linux-stable/include/linux/vgaarb.h
Daniel Vetter b754b35b08 vgaarbiter: rst-ifiy and polish kerneldoc
Move the documentation into Documentation/gpu, link it up and pull in
the kernel doc.

No actual text changes except that I did polish the kerneldoc a bit,
especially for vga_client_register().

v2: Remove some rst from vga-switcheroo.rst that I don't understand,
but which seems to be the reason why the new vgaarbiter.rst sometimes
drops out of the sidebar index.

v3: Drop one level of headings and clarify the vgaarb one a bit.

v4: Fix some typos (Sean).

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471034937-651-20-git-send-email-daniel.vetter@ffwll.ch
2016-08-16 18:49:56 +02:00

158 lines
5.1 KiB
C

/*
* The VGA aribiter manages VGA space routing and VGA resource decode to
* allow multiple VGA devices to be used in a system in a safe way.
*
* (C) Copyright 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
* (C) Copyright 2007 Paulo R. Zanoni <przanoni@gmail.com>
* (C) Copyright 2007, 2009 Tiago Vignatti <vignatti@freedesktop.org>
*
* 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 OR COPYRIGHT HOLDERS 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.
*
*/
#ifndef LINUX_VGA_H
#define LINUX_VGA_H
#include <video/vga.h>
/* Legacy VGA regions */
#define VGA_RSRC_NONE 0x00
#define VGA_RSRC_LEGACY_IO 0x01
#define VGA_RSRC_LEGACY_MEM 0x02
#define VGA_RSRC_LEGACY_MASK (VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM)
/* Non-legacy access */
#define VGA_RSRC_NORMAL_IO 0x04
#define VGA_RSRC_NORMAL_MEM 0x08
/* Passing that instead of a pci_dev to use the system "default"
* device, that is the one used by vgacon. Archs will probably
* have to provide their own vga_default_device();
*/
#define VGA_DEFAULT_DEVICE (NULL)
struct pci_dev;
/* For use by clients */
/**
* vga_set_legacy_decoding
*
* @pdev: pci device of the VGA card
* @decodes: bit mask of what legacy regions the card decodes
*
* Indicates to the arbiter if the card decodes legacy VGA IOs,
* legacy VGA Memory, both, or none. All cards default to both,
* the card driver (fbdev for example) should tell the arbiter
* if it has disabled legacy decoding, so the card can be left
* out of the arbitration process (and can be safe to take
* interrupts at any time.
*/
#if defined(CONFIG_VGA_ARB)
extern void vga_set_legacy_decoding(struct pci_dev *pdev,
unsigned int decodes);
#else
static inline void vga_set_legacy_decoding(struct pci_dev *pdev,
unsigned int decodes) { };
#endif
#if defined(CONFIG_VGA_ARB)
extern int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible);
#else
static inline int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible) { return 0; }
#endif
/**
* vga_get_interruptible
* @pdev: pci device of the VGA card or NULL for the system default
* @rsrc: bit mask of resources to acquire and lock
*
* Shortcut to vga_get with interruptible set to true.
*
* On success, release the VGA resource again with vga_put().
*/
static inline int vga_get_interruptible(struct pci_dev *pdev,
unsigned int rsrc)
{
return vga_get(pdev, rsrc, 1);
}
/**
* vga_get_uninterruptible - shortcut to vga_get()
* @pdev: pci device of the VGA card or NULL for the system default
* @rsrc: bit mask of resources to acquire and lock
*
* Shortcut to vga_get with interruptible set to false.
*
* On success, release the VGA resource again with vga_put().
*/
static inline int vga_get_uninterruptible(struct pci_dev *pdev,
unsigned int rsrc)
{
return vga_get(pdev, rsrc, 0);
}
#if defined(CONFIG_VGA_ARB)
extern int vga_tryget(struct pci_dev *pdev, unsigned int rsrc);
#else
static inline int vga_tryget(struct pci_dev *pdev, unsigned int rsrc) { return 0; }
#endif
#if defined(CONFIG_VGA_ARB)
extern void vga_put(struct pci_dev *pdev, unsigned int rsrc);
#else
#define vga_put(pdev, rsrc)
#endif
#ifdef CONFIG_VGA_ARB
extern struct pci_dev *vga_default_device(void);
extern void vga_set_default_device(struct pci_dev *pdev);
#else
static inline struct pci_dev *vga_default_device(void) { return NULL; };
static inline void vga_set_default_device(struct pci_dev *pdev) { };
#endif
/*
* Architectures should define this if they have several
* independent PCI domains that can afford concurrent VGA
* decoding
*/
#ifndef __ARCH_HAS_VGA_CONFLICT
static inline int vga_conflicts(struct pci_dev *p1, struct pci_dev *p2)
{
return 1;
}
#endif
#if defined(CONFIG_VGA_ARB)
int vga_client_register(struct pci_dev *pdev, void *cookie,
void (*irq_set_state)(void *cookie, bool state),
unsigned int (*set_vga_decode)(void *cookie, bool state));
#else
static inline int vga_client_register(struct pci_dev *pdev, void *cookie,
void (*irq_set_state)(void *cookie, bool state),
unsigned int (*set_vga_decode)(void *cookie, bool state))
{
return 0;
}
#endif
#endif /* LINUX_VGA_H */