Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1 | /* |
Jesse Barnes | e2d4304 | 2009-09-17 09:40:31 -0700 | [diff] [blame] | 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. |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 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 | |
| 10 | #ifndef LINUX_VGA_H |
| 11 | |
| 12 | #include <asm/vga.h> |
| 13 | |
| 14 | /* Legacy VGA regions */ |
| 15 | #define VGA_RSRC_NONE 0x00 |
| 16 | #define VGA_RSRC_LEGACY_IO 0x01 |
| 17 | #define VGA_RSRC_LEGACY_MEM 0x02 |
| 18 | #define VGA_RSRC_LEGACY_MASK (VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM) |
| 19 | /* Non-legacy access */ |
| 20 | #define VGA_RSRC_NORMAL_IO 0x04 |
| 21 | #define VGA_RSRC_NORMAL_MEM 0x08 |
| 22 | |
| 23 | /* Passing that instead of a pci_dev to use the system "default" |
| 24 | * device, that is the one used by vgacon. Archs will probably |
| 25 | * have to provide their own vga_default_device(); |
| 26 | */ |
| 27 | #define VGA_DEFAULT_DEVICE (NULL) |
| 28 | |
| 29 | /* For use by clients */ |
| 30 | |
| 31 | /** |
| 32 | * vga_set_legacy_decoding |
| 33 | * |
| 34 | * @pdev: pci device of the VGA card |
| 35 | * @decodes: bit mask of what legacy regions the card decodes |
| 36 | * |
| 37 | * Indicates to the arbiter if the card decodes legacy VGA IOs, |
| 38 | * legacy VGA Memory, both, or none. All cards default to both, |
| 39 | * the card driver (fbdev for example) should tell the arbiter |
| 40 | * if it has disabled legacy decoding, so the card can be left |
| 41 | * out of the arbitration process (and can be safe to take |
| 42 | * interrupts at any time. |
| 43 | */ |
| 44 | extern void vga_set_legacy_decoding(struct pci_dev *pdev, |
Ingo Molnar | 7c32928 | 2009-09-23 09:52:18 +1000 | [diff] [blame] | 45 | unsigned int decodes); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 46 | |
| 47 | /** |
| 48 | * vga_get - acquire & locks VGA resources |
| 49 | * |
Dave Airlie | 6ac3bd5 | 2009-08-19 15:21:57 +1000 | [diff] [blame] | 50 | * @pdev: pci device of the VGA card or NULL for the system default |
| 51 | * @rsrc: bit mask of resources to acquire and lock |
| 52 | * @interruptible: blocking should be interruptible by signals ? |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 53 | * |
| 54 | * This function acquires VGA resources for the given |
| 55 | * card and mark those resources locked. If the resource requested |
| 56 | * are "normal" (and not legacy) resources, the arbiter will first check |
| 57 | * wether the card is doing legacy decoding for that type of resource. If |
| 58 | * yes, the lock is "converted" into a legacy resource lock. |
| 59 | * The arbiter will first look for all VGA cards that might conflict |
| 60 | * and disable their IOs and/or Memory access, inlcuding VGA forwarding |
| 61 | * on P2P bridges if necessary, so that the requested resources can |
| 62 | * be used. Then, the card is marked as locking these resources and |
| 63 | * the IO and/or Memory accesse are enabled on the card (including |
| 64 | * VGA forwarding on parent P2P bridges if any). |
| 65 | * This function will block if some conflicting card is already locking |
| 66 | * one of the required resources (or any resource on a different bus |
| 67 | * segment, since P2P bridges don't differenciate VGA memory and IO |
| 68 | * afaik). You can indicate wether this blocking should be interruptible |
| 69 | * by a signal (for userland interface) or not. |
| 70 | * Must not be called at interrupt time or in atomic context. |
| 71 | * If the card already owns the resources, the function succeeds. |
| 72 | * Nested calls are supported (a per-resource counter is maintained) |
| 73 | */ |
| 74 | |
| 75 | extern int vga_get(struct pci_dev *pdev, unsigned int rsrc, |
| 76 | int interruptible); |
| 77 | |
| 78 | /** |
| 79 | * vga_get_interruptible |
| 80 | * |
| 81 | * Shortcut to vga_get |
| 82 | */ |
| 83 | |
| 84 | static inline int vga_get_interruptible(struct pci_dev *pdev, |
Dave Airlie | 6ac3bd5 | 2009-08-19 15:21:57 +1000 | [diff] [blame] | 85 | unsigned int rsrc) |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 86 | { |
| 87 | return vga_get(pdev, rsrc, 1); |
| 88 | } |
| 89 | |
| 90 | /** |
Dave Airlie | 6ac3bd5 | 2009-08-19 15:21:57 +1000 | [diff] [blame] | 91 | * vga_get_uninterruptible |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 92 | * |
| 93 | * Shortcut to vga_get |
| 94 | */ |
| 95 | |
| 96 | static inline int vga_get_uninterruptible(struct pci_dev *pdev, |
Dave Airlie | 6ac3bd5 | 2009-08-19 15:21:57 +1000 | [diff] [blame] | 97 | unsigned int rsrc) |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 98 | { |
| 99 | return vga_get(pdev, rsrc, 0); |
| 100 | } |
| 101 | |
| 102 | /** |
| 103 | * vga_tryget - try to acquire & lock legacy VGA resources |
| 104 | * |
| 105 | * @pdev: pci devivce of VGA card or NULL for system default |
| 106 | * @rsrc: bit mask of resources to acquire and lock |
| 107 | * |
| 108 | * This function performs the same operation as vga_get(), but |
| 109 | * will return an error (-EBUSY) instead of blocking if the resources |
| 110 | * are already locked by another card. It can be called in any context |
| 111 | */ |
| 112 | |
| 113 | extern int vga_tryget(struct pci_dev *pdev, unsigned int rsrc); |
| 114 | |
| 115 | /** |
| 116 | * vga_put - release lock on legacy VGA resources |
| 117 | * |
| 118 | * @pdev: pci device of VGA card or NULL for system default |
| 119 | * @rsrc: but mask of resource to release |
| 120 | * |
| 121 | * This function releases resources previously locked by vga_get() |
| 122 | * or vga_tryget(). The resources aren't disabled right away, so |
| 123 | * that a subsequence vga_get() on the same card will succeed |
| 124 | * immediately. Resources have a counter, so locks are only |
| 125 | * released if the counter reaches 0. |
| 126 | */ |
| 127 | |
| 128 | extern void vga_put(struct pci_dev *pdev, unsigned int rsrc); |
| 129 | |
| 130 | |
| 131 | /** |
| 132 | * vga_default_device |
| 133 | * |
| 134 | * This can be defined by the platform. The default implementation |
| 135 | * is rather dumb and will probably only work properly on single |
| 136 | * vga card setups and/or x86 platforms. |
| 137 | * |
| 138 | * If your VGA default device is not PCI, you'll have to return |
| 139 | * NULL here. In this case, I assume it will not conflict with |
| 140 | * any PCI card. If this is not true, I'll have to define two archs |
| 141 | * hooks for enabling/disabling the VGA default device if that is |
| 142 | * possible. This may be a problem with real _ISA_ VGA cards, in |
| 143 | * addition to a PCI one. I don't know at this point how to deal |
| 144 | * with that card. Can theirs IOs be disabled at all ? If not, then |
| 145 | * I suppose it's a matter of having the proper arch hook telling |
| 146 | * us about it, so we basically never allow anybody to succeed a |
| 147 | * vga_get()... |
| 148 | */ |
| 149 | |
| 150 | #ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE |
| 151 | extern struct pci_dev *vga_default_device(void); |
| 152 | #endif |
| 153 | |
| 154 | /** |
| 155 | * vga_conflicts |
| 156 | * |
| 157 | * Architectures should define this if they have several |
| 158 | * independant PCI domains that can afford concurrent VGA |
| 159 | * decoding |
| 160 | */ |
| 161 | |
| 162 | #ifndef __ARCH_HAS_VGA_CONFLICT |
| 163 | static inline int vga_conflicts(struct pci_dev *p1, struct pci_dev *p2) |
| 164 | { |
| 165 | return 1; |
| 166 | } |
| 167 | #endif |
| 168 | |
Dave Airlie | 6ac3bd5 | 2009-08-19 15:21:57 +1000 | [diff] [blame] | 169 | /** |
| 170 | * vga_client_register |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 171 | * |
Dave Airlie | 6ac3bd5 | 2009-08-19 15:21:57 +1000 | [diff] [blame] | 172 | * @pdev: pci device of the VGA client |
| 173 | * @cookie: client cookie to be used in callbacks |
| 174 | * @irq_set_state: irq state change callback |
| 175 | * @set_vga_decode: vga decode change callback |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 176 | * |
Dave Airlie | 6ac3bd5 | 2009-08-19 15:21:57 +1000 | [diff] [blame] | 177 | * return value: 0 on success, -1 on failure |
| 178 | * Register a client with the VGA arbitration logic |
| 179 | * |
| 180 | * Clients have two callback mechanisms they can use. |
| 181 | * irq enable/disable callback - |
| 182 | * If a client can't disable its GPUs VGA resources, then we |
| 183 | * need to be able to ask it to turn off its irqs when we |
| 184 | * turn off its mem and io decoding. |
| 185 | * set_vga_decode |
| 186 | * If a client can disable its GPU VGA resource, it will |
| 187 | * get a callback from this to set the encode/decode state |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 188 | * |
| 189 | * Rationale: we cannot disable VGA decode resources unconditionally |
| 190 | * some single GPU laptops seem to require ACPI or BIOS access to the |
| 191 | * VGA registers to control things like backlights etc. |
| 192 | * Hopefully newer multi-GPU laptops do something saner, and desktops |
| 193 | * won't have any special ACPI for this. |
Dave Airlie | 6ac3bd5 | 2009-08-19 15:21:57 +1000 | [diff] [blame] | 194 | * They driver will get a callback when VGA arbitration is first used |
| 195 | * by userspace since we some older X servers have issues. |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 196 | */ |
Ingo Molnar | 7c32928 | 2009-09-23 09:52:18 +1000 | [diff] [blame] | 197 | #if defined(CONFIG_VGA_ARB) |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 198 | int vga_client_register(struct pci_dev *pdev, void *cookie, |
| 199 | void (*irq_set_state)(void *cookie, bool state), |
| 200 | unsigned int (*set_vga_decode)(void *cookie, bool state)); |
Ingo Molnar | 7c32928 | 2009-09-23 09:52:18 +1000 | [diff] [blame] | 201 | #else |
| 202 | static inline int vga_client_register(struct pci_dev *pdev, void *cookie, |
| 203 | void (*irq_set_state)(void *cookie, bool state), |
| 204 | unsigned int (*set_vga_decode)(void *cookie, bool state)) |
| 205 | { |
| 206 | return 0; |
| 207 | } |
| 208 | #endif |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 209 | |
| 210 | #endif /* LINUX_VGA_H */ |