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Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +10001/*
Jesse Barnese2d43042009-09-17 09:40:31 -07002 * The VGA aribiter manages VGA space routing and VGA resource decode to
3 * allow multiple VGA devices to be used in a system in a safe way.
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +10004 *
5 * (C) Copyright 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
6 * (C) Copyright 2007 Paulo R. Zanoni <przanoni@gmail.com>
7 * (C) Copyright 2007, 2009 Tiago Vignatti <vignatti@freedesktop.org>
Tiago Vignattic0db9cb2010-05-24 18:24:31 +03008 *
9 * Permission is hereby granted, free of charge, to any person obtaining a
10 * copy of this software and associated documentation files (the "Software"),
11 * to deal in the Software without restriction, including without limitation
12 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
13 * and/or sell copies of the Software, and to permit persons to whom the
14 * Software is furnished to do so, subject to the following conditions:
15 *
16 * The above copyright notice and this permission notice (including the next
17 * paragraph) shall be included in all copies or substantial portions of the
18 * Software.
19 *
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
23 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
25 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
26 * DEALINGS
27 * IN THE SOFTWARE.
28 *
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +100029 */
30
31#ifndef LINUX_VGA_H
Doug Goldsteina6a1a092010-07-20 15:22:25 -070032#define LINUX_VGA_H
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +100033
Matthew Garrett1a39b312012-04-16 16:26:02 -040034#include <video/vga.h>
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +100035
36/* Legacy VGA regions */
37#define VGA_RSRC_NONE 0x00
38#define VGA_RSRC_LEGACY_IO 0x01
39#define VGA_RSRC_LEGACY_MEM 0x02
40#define VGA_RSRC_LEGACY_MASK (VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM)
41/* Non-legacy access */
42#define VGA_RSRC_NORMAL_IO 0x04
43#define VGA_RSRC_NORMAL_MEM 0x08
44
45/* Passing that instead of a pci_dev to use the system "default"
46 * device, that is the one used by vgacon. Archs will probably
47 * have to provide their own vga_default_device();
48 */
49#define VGA_DEFAULT_DEVICE (NULL)
50
Randy Dunlap6069a4c2012-01-30 11:43:52 -080051struct pci_dev;
52
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +100053/* For use by clients */
54
55/**
56 * vga_set_legacy_decoding
57 *
58 * @pdev: pci device of the VGA card
59 * @decodes: bit mask of what legacy regions the card decodes
60 *
61 * Indicates to the arbiter if the card decodes legacy VGA IOs,
62 * legacy VGA Memory, both, or none. All cards default to both,
63 * the card driver (fbdev for example) should tell the arbiter
64 * if it has disabled legacy decoding, so the card can be left
65 * out of the arbitration process (and can be safe to take
66 * interrupts at any time.
67 */
Alex Williamson81b5c7b2013-08-28 09:39:08 -060068#if defined(CONFIG_VGA_ARB)
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +100069extern void vga_set_legacy_decoding(struct pci_dev *pdev,
Ingo Molnar7c329282009-09-23 09:52:18 +100070 unsigned int decodes);
Alex Williamson81b5c7b2013-08-28 09:39:08 -060071#else
72static inline void vga_set_legacy_decoding(struct pci_dev *pdev,
73 unsigned int decodes)
74{
75}
76#endif
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +100077
78/**
79 * vga_get - acquire & locks VGA resources
80 *
Dave Airlie6ac3bd52009-08-19 15:21:57 +100081 * @pdev: pci device of the VGA card or NULL for the system default
82 * @rsrc: bit mask of resources to acquire and lock
83 * @interruptible: blocking should be interruptible by signals ?
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +100084 *
85 * This function acquires VGA resources for the given
86 * card and mark those resources locked. If the resource requested
87 * are "normal" (and not legacy) resources, the arbiter will first check
Adam Buchbinder48fc7f72012-09-19 21:48:00 -040088 * whether the card is doing legacy decoding for that type of resource. If
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +100089 * yes, the lock is "converted" into a legacy resource lock.
90 * The arbiter will first look for all VGA cards that might conflict
Lucas De Marchi25985ed2011-03-30 22:57:33 -030091 * and disable their IOs and/or Memory access, including VGA forwarding
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +100092 * on P2P bridges if necessary, so that the requested resources can
93 * be used. Then, the card is marked as locking these resources and
94 * the IO and/or Memory accesse are enabled on the card (including
95 * VGA forwarding on parent P2P bridges if any).
96 * This function will block if some conflicting card is already locking
97 * one of the required resources (or any resource on a different bus
98 * segment, since P2P bridges don't differenciate VGA memory and IO
Adam Buchbinder48fc7f72012-09-19 21:48:00 -040099 * afaik). You can indicate whether this blocking should be interruptible
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +1000100 * by a signal (for userland interface) or not.
101 * Must not be called at interrupt time or in atomic context.
102 * If the card already owns the resources, the function succeeds.
103 * Nested calls are supported (a per-resource counter is maintained)
104 */
105
Chris Wilson04cbe1d2010-08-19 21:29:43 +0100106#if defined(CONFIG_VGA_ARB)
107extern int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible);
108#else
109static inline int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible) { return 0; }
110#endif
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +1000111
112/**
113 * vga_get_interruptible
114 *
115 * Shortcut to vga_get
116 */
117
118static inline int vga_get_interruptible(struct pci_dev *pdev,
Dave Airlie6ac3bd52009-08-19 15:21:57 +1000119 unsigned int rsrc)
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +1000120{
121 return vga_get(pdev, rsrc, 1);
122}
123
124/**
Dave Airlie6ac3bd52009-08-19 15:21:57 +1000125 * vga_get_uninterruptible
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +1000126 *
127 * Shortcut to vga_get
128 */
129
130static inline int vga_get_uninterruptible(struct pci_dev *pdev,
Dave Airlie6ac3bd52009-08-19 15:21:57 +1000131 unsigned int rsrc)
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +1000132{
133 return vga_get(pdev, rsrc, 0);
134}
135
136/**
137 * vga_tryget - try to acquire & lock legacy VGA resources
138 *
139 * @pdev: pci devivce of VGA card or NULL for system default
140 * @rsrc: bit mask of resources to acquire and lock
141 *
142 * This function performs the same operation as vga_get(), but
143 * will return an error (-EBUSY) instead of blocking if the resources
144 * are already locked by another card. It can be called in any context
145 */
146
Chris Wilson04cbe1d2010-08-19 21:29:43 +0100147#if defined(CONFIG_VGA_ARB)
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +1000148extern int vga_tryget(struct pci_dev *pdev, unsigned int rsrc);
Chris Wilson04cbe1d2010-08-19 21:29:43 +0100149#else
150static inline int vga_tryget(struct pci_dev *pdev, unsigned int rsrc) { return 0; }
151#endif
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +1000152
153/**
154 * vga_put - release lock on legacy VGA resources
155 *
156 * @pdev: pci device of VGA card or NULL for system default
157 * @rsrc: but mask of resource to release
158 *
159 * This function releases resources previously locked by vga_get()
160 * or vga_tryget(). The resources aren't disabled right away, so
161 * that a subsequence vga_get() on the same card will succeed
162 * immediately. Resources have a counter, so locks are only
163 * released if the counter reaches 0.
164 */
165
Chris Wilson04cbe1d2010-08-19 21:29:43 +0100166#if defined(CONFIG_VGA_ARB)
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +1000167extern void vga_put(struct pci_dev *pdev, unsigned int rsrc);
Chris Wilson04cbe1d2010-08-19 21:29:43 +0100168#else
169#define vga_put(pdev, rsrc)
170#endif
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +1000171
172
173/**
174 * vga_default_device
175 *
176 * This can be defined by the platform. The default implementation
177 * is rather dumb and will probably only work properly on single
178 * vga card setups and/or x86 platforms.
179 *
180 * If your VGA default device is not PCI, you'll have to return
181 * NULL here. In this case, I assume it will not conflict with
182 * any PCI card. If this is not true, I'll have to define two archs
183 * hooks for enabling/disabling the VGA default device if that is
184 * possible. This may be a problem with real _ISA_ VGA cards, in
185 * addition to a PCI one. I don't know at this point how to deal
186 * with that card. Can theirs IOs be disabled at all ? If not, then
187 * I suppose it's a matter of having the proper arch hook telling
188 * us about it, so we basically never allow anybody to succeed a
189 * vga_get()...
190 */
191
192#ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE
Matthew Garrett6e079d52012-05-03 09:29:01 +0100193#ifdef CONFIG_VGA_ARB
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +1000194extern struct pci_dev *vga_default_device(void);
Matthew Garrett1a39b312012-04-16 16:26:02 -0400195extern void vga_set_default_device(struct pci_dev *pdev);
Matthew Garrett6e079d52012-05-03 09:29:01 +0100196#else
197static inline struct pci_dev *vga_default_device(void) { return NULL; };
198static inline void vga_set_default_device(struct pci_dev *pdev) { };
199#endif
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +1000200#endif
201
202/**
203 * vga_conflicts
204 *
205 * Architectures should define this if they have several
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300206 * independent PCI domains that can afford concurrent VGA
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +1000207 * decoding
208 */
209
210#ifndef __ARCH_HAS_VGA_CONFLICT
211static inline int vga_conflicts(struct pci_dev *p1, struct pci_dev *p2)
212{
213 return 1;
214}
215#endif
216
Dave Airlie6ac3bd52009-08-19 15:21:57 +1000217/**
218 * vga_client_register
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +1000219 *
Dave Airlie6ac3bd52009-08-19 15:21:57 +1000220 * @pdev: pci device of the VGA client
221 * @cookie: client cookie to be used in callbacks
222 * @irq_set_state: irq state change callback
223 * @set_vga_decode: vga decode change callback
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +1000224 *
Dave Airlie6ac3bd52009-08-19 15:21:57 +1000225 * return value: 0 on success, -1 on failure
226 * Register a client with the VGA arbitration logic
227 *
228 * Clients have two callback mechanisms they can use.
229 * irq enable/disable callback -
230 * If a client can't disable its GPUs VGA resources, then we
231 * need to be able to ask it to turn off its irqs when we
232 * turn off its mem and io decoding.
233 * set_vga_decode
234 * If a client can disable its GPU VGA resource, it will
235 * get a callback from this to set the encode/decode state
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +1000236 *
237 * Rationale: we cannot disable VGA decode resources unconditionally
238 * some single GPU laptops seem to require ACPI or BIOS access to the
239 * VGA registers to control things like backlights etc.
240 * Hopefully newer multi-GPU laptops do something saner, and desktops
241 * won't have any special ACPI for this.
Dave Airlie6ac3bd52009-08-19 15:21:57 +1000242 * They driver will get a callback when VGA arbitration is first used
243 * by userspace since we some older X servers have issues.
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +1000244 */
Ingo Molnar7c329282009-09-23 09:52:18 +1000245#if defined(CONFIG_VGA_ARB)
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +1000246int vga_client_register(struct pci_dev *pdev, void *cookie,
247 void (*irq_set_state)(void *cookie, bool state),
248 unsigned int (*set_vga_decode)(void *cookie, bool state));
Ingo Molnar7c329282009-09-23 09:52:18 +1000249#else
250static inline int vga_client_register(struct pci_dev *pdev, void *cookie,
251 void (*irq_set_state)(void *cookie, bool state),
252 unsigned int (*set_vga_decode)(void *cookie, bool state))
253{
254 return 0;
255}
256#endif
Benjamin Herrenschmidtdeb2d2e2009-08-11 15:52:06 +1000257
258#endif /* LINUX_VGA_H */