[PATCH v2 03/10] drm/aperture: Move fbdev conflict helpers into drm_aperture.h

[Daniel Vetter]

On Thu, Mar 18, 2021 at 11:29:14AM +0100, Thomas Zimmermann wrote:
> Fbdev's helpers for handling conflicting framebuffers are related to
> framebuffer apertures, not console emulation. Therefore move them into a
> drm_aperture.h, which will contain the interfaces for the new aperture
> helpers.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
> Tested-by: nerdopolis <bluescreen_avenger at verizon.net>
> ---
>  Documentation/gpu/drm-internals.rst |  6 +++
>  include/drm/drm_aperture.h          | 60 +++++++++++++++++++++++++++++
>  include/drm/drm_fb_helper.h         | 56 ++-------------------------
>  3 files changed, 69 insertions(+), 53 deletions(-)
>  create mode 100644 include/drm/drm_aperture.h
> 
> diff --git a/Documentation/gpu/drm-internals.rst b/Documentation/gpu/drm-internals.rst
> index 12272b168580..4c7642d2ca34 100644
> --- a/Documentation/gpu/drm-internals.rst
> +++ b/Documentation/gpu/drm-internals.rst
> @@ -75,6 +75,12 @@ update it, its value is mostly useless. The DRM core prints it to the
>  kernel log at initialization time and passes it to userspace through the
>  DRM_IOCTL_VERSION ioctl.
>  
> +Managing Ownership of the Framebuffer Aperture
> +----------------------------------------------
> +
> +.. kernel-doc:: include/drm/drm_aperture.h
> +   :internal:
> +
>  Device Instance and Driver Handling
>  -----------------------------------
>  
> diff --git a/include/drm/drm_aperture.h b/include/drm/drm_aperture.h
> new file mode 100644
> index 000000000000..13766efe9517
> --- /dev/null
> +++ b/include/drm/drm_aperture.h
> @@ -0,0 +1,60 @@
> +/* SPDX-License-Identifier: MIT */
> +
> +#ifndef _DRM_APERTURE_H_
> +#define _DRM_APERTURE_H_
> +
> +#include <linux/fb.h>
> +#include <linux/vgaarb.h>
> +
> +/**
> + * drm_fb_helper_remove_conflicting_framebuffers - remove firmware-configured framebuffers

Annoying bikeshed, but I'd give them drm_aperture_ prefixes, for ocd
consistency. Also make them real functions, they're quite big and will
grow more in the next patch.

I'm also not super happy about the naming here but oh well.

Either way: Acked-by: Daniel Vetter <daniel.vetter at ffwll.ch>

> + * @a: memory range, users of which are to be removed
> + * @name: requesting driver name
> + * @primary: also kick vga16fb if present
> + *
> + * This function removes framebuffer devices (initialized by firmware/bootloader)
> + * which use memory range described by @a. If @a is NULL all such devices are
> + * removed.
> + */
> +static inline int
> +drm_fb_helper_remove_conflicting_framebuffers(struct apertures_struct *a,
> +					      const char *name, bool primary)
> +{
> +#if IS_REACHABLE(CONFIG_FB)
> +	return remove_conflicting_framebuffers(a, name, primary);
> +#else
> +	return 0;
> +#endif
> +}
> +
> +/**
> + * drm_fb_helper_remove_conflicting_pci_framebuffers - remove firmware-configured
> + *                                                     framebuffers for PCI devices
> + * @pdev: PCI device
> + * @name: requesting driver name
> + *
> + * This function removes framebuffer devices (eg. initialized by firmware)
> + * 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.
> + */
> +static inline int
> +drm_fb_helper_remove_conflicting_pci_framebuffers(struct pci_dev *pdev,
> +						  const char *name)
> +{
> +	int ret = 0;
> +
> +	/*
> +	 * 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, name);
> +#endif
> +	if (ret == 0)
> +		ret = vga_remove_vgacon(pdev);
> +	return ret;
> +}
> +
> +#endif
> diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
> index 3b273f9ca39a..d06a3942fddb 100644
> --- a/include/drm/drm_fb_helper.h
> +++ b/include/drm/drm_fb_helper.h
> @@ -30,13 +30,13 @@
>  #ifndef DRM_FB_HELPER_H
>  #define DRM_FB_HELPER_H
>  
> -struct drm_fb_helper;
> -
> +#include <drm/drm_aperture.h>
>  #include <drm/drm_client.h>
>  #include <drm/drm_crtc.h>
>  #include <drm/drm_device.h>
>  #include <linux/kgdb.h>
> -#include <linux/vgaarb.h>
> +
> +struct drm_fb_helper;
>  
>  enum mode_set_atomic {
>  	LEAVE_ATOMIC_MODE_SET,
> @@ -451,54 +451,4 @@ drm_fbdev_generic_setup(struct drm_device *dev, unsigned int preferred_bpp)
>  
>  #endif
>  
> -/**
> - * drm_fb_helper_remove_conflicting_framebuffers - remove firmware-configured framebuffers
> - * @a: memory range, users of which are to be removed
> - * @name: requesting driver name
> - * @primary: also kick vga16fb if present
> - *
> - * This function removes framebuffer devices (initialized by firmware/bootloader)
> - * which use memory range described by @a. If @a is NULL all such devices are
> - * removed.
> - */
> -static inline int
> -drm_fb_helper_remove_conflicting_framebuffers(struct apertures_struct *a,
> -					      const char *name, bool primary)
> -{
> -#if IS_REACHABLE(CONFIG_FB)
> -	return remove_conflicting_framebuffers(a, name, primary);
> -#else
> -	return 0;
> -#endif
> -}
> -
> -/**
> - * drm_fb_helper_remove_conflicting_pci_framebuffers - remove firmware-configured framebuffers for PCI devices
> - * @pdev: PCI device
> - * @name: requesting driver name
> - *
> - * This function removes framebuffer devices (eg. initialized by firmware)
> - * 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.
> - */
> -static inline int
> -drm_fb_helper_remove_conflicting_pci_framebuffers(struct pci_dev *pdev,
> -						  const char *name)
> -{
> -	int ret = 0;
> -
> -	/*
> -	 * 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, name);
> -#endif
> -	if (ret == 0)
> -		ret = vga_remove_vgacon(pdev);
> -	return ret;
> -}
> -
>  #endif
> -- 
> 2.30.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch