252 lines
9.0 KiB
C
252 lines
9.0 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.
|
|
*/
|
|
extern void vga_set_legacy_decoding(struct pci_dev *pdev,
|
|
unsigned int decodes);
|
|
|
|
/**
|
|
* vga_get - acquire & locks VGA resources
|
|
*
|
|
* @pdev: pci device of the VGA card or NULL for the system default
|
|
* @rsrc: bit mask of resources to acquire and lock
|
|
* @interruptible: blocking should be interruptible by signals ?
|
|
*
|
|
* This function acquires VGA resources for the given
|
|
* card and mark those resources locked. If the resource requested
|
|
* are "normal" (and not legacy) resources, the arbiter will first check
|
|
* wether the card is doing legacy decoding for that type of resource. If
|
|
* yes, the lock is "converted" into a legacy resource lock.
|
|
* The arbiter will first look for all VGA cards that might conflict
|
|
* and disable their IOs and/or Memory access, including VGA forwarding
|
|
* on P2P bridges if necessary, so that the requested resources can
|
|
* be used. Then, the card is marked as locking these resources and
|
|
* the IO and/or Memory accesse are enabled on the card (including
|
|
* VGA forwarding on parent P2P bridges if any).
|
|
* This function will block if some conflicting card is already locking
|
|
* one of the required resources (or any resource on a different bus
|
|
* segment, since P2P bridges don't differenciate VGA memory and IO
|
|
* afaik). You can indicate wether this blocking should be interruptible
|
|
* by a signal (for userland interface) or not.
|
|
* Must not be called at interrupt time or in atomic context.
|
|
* If the card already owns the resources, the function succeeds.
|
|
* Nested calls are supported (a per-resource counter is maintained)
|
|
*/
|
|
|
|
#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
|
|
*
|
|
* Shortcut to vga_get
|
|
*/
|
|
|
|
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
|
|
*/
|
|
|
|
static inline int vga_get_uninterruptible(struct pci_dev *pdev,
|
|
unsigned int rsrc)
|
|
{
|
|
return vga_get(pdev, rsrc, 0);
|
|
}
|
|
|
|
/**
|
|
* vga_tryget - try to acquire & lock legacy VGA resources
|
|
*
|
|
* @pdev: pci devivce of VGA card or NULL for system default
|
|
* @rsrc: bit mask of resources to acquire and lock
|
|
*
|
|
* This function performs the same operation as vga_get(), but
|
|
* will return an error (-EBUSY) instead of blocking if the resources
|
|
* are already locked by another card. It can be called in any context
|
|
*/
|
|
|
|
#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
|
|
|
|
/**
|
|
* vga_put - release lock on legacy VGA resources
|
|
*
|
|
* @pdev: pci device of VGA card or NULL for system default
|
|
* @rsrc: but mask of resource to release
|
|
*
|
|
* This function releases resources previously locked by vga_get()
|
|
* or vga_tryget(). The resources aren't disabled right away, so
|
|
* that a subsequence vga_get() on the same card will succeed
|
|
* immediately. Resources have a counter, so locks are only
|
|
* released if the counter reaches 0.
|
|
*/
|
|
|
|
#if defined(CONFIG_VGA_ARB)
|
|
extern void vga_put(struct pci_dev *pdev, unsigned int rsrc);
|
|
#else
|
|
#define vga_put(pdev, rsrc)
|
|
#endif
|
|
|
|
|
|
/**
|
|
* vga_default_device
|
|
*
|
|
* This can be defined by the platform. The default implementation
|
|
* is rather dumb and will probably only work properly on single
|
|
* vga card setups and/or x86 platforms.
|
|
*
|
|
* If your VGA default device is not PCI, you'll have to return
|
|
* NULL here. In this case, I assume it will not conflict with
|
|
* any PCI card. If this is not true, I'll have to define two archs
|
|
* hooks for enabling/disabling the VGA default device if that is
|
|
* possible. This may be a problem with real _ISA_ VGA cards, in
|
|
* addition to a PCI one. I don't know at this point how to deal
|
|
* with that card. Can theirs IOs be disabled at all ? If not, then
|
|
* I suppose it's a matter of having the proper arch hook telling
|
|
* us about it, so we basically never allow anybody to succeed a
|
|
* vga_get()...
|
|
*/
|
|
|
|
#ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE
|
|
#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
|
|
#endif
|
|
|
|
/**
|
|
* vga_conflicts
|
|
*
|
|
* 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
|
|
|
|
/**
|
|
* vga_client_register
|
|
*
|
|
* @pdev: pci device of the VGA client
|
|
* @cookie: client cookie to be used in callbacks
|
|
* @irq_set_state: irq state change callback
|
|
* @set_vga_decode: vga decode change callback
|
|
*
|
|
* return value: 0 on success, -1 on failure
|
|
* Register a client with the VGA arbitration logic
|
|
*
|
|
* Clients have two callback mechanisms they can use.
|
|
* irq enable/disable callback -
|
|
* If a client can't disable its GPUs VGA resources, then we
|
|
* need to be able to ask it to turn off its irqs when we
|
|
* turn off its mem and io decoding.
|
|
* set_vga_decode
|
|
* If a client can disable its GPU VGA resource, it will
|
|
* get a callback from this to set the encode/decode state
|
|
*
|
|
* Rationale: we cannot disable VGA decode resources unconditionally
|
|
* some single GPU laptops seem to require ACPI or BIOS access to the
|
|
* VGA registers to control things like backlights etc.
|
|
* Hopefully newer multi-GPU laptops do something saner, and desktops
|
|
* won't have any special ACPI for this.
|
|
* They driver will get a callback when VGA arbitration is first used
|
|
* by userspace since we some older X servers have issues.
|
|
*/
|
|
#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 */
|