[PATCH 28/28] drm: Remove DRM aperture helpers
Deucher, Alexander
Alexander.Deucher at amd.com
Mon Sep 30 14:06:27 UTC 2024
[Public]
> -----Original Message-----
> From: amd-gfx <amd-gfx-bounces at lists.freedesktop.org> On Behalf Of Thomas
> Zimmermann
> Sent: Monday, September 30, 2024 9:03 AM
> To: javierm at redhat.com; airlied at gmail.com; simona at ffwll.ch;
> maarten.lankhorst at linux.intel.com; mripard at kernel.org
> Cc: dri-devel at lists.freedesktop.org; amd-gfx at lists.freedesktop.org; intel-
> gfx at lists.freedesktop.org; intel-xe at lists.freedesktop.org; Thomas Zimmermann
> <tzimmermann at suse.de>; Jonathan Corbet <corbet at lwn.net>
> Subject: [PATCH 28/28] drm: Remove DRM aperture helpers
>
> 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>
Series is:
Acked-by: Alex Deucher <alexander.deucher at amd.com>
> ---
> 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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