| /* | |
| * 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 | |
| /* 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 | |
| extern struct pci_dev *vga_default_device(void); | |
| #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 */ |