[linux-block.git] / drivers / gpu / drm / drm_aperture.c

// SPDX-License-Identifier: MIT

#include <linux/device.h>
#include <linux/fb.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/pci.h>
#include <linux/platform_device.h> /* for firmware helpers */
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/vgaarb.h>

#include <drm/drm_aperture.h>
#include <drm/drm_drv.h>
#include <drm/drm_print.h>

/**
 * DOC: overview
 *
 * A graphics device might be supported by different drivers, but only one
 * driver can be active at any given time. Many systems load a generic
 * graphics drivers, such as EFI-GOP or VESA, early during the boot process.
 * During later boot stages, they replace the generic driver with a dedicated,
 * hardware-specific driver. To take over the device the dedicated driver
 * first has to remove the generic driver. DRM aperture functions manage
 * ownership of DRM framebuffer memory and hand-over between drivers.
 *
 * DRM drivers should call drm_aperture_remove_conflicting_framebuffers()
 * at the top of their probe function. The function removes any generic
 * driver that is currently associated with the given framebuffer memory.
 * If the framebuffer is located at PCI BAR 0, the rsp code looks as in the
 * example given below.
 *
 * .. code-block:: c
 *
 *	static const struct drm_driver example_driver = {
 *		...
 *	};
 *
 *	static int remove_conflicting_framebuffers(struct pci_dev *pdev)
 *	{
 *		bool primary = false;
 *		resource_size_t base, size;
 *		int ret;
 *
 *		base = pci_resource_start(pdev, 0);
 *		size = pci_resource_len(pdev, 0);
 *	#ifdef CONFIG_X86
 *		primary = pdev->resource[PCI_ROM_RESOURCE].flags & IORESOURCE_ROM_SHADOW;
 *	#endif
 *
 *		return drm_aperture_remove_conflicting_framebuffers(base, size, primary,
 *		                                                    &example_driver);
 *	}
 *
 *	static int probe(struct pci_dev *pdev)
 *	{
 *		int ret;
 *
 *		// Remove any generic drivers...
 *		ret = remove_conflicting_framebuffers(pdev);
 *		if (ret)
 *			return ret;
 *
 *		// ... and initialize the hardware.
 *		...
 *
 *		drm_dev_register();
 *
 *		return 0;
 *	}
 *
 * PCI device drivers should call
 * drm_aperture_remove_conflicting_pci_framebuffers() and let it detect the
 * framebuffer apertures automatically. Device drivers without knowledge of
 * the framebuffer's location shall call drm_aperture_remove_framebuffers(),
 * which removes all drivers for known framebuffer.
 *
 * Drivers that are susceptible to being removed by other drivers, such as
 * generic EFI or VESA drivers, have to register themselves as owners of their
 * given framebuffer memory. Ownership of the framebuffer memory is achieved
 * by calling devm_aperture_acquire_from_firmware(). On success, the driver
 * is the owner of the framebuffer range. The function fails if the
 * framebuffer is already by another driver. See below for an example.
 *
 * .. code-block:: c
 *
 *	static int acquire_framebuffers(struct drm_device *dev, struct platform_device *pdev)
 *	{
 *		resource_size_t base, size;
 *
 *		mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 *		if (!mem)
 *			return -EINVAL;
 *		base = mem->start;
 *		size = resource_size(mem);
 *
 *		return devm_acquire_aperture_from_firmware(dev, base, size);
 *	}
 *
 *	static int probe(struct platform_device *pdev)
 *	{
 *		struct drm_device *dev;
 *		int ret;
 *
 *		// ... Initialize the device...
 *		dev = devm_drm_dev_alloc();
 *		...
 *
 *		// ... and acquire ownership of the framebuffer.
 *		ret = acquire_framebuffers(dev, pdev);
 *		if (ret)
 *			return ret;
 *
 *		drm_dev_register(dev, 0);
 *
 *		return 0;
 *	}
 *
 * The generic driver is now subject to forced removal by other drivers. This
 * only works for platform drivers that support hot unplug.
 * When a driver calls drm_aperture_remove_conflicting_framebuffers() et al
 * for the registered framebuffer range, the aperture helpers call
 * platform_device_unregister() and the generic driver unloads itself. It
 * may not access the device's registers, framebuffer memory, ROM, etc
 * afterwards.
 */

struct drm_aperture {
	struct drm_device *dev;
	resource_size_t base;
	resource_size_t size;
	struct list_head lh;
	void (*detach)(struct drm_device *dev);
};

static LIST_HEAD(drm_apertures);
static DEFINE_MUTEX(drm_apertures_lock);

static bool overlap(resource_size_t base1, resource_size_t end1,
		    resource_size_t base2, resource_size_t end2)
{
	return (base1 < end2) && (end1 > base2);
}

static void devm_aperture_acquire_release(void *data)
{
	struct drm_aperture *ap = data;
	bool detached = !ap->dev;

	if (detached)
		return;

	mutex_lock(&drm_apertures_lock);
	list_del(&ap->lh);
	mutex_unlock(&drm_apertures_lock);
}

static int devm_aperture_acquire(struct drm_device *dev,
				 resource_size_t base, resource_size_t size,
				 void (*detach)(struct drm_device *))
{
	size_t end = base + size;
	struct list_head *pos;
	struct drm_aperture *ap;

	mutex_lock(&drm_apertures_lock);

	list_for_each(pos, &drm_apertures) {
		ap = container_of(pos, struct drm_aperture, lh);
		if (overlap(base, end, ap->base, ap->base + ap->size)) {
			mutex_unlock(&drm_apertures_lock);
			return -EBUSY;
		}
	}

	ap = devm_kzalloc(dev->dev, sizeof(*ap), GFP_KERNEL);
	if (!ap) {
		mutex_unlock(&drm_apertures_lock);
		return -ENOMEM;
	}

	ap->dev = dev;
	ap->base = base;
	ap->size = size;
	ap->detach = detach;
	INIT_LIST_HEAD(&ap->lh);

	list_add(&ap->lh, &drm_apertures);

	mutex_unlock(&drm_apertures_lock);

	return devm_add_action_or_reset(dev->dev, devm_aperture_acquire_release, ap);
}

static void drm_aperture_detach_firmware(struct drm_device *dev)
{
	struct platform_device *pdev = to_platform_device(dev->dev);

	/*
	 * Remove the device from the device hierarchy. This is the right thing
	 * to do for firmware-based DRM drivers, such as EFI, VESA or VGA. After
	 * the new driver takes over the hardware, the firmware device's state
	 * will be lost.
	 *
	 * For non-platform devices, a new callback would be required.
	 *
	 * If the aperture helpers ever need to handle native drivers, this call
	 * would only have to unplug the DRM device, so that the hardware device
	 * stays around after detachment.
	 */
	platform_device_unregister(pdev);
}

/**
 * devm_aperture_acquire_from_firmware - Acquires ownership of a firmware framebuffer
 *                                       on behalf of a DRM driver.
 * @dev:	the DRM device to own the framebuffer memory
 * @base:	the framebuffer's byte offset in physical memory
 * @size:	the framebuffer size in bytes
 *
 * Installs the given device as the new owner of the framebuffer. The function
 * expects the framebuffer to be provided by a platform device that has been
 * set up by firmware. Firmware can be any generic interface, such as EFI,
 * VESA, VGA, etc. If the native hardware driver takes over ownership of the
 * framebuffer range, the firmware state gets lost. Aperture helpers will then
 * unregister the platform device automatically. Acquired apertures are
 * released automatically if the underlying device goes away.
 *
 * The function fails if the framebuffer range, or parts of it, is currently
 * owned by another driver. To evict current owners, callers should use
 * drm_aperture_remove_conflicting_framebuffers() et al. before calling this
 * function. The function also fails if the given device is not a platform
 * device.
 *
 * Returns:
 * 0 on success, or a negative errno value otherwise.
 */
int devm_aperture_acquire_from_firmware(struct drm_device *dev, resource_size_t base,
					resource_size_t size)
{
	if (drm_WARN_ON(dev, !dev_is_platform(dev->dev)))
		return -EINVAL;

	return devm_aperture_acquire(dev, base, size, drm_aperture_detach_firmware);
}
EXPORT_SYMBOL(devm_aperture_acquire_from_firmware);

static void drm_aperture_detach_drivers(resource_size_t base, resource_size_t size)
{
	resource_size_t end = base + size;
	struct list_head *pos, *n;

	mutex_lock(&drm_apertures_lock);

	list_for_each_safe(pos, n, &drm_apertures) {
		struct drm_aperture *ap =
			container_of(pos, struct drm_aperture, lh);
		struct drm_device *dev = ap->dev;

		if (WARN_ON_ONCE(!dev))
			continue;

		if (!overlap(base, end, ap->base, ap->base + ap->size))
			continue;

		ap->dev = NULL; /* detach from device */
		list_del(&ap->lh);

		ap->detach(dev);
	}

	mutex_unlock(&drm_apertures_lock);
}

/**
 * drm_aperture_remove_conflicting_framebuffers - remove existing framebuffers in the given range
 * @base: the aperture's base address in physical memory
 * @size: aperture size in bytes
 * @primary: also kick vga16fb if present
 * @req_driver: requesting DRM driver
 *
 * This function removes graphics device drivers which use memory range described by
 * @base and @size.
 *
 * Returns:
 * 0 on success, or a negative errno code otherwise
 */
int drm_aperture_remove_conflicting_framebuffers(resource_size_t base, resource_size_t size,
						 bool primary, const struct drm_driver *req_driver)
{
#if IS_REACHABLE(CONFIG_FB)
	struct apertures_struct *a;
	int ret;

	a = alloc_apertures(1);
	if (!a)
		return -ENOMEM;

	a->ranges[0].base = base;
	a->ranges[0].size = size;

	ret = remove_conflicting_framebuffers(a, req_driver->name, primary);
	kfree(a);

	if (ret)
		return ret;
#endif

	drm_aperture_detach_drivers(base, size);

	return 0;
}
EXPORT_SYMBOL(drm_aperture_remove_conflicting_framebuffers);

/**
 * drm_aperture_remove_conflicting_pci_framebuffers - remove existing framebuffers for PCI devices
 * @pdev: PCI device
 * @req_driver: requesting DRM driver
 *
 * This function removes graphics device drivers using memory range configured
 * for any of @pdev's memory bars. The function assumes that PCI device with
 * shadowed ROM drives a primary display and so kicks out vga16fb.
 *
 * Returns:
 * 0 on success, or a negative errno code otherwise
 */
int drm_aperture_remove_conflicting_pci_framebuffers(struct pci_dev *pdev,
						     const struct drm_driver *req_driver)
{
	resource_size_t base, size;
	int bar, ret = 0;

	for (bar = 0; bar < PCI_STD_NUM_BARS; ++bar) {
		if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM))
			continue;
		base = pci_resource_start(pdev, bar);
		size = pci_resource_len(pdev, bar);
		drm_aperture_detach_drivers(base, size);
	}

	/*
	 * WARNING: Apparently we must kick fbdev drivers before vgacon,
	 * otherwise the vga fbdev driver falls over.
	 */
#if IS_REACHABLE(CONFIG_FB)
	ret = remove_conflicting_pci_framebuffers(pdev, req_driver->name);
#endif
	if (ret == 0)
		ret = vga_remove_vgacon(pdev);
	return ret;
}
EXPORT_SYMBOL(drm_aperture_remove_conflicting_pci_framebuffers);
Commit	Line	Data
29160591 TZ	1	// SPDX-License-Identifier: MIT
29160591 TZ	2
730e7992	3	#include <linux/device.h>
603dc7ed	4	#include <linux/fb.h>
730e7992 TZ	5	#include <linux/list.h>
	6	#include <linux/mutex.h>
	7	#include <linux/pci.h>
	8	#include <linux/platform_device.h> /* for firmware helpers */
	9	#include <linux/slab.h>
	10	#include <linux/types.h>
603dc7ed TZ	11	#include <linux/vgaarb.h>
603dc7ed TZ	12
29160591	13	#include <drm/drm_aperture.h>
730e7992 TZ	14	#include <drm/drm_drv.h>
730e7992 TZ	15	#include <drm/drm_print.h>
29160591 TZ	16
	17	/**
	18	* DOC: overview
	19	*
	20	* A graphics device might be supported by different drivers, but only one
	21	* driver can be active at any given time. Many systems load a generic
	22	* graphics drivers, such as EFI-GOP or VESA, early during the boot process.
	23	* During later boot stages, they replace the generic driver with a dedicated,
	24	* hardware-specific driver. To take over the device the dedicated driver
	25	* first has to remove the generic driver. DRM aperture functions manage
	26	* ownership of DRM framebuffer memory and hand-over between drivers.
	27	*
	28	* DRM drivers should call drm_aperture_remove_conflicting_framebuffers()
	29	* at the top of their probe function. The function removes any generic
	30	* driver that is currently associated with the given framebuffer memory.
	31	* If the framebuffer is located at PCI BAR 0, the rsp code looks as in the
	32	* example given below.
	33	*
	34	* .. code-block:: c
	35	*
97c9bfe3 TZ	36	* static const struct drm_driver example_driver = {
	37	* ...
	38	* };
	39	*
29160591 TZ	40	* static int remove_conflicting_framebuffers(struct pci_dev *pdev)
	41	* {
	42	* bool primary = false;
	43	* resource_size_t base, size;
	44	* int ret;
	45	*
	46	* base = pci_resource_start(pdev, 0);
	47	* size = pci_resource_len(pdev, 0);
	48	* #ifdef CONFIG_X86
	49	* primary = pdev->resource[PCI_ROM_RESOURCE].flags & IORESOURCE_ROM_SHADOW;
	50	* #endif
	51	*
	52	* return drm_aperture_remove_conflicting_framebuffers(base, size, primary,
97c9bfe3	53	* &example_driver);
29160591 TZ	54	* }
	55	*
	56	* static int probe(struct pci_dev *pdev)
	57	* {
	58	* int ret;
	59	*
	60	* // Remove any generic drivers...
	61	* ret = remove_conflicting_framebuffers(pdev);
	62	* if (ret)
	63	* return ret;
	64	*
	65	* // ... and initialize the hardware.
	66	* ...
	67	*
	68	* drm_dev_register();
	69	*
	70	* return 0;
	71	* }
	72	*
	73	* PCI device drivers should call
	74	* drm_aperture_remove_conflicting_pci_framebuffers() and let it detect the
	75	* framebuffer apertures automatically. Device drivers without knowledge of
	76	* the framebuffer's location shall call drm_aperture_remove_framebuffers(),
	77	* which removes all drivers for known framebuffer.
730e7992 TZ	78	*
	79	* Drivers that are susceptible to being removed by other drivers, such as
	80	* generic EFI or VESA drivers, have to register themselves as owners of their
0ae865ef	81	* given framebuffer memory. Ownership of the framebuffer memory is achieved
730e7992 TZ	82	* by calling devm_aperture_acquire_from_firmware(). On success, the driver
	83	* is the owner of the framebuffer range. The function fails if the
	84	* framebuffer is already by another driver. See below for an example.
	85	*
	86	* .. code-block:: c
	87	*
	88	* static int acquire_framebuffers(struct drm_device dev, struct platform_device pdev)
	89	* {
	90	* resource_size_t base, size;
	91	*
	92	* mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	93	* if (!mem)
	94	* return -EINVAL;
	95	* base = mem->start;
	96	* size = resource_size(mem);
	97	*
	98	* return devm_acquire_aperture_from_firmware(dev, base, size);
	99	* }
	100	*
	101	* static int probe(struct platform_device *pdev)
	102	* {
	103	* struct drm_device *dev;
	104	* int ret;
	105	*
	106	* // ... Initialize the device...
	107	* dev = devm_drm_dev_alloc();
	108	* ...
	109	*
	110	* // ... and acquire ownership of the framebuffer.
	111	* ret = acquire_framebuffers(dev, pdev);
	112	* if (ret)
	113	* return ret;
	114	*
	115	* drm_dev_register(dev, 0);
	116	*
	117	* return 0;
	118	* }
	119	*
	120	* The generic driver is now subject to forced removal by other drivers. This
	121	* only works for platform drivers that support hot unplug.
	122	* When a driver calls drm_aperture_remove_conflicting_framebuffers() et al
	123	* for the registered framebuffer range, the aperture helpers call
	124	* platform_device_unregister() and the generic driver unloads itself. It
	125	* may not access the device's registers, framebuffer memory, ROM, etc
	126	* afterwards.
29160591 TZ	127	*/
29160591 TZ	128
730e7992 TZ	129	struct drm_aperture {
	130	struct drm_device *dev;
	131	resource_size_t base;
	132	resource_size_t size;
	133	struct list_head lh;
	134	void (detach)(struct drm_device dev);
	135	};
	136
	137	static LIST_HEAD(drm_apertures);
	138	static DEFINE_MUTEX(drm_apertures_lock);
	139
	140	static bool overlap(resource_size_t base1, resource_size_t end1,
	141	resource_size_t base2, resource_size_t end2)
	142	{
	143	return (base1 < end2) && (end1 > base2);
	144	}
	145
	146	static void devm_aperture_acquire_release(void *data)
	147	{
	148	struct drm_aperture *ap = data;
	149	bool detached = !ap->dev;
	150
	151	if (detached)
	152	return;
	153
	154	mutex_lock(&drm_apertures_lock);
	155	list_del(&ap->lh);
	156	mutex_unlock(&drm_apertures_lock);
	157	}
	158
	159	static int devm_aperture_acquire(struct drm_device *dev,
	160	resource_size_t base, resource_size_t size,
	161	void (detach)(struct drm_device ))
	162	{
	163	size_t end = base + size;
	164	struct list_head *pos;
	165	struct drm_aperture *ap;
	166
	167	mutex_lock(&drm_apertures_lock);
	168
	169	list_for_each(pos, &drm_apertures) {
	170	ap = container_of(pos, struct drm_aperture, lh);
858aa5a4 ZW	171	if (overlap(base, end, ap->base, ap->base + ap->size)) {
858aa5a4 ZW	172	mutex_unlock(&drm_apertures_lock);
730e7992	173	return -EBUSY;
858aa5a4	174	}
730e7992 TZ	175	}
	176
	177	ap = devm_kzalloc(dev->dev, sizeof(*ap), GFP_KERNEL);
858aa5a4 ZW	178	if (!ap) {
858aa5a4 ZW	179	mutex_unlock(&drm_apertures_lock);
730e7992	180	return -ENOMEM;
858aa5a4	181	}
730e7992 TZ	182
	183	ap->dev = dev;
	184	ap->base = base;
	185	ap->size = size;
	186	ap->detach = detach;
	187	INIT_LIST_HEAD(&ap->lh);
	188
	189	list_add(&ap->lh, &drm_apertures);
	190
	191	mutex_unlock(&drm_apertures_lock);
	192
	193	return devm_add_action_or_reset(dev->dev, devm_aperture_acquire_release, ap);
	194	}
	195
	196	static void drm_aperture_detach_firmware(struct drm_device *dev)
	197	{
	198	struct platform_device *pdev = to_platform_device(dev->dev);
	199
	200	/*
	201	* Remove the device from the device hierarchy. This is the right thing
	202	* to do for firmware-based DRM drivers, such as EFI, VESA or VGA. After
	203	* the new driver takes over the hardware, the firmware device's state
	204	* will be lost.
	205	*
	206	* For non-platform devices, a new callback would be required.
	207	*
	208	* If the aperture helpers ever need to handle native drivers, this call
	209	* would only have to unplug the DRM device, so that the hardware device
	210	* stays around after detachment.
	211	*/
	212	platform_device_unregister(pdev);
	213	}
	214
	215	/**
	216	* devm_aperture_acquire_from_firmware - Acquires ownership of a firmware framebuffer
	217	* on behalf of a DRM driver.
	218	* @dev: the DRM device to own the framebuffer memory
	219	* @base: the framebuffer's byte offset in physical memory
	220	* @size: the framebuffer size in bytes
	221	*
	222	* Installs the given device as the new owner of the framebuffer. The function
	223	* expects the framebuffer to be provided by a platform device that has been
	224	* set up by firmware. Firmware can be any generic interface, such as EFI,
	225	* VESA, VGA, etc. If the native hardware driver takes over ownership of the
	226	* framebuffer range, the firmware state gets lost. Aperture helpers will then
	227	* unregister the platform device automatically. Acquired apertures are
	228	* released automatically if the underlying device goes away.
	229	*
	230	* The function fails if the framebuffer range, or parts of it, is currently
	231	* owned by another driver. To evict current owners, callers should use
	232	* drm_aperture_remove_conflicting_framebuffers() et al. before calling this
	233	* function. The function also fails if the given device is not a platform
	234	* device.
	235	*
	236	* Returns:
	237	* 0 on success, or a negative errno value otherwise.
	238	*/
	239	int devm_aperture_acquire_from_firmware(struct drm_device *dev, resource_size_t base,
	240	resource_size_t size)
	241	{
	242	if (drm_WARN_ON(dev, !dev_is_platform(dev->dev)))
	243	return -EINVAL;
	244
	245	return devm_aperture_acquire(dev, base, size, drm_aperture_detach_firmware);
246	}
247	EXPORT_SYMBOL(devm_aperture_acquire_from_firmware);
248
249	static void drm_aperture_detach_drivers(resource_size_t base, resource_size_t size)
250	{
251	resource_size_t end = base + size;
252	struct list_head pos, n;
253
254	mutex_lock(&drm_apertures_lock);
255
256	list_for_each_safe(pos, n, &drm_apertures) {
257	struct drm_aperture *ap =
258	container_of(pos, struct drm_aperture, lh);
259	struct drm_device *dev = ap->dev;
260
261	if (WARN_ON_ONCE(!dev))
262	continue;
263
264	if (!overlap(base, end, ap->base, ap->base + ap->size))
265	continue;
266
267	ap->dev = NULL; /* detach from device */
268	list_del(&ap->lh);
269
270	ap->detach(dev);
271	}
272
273	mutex_unlock(&drm_apertures_lock);
274	}
275
29160591 TZ	276	/**
	277	* drm_aperture_remove_conflicting_framebuffers - remove existing framebuffers in the given range
	278	* @base: the aperture's base address in physical memory
	279	* @size: aperture size in bytes
	280	* @primary: also kick vga16fb if present
97c9bfe3	281	* @req_driver: requesting DRM driver
29160591 TZ	282	*
	283	* This function removes graphics device drivers which use memory range described by
	284	* @base and @size.
	285	*
	286	* Returns:
	287	* 0 on success, or a negative errno code otherwise
	288	*/
	289	int drm_aperture_remove_conflicting_framebuffers(resource_size_t base, resource_size_t size,
97c9bfe3	290	bool primary, const struct drm_driver *req_driver)
29160591	291	{
603dc7ed	292	#if IS_REACHABLE(CONFIG_FB)
29160591 TZ	293	struct apertures_struct *a;
	294	int ret;
	295
	296	a = alloc_apertures(1);
	297	if (!a)
	298	return -ENOMEM;
	299
	300	a->ranges[0].base = base;
	301	a->ranges[0].size = size;
	302
97c9bfe3	303	ret = remove_conflicting_framebuffers(a, req_driver->name, primary);
29160591 TZ	304	kfree(a);
29160591 TZ	305
730e7992 TZ	306	if (ret)
730e7992 TZ	307	return ret;
603dc7ed	308	#endif
730e7992 TZ	309
	310	drm_aperture_detach_drivers(base, size);
	311
	312	return 0;
29160591 TZ	313	}
	314	EXPORT_SYMBOL(drm_aperture_remove_conflicting_framebuffers);
	315
	316	/**
	317	* drm_aperture_remove_conflicting_pci_framebuffers - remove existing framebuffers for PCI devices
	318	* @pdev: PCI device
97c9bfe3	319	* @req_driver: requesting DRM driver
29160591 TZ	320	*
	321	* This function removes graphics device drivers using memory range configured
	322	* for any of @pdev's memory bars. The function assumes that PCI device with
	323	* shadowed ROM drives a primary display and so kicks out vga16fb.
	324	*
	325	* Returns:
	326	* 0 on success, or a negative errno code otherwise
	327	*/
97c9bfe3 TZ	328	int drm_aperture_remove_conflicting_pci_framebuffers(struct pci_dev *pdev,
97c9bfe3 TZ	329	const struct drm_driver *req_driver)
29160591	330	{
730e7992 TZ	331	resource_size_t base, size;
	332	int bar, ret = 0;
	333
	334	for (bar = 0; bar < PCI_STD_NUM_BARS; ++bar) {
	335	if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM))
	336	continue;
	337	base = pci_resource_start(pdev, bar);
	338	size = pci_resource_len(pdev, bar);
	339	drm_aperture_detach_drivers(base, size);
	340	}
603dc7ed TZ	341
	342	/*
	343	* WARNING: Apparently we must kick fbdev drivers before vgacon,
	344	* otherwise the vga fbdev driver falls over.
	345	*/
	346	#if IS_REACHABLE(CONFIG_FB)
97c9bfe3	347	ret = remove_conflicting_pci_framebuffers(pdev, req_driver->name);
603dc7ed TZ	348	#endif
	349	if (ret == 0)
	350	ret = vga_remove_vgacon(pdev);
	351	return ret;
29160591 TZ	352	}
29160591 TZ	353	EXPORT_SYMBOL(drm_aperture_remove_conflicting_pci_framebuffers);