dist/drm/drm_agpsupport.c

/*        $NetBSD: drm_agpsupport.c,v 1.13 2022/07/19 22:24:33 riastradh Exp $  */

/*
 * \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 <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: drm_agpsupport.c,v 1.13 2022/07/19 22:24:33 riastradh Exp $");

#include <linux/module.h>
#include <linux/pci.h>
#include <linux/slab.h>

#include <asm/agp.h>

#include <drm/drm_agpsupport.h>
#include <drm/drm_device.h>
#include <drm/drm_drv.h>
#include <drm/drm_file.h>
#include <drm/drm_print.h>

#include "drm_legacy.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.
 */
static int drm_agp_info_hook(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;
#if __NetBSD__
          info->agp_version_major = 1;
          info->agp_version_minor = 0;
          info->mode = kern->aki_info.ai_mode;
          info->aperture_base = kern->aki_info.ai_aperture_base;
          info->aperture_size = kern->aki_info.ai_aperture_size;
          info->memory_allowed = kern->aki_info.ai_memory_allowed;
          info->memory_used = kern->aki_info.ai_memory_used;
          info->id_vendor = PCI_VENDOR(kern->aki_info.ai_devid);
          info->id_device = PCI_PRODUCT(kern->aki_info.ai_devid);
#else
          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;
#endif

          return 0;
}
EXPORT_SYMBOL(drm_agp_info);

static int drm_agp_info_ioctl_hook(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.
 */
static int drm_agp_acquire_hook(struct drm_device * dev)
{
          if (!dev->agp)
                    return -ENODEV;
          if (dev->agp->acquired)
                    return -EBUSY;
          dev->agp->bridge = agp_backend_acquire(dev->pdev);
          if (!dev->agp->bridge)
                    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.
 */
static int drm_agp_acquire_ioctl_hook(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.
 */
static int drm_agp_release_hook(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);

static int drm_agp_release_ioctl_hook(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.
 */
static int drm_agp_enable_hook(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);

static int drm_agp_enable_ioctl_hook(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.
 */
static int drm_agp_alloc_hook(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;
          entry = kzalloc(sizeof(*entry), GFP_KERNEL);
          if (!entry)
                    return -ENOMEM;

          pages = DIV_ROUND_UP(request->size, AGP_PAGE_SIZE);
          type = (u32) request->type;
          memory = agp_allocate_memory(dev->agp->bridge, pages, type);
          if (!memory) {
                    kfree(entry);
                    return -ENOMEM;
          }

#ifdef __NetBSD__
          /* I presume the `+ 1' is there to avoid an id of 0 or something.  */
          entry->handle = (unsigned long)memory->am_id + 1;
#else
          entry->handle = (unsigned long)memory->key + 1;
#endif
          entry->memory = memory;
          entry->bound = 0;
          entry->pages = pages;
          list_add(&entry->head, &dev->agp->memory);

          request->handle = entry->handle;
#ifdef __NetBSD__
          {
                    struct agp_memory_info info;
                    agp_memory_info(dev->agp->bridge, memory, &info);
                    request->physical = info.ami_physical;
          }
#else
          request->physical = memory->physical;
#endif

          return 0;
}
EXPORT_SYMBOL(drm_agp_alloc);


static int drm_agp_alloc_ioctl_hook(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.
 */
static int drm_agp_unbind_hook(struct drm_device *dev, struct drm_agp_binding *request)
{
          struct drm_agp_mem *entry;
          int ret;

          if (!dev->agp || !dev->agp->acquired)
                    return -EINVAL;
          entry = drm_agp_lookup_entry(dev, request->handle);
          if (!entry || !entry->bound)
                    return -EINVAL;
#ifdef __NetBSD__
          ret = drm_unbind_agp(dev->agp->bridge, entry->memory);
#else
          ret = drm_unbind_agp(entry->memory);
#endif
          if (ret == 0)
                    entry->bound = 0;
          return ret;
}
EXPORT_SYMBOL(drm_agp_unbind);


static int drm_agp_unbind_ioctl_hook(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.
 */
static int drm_agp_bind_hook(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;
          entry = drm_agp_lookup_entry(dev, request->handle);
          if (!entry || entry->bound)
                    return -EINVAL;
          page = DIV_ROUND_UP(request->offset, AGP_PAGE_SIZE);
#ifdef __NetBSD__
          if ((retcode = drm_bind_agp(dev->agp->bridge, entry->memory, page)))
                    return retcode;
#else
          retcode = drm_bind_agp(entry->memory, page);
          if (retcode)
                    return retcode;
#endif
          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);


static int drm_agp_bind_ioctl_hook(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 is 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.
 */
static int drm_agp_free_hook(struct drm_device *dev, struct drm_agp_buffer *request)
{
          struct drm_agp_mem *entry;

          if (!dev->agp || !dev->agp->acquired)
                    return -EINVAL;
          entry = drm_agp_lookup_entry(dev, request->handle);
          if (!entry)
                    return -EINVAL;
          if (entry->bound)
#ifdef __NetBSD__
                    drm_unbind_agp(dev->agp->bridge, entry->memory);
#else
                    drm_unbind_agp(entry->memory);
#endif

          list_del(&entry->head);

#ifdef __NetBSD__
          drm_free_agp(dev->agp->bridge, entry->memory, entry->pages);
#else
          drm_free_agp(entry->memory, entry->pages);
#endif
          kfree(entry);
          return 0;
}
EXPORT_SYMBOL(drm_agp_free);


static int drm_agp_free_ioctl_hook(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.
 */
static struct drm_agp_head *drm_agp_init_hook(struct drm_device *dev)
{
          struct drm_agp_head *head = NULL;

          head = kzalloc(sizeof(*head), GFP_KERNEL);
          if (!head)
                    return NULL;
          head->bridge = agp_find_bridge(dev->pdev);
          if (!head->bridge) {
                    head->bridge = agp_backend_acquire(dev->pdev);
                    if (!head->bridge) {
                              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);
          }
#ifndef __NetBSD__
          /* Why would anything even attach in this case?  */
          if (head->agp_info.chipset == NOT_SUPPORTED) {
                    kfree(head);
                    return NULL;
          }
#endif
          INIT_LIST_HEAD(&head->memory);
#ifdef __NetBSD__
          head->cant_use_aperture = false; /* XXX */
          head->page_mask = ~0UL;
          head->base = head->agp_info.aki_info.ai_aperture_base;
#else
          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;
#endif
          return head;
}
/* Only exported for i810.ko */
EXPORT_SYMBOL(drm_agp_init);

/**
 * drm_legacy_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.
 *
 * Cleanup is only done for drivers who have DRIVER_LEGACY set.
 */
static void drm_agp_clear_hook(struct drm_device *dev)
{
          struct drm_agp_mem *entry, *tempe;

          if (!dev->agp)
                    return;
          if (!drm_core_check_feature(dev, DRIVER_LEGACY))
                    return;

          list_for_each_entry_safe(entry, tempe, &dev->agp->memory, head) {
#ifdef __NetBSD__
                    if (entry->bound)
                              drm_unbind_agp(dev->agp->bridge, entry->memory);
                    drm_free_agp(dev->agp->bridge, entry->memory, entry->pages);
#else
                    if (entry->bound)
                              drm_unbind_agp(entry->memory);
                    drm_free_agp(entry->memory, entry->pages);
#endif
                    kfree(entry);
          }
          INIT_LIST_HEAD(&dev->agp->memory);

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

          dev->agp->acquired = 0;
          dev->agp->enabled = 0;
}

#ifdef __NetBSD__

static void
drm_agp_flush_hook(void)
{

          agp_flush_cache();
}

static const struct drm_agp_hooks agp_hooks = {
          .agph_info = drm_agp_info_hook,
          .agph_info_ioctl = drm_agp_info_ioctl_hook,
          .agph_acquire = drm_agp_acquire_hook,
          .agph_acquire_ioctl = drm_agp_acquire_ioctl_hook,
          .agph_release = drm_agp_release_hook,
          .agph_release_ioctl = drm_agp_release_ioctl_hook,
          .agph_enable = drm_agp_enable_hook,
          .agph_enable_ioctl = drm_agp_enable_ioctl_hook,
          .agph_alloc = drm_agp_alloc_hook,
          .agph_alloc_ioctl = drm_agp_alloc_ioctl_hook,
          .agph_unbind = drm_agp_unbind_hook,
          .agph_unbind_ioctl = drm_agp_unbind_ioctl_hook,
          .agph_bind = drm_agp_bind_hook,
          .agph_bind_ioctl = drm_agp_bind_ioctl_hook,
          .agph_free = drm_agp_free_hook,
          .agph_free_ioctl = drm_agp_free_ioctl_hook,
          .agph_init = drm_agp_init_hook,
          .agph_clear = drm_agp_clear_hook,
          .agph_flush = drm_agp_flush_hook,
};

#include <sys/module.h>
#include <sys/once.h>

MODULE(MODULE_CLASS_MISC, drmkms_agp, "drmkms"); /* XXX agp */

static int
drmkms_agp_init(void)
{

          return drm_agp_register(&agp_hooks);
}

int
drmkms_agp_guarantee_initialized(void)
{
#ifdef _MODULE
          return 0;
#else
          static ONCE_DECL(drmkms_agp_init_once);

          return RUN_ONCE(&drmkms_agp_init_once, &drmkms_agp_init);
#endif
}

static int
drmkms_agp_fini(void)
{

          return drm_agp_deregister(&agp_hooks);
}

static int
drmkms_agp_modcmd(modcmd_t cmd, void *arg __unused)
{
          int error;

          switch (cmd) {
          case MODULE_CMD_INIT:
#ifdef _MODULE
                    error = drmkms_agp_init();
#else
                    error = drmkms_agp_guarantee_initialized();
#endif
                    if (error)
                              return error;
                    return 0;
          case MODULE_CMD_AUTOUNLOAD:
                    return EBUSY;
          case MODULE_CMD_FINI:
                    error = drmkms_agp_fini();
                    if (error)
                              return error;
                    return 0;
          default:
                    return ENOTTY;
          }
}

#endif    /* __NetBSD__ */