Loading...
1/*
2 * 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.
4 *
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>
8 *
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 *
29 */
30
31#ifndef LINUX_VGA_H
32#define LINUX_VGA_H
33
34#include <video/vga.h>
35
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
51struct pci_dev;
52
53/* 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 */
68#if defined(CONFIG_VGA_ARB)
69extern void vga_set_legacy_decoding(struct pci_dev *pdev,
70 unsigned int decodes);
71#else
72static inline void vga_set_legacy_decoding(struct pci_dev *pdev,
73 unsigned int decodes) { };
74#endif
75
76#if defined(CONFIG_VGA_ARB)
77extern int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible);
78#else
79static inline int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible) { return 0; }
80#endif
81
82/**
83 * vga_get_interruptible
84 * @pdev: pci device of the VGA card or NULL for the system default
85 * @rsrc: bit mask of resources to acquire and lock
86 *
87 * Shortcut to vga_get with interruptible set to true.
88 *
89 * On success, release the VGA resource again with vga_put().
90 */
91static inline int vga_get_interruptible(struct pci_dev *pdev,
92 unsigned int rsrc)
93{
94 return vga_get(pdev, rsrc, 1);
95}
96
97/**
98 * vga_get_uninterruptible - shortcut to vga_get()
99 * @pdev: pci device of the VGA card or NULL for the system default
100 * @rsrc: bit mask of resources to acquire and lock
101 *
102 * Shortcut to vga_get with interruptible set to false.
103 *
104 * On success, release the VGA resource again with vga_put().
105 */
106static inline int vga_get_uninterruptible(struct pci_dev *pdev,
107 unsigned int rsrc)
108{
109 return vga_get(pdev, rsrc, 0);
110}
111
112#if defined(CONFIG_VGA_ARB)
113extern void vga_put(struct pci_dev *pdev, unsigned int rsrc);
114#else
115#define vga_put(pdev, rsrc)
116#endif
117
118
119#ifdef CONFIG_VGA_ARB
120extern struct pci_dev *vga_default_device(void);
121extern void vga_set_default_device(struct pci_dev *pdev);
122extern int vga_remove_vgacon(struct pci_dev *pdev);
123#else
124static inline struct pci_dev *vga_default_device(void) { return NULL; };
125static inline void vga_set_default_device(struct pci_dev *pdev) { };
126static inline int vga_remove_vgacon(struct pci_dev *pdev) { return 0; };
127#endif
128
129/*
130 * Architectures should define this if they have several
131 * independent PCI domains that can afford concurrent VGA
132 * decoding
133 */
134#ifndef __ARCH_HAS_VGA_CONFLICT
135static inline int vga_conflicts(struct pci_dev *p1, struct pci_dev *p2)
136{
137 return 1;
138}
139#endif
140
141#if defined(CONFIG_VGA_ARB)
142int vga_client_register(struct pci_dev *pdev, void *cookie,
143 void (*irq_set_state)(void *cookie, bool state),
144 unsigned int (*set_vga_decode)(void *cookie, bool state));
145#else
146static inline int vga_client_register(struct pci_dev *pdev, void *cookie,
147 void (*irq_set_state)(void *cookie, bool state),
148 unsigned int (*set_vga_decode)(void *cookie, bool state))
149{
150 return 0;
151}
152#endif
153
154#endif /* LINUX_VGA_H */
1/*
2 * 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.
4 *
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>
8 *
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 *
29 */
30
31#ifndef LINUX_VGA_H
32#define LINUX_VGA_H
33
34#include <video/vga.h>
35
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
51struct pci_dev;
52
53/* 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 */
68extern void vga_set_legacy_decoding(struct pci_dev *pdev,
69 unsigned int decodes);
70
71/**
72 * vga_get - acquire & locks VGA resources
73 *
74 * @pdev: pci device of the VGA card or NULL for the system default
75 * @rsrc: bit mask of resources to acquire and lock
76 * @interruptible: blocking should be interruptible by signals ?
77 *
78 * This function acquires VGA resources for the given
79 * card and mark those resources locked. If the resource requested
80 * are "normal" (and not legacy) resources, the arbiter will first check
81 * wether the card is doing legacy decoding for that type of resource. If
82 * yes, the lock is "converted" into a legacy resource lock.
83 * The arbiter will first look for all VGA cards that might conflict
84 * and disable their IOs and/or Memory access, including VGA forwarding
85 * on P2P bridges if necessary, so that the requested resources can
86 * be used. Then, the card is marked as locking these resources and
87 * the IO and/or Memory accesse are enabled on the card (including
88 * VGA forwarding on parent P2P bridges if any).
89 * This function will block if some conflicting card is already locking
90 * one of the required resources (or any resource on a different bus
91 * segment, since P2P bridges don't differenciate VGA memory and IO
92 * afaik). You can indicate wether this blocking should be interruptible
93 * by a signal (for userland interface) or not.
94 * Must not be called at interrupt time or in atomic context.
95 * If the card already owns the resources, the function succeeds.
96 * Nested calls are supported (a per-resource counter is maintained)
97 */
98
99#if defined(CONFIG_VGA_ARB)
100extern int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible);
101#else
102static inline int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible) { return 0; }
103#endif
104
105/**
106 * vga_get_interruptible
107 *
108 * Shortcut to vga_get
109 */
110
111static inline int vga_get_interruptible(struct pci_dev *pdev,
112 unsigned int rsrc)
113{
114 return vga_get(pdev, rsrc, 1);
115}
116
117/**
118 * vga_get_uninterruptible
119 *
120 * Shortcut to vga_get
121 */
122
123static inline int vga_get_uninterruptible(struct pci_dev *pdev,
124 unsigned int rsrc)
125{
126 return vga_get(pdev, rsrc, 0);
127}
128
129/**
130 * vga_tryget - try to acquire & lock legacy VGA resources
131 *
132 * @pdev: pci devivce of VGA card or NULL for system default
133 * @rsrc: bit mask of resources to acquire and lock
134 *
135 * This function performs the same operation as vga_get(), but
136 * will return an error (-EBUSY) instead of blocking if the resources
137 * are already locked by another card. It can be called in any context
138 */
139
140#if defined(CONFIG_VGA_ARB)
141extern int vga_tryget(struct pci_dev *pdev, unsigned int rsrc);
142#else
143static inline int vga_tryget(struct pci_dev *pdev, unsigned int rsrc) { return 0; }
144#endif
145
146/**
147 * vga_put - release lock on legacy VGA resources
148 *
149 * @pdev: pci device of VGA card or NULL for system default
150 * @rsrc: but mask of resource to release
151 *
152 * This function releases resources previously locked by vga_get()
153 * or vga_tryget(). The resources aren't disabled right away, so
154 * that a subsequence vga_get() on the same card will succeed
155 * immediately. Resources have a counter, so locks are only
156 * released if the counter reaches 0.
157 */
158
159#if defined(CONFIG_VGA_ARB)
160extern void vga_put(struct pci_dev *pdev, unsigned int rsrc);
161#else
162#define vga_put(pdev, rsrc)
163#endif
164
165
166/**
167 * vga_default_device
168 *
169 * This can be defined by the platform. The default implementation
170 * is rather dumb and will probably only work properly on single
171 * vga card setups and/or x86 platforms.
172 *
173 * If your VGA default device is not PCI, you'll have to return
174 * NULL here. In this case, I assume it will not conflict with
175 * any PCI card. If this is not true, I'll have to define two archs
176 * hooks for enabling/disabling the VGA default device if that is
177 * possible. This may be a problem with real _ISA_ VGA cards, in
178 * addition to a PCI one. I don't know at this point how to deal
179 * with that card. Can theirs IOs be disabled at all ? If not, then
180 * I suppose it's a matter of having the proper arch hook telling
181 * us about it, so we basically never allow anybody to succeed a
182 * vga_get()...
183 */
184
185#ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE
186#ifdef CONFIG_VGA_ARB
187extern struct pci_dev *vga_default_device(void);
188extern void vga_set_default_device(struct pci_dev *pdev);
189#else
190static inline struct pci_dev *vga_default_device(void) { return NULL; };
191static inline void vga_set_default_device(struct pci_dev *pdev) { };
192#endif
193#endif
194
195/**
196 * vga_conflicts
197 *
198 * Architectures should define this if they have several
199 * independent PCI domains that can afford concurrent VGA
200 * decoding
201 */
202
203#ifndef __ARCH_HAS_VGA_CONFLICT
204static inline int vga_conflicts(struct pci_dev *p1, struct pci_dev *p2)
205{
206 return 1;
207}
208#endif
209
210/**
211 * vga_client_register
212 *
213 * @pdev: pci device of the VGA client
214 * @cookie: client cookie to be used in callbacks
215 * @irq_set_state: irq state change callback
216 * @set_vga_decode: vga decode change callback
217 *
218 * return value: 0 on success, -1 on failure
219 * Register a client with the VGA arbitration logic
220 *
221 * Clients have two callback mechanisms they can use.
222 * irq enable/disable callback -
223 * If a client can't disable its GPUs VGA resources, then we
224 * need to be able to ask it to turn off its irqs when we
225 * turn off its mem and io decoding.
226 * set_vga_decode
227 * If a client can disable its GPU VGA resource, it will
228 * get a callback from this to set the encode/decode state
229 *
230 * Rationale: we cannot disable VGA decode resources unconditionally
231 * some single GPU laptops seem to require ACPI or BIOS access to the
232 * VGA registers to control things like backlights etc.
233 * Hopefully newer multi-GPU laptops do something saner, and desktops
234 * won't have any special ACPI for this.
235 * They driver will get a callback when VGA arbitration is first used
236 * by userspace since we some older X servers have issues.
237 */
238#if defined(CONFIG_VGA_ARB)
239int vga_client_register(struct pci_dev *pdev, void *cookie,
240 void (*irq_set_state)(void *cookie, bool state),
241 unsigned int (*set_vga_decode)(void *cookie, bool state));
242#else
243static inline int vga_client_register(struct pci_dev *pdev, void *cookie,
244 void (*irq_set_state)(void *cookie, bool state),
245 unsigned int (*set_vga_decode)(void *cookie, bool state))
246{
247 return 0;
248}
249#endif
250
251#endif /* LINUX_VGA_H */