr - agpmem->bound) >> PAGE_SHIFT;
	page = agpmem->memory->pages[offset];
	get_page(page);
	vmf->page = page;

	DRM_DEBUG
	("baddr = 0x%llx page = 0x%p, offset = 0x%llx, count=%d\n",
	(unsigned long long)baddr,
	agpmem->memory->pages[offset],
	(unsigned long long)offset,
	page_count(page));
	return 0;
	}
	vm_fault_error:
	return VM_FAULT_SIGBUS; /* Disallow mremap */
	}
	#else /* __OS_HAS_AGP */
	static int drm_do_vm_fault(struct vm_area_struct vma, struct vm_fault vmf)
	{
	return VM_FAULT_SIGBUS;
	}
	#endif /* __OS_HAS_AGP */

	/**
	* \c nopage method for shared virtual memory.
	*
	* \param vma virtual memory area.
	* \param address access address.
	* \return pointer to the page structure.
	*
	* Get the mapping, find the real physical page to map, get the page, and
	* return it.
	*/
	static int drm_do_vm_shm_fault(struct vm_area_struct vma, struct vm_fault vmf)
	{
	struct drm_local_map *map = vma->vm_private_data;
	unsigned long offset;
	unsigned long i;
	struct page *page;

	if (!map)
	return VM_FAULT_SIGBUS; /* Nothing allocated */

	offset = (unsigned long)vmf->virtual_address - vma->vm_start;
	i = (unsigned long)map->handle + offset;
	page = vmalloc_to_page((void *)i);
	if (!page)
	return VM_FAULT_SIGBUS;
	get_page(page);
	vmf->page = page;

	DRM_DEBUG("shm_fault 0x%lx\n", offset);
	return 0;
	}

	/**
	* \c close method for shared virtual memory.
	*
	* \param vma virtual memory area.
	*
	* Deletes map information if we are the last
	* person to close a mapping and it's not in the global maplist.
	*/
	static void drm_vm_shm_close(struct vm_area_struct *vma)
	{
	struct drm_file *priv = vma->vm_file->private_data;
	struct drm_device *dev = priv->minor->dev;
	struct drm_vma_entry pt, temp;
	struct drm_local_map *map;
	struct drm_map_list *r_list;
	int found_maps = 0;

	DRM_DEBUG("0x%08lx,0x%08lx\n",
	vma->vm_start, vma->vm_end - vma->vm_start);
	atomic_dec(&dev->vma_count);

	map = vma->vm_private_data;

	mutex_lock(&dev->struct_mutex);
	list_for_each_entry_safe(pt, temp, &dev->vmalist, head) {
	if (pt->vma->vm_private_data == map)
	found_maps++;
	if (pt->vma == vma) {
	list_del(&pt->head);
	kfree(pt);
	}
	}

	/* We were the only map that was found */
	if (found_maps == 1 && map->flags & _DRM_REMOVABLE) {
	/* Check to see if we are in the maplist, if we are not, then
	* we delete this mappings information.
	*/
	found_maps = 0;
	list_for_each_entry(r_list, &dev->maplist, head) {
	if (r_list->map == map)
	found_maps++;
	}

	if (!found_maps) {
	drm_dma_handle_t dmah;

	switch (map->type) {
	case _DRM_REGISTERS:
	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);
	}
	iounmap(map->handle);
	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;
	case _DRM_GEM:
	DRM_ERROR("tried to rmmap GEM object\n");
	break;
	}
	kfree(map);
	}
	}
	mutex_unlock(&dev->struct_mutex);
	}

	/**
	* \c fault method for DMA virtual memory.
	*
	* \param vma virtual memory area.
	* \param address access address.
	* \return pointer to the page structure.
	*
	* Determine the page number from the page offset and get it from drm_device_dma::pagelist.
	*/
	static int drm_do_vm_dma_fault(struct vm_area_struct vma, struct vm_fault vmf)
	{
	struct drm_file *priv = vma->vm_file->private_data;
	struct drm_device *dev = priv->minor->dev;
	struct drm_device_dma *dma = dev->dma;
	unsigned long offset;
	unsigned long page_nr;
	struct page *page;

	if (!dma)
	return VM_FAULT_SIGBUS; /* Error */
	if (!dma->pagelist)
	return VM_FAULT_SIGBUS; /* Nothing allocated */

	offset = (unsigned long)vmf->virtual_address - vma->vm_start; /* vm_[pg]off[set] should be 0 */
	page_nr = offset >> PAGE_SHIFT; /* page_nr could just be vmf->pgoff */
	page = virt_to_page((dma->pagelist[page_nr] + (offset & (~PAGE_MASK))));

	get_page(page);
	vmf->page = page;

	DRM_DEBUG("dma_fault 0x%lx (page %lu)\n", offset, page_nr);
	return 0;
	}

	/**
	* \c fault method for scatter-gather virtual memory.
	*
	* \param vma virtual memory area.
	* \param address access address.
	* \return pointer to the page structure.
	*
	* Determine the map offset from the page offset and get it from drm_sg_mem::pagelist.
	*/
	static int drm_do_vm_sg_fault(struct vm_area_struct vma, struct vm_fault vmf)
	{
	struct drm_local_map *map = vma->vm_private_data;
	struct drm_file *priv = vma->vm_file->private_data;
	struct drm_device *dev = priv->minor->dev;
	struct drm_sg_mem *entry = dev->sg;
	unsigned long offset;
	unsigned long map_offset;
	unsigned long page_offset;
	struct page *page;

	if (!entry)
	return VM_FAULT_SIGBUS; /* Error */
	if (!entry->pagelist)
	return VM_FAULT_SIGBUS; /* Nothing allocated */

	offset = (unsigned long)vmf->virtual_address - vma->vm_start;
	map_offset = map->offset - (unsigned long)dev->sg->virtual;
	page_offset = (offset >> PAGE_SHIFT) + (map_offset >> PAGE_SHIFT);
	page = entry->pagelist[page_offset];
	get_page(page);
	vmf->page = page;

	return 0;
	}

	static int drm_vm_fault(struct vm_area_struct vma, struct vm_fault vmf)
	{
	return drm_do_vm_fault(vma, vmf);
	}

	static int drm_vm_shm_fault(struct vm_area_struct vma, struct vm_fault vmf)
	{
	return drm_do_vm_shm_fault(vma, vmf);
	}

	static int drm_vm_dma_fault(struct vm_area_struct vma, struct vm_fault vmf)
	{
	return drm_do_vm_dma_fault(vma, vmf);
	}

	static int drm_vm_sg_fault(struct vm_area_struct vma, struct vm_fault vmf)
	{
	return drm_do_vm_sg_fault(vma, vmf);
	}

	/** AGP virtual memory operations */
	static const struct vm_operations_struct drm_vm_ops = {
	.fault = drm_vm_fault,
	.open = drm_vm_open,
	.close = drm_vm_close,
	};

	/** Shared virtual memory operations */
	static const struct vm_operations_struct drm_vm_shm_ops = {
	.fault = drm_vm_shm_fault,
	.open = drm_vm_open,
	.close = drm_vm_shm_close,
	};

	/** DMA virtual memory operations */
	static const struct vm_operations_struct drm_vm_dma_ops = {
	.fault = drm_vm_dma_fault,
	.open = drm_vm_open,
	.close = drm_vm_close,
	};

	/** Scatter-gather virtual memory operations */
	static const struct vm_operations_struct drm_vm_sg_ops = {
	.fault = drm_vm_sg_fault,
	.open = drm_vm_open,
	.close = drm_vm_close,
	};

	/**
	* \c open method for shared virtual memory.
	*
	* \param vma virtual memory area.
	*
	* Create a new drm_vma_entry structure as the \p vma private data entry and
	* add it to drm_device::vmalist.
	*/
	void drm_vm_open_locked(struct vm_area_struct *vma)
	{
	struct drm_file *priv = vma->vm_file->private_data;
	struct drm_device *dev = priv->minor->dev;
	struct drm_vma_entry *vma_entry;

	DRM_DEBUG("0x%08lx,0x%08lx\n",
	vma->vm_start, vma->vm_end - vma->vm_start);
	atomic_inc(&dev->vma_count);

	vma_entry = kmalloc(sizeof(*vma_entry), GFP_KERNEL);
	if (vma_entry) {
	vma_entry->vma = vma;
	vma_entry->pid = current->pid;
	list_add(&vma_entry->head, &dev->vmalist);
	}
	}

	static void drm_vm_open(struct vm_area_struct *vma)
	{
	struct drm_file *priv = vma->vm_file->private_data;
	struct drm_device *dev = priv->minor->dev;

	mutex_lock(&dev->struct_mutex);
	drm_vm_open_locked(vma);
	mutex_unlock(&dev->struct_mutex);
	}

	/**
	* \c close method for all virtual memory types.
	*
	* \param vma virtual memory area.
	*
	* Search the \p vma private data entry in drm_device::vmalist, unlink it, and
	* free it.
	*/
	static void drm_vm_close(struct vm_area_struct *vma)
	{
	struct drm_file *priv = vma->vm_file->private_data;
	struct drm_device *dev = priv->minor->dev;
	struct drm_vma_entry pt, temp;

	DRM_DEBUG("0x%08lx,0x%08lx\n",
	vma->vm_start, vma->vm_end - vma->vm_start);
	atomic_dec(&dev->vma_count);

	mutex_lock(&dev->struct_mutex);
	list_for_each_entry_safe(pt, temp, &dev->vmalist, head) {
	if (pt->vma == vma) {
	list_del(&pt->head);
	kfree(pt);
	break;
	}
	}
	mutex_unlock(&dev->struct_mutex);
	}

	/**
	* mmap DMA memory.
	*
	* \param file_priv DRM file private.
	* \param vma virtual memory area.
	* \return zero on success or a negative number on failure.
	*
	* Sets the virtual memory area operations structure to vm_dma_ops, the file
	* pointer, and calls vm_open().
	*/
	static int drm_mmap_dma(struct file filp, struct vm_area_struct vma)
	{
	struct drm_file *priv = filp->private_data;
	struct drm_device *dev;
	struct drm_device_dma *dma;
	unsigned long length = vma->vm_end - vma->vm_start;

	dev = priv->minor->dev;
	dma = dev->dma;
	DRM_DEBUG("start = 0x%lx, end = 0x%lx, page offset = 0x%lx\n",
	vma->vm_start, vma->vm_end, vma->vm_pgoff);

	/* Length must match exact page count */
	if (!dma \|\| (length >> PAGE_SHIFT) != dma->page_count) {
	return -EINVAL;
	}

	if (!capable(CAP_SYS_ADMIN) &&
	(dma->flags & _DRM_DMA_USE_PCI_RO)) {
	vma->vm_flags &= ~(VM_WRITE \| VM_MAYWRITE);
	#if defined(__i386__) \|\| defined(__x86_64__)
	pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
	#else
	/* Ye gads this is ugly. With more thought
	we could move this up higher and use
	`protection_map' instead. */
	vma->vm_page_prot =
	__pgprot(pte_val
	(pte_wrprotect
	(__pte(pgprot_val(vma->vm_page_prot)))));
	#endif
	}

	vma->vm_ops = &drm_vm_dma_ops;

	vma->vm_flags \|= VM_RESERVED; /* Don't swap */
	vma->vm_flags \|= VM_DONTEXPAND;

	vma->vm_file = filp; /* Needed for drm_vm_open() */
	drm_vm_open_locked(vma);
	return 0;
	}

	resource_size_t drm_core_get_map_ofs(struct drm_local_map * map)
	{
	return map->offset;
	}

	EXPORT_SYMBOL(drm_core_get_map_ofs);

	resource_size_t drm_core_get_reg_ofs(struct drm_device *dev)
	{
	#ifdef __alpha__
	return dev->hose->dense_mem_base - dev->hose->mem_space->start;
	#else
	return 0;
	#endif
	}

	EXPORT_SYMBOL(drm_core_get_reg_ofs);

	/**
	* mmap DMA memory.
	*
	* \param file_priv DRM file private.
	* \param vma virtual memory area.
	* \return zero on success or a negative number on failure.
	*
	* If the virtual memory area has no offset associated with it then it's a DMA
	* area, so calls mmap_dma(). Otherwise searches the map in drm_device::maplist,
	* checks that the restricted flag is not set, sets the virtual memory operations
	* according to the mapping type and remaps the pages. Finally sets the file
	* pointer and calls vm_open().
	*/
	int drm_mmap_locked(struct file filp, struct vm_area_struct vma)
	{
	struct drm_file *priv = filp->private_data;
	struct drm_device *dev = priv->minor->dev;
	struct drm_local_map *map = NULL;
	resource_size_t offset = 0;
	struct drm_hash_item *hash;

	DRM_DEBUG("start = 0x%lx, end = 0x%lx, page offset = 0x%lx\n",
	vma->vm_start, vma->vm_end, vma->vm_pgoff);

	if (!priv->authenticated)
	return -EACCES;

	/* We check for "dma". On Apple's UniNorth, it's valid to have
	* the AGP mapped at physical address 0
	* --BenH.
	*/
	if (!vma->vm_pgoff
	#if __OS_HAS_AGP
	&& (!dev->agp
	\|\| dev->agp->agp_info.device->vendor != PCI_VENDOR_ID_APPLE)
	#endif
	)
	return drm_mmap_dma(filp, vma);

	if (drm_ht_find_item(&dev->map_hash, vma->vm_pgoff, &hash)) {
	DRM_ERROR("Could not find map\n");
	return -EINVAL;
	}

	map = drm_hash_entry(hash, struct drm_map_list, hash)->map;
	if (!map \|\| ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN)))
	return -EPERM;

	/* Check for valid size. */
	if (map->size < vma->vm_end - vma->vm_start)
	return -EINVAL;

	if (!capable(CAP_SYS_ADMIN) && (map->flags & _DRM_READ_ONLY)) {
	vma->vm_flags &= ~(VM_WRITE \| VM_MAYWRITE);
	#if defined(__i386__) \|\| defined(__x86_64__)
	pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
	#else
	/* Ye gads this is ugly. With more thought
	we could move this up higher and use
	`protection_map' instead. */
	vma->vm_page_prot =
	__pgprot(pte_val
	(pte_wrprotect
	(__pte(pgprot_val(vma->vm_page_prot)))));
	#endif
	}

	switch (map->type) {
	#if !defined(__arm__)
	case _DRM_AGP:
	if (drm_core_has_AGP(dev) && dev->agp->cant_use_aperture) {
	/*
	* On some platforms we can't talk to bus dma address from the CPU, so for
	* memory of type DRM_AGP, we'll deal with sorting out the real physical
	* pages and mappings in fault()
	*/
	#if defined(__powerpc__)
	pgprot_val(vma->vm_page_prot) \|= _PAGE_NO_CACHE;
	#endif
	vma->vm_ops = &drm_vm_ops;
	break;
	}
	/* fall through to _DRM_FRAME_BUFFER... */
	#endif
	case _DRM_FRAME_BUFFER:
	case _DRM_REGISTERS:
	offset = dev->driver->get_reg_ofs(dev);
	vma->vm_flags \|= VM_IO; /* not in core dump */
	vma->vm_page_prot = drm_io_prot(map->type, vma);
	#if !defined(__arm__)
	if (io_remap_pfn_range(vma, vma->vm_start,
	(map->offset + offset) >> PAGE_SHIFT,
	vma->vm_end - vma->vm_start,
	vma->vm_page_prot))
	return -EAGAIN;
	#else
	if (remap_pfn_range(vma, vma->vm_start,
	(map->offset + offset) >> PAGE_SHIFT,
	vma->vm_end - vma->vm_start,
	vma->vm_page_prot))
	return -EAGAIN;
	#endif

	DRM_DEBUG(" Type = %d; start = 0x%lx, end = 0x%lx,"
	" offset = 0x%llx\n",
	map->type,
	vma->vm_start, vma->vm_end, (unsigned long long)(map->offset + offset));

	vma->vm_ops = &drm_vm_ops;
	break;
	case _DRM_CONSISTENT:
	/* Consistent memory is really like shared memory. But
	* it's allocated in a different way, so avoid fault */
	if (remap_pfn_range(vma, vma->vm_start,
	page_to_pfn(virt_to_page(map->handle)),
	vma->vm_end - vma->vm_start, vma->vm_page_prot))
	return -EAGAIN;
	vma->vm_page_prot = drm_dma_prot(map->type, vma);
	/* fall through to _DRM_SHM */
	case _DRM_SHM:
	vma->vm_ops = &drm_vm_shm_ops;
	vma->vm_private_data = (void *)map;
	/* Don't let this area swap. Change when
	DRM_KERNEL advisory is supported. */
	vma->vm_flags \|= VM_RESERVED;
	break;
	case _DRM_SCATTER_GATHER:
	vma->vm_ops = &drm_vm_sg_ops;
	vma->vm_private_data = (void *)map;
	vma->vm_flags \|= VM_RESERVED;
	vma->vm_page_prot = drm_dma_prot(map->type, vma);
	break;
	default:
	return -EINVAL; /* This should never happen. */
	}
	vma->vm_flags \|= VM_RESERVED; /* Don't swap */
	vma->vm_flags \|= VM_DONTEXPAND;

	vma->vm_file = filp; /* Needed for drm_vm_open() */
	drm_vm_open_locked(vma);
	return 0;
	}

	int drm_mmap(struct file filp, struct vm_area_struct vma)
	{
	struct drm_file *priv = filp->private_data;
	struct drm_device *dev = priv->minor->dev;
	int ret;

	mutex_lock(&dev->struct_mutex);
	ret = drm_mmap_locked(filp, vma);
	mutex_unlock(&dev->struct_mutex);

	return ret;
	}
	EXPORT_SYMBOL(drm_mmap);