drivers/gpu/drm/drm_pci.c - kernel/msm-4.19 - Gitiles

 /*
  * Copyright 2003 José Fonseca.
  * Copyright 2003 Leif Delgass.
  * 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 THE
  * AUTHORS 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/pci.h>
 #include <linux/slab.h>
 #include <linux/dma-mapping.h>
 #include <linux/export.h>
 #include <drm/drmP.h>
 #include "drm_internal.h"
 #include "drm_legacy.h"

 /**
  * drm_pci_alloc - Allocate a PCI consistent memory block, for DMA.
  * @dev: DRM device
  * @size: size of block to allocate
  * @align: alignment of block
  *
  * Return: A handle to the allocated memory block on success or NULL on
  * failure.
  */
 drm_dma_handle_t *drm_pci_alloc(struct drm_device * dev, size_t size, size_t align)
 {
 	drm_dma_handle_t *dmah;
 	unsigned long addr;
 	size_t sz;

 	/* pci_alloc_consistent only guarantees alignment to the smallest
 	 * PAGE_SIZE order which is greater than or equal to the requested size.
 	 * Return NULL here for now to make sure nobody tries for larger alignment
 	 */
 	if (align > size)
 		return NULL;

 	dmah = kmalloc(sizeof(drm_dma_handle_t), GFP_KERNEL);
 	if (!dmah)
 		return NULL;

 	dmah->size = size;
 	dmah->vaddr = dma_alloc_coherent(&dev->pdev->dev, size, &dmah->busaddr, GFP_KERNEL | __GFP_COMP);

 	if (dmah->vaddr == NULL) {
 		kfree(dmah);
 		return NULL;
 	}

 	memset(dmah->vaddr, 0, size);

 	/* XXX - Is virt_to_page() legal for consistent mem? */
 	/* Reserve */
 	for (addr = (unsigned long)dmah->vaddr, sz = size;
 	     sz > 0; addr += PAGE_SIZE, sz -= PAGE_SIZE) {
 		SetPageReserved(virt_to_page((void *)addr));
 	}

 	return dmah;
 }

 EXPORT_SYMBOL(drm_pci_alloc);

 /*
  * Free a PCI consistent memory block without freeing its descriptor.
  *
  * This function is for internal use in the Linux-specific DRM core code.
  */
 void __drm_legacy_pci_free(struct drm_device * dev, drm_dma_handle_t * dmah)
 {
 	unsigned long addr;
 	size_t sz;

 	if (dmah->vaddr) {
 		/* XXX - Is virt_to_page() legal for consistent mem? */
 		/* Unreserve */
 		for (addr = (unsigned long)dmah->vaddr, sz = dmah->size;
 		     sz > 0; addr += PAGE_SIZE, sz -= PAGE_SIZE) {
 			ClearPageReserved(virt_to_page((void *)addr));
 		}
 		dma_free_coherent(&dev->pdev->dev, dmah->size, dmah->vaddr,
 				  dmah->busaddr);
 	}
 }

 /**
  * drm_pci_free - Free a PCI consistent memory block
  * @dev: DRM device
  * @dmah: handle to memory block
  */
 void drm_pci_free(struct drm_device * dev, drm_dma_handle_t * dmah)
 {
 	__drm_legacy_pci_free(dev, dmah);
 	kfree(dmah);
 }

 EXPORT_SYMBOL(drm_pci_free);

 #ifdef CONFIG_PCI

 static int drm_get_pci_domain(struct drm_device *dev)
 {
 #ifndef __alpha__
 	/* For historical reasons, drm_get_pci_domain() is busticated
 	 * on most archs and has to remain so for userspace interface
 	 * < 1.4, except on alpha which was right from the beginning
 	 */
 	if (dev->if_version < 0x10004)
 		return 0;
 #endif /* __alpha__ */

 	return pci_domain_nr(dev->pdev->bus);
 }

 int drm_pci_set_busid(struct drm_device *dev, struct drm_master *master)
 {
 	master->unique = kasprintf(GFP_KERNEL, "pci:%04x:%02x:%02x.%d",
 					drm_get_pci_domain(dev),
 					dev->pdev->bus->number,
 					PCI_SLOT(dev->pdev->devfn),
 					PCI_FUNC(dev->pdev->devfn));
 	if (!master->unique)
 		return -ENOMEM;

 	master->unique_len = strlen(master->unique);
 	return 0;
 }
 EXPORT_SYMBOL(drm_pci_set_busid);

 static int drm_pci_irq_by_busid(struct drm_device *dev, struct drm_irq_busid *p)
 {
 	if ((p->busnum >> 8) != drm_get_pci_domain(dev) ||
 	    (p->busnum & 0xff) != dev->pdev->bus->number ||
 	    p->devnum != PCI_SLOT(dev->pdev->devfn) || p->funcnum != PCI_FUNC(dev->pdev->devfn))
 		return -EINVAL;

 	p->irq = dev->pdev->irq;

 	DRM_DEBUG("%d:%d:%d => IRQ %d\n", p->busnum, p->devnum, p->funcnum,
 		  p->irq);
 	return 0;
 }

 /**
  * drm_irq_by_busid - Get interrupt from bus ID
  * @dev: DRM device
  * @data: IOCTL parameter pointing to a drm_irq_busid structure
  * @file_priv: DRM file private.
  *
  * Finds the PCI device with the specified bus id and gets its IRQ number.
  * This IOCTL is deprecated, and will now return EINVAL for any busid not equal
  * to that of the device that this DRM instance attached to.
  *
  * Return: 0 on success or a negative error code on failure.
  */
 int drm_irq_by_busid(struct drm_device *dev, void *data,
 		     struct drm_file *file_priv)
 {
 	struct drm_irq_busid *p = data;

 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
 		return -EINVAL;

 	/* UMS was only ever support on PCI devices. */
 	if (WARN_ON(!dev->pdev))
 		return -EINVAL;

 	if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
 		return -EINVAL;

 	return drm_pci_irq_by_busid(dev, p);
 }

 static void drm_pci_agp_init(struct drm_device *dev)
 {
 	if (drm_core_check_feature(dev, DRIVER_USE_AGP)) {
 		if (drm_pci_device_is_agp(dev))
 			dev->agp = drm_agp_init(dev);
 		if (dev->agp) {
 			dev->agp->agp_mtrr = arch_phys_wc_add(
 				dev->agp->agp_info.aper_base,
 				dev->agp->agp_info.aper_size *
 				1024 * 1024);
 		}
 	}
 }

 void drm_pci_agp_destroy(struct drm_device *dev)
 {
 	if (dev->agp) {
 		arch_phys_wc_del(dev->agp->agp_mtrr);
 		drm_legacy_agp_clear(dev);
 		kfree(dev->agp);
 		dev->agp = NULL;
 	}
 }

 /**
  * drm_get_pci_dev - Register a PCI device with the DRM subsystem
  * @pdev: PCI device
  * @ent: entry from the PCI ID table that matches @pdev
  * @driver: DRM device driver
  *
  * Attempt to gets inter module "drm" information. If we are first
  * then register the character device and inter module information.
  * Try and register, if we fail to register, backout previous work.
  *
  * NOTE: This function is deprecated, please use drm_dev_alloc() and
  * drm_dev_register() instead and remove your ->load() callback.
  *
  * Return: 0 on success or a negative error code on failure.
  */
 int drm_get_pci_dev(struct pci_dev *pdev, const struct pci_device_id *ent,
 		    struct drm_driver *driver)
 {
 	struct drm_device *dev;
 	int ret;

 	DRM_DEBUG("\n");

 	dev = drm_dev_alloc(driver, &pdev->dev);
 	if (IS_ERR(dev))
 		return PTR_ERR(dev);

 	ret = pci_enable_device(pdev);
 	if (ret)
 		goto err_free;

 	dev->pdev = pdev;
 #ifdef __alpha__
 	dev->hose = pdev->sysdata;
 #endif

 	if (drm_core_check_feature(dev, DRIVER_MODESET))
 		pci_set_drvdata(pdev, dev);

 	drm_pci_agp_init(dev);

 	ret = drm_dev_register(dev, ent->driver_data);
 	if (ret)
 		goto err_agp;

 	/* No locking needed since shadow-attach is single-threaded since it may
 	 * only be called from the per-driver module init hook. */
 	if (drm_core_check_feature(dev, DRIVER_LEGACY))
 		list_add_tail(&dev->legacy_dev_list, &driver->legacy_dev_list);

 	return 0;

 err_agp:
 	drm_pci_agp_destroy(dev);
 	pci_disable_device(pdev);
 err_free:
 	drm_dev_unref(dev);
 	return ret;
 }
 EXPORT_SYMBOL(drm_get_pci_dev);

 /**
  * drm_pci_init - Register matching PCI devices with the DRM subsystem
  * @driver: DRM device driver
  * @pdriver: PCI device driver
  *
  * Initializes a drm_device structures, registering the stubs and initializing
  * the AGP device.
  *
  * NOTE: This function is deprecated. Modern modesetting drm drivers should use
  * pci_register_driver() directly, this function only provides shadow-binding
  * support for old legacy drivers on top of that core pci function.
  *
  * Return: 0 on success or a negative error code on failure.
  */
 int drm_pci_init(struct drm_driver *driver, struct pci_driver *pdriver)
 {
 	struct pci_dev *pdev = NULL;
 	const struct pci_device_id *pid;
 	int i;

 	DRM_DEBUG("\n");

 	if (!(driver->driver_features & DRIVER_LEGACY))
 		return pci_register_driver(pdriver);

 	/* If not using KMS, fall back to stealth mode manual scanning. */
 	INIT_LIST_HEAD(&driver->legacy_dev_list);
 	for (i = 0; pdriver->id_table[i].vendor != 0; i++) {
 		pid = &pdriver->id_table[i];

 		/* Loop around setting up a DRM device for each PCI device
 		 * matching our ID and device class.  If we had the internal
 		 * function that pci_get_subsys and pci_get_class used, we'd
 		 * be able to just pass pid in instead of doing a two-stage
 		 * thing.
 		 */
 		pdev = NULL;
 		while ((pdev =
 			pci_get_subsys(pid->vendor, pid->device, pid->subvendor,
 				       pid->subdevice, pdev)) != NULL) {
 			if ((pdev->class & pid->class_mask) != pid->class)
 				continue;

 			/* stealth mode requires a manual probe */
 			pci_dev_get(pdev);
 			drm_get_pci_dev(pdev, pid, driver);
 		}
 	}
 	return 0;
 }

 int drm_pcie_get_speed_cap_mask(struct drm_device *dev, u32 *mask)
 {
 	struct pci_dev *root;
 	u32 lnkcap, lnkcap2;

 	*mask = 0;
 	if (!dev->pdev)
 		return -EINVAL;

 	root = dev->pdev->bus->self;

 	/* we've been informed via and serverworks don't make the cut */
 	if (root->vendor == PCI_VENDOR_ID_VIA ||
 	    root->vendor == PCI_VENDOR_ID_SERVERWORKS)
 		return -EINVAL;

 	pcie_capability_read_dword(root, PCI_EXP_LNKCAP, &lnkcap);
 	pcie_capability_read_dword(root, PCI_EXP_LNKCAP2, &lnkcap2);

 	if (lnkcap2) {	/* PCIe r3.0-compliant */
 		if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_2_5GB)
 			*mask |= DRM_PCIE_SPEED_25;
 		if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_5_0GB)
 			*mask |= DRM_PCIE_SPEED_50;
 		if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_8_0GB)
 			*mask |= DRM_PCIE_SPEED_80;
 	} else {	/* pre-r3.0 */
 		if (lnkcap & PCI_EXP_LNKCAP_SLS_2_5GB)
 			*mask |= DRM_PCIE_SPEED_25;
 		if (lnkcap & PCI_EXP_LNKCAP_SLS_5_0GB)
 			*mask |= (DRM_PCIE_SPEED_25 | DRM_PCIE_SPEED_50);
 	}

 	DRM_INFO("probing gen 2 caps for device %x:%x = %x/%x\n", root->vendor, root->device, lnkcap, lnkcap2);
 	return 0;
 }
 EXPORT_SYMBOL(drm_pcie_get_speed_cap_mask);

 int drm_pcie_get_max_link_width(struct drm_device *dev, u32 *mlw)
 {
 	struct pci_dev *root;
 	u32 lnkcap;

 	*mlw = 0;
 	if (!dev->pdev)
 		return -EINVAL;

 	root = dev->pdev->bus->self;

 	pcie_capability_read_dword(root, PCI_EXP_LNKCAP, &lnkcap);

 	*mlw = (lnkcap & PCI_EXP_LNKCAP_MLW) >> 4;

 	DRM_INFO("probing mlw for device %x:%x = %x\n", root->vendor, root->device, lnkcap);
 	return 0;
 }
 EXPORT_SYMBOL(drm_pcie_get_max_link_width);

 #else

 int drm_pci_init(struct drm_driver *driver, struct pci_driver *pdriver)
 {
 	return -1;
 }

 void drm_pci_agp_destroy(struct drm_device *dev) {}

 int drm_irq_by_busid(struct drm_device *dev, void *data,
 		     struct drm_file *file_priv)
 {
 	return -EINVAL;
 }
 #endif

 EXPORT_SYMBOL(drm_pci_init);

 /**
  * drm_pci_exit - Unregister matching PCI devices from the DRM subsystem
  * @driver: DRM device driver
  * @pdriver: PCI device driver
  *
  * Unregisters one or more devices matched by a PCI driver from the DRM
  * subsystem.
  *
  * NOTE: This function is deprecated. Modern modesetting drm drivers should use
  * pci_unregister_driver() directly, this function only provides shadow-binding
  * support for old legacy drivers on top of that core pci function.
  */
 void drm_pci_exit(struct drm_driver *driver, struct pci_driver *pdriver)
 {
 	struct drm_device *dev, *tmp;
 	DRM_DEBUG("\n");

 	if (!(driver->driver_features & DRIVER_LEGACY)) {
 		pci_unregister_driver(pdriver);
 	} else {
 		list_for_each_entry_safe(dev, tmp, &driver->legacy_dev_list,
 					 legacy_dev_list) {
 			list_del(&dev->legacy_dev_list);
 			drm_put_dev(dev);
 		}
 	}
 	DRM_INFO("Module unloaded\n");
 }
 EXPORT_SYMBOL(drm_pci_exit);
	/*
	* Copyright 2003 José Fonseca.
	* Copyright 2003 Leif Delgass.
	* 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 THE
	* AUTHORS 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/pci.h>
	#include <linux/slab.h>
	#include <linux/dma-mapping.h>
	#include <linux/export.h>
	#include <drm/drmP.h>
	#include "drm_internal.h"
	#include "drm_legacy.h"

	/**
	* drm_pci_alloc - Allocate a PCI consistent memory block, for DMA.
	* @dev: DRM device
	* @size: size of block to allocate
	* @align: alignment of block
	*
	* Return: A handle to the allocated memory block on success or NULL on
	* failure.
	*/
	drm_dma_handle_t drm_pci_alloc(struct drm_device dev, size_t size, size_t align)
	{
	drm_dma_handle_t *dmah;
	unsigned long addr;
	size_t sz;

	/* pci_alloc_consistent only guarantees alignment to the smallest
	* PAGE_SIZE order which is greater than or equal to the requested size.
	* Return NULL here for now to make sure nobody tries for larger alignment
	*/
	if (align > size)
	return NULL;

	dmah = kmalloc(sizeof(drm_dma_handle_t), GFP_KERNEL);
	if (!dmah)
	return NULL;

	dmah->size = size;
	dmah->vaddr = dma_alloc_coherent(&dev->pdev->dev, size, &dmah->busaddr, GFP_KERNEL \| __GFP_COMP);

	if (dmah->vaddr == NULL) {
	kfree(dmah);
	return NULL;
	}

	memset(dmah->vaddr, 0, size);

	/* XXX - Is virt_to_page() legal for consistent mem? */
	/* Reserve */
	for (addr = (unsigned long)dmah->vaddr, sz = size;
	sz > 0; addr += PAGE_SIZE, sz -= PAGE_SIZE) {
	SetPageReserved(virt_to_page((void *)addr));
	}

	return dmah;
	}

	EXPORT_SYMBOL(drm_pci_alloc);

	/*
	* Free a PCI consistent memory block without freeing its descriptor.
	*
	* This function is for internal use in the Linux-specific DRM core code.
	*/
	void __drm_legacy_pci_free(struct drm_device * dev, drm_dma_handle_t * dmah)
	{
	unsigned long addr;
	size_t sz;

	if (dmah->vaddr) {
	/* XXX - Is virt_to_page() legal for consistent mem? */
	/* Unreserve */
	for (addr = (unsigned long)dmah->vaddr, sz = dmah->size;
	sz > 0; addr += PAGE_SIZE, sz -= PAGE_SIZE) {
	ClearPageReserved(virt_to_page((void *)addr));
	}
	dma_free_coherent(&dev->pdev->dev, dmah->size, dmah->vaddr,
	dmah->busaddr);
	}
	}

	/**
	* drm_pci_free - Free a PCI consistent memory block
	* @dev: DRM device
	* @dmah: handle to memory block
	*/
	void drm_pci_free(struct drm_device * dev, drm_dma_handle_t * dmah)
	{
	__drm_legacy_pci_free(dev, dmah);
	kfree(dmah);
	}

	EXPORT_SYMBOL(drm_pci_free);

	#ifdef CONFIG_PCI

	static int drm_get_pci_domain(struct drm_device *dev)
	{
	#ifndef __alpha__
	/* For historical reasons, drm_get_pci_domain() is busticated
	* on most archs and has to remain so for userspace interface
	* < 1.4, except on alpha which was right from the beginning
	*/
	if (dev->if_version < 0x10004)
	return 0;
	#endif /* __alpha__ */

	return pci_domain_nr(dev->pdev->bus);
	}

	int drm_pci_set_busid(struct drm_device dev, struct drm_master master)
	{
	master->unique = kasprintf(GFP_KERNEL, "pci:%04x:%02x:%02x.%d",
	drm_get_pci_domain(dev),
	dev->pdev->bus->number,
	PCI_SLOT(dev->pdev->devfn),
	PCI_FUNC(dev->pdev->devfn));
	if (!master->unique)
	return -ENOMEM;

	master->unique_len = strlen(master->unique);
	return 0;
	}
	EXPORT_SYMBOL(drm_pci_set_busid);

	static int drm_pci_irq_by_busid(struct drm_device dev, struct drm_irq_busid p)
	{
	if ((p->busnum >> 8) != drm_get_pci_domain(dev) \|\|
	(p->busnum & 0xff) != dev->pdev->bus->number \|\|
	p->devnum != PCI_SLOT(dev->pdev->devfn) \|\| p->funcnum != PCI_FUNC(dev->pdev->devfn))
	return -EINVAL;

	p->irq = dev->pdev->irq;

	DRM_DEBUG("%d:%d:%d => IRQ %d\n", p->busnum, p->devnum, p->funcnum,
	p->irq);
	return 0;
	}

	/**
	* drm_irq_by_busid - Get interrupt from bus ID
	* @dev: DRM device
	* @data: IOCTL parameter pointing to a drm_irq_busid structure
	* @file_priv: DRM file private.
	*
	* Finds the PCI device with the specified bus id and gets its IRQ number.
	* This IOCTL is deprecated, and will now return EINVAL for any busid not equal
	* to that of the device that this DRM instance attached to.
	*
	* Return: 0 on success or a negative error code on failure.
	*/
	int drm_irq_by_busid(struct drm_device dev, void data,
	struct drm_file *file_priv)
	{
	struct drm_irq_busid *p = data;

	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
	return -EINVAL;

	/* UMS was only ever support on PCI devices. */
	if (WARN_ON(!dev->pdev))
	return -EINVAL;

	if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
	return -EINVAL;

	return drm_pci_irq_by_busid(dev, p);
	}

	static void drm_pci_agp_init(struct drm_device *dev)
	{
	if (drm_core_check_feature(dev, DRIVER_USE_AGP)) {
	if (drm_pci_device_is_agp(dev))
	dev->agp = drm_agp_init(dev);
	if (dev->agp) {
	dev->agp->agp_mtrr = arch_phys_wc_add(
	dev->agp->agp_info.aper_base,
	dev->agp->agp_info.aper_size *
	1024 * 1024);
	}
	}
	}

	void drm_pci_agp_destroy(struct drm_device *dev)
	{
	if (dev->agp) {
	arch_phys_wc_del(dev->agp->agp_mtrr);
	drm_legacy_agp_clear(dev);
	kfree(dev->agp);
	dev->agp = NULL;
	}
	}

	/**
	* drm_get_pci_dev - Register a PCI device with the DRM subsystem
	* @pdev: PCI device
	* @ent: entry from the PCI ID table that matches @pdev
	* @driver: DRM device driver
	*
	* Attempt to gets inter module "drm" information. If we are first
	* then register the character device and inter module information.
	* Try and register, if we fail to register, backout previous work.
	*
	* NOTE: This function is deprecated, please use drm_dev_alloc() and
	* drm_dev_register() instead and remove your ->load() callback.
	*
	* Return: 0 on success or a negative error code on failure.
	*/
	int drm_get_pci_dev(struct pci_dev pdev, const struct pci_device_id ent,
	struct drm_driver *driver)
	{
	struct drm_device *dev;
	int ret;

	DRM_DEBUG("\n");

	dev = drm_dev_alloc(driver, &pdev->dev);
	if (IS_ERR(dev))
	return PTR_ERR(dev);

	ret = pci_enable_device(pdev);
	if (ret)
	goto err_free;

	dev->pdev = pdev;
	#ifdef __alpha__
	dev->hose = pdev->sysdata;
	#endif

	if (drm_core_check_feature(dev, DRIVER_MODESET))
	pci_set_drvdata(pdev, dev);

	drm_pci_agp_init(dev);

	ret = drm_dev_register(dev, ent->driver_data);
	if (ret)
	goto err_agp;

	/* No locking needed since shadow-attach is single-threaded since it may
	* only be called from the per-driver module init hook. */
	if (drm_core_check_feature(dev, DRIVER_LEGACY))
	list_add_tail(&dev->legacy_dev_list, &driver->legacy_dev_list);

	return 0;

	err_agp:
	drm_pci_agp_destroy(dev);
	pci_disable_device(pdev);
	err_free:
	drm_dev_unref(dev);
	return ret;
	}
	EXPORT_SYMBOL(drm_get_pci_dev);

	/**
	* drm_pci_init - Register matching PCI devices with the DRM subsystem
	* @driver: DRM device driver
	* @pdriver: PCI device driver
	*
	* Initializes a drm_device structures, registering the stubs and initializing
	* the AGP device.
	*
	* NOTE: This function is deprecated. Modern modesetting drm drivers should use
	* pci_register_driver() directly, this function only provides shadow-binding
	* support for old legacy drivers on top of that core pci function.
	*
	* Return: 0 on success or a negative error code on failure.
	*/
	int drm_pci_init(struct drm_driver driver, struct pci_driver pdriver)
	{
	struct pci_dev *pdev = NULL;
	const struct pci_device_id *pid;
	int i;

	DRM_DEBUG("\n");

	if (!(driver->driver_features & DRIVER_LEGACY))
	return pci_register_driver(pdriver);

	/* If not using KMS, fall back to stealth mode manual scanning. */
	INIT_LIST_HEAD(&driver->legacy_dev_list);
	for (i = 0; pdriver->id_table[i].vendor != 0; i++) {
	pid = &pdriver->id_table[i];

	/* Loop around setting up a DRM device for each PCI device
	* matching our ID and device class. If we had the internal
	* function that pci_get_subsys and pci_get_class used, we'd
	* be able to just pass pid in instead of doing a two-stage
	* thing.
	*/
	pdev = NULL;
	while ((pdev =
	pci_get_subsys(pid->vendor, pid->device, pid->subvendor,
	pid->subdevice, pdev)) != NULL) {
	if ((pdev->class & pid->class_mask) != pid->class)
	continue;

	/* stealth mode requires a manual probe */
	pci_dev_get(pdev);
	drm_get_pci_dev(pdev, pid, driver);
	}
	}
	return 0;
	}

	int drm_pcie_get_speed_cap_mask(struct drm_device dev, u32 mask)
	{
	struct pci_dev *root;
	u32 lnkcap, lnkcap2;

	*mask = 0;
	if (!dev->pdev)
	return -EINVAL;

	root = dev->pdev->bus->self;

	/* we've been informed via and serverworks don't make the cut */
	if (root->vendor == PCI_VENDOR_ID_VIA \|\|
	root->vendor == PCI_VENDOR_ID_SERVERWORKS)
	return -EINVAL;

	pcie_capability_read_dword(root, PCI_EXP_LNKCAP, &lnkcap);
	pcie_capability_read_dword(root, PCI_EXP_LNKCAP2, &lnkcap2);

	if (lnkcap2) { /* PCIe r3.0-compliant */
	if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_2_5GB)
	*mask \|= DRM_PCIE_SPEED_25;
	if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_5_0GB)
	*mask \|= DRM_PCIE_SPEED_50;
	if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_8_0GB)
	*mask \|= DRM_PCIE_SPEED_80;
	} else { /* pre-r3.0 */
	if (lnkcap & PCI_EXP_LNKCAP_SLS_2_5GB)
	*mask \|= DRM_PCIE_SPEED_25;
	if (lnkcap & PCI_EXP_LNKCAP_SLS_5_0GB)
	*mask \|= (DRM_PCIE_SPEED_25 \| DRM_PCIE_SPEED_50);
	}

	DRM_INFO("probing gen 2 caps for device %x:%x = %x/%x\n", root->vendor, root->device, lnkcap, lnkcap2);
	return 0;
	}
	EXPORT_SYMBOL(drm_pcie_get_speed_cap_mask);

	int drm_pcie_get_max_link_width(struct drm_device dev, u32 mlw)
	{
	struct pci_dev *root;
	u32 lnkcap;

	*mlw = 0;
	if (!dev->pdev)
	return -EINVAL;

	root = dev->pdev->bus->self;

	pcie_capability_read_dword(root, PCI_EXP_LNKCAP, &lnkcap);

	*mlw = (lnkcap & PCI_EXP_LNKCAP_MLW) >> 4;

	DRM_INFO("probing mlw for device %x:%x = %x\n", root->vendor, root->device, lnkcap);
	return 0;
	}
	EXPORT_SYMBOL(drm_pcie_get_max_link_width);

	#else

	int drm_pci_init(struct drm_driver driver, struct pci_driver pdriver)
	{
	return -1;
	}

	void drm_pci_agp_destroy(struct drm_device *dev) {}

	int drm_irq_by_busid(struct drm_device dev, void data,
	struct drm_file *file_priv)
	{
	return -EINVAL;
	}
	#endif

	EXPORT_SYMBOL(drm_pci_init);

	/**
	* drm_pci_exit - Unregister matching PCI devices from the DRM subsystem
	* @driver: DRM device driver
	* @pdriver: PCI device driver
	*
	* Unregisters one or more devices matched by a PCI driver from the DRM
	* subsystem.
	*
	* NOTE: This function is deprecated. Modern modesetting drm drivers should use
	* pci_unregister_driver() directly, this function only provides shadow-binding
	* support for old legacy drivers on top of that core pci function.
	*/
	void drm_pci_exit(struct drm_driver driver, struct pci_driver pdriver)
	{
	struct drm_device dev, tmp;
	DRM_DEBUG("\n");

	if (!(driver->driver_features & DRIVER_LEGACY)) {
	pci_unregister_driver(pdriver);
	} else {
	list_for_each_entry_safe(dev, tmp, &driver->legacy_dev_list,
	legacy_dev_list) {
	list_del(&dev->legacy_dev_list);
	drm_put_dev(dev);
	}
	}
	DRM_INFO("Module unloaded\n");
	}
	EXPORT_SYMBOL(drm_pci_exit);