[PATCH 28/28] drm: Remove DRM aperture helpers

Thomas Zimmermann tzimmermann at suse.de
Mon Sep 30 13:03:26 UTC 2024


The DRM aperture helpers are wrappers around video helpers from
<linux/aperture.h>. There are no callers of these functions. Remove
them entirely.

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
Cc: Jonathan Corbet <corbet at lwn.net>
---
 Documentation/gpu/drm-internals.rst |  12 --
 MAINTAINERS                         |   2 -
 drivers/gpu/drm/Makefile            |   1 -
 drivers/gpu/drm/drm_aperture.c      | 192 ----------------------------
 include/drm/drm_aperture.h          |  38 ------
 5 files changed, 245 deletions(-)
 delete mode 100644 drivers/gpu/drm/drm_aperture.c
 delete mode 100644 include/drm/drm_aperture.h

diff --git a/Documentation/gpu/drm-internals.rst b/Documentation/gpu/drm-internals.rst
index 11d9a5730fb2..cb9ae282771c 100644
--- a/Documentation/gpu/drm-internals.rst
+++ b/Documentation/gpu/drm-internals.rst
@@ -75,18 +75,6 @@ Module Initialization
 .. kernel-doc:: include/drm/drm_module.h
    :doc: overview
 
-Managing Ownership of the Framebuffer Aperture
-----------------------------------------------
-
-.. kernel-doc:: drivers/gpu/drm/drm_aperture.c
-   :doc: overview
-
-.. kernel-doc:: include/drm/drm_aperture.h
-   :internal:
-
-.. kernel-doc:: drivers/gpu/drm/drm_aperture.c
-   :export:
-
 Device Instance and Driver Handling
 -----------------------------------
 
diff --git a/MAINTAINERS b/MAINTAINERS
index 5a0b7bfb6315..e71e12085a9f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7097,12 +7097,10 @@ M:	Javier Martinez Canillas <javierm at redhat.com>
 L:	dri-devel at lists.freedesktop.org
 S:	Maintained
 T:	git https://gitlab.freedesktop.org/drm/misc/kernel.git
-F:	drivers/gpu/drm/drm_aperture.c
 F:	drivers/gpu/drm/tiny/ofdrm.c
 F:	drivers/gpu/drm/tiny/simpledrm.c
 F:	drivers/video/aperture.c
 F:	drivers/video/nomodeset.c
-F:	include/drm/drm_aperture.h
 F:	include/linux/aperture.h
 F:	include/video/nomodeset.h
 
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 3894f43f6d47..31d8bf60a2fd 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -34,7 +34,6 @@ endif
 subdir-ccflags-$(CONFIG_DRM_WERROR) += -Werror
 
 drm-y := \
-	drm_aperture.o \
 	drm_atomic.o \
 	drm_atomic_uapi.o \
 	drm_auth.o \
diff --git a/drivers/gpu/drm/drm_aperture.c b/drivers/gpu/drm/drm_aperture.c
deleted file mode 100644
index 5729f3bb4398..000000000000
--- a/drivers/gpu/drm/drm_aperture.c
+++ /dev/null
@@ -1,192 +0,0 @@
-// SPDX-License-Identifier: MIT
-
-#include <linux/aperture.h>
-#include <linux/platform_device.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)
- *	{
- *		resource_size_t base, size;
- *		int ret;
- *
- *		base = pci_resource_start(pdev, 0);
- *		size = pci_resource_len(pdev, 0);
- *
- *		return drm_aperture_remove_conflicting_framebuffers(base, size,
- *		                                                    &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 owned 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.
- */
-
-/**
- * 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)
-{
-	struct platform_device *pdev;
-
-	if (drm_WARN_ON(dev, !dev_is_platform(dev->dev)))
-		return -EINVAL;
-
-	pdev = to_platform_device(dev->dev);
-
-	return devm_aperture_acquire_for_platform_device(pdev, base, size);
-}
-EXPORT_SYMBOL(devm_aperture_acquire_from_firmware);
-
-/**
- * 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
- * @req_driver: requesting DRM driver
- *
- * This function removes graphics device drivers which use the 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,
-						 const struct drm_driver *req_driver)
-{
-	return aperture_remove_conflicting_devices(base, size, req_driver->name);
-}
-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 the memory range configured
- * for any of @pdev's memory bars. The function assumes that a 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)
-{
-	return aperture_remove_conflicting_pci_devices(pdev, req_driver->name);
-}
-EXPORT_SYMBOL(drm_aperture_remove_conflicting_pci_framebuffers);
diff --git a/include/drm/drm_aperture.h b/include/drm/drm_aperture.h
deleted file mode 100644
index cbe33b49fd5d..000000000000
--- a/include/drm/drm_aperture.h
+++ /dev/null
@@ -1,38 +0,0 @@
-/* SPDX-License-Identifier: MIT */
-
-#ifndef _DRM_APERTURE_H_
-#define _DRM_APERTURE_H_
-
-#include <linux/types.h>
-
-struct drm_device;
-struct drm_driver;
-struct pci_dev;
-
-int devm_aperture_acquire_from_firmware(struct drm_device *dev, resource_size_t base,
-					resource_size_t size);
-
-int drm_aperture_remove_conflicting_framebuffers(resource_size_t base, resource_size_t size,
-						 const struct drm_driver *req_driver);
-
-int drm_aperture_remove_conflicting_pci_framebuffers(struct pci_dev *pdev,
-						     const struct drm_driver *req_driver);
-
-/**
- * drm_aperture_remove_framebuffers - remove all existing framebuffers
- * @req_driver: requesting DRM driver
- *
- * This function removes all graphics device drivers. Use this function on systems
- * that can have their framebuffer located anywhere in memory.
- *
- * Returns:
- * 0 on success, or a negative errno code otherwise
- */
-static inline int
-drm_aperture_remove_framebuffers(const struct drm_driver *req_driver)
-{
-	return drm_aperture_remove_conflicting_framebuffers(0, (resource_size_t)-1,
-							    req_driver);
-}
-
-#endif
-- 
2.46.0



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