text: /**
   * \file drm_agpsupport.c
   * DRM support for AGP/GART backend
   *
   * \author Rickard E. (Rik) Faith <faith@valinux.com>
   * \author Gareth Hughes <gareth@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 <drm/drmP.h>
  #include <linux/module.h>
  #include <linux/slab.h>
  #include "drm_legacy.h"
  
  #include <asm/agp.h>
  
  /**
   * Get AGP information.
   *
   * \param inode device inode.
   * \param file_priv DRM file private.
   * \param cmd command.
   * \param arg pointer to a (output) drm_agp_info structure.
   * \return zero on success or a negative number on failure.
   *
   * Verifies the AGP device has been initialized and acquired and fills in the
   * drm_agp_info structure with the information in drm_agp_head::agp_info.
   */
  int drm_agp_info(struct drm_device *dev, struct drm_agp_info *info)
  {
  	struct agp_kern_info *kern;
  
  	if (!dev->agp || !dev->agp->acquired)
  		return -EINVAL;
  
  	kern = &dev->agp->agp_info;
  	info->agp_version_major = kern->version.major;
  	info->agp_version_minor = kern->version.minor;
  	info->mode = kern->mode;
  	info->aperture_base = kern->aper_base;
  	info->aperture_size = kern->aper_size * 1024 * 1024;
  	info->memory_allowed = kern->max_memory << PAGE_SHIFT;
  	info->memory_used = kern->current_memory << PAGE_SHIFT;
  	info->id_vendor = kern->device->vendor;
  	info->id_device = kern->device->device;
  
  	return 0;
  }
  
  EXPORT_SYMBOL(drm_agp_info);
  
  int drm_agp_info_ioctl(struct drm_device *dev, void *data,
  		       struct drm_file *file_priv)
  {
  	struct drm_agp_info *info = data;
  	int err;
  
  	err = drm_agp_info(dev, info);
  	if (err)
  		return err;
  
  	return 0;
  }
  
  /**
   * Acquire the AGP device.
   *
   * \param dev DRM device that is to acquire AGP.
   * \return zero on success or a negative number on failure.
   *
   * Verifies the AGP device hasn't been acquired before and calls
   * \c agp_backend_acquire.
   */
  int drm_agp_acquire(struct drm_device * dev)
  {
  	if (!dev->agp)
  		return -ENODEV;
  	if (dev->agp->acquired)
  		return -EBUSY;
  	if (!(dev->agp->bridge = agp_backend_acquire(dev->pdev)))
  		return -ENODEV;
  	dev->agp->acquired = 1;
  	return 0;
  }
  
  EXPORT_SYMBOL(drm_agp_acquire);
  
  /**
   * Acquire the AGP device (ioctl).
   *
   * \param inode device inode.
   * \param file_priv DRM file private.
   * \param cmd command.
   * \param arg user argument.
   * \return zero on success or a negative number on failure.
   *
   * Verifies the AGP device hasn't been acquired before and calls
   * \c agp_backend_acquire.
   */
  int drm_agp_acquire_ioctl(struct drm_device *dev, void *data,
  			  struct drm_file *file_priv)
  {
  	return drm_agp_acquire((struct drm_device *) file_priv->minor->dev);
  }
  
  /**
   * Release the AGP device.
   *
   * \param dev DRM device that is to release AGP.
   * \return zero on success or a negative number on failure.
   *
   * Verifies the AGP device has been acquired and calls \c agp_backend_release.
   */
  int drm_agp_release(struct drm_device * dev)
  {
  	if (!dev->agp || !dev->agp->acquired)
  		return -EINVAL;
  	agp_backend_release(dev->agp->bridge);
  	dev->agp->acquired = 0;
  	return 0;
  }
  EXPORT_SYMBOL(drm_agp_release);
  
  int drm_agp_release_ioctl(struct drm_device *dev, void *data,
  			  struct drm_file *file_priv)
  {
  	return drm_agp_release(dev);
  }
  
  /**
   * Enable the AGP bus.
   *
   * \param dev DRM device that has previously acquired AGP.
   * \param mode Requested AGP mode.
   * \return zero on success or a negative number on failure.
   *
   * Verifies the AGP device has been acquired but not enabled, and calls
   * \c agp_enable.
   */
  int drm_agp_enable(struct drm_device * dev, struct drm_agp_mode mode)
  {
  	if (!dev->agp || !dev->agp->acquired)
  		return -EINVAL;
  
  	dev->agp->mode = mode.mode;
  	agp_enable(dev->agp->bridge, mode.mode);
  	dev->agp->enabled = 1;
  	return 0;
  }
  
  EXPORT_SYMBOL(drm_agp_enable);
  
  int drm_agp_enable_ioctl(struct drm_device *dev, void *data,
  			 struct drm_file *file_priv)
  {
  	struct drm_agp_mode *mode = data;
  
  	return drm_agp_enable(dev, *mode);
  }
  
  /**
   * Allocate AGP memory.
   *
   * \param inode device inode.
   * \param file_priv file private pointer.
   * \param cmd command.
   * \param arg pointer to a drm_agp_buffer structure.
   * \return zero on success or a negative number on failure.
   *
   * Verifies the AGP device is present and has been acquired, allocates the
   * memory via agp_allocate_memory() and creates a drm_agp_mem entry for it.
   */
  int drm_agp_alloc(struct drm_device *dev, struct drm_agp_buffer *request)
  {
  	struct drm_agp_mem *entry;
  	struct agp_memory *memory;
  	unsigned long pages;
  	u32 type;
  
  	if (!dev->agp || !dev->agp->acquired)
  		return -EINVAL;
  	if (!(entry = kzalloc(sizeof(*entry), GFP_KERNEL)))
  		return -ENOMEM;
  
  	pages = (request->size + PAGE_SIZE - 1) / PAGE_SIZE;
  	type = (u32) request->type;
  	if (!(memory = agp_allocate_memory(dev->agp->bridge, pages, type))) {
  		kfree(entry);
  		return -ENOMEM;
  	}
  
  	entry->handle = (unsigned long)memory->key + 1;
  	entry->memory = memory;
  	entry->bound = 0;
  	entry->pages = pages;
  	list_add(&entry->head, &dev->agp->memory);
  
  	request->handle = entry->handle;
  	request->physical = memory->physical;
  
  	return 0;
  }
  EXPORT_SYMBOL(drm_agp_alloc);
  
  
  int drm_agp_alloc_ioctl(struct drm_device *dev, void *data,
  			struct drm_file *file_priv)
  {
  	struct drm_agp_buffer *request = data;
  
  	return drm_agp_alloc(dev, request);
  }
  
  /**
   * Search for the AGP memory entry associated with a handle.
   *
   * \param dev DRM device structure.
   * \param handle AGP memory handle.
   * \return pointer to the drm_agp_mem structure associated with \p handle.
   *
   * Walks through drm_agp_head::memory until finding a matching handle.
   */
  static struct drm_agp_mem *drm_agp_lookup_entry(struct drm_device * dev,
  					   unsigned long handle)
  {
  	struct drm_agp_mem *entry;
  
  	list_for_each_entry(entry, &dev->agp->memory, head) {
  		if (entry->handle == handle)
  			return entry;
  	}
  	return NULL;
  }
  
  /**
   * Unbind AGP memory from the GATT (ioctl).
   *
   * \param inode device inode.
   * \param file_priv DRM file private.
   * \param cmd command.
   * \param arg pointer to a drm_agp_binding structure.
   * \return zero on success or a negative number on failure.
   *
   * Verifies the AGP device is present and acquired, looks-up the AGP memory
   * entry and passes it to the unbind_agp() function.
   */
  int drm_agp_unbind(struct drm_device *dev, struct drm_agp_binding *request)
  {
  	struct drm_agp_mem *entry;
  	int ret;
  
  	if (!dev->agp || !dev->agp->acquired)
  		return -EINVAL;
  	if (!(entry = drm_agp_lookup_entry(dev, request->handle)))
  		return -EINVAL;
  	if (!entry->bound)
  		return -EINVAL;
  	ret = drm_unbind_agp(entry->memory);
  	if (ret == 0)
  		entry->bound = 0;
  	return ret;
  }
  EXPORT_SYMBOL(drm_agp_unbind);
  
  
  int drm_agp_unbind_ioctl(struct drm_device *dev, void *data,
  			 struct drm_file *file_priv)
  {
  	struct drm_agp_binding *request = data;
  
  	return drm_agp_unbind(dev, request);
  }
  
  /**
   * Bind AGP memory into the GATT (ioctl)
   *
   * \param inode device inode.
   * \param file_priv DRM file private.
   * \param cmd command.
   * \param arg pointer to a drm_agp_binding structure.
   * \return zero on success or a negative number on failure.
   *
   * Verifies the AGP device is present and has been acquired and that no memory
   * is currently bound into the GATT. Looks-up the AGP memory entry and passes
   * it to bind_agp() function.
   */
  int drm_agp_bind(struct drm_device *dev, struct drm_agp_binding *request)
  {
  	struct drm_agp_mem *entry;
  	int retcode;
  	int page;
  
  	if (!dev->agp || !dev->agp->acquired)
  		return -EINVAL;
  	if (!(entry = drm_agp_lookup_entry(dev, request->handle)))
  		return -EINVAL;
  	if (entry->bound)
  		return -EINVAL;
  	page = (request->offset + PAGE_SIZE - 1) / PAGE_SIZE;
  	if ((retcode = drm_bind_agp(entry->memory, page)))
  		return retcode;
  	entry->bound = dev->agp->base + (page << PAGE_SHIFT);
  	DRM_DEBUG("base = 0x%lx entry->bound = 0x%lx\n",
  		  dev->agp->base, entry->bound);
  	return 0;
  }
  EXPORT_SYMBOL(drm_agp_bind);
  
  
  int drm_agp_bind_ioctl(struct drm_device *dev, void *data,
  		       struct drm_file *file_priv)
  {
  	struct drm_agp_binding *request = data;
  
  	return drm_agp_bind(dev, request);
  }
  
  /**
   * Free AGP memory (ioctl).
   *
   * \param inode device inode.
   * \param file_priv DRM file private.
   * \param cmd command.
   * \param arg pointer to a drm_agp_buffer structure.
   * \return zero on success or a negative number on failure.
   *
   * Verifies the AGP device is present and has been acquired and looks up the
   * AGP memory entry. If the memory it's currently bound, unbind it via
   * unbind_agp(). Frees it via free_agp() as well as the entry itself
   * and unlinks from the doubly linked list it's inserted in.
   */
  int drm_agp_free(struct drm_device *dev, struct drm_agp_buffer *request)
  {
  	struct drm_agp_mem *entry;
  
  	if (!dev->agp || !dev->agp->acquired)
  		return -EINVAL;
  	if (!(entry = drm_agp_lookup_entry(dev, request->handle)))
  		return -EINVAL;
  	if (entry->bound)
  		drm_unbind_agp(entry->memory);
  
  	list_del(&entry->head);
  
  	drm_free_agp(entry->memory, entry->pages);
  	kfree(entry);
  	return 0;
  }
  EXPORT_SYMBOL(drm_agp_free);
  
  
  
  int drm_agp_free_ioctl(struct drm_device *dev, void *data,
  		       struct drm_file *file_priv)
  {
  	struct drm_agp_buffer *request = data;
  
  	return drm_agp_free(dev, request);
  }
  
  /**
   * Initialize the AGP resources.
   *
   * \return pointer to a drm_agp_head structure.
   *
   * Gets the drm_agp_t structure which is made available by the agpgart module
   * via the inter_module_* functions. Creates and initializes a drm_agp_head
   * structure.
   *
   * Note that final cleanup of the kmalloced structure is directly done in
   * drm_pci_agp_destroy.
   */
  struct drm_agp_head *drm_agp_init(struct drm_device *dev)
  {
  	struct drm_agp_head *head = NULL;
  
  	if (!(head = kzalloc(sizeof(*head), GFP_KERNEL)))
  		return NULL;
  	head->bridge = agp_find_bridge(dev->pdev);
  	if (!head->bridge) {
  		if (!(head->bridge = agp_backend_acquire(dev->pdev))) {
  			kfree(head);
  			return NULL;
  		}
  		agp_copy_info(head->bridge, &head->agp_info);
  		agp_backend_release(head->bridge);
  	} else {
  		agp_copy_info(head->bridge, &head->agp_info);
  	}
  	if (head->agp_info.chipset == NOT_SUPPORTED) {
  		kfree(head);
  		return NULL;
  	}
  	INIT_LIST_HEAD(&head->memory);
  	head->cant_use_aperture = head->agp_info.cant_use_aperture;
  	head->page_mask = head->agp_info.page_mask;
  	head->base = head->agp_info.aper_base;
  	return head;
  }
  
  /**
   * drm_agp_clear - Clear AGP resource list
   * @dev: DRM device
   *
   * Iterate over all AGP resources and remove them. But keep the AGP head
   * intact so it can still be used. It is safe to call this if AGP is disabled or
   * was already removed.
   *
   * If DRIVER_MODESET is active, nothing is done to protect the modesetting
   * resources from getting destroyed. Drivers are responsible of cleaning them up
   * during device shutdown.
   */
  void drm_agp_clear(struct drm_device *dev)
  {
  	struct drm_agp_mem *entry, *tempe;
  
  	if (!dev->agp)
  		return;
  	if (drm_core_check_feature(dev, DRIVER_MODESET))
  		return;
  
  	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);
  		kfree(entry);
  	}
  	INIT_LIST_HEAD(&dev->agp->memory);
  
  	if (dev->agp->acquired)
  		drm_agp_release(dev);
  
  	dev->agp->acquired = 0;
  	dev->agp->enabled = 0;
  }
  
  /**
   * Binds a collection of pages into AGP memory at the given offset, returning
   * the AGP memory structure containing them.
   *
   * No reference is held on the pages during this time -- it is up to the
   * caller to handle that.
   */
  struct agp_memory *
  drm_agp_bind_pages(struct drm_device *dev,
  		   struct page **pages,
  		   unsigned long num_pages,
  		   uint32_t gtt_offset,
  		   u32 type)
  {
  	struct agp_memory *mem;
  	int ret, i;
  
  	DRM_DEBUG("\n");
  
  	mem = agp_allocate_memory(dev->agp->bridge, num_pages,
  				      type);
  	if (mem == NULL) {
  		DRM_ERROR("Failed to allocate memory for %ld pages\n",
  			  num_pages);
  		return NULL;
  	}
  
  	for (i = 0; i < num_pages; i++)
  		mem->pages[i] = pages[i];
  	mem->page_count = num_pages;
  
  	mem->is_flushed = true;
  	ret = agp_bind_memory(mem, gtt_offset / PAGE_SIZE);
  	if (ret != 0) {
  		DRM_ERROR("Failed to bind AGP memory: %d\n", ret);
  		agp_free_memory(mem);
  		return NULL;
  	}
  
  	return mem;
  }
  EXPORT_SYMBOL(drm_agp_bind_pages);
  