Merge branch 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6.git] / drivers / gpu / vga / vga_switcheroo.c
1 /*
2  * Copyright (c) 2010 Red Hat Inc.
3  * Author : Dave Airlie <airlied@redhat.com>
4  *
5  *
6  * Licensed under GPLv2
7  *
8  * vga_switcheroo.c - Support for laptop with dual GPU using one set of outputs
9
10  Switcher interface - methods require for ATPX and DCM
11  - switchto - this throws the output MUX switch
12  - discrete_set_power - sets the power state for the discrete card
13
14  GPU driver interface
15  - set_gpu_state - this should do the equiv of s/r for the card
16                   - this should *not* set the discrete power state
17  - switch_check  - check if the device is in a position to switch now
18  */
19
20 #include <linux/module.h>
21 #include <linux/dmi.h>
22 #include <linux/seq_file.h>
23 #include <linux/uaccess.h>
24 #include <linux/fs.h>
25 #include <linux/debugfs.h>
26 #include <linux/fb.h>
27
28 #include <linux/pci.h>
29 #include <linux/vga_switcheroo.h>
30
31 struct vga_switcheroo_client {
32         struct pci_dev *pdev;
33         struct fb_info *fb_info;
34         int pwr_state;
35         void (*set_gpu_state)(struct pci_dev *pdev, enum vga_switcheroo_state);
36         void (*reprobe)(struct pci_dev *pdev);
37         bool (*can_switch)(struct pci_dev *pdev);
38         int id;
39         bool active;
40 };
41
42 static DEFINE_MUTEX(vgasr_mutex);
43
44 struct vgasr_priv {
45
46         bool active;
47         bool delayed_switch_active;
48         enum vga_switcheroo_client_id delayed_client_id;
49
50         struct dentry *debugfs_root;
51         struct dentry *switch_file;
52
53         int registered_clients;
54         struct vga_switcheroo_client clients[VGA_SWITCHEROO_MAX_CLIENTS];
55
56         struct vga_switcheroo_handler *handler;
57 };
58
59 static int vga_switcheroo_debugfs_init(struct vgasr_priv *priv);
60 static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv);
61
62 /* only one switcheroo per system */
63 static struct vgasr_priv vgasr_priv;
64
65 int vga_switcheroo_register_handler(struct vga_switcheroo_handler *handler)
66 {
67         mutex_lock(&vgasr_mutex);
68         if (vgasr_priv.handler) {
69                 mutex_unlock(&vgasr_mutex);
70                 return -EINVAL;
71         }
72
73         vgasr_priv.handler = handler;
74         mutex_unlock(&vgasr_mutex);
75         return 0;
76 }
77 EXPORT_SYMBOL(vga_switcheroo_register_handler);
78
79 void vga_switcheroo_unregister_handler(void)
80 {
81         mutex_lock(&vgasr_mutex);
82         vgasr_priv.handler = NULL;
83         mutex_unlock(&vgasr_mutex);
84 }
85 EXPORT_SYMBOL(vga_switcheroo_unregister_handler);
86
87 static void vga_switcheroo_enable(void)
88 {
89         int i;
90         int ret;
91         /* call the handler to init */
92         vgasr_priv.handler->init();
93
94         for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
95                 ret = vgasr_priv.handler->get_client_id(vgasr_priv.clients[i].pdev);
96                 if (ret < 0)
97                         return;
98
99                 vgasr_priv.clients[i].id = ret;
100         }
101         vga_switcheroo_debugfs_init(&vgasr_priv);
102         vgasr_priv.active = true;
103 }
104
105 int vga_switcheroo_register_client(struct pci_dev *pdev,
106                                    void (*set_gpu_state)(struct pci_dev *pdev, enum vga_switcheroo_state),
107                                    void (*reprobe)(struct pci_dev *pdev),
108                                    bool (*can_switch)(struct pci_dev *pdev))
109 {
110         int index;
111
112         mutex_lock(&vgasr_mutex);
113         /* don't do IGD vs DIS here */
114         if (vgasr_priv.registered_clients & 1)
115                 index = 1;
116         else
117                 index = 0;
118
119         vgasr_priv.clients[index].pwr_state = VGA_SWITCHEROO_ON;
120         vgasr_priv.clients[index].pdev = pdev;
121         vgasr_priv.clients[index].set_gpu_state = set_gpu_state;
122         vgasr_priv.clients[index].reprobe = reprobe;
123         vgasr_priv.clients[index].can_switch = can_switch;
124         vgasr_priv.clients[index].id = -1;
125         if (pdev->resource[PCI_ROM_RESOURCE].flags & IORESOURCE_ROM_SHADOW)
126                 vgasr_priv.clients[index].active = true;
127
128         vgasr_priv.registered_clients |= (1 << index);
129
130         /* if we get two clients + handler */
131         if (vgasr_priv.registered_clients == 0x3 && vgasr_priv.handler) {
132                 printk(KERN_INFO "vga_switcheroo: enabled\n");
133                 vga_switcheroo_enable();
134         }
135         mutex_unlock(&vgasr_mutex);
136         return 0;
137 }
138 EXPORT_SYMBOL(vga_switcheroo_register_client);
139
140 void vga_switcheroo_unregister_client(struct pci_dev *pdev)
141 {
142         int i;
143
144         mutex_lock(&vgasr_mutex);
145         for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
146                 if (vgasr_priv.clients[i].pdev == pdev) {
147                         vgasr_priv.registered_clients &= ~(1 << i);
148                         break;
149                 }
150         }
151
152         printk(KERN_INFO "vga_switcheroo: disabled\n");
153         vga_switcheroo_debugfs_fini(&vgasr_priv);
154         vgasr_priv.active = false;
155         mutex_unlock(&vgasr_mutex);
156 }
157 EXPORT_SYMBOL(vga_switcheroo_unregister_client);
158
159 void vga_switcheroo_client_fb_set(struct pci_dev *pdev,
160                                  struct fb_info *info)
161 {
162         int i;
163
164         mutex_lock(&vgasr_mutex);
165         for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
166                 if (vgasr_priv.clients[i].pdev == pdev) {
167                         vgasr_priv.clients[i].fb_info = info;
168                         break;
169                 }
170         }
171         mutex_unlock(&vgasr_mutex);
172 }
173 EXPORT_SYMBOL(vga_switcheroo_client_fb_set);
174
175 static int vga_switcheroo_show(struct seq_file *m, void *v)
176 {
177         int i;
178         mutex_lock(&vgasr_mutex);
179         for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
180                 seq_printf(m, "%d:%s:%c:%s:%s\n", i,
181                            vgasr_priv.clients[i].id == VGA_SWITCHEROO_DIS ? "DIS" : "IGD",
182                            vgasr_priv.clients[i].active ? '+' : ' ',
183                            vgasr_priv.clients[i].pwr_state ? "Pwr" : "Off",
184                            pci_name(vgasr_priv.clients[i].pdev));
185         }
186         mutex_unlock(&vgasr_mutex);
187         return 0;
188 }
189
190 static int vga_switcheroo_debugfs_open(struct inode *inode, struct file *file)
191 {
192         return single_open(file, vga_switcheroo_show, NULL);
193 }
194
195 static int vga_switchon(struct vga_switcheroo_client *client)
196 {
197         if (vgasr_priv.handler->power_state)
198                 vgasr_priv.handler->power_state(client->id, VGA_SWITCHEROO_ON);
199         /* call the driver callback to turn on device */
200         client->set_gpu_state(client->pdev, VGA_SWITCHEROO_ON);
201         client->pwr_state = VGA_SWITCHEROO_ON;
202         return 0;
203 }
204
205 static int vga_switchoff(struct vga_switcheroo_client *client)
206 {
207         /* call the driver callback to turn off device */
208         client->set_gpu_state(client->pdev, VGA_SWITCHEROO_OFF);
209         if (vgasr_priv.handler->power_state)
210                 vgasr_priv.handler->power_state(client->id, VGA_SWITCHEROO_OFF);
211         client->pwr_state = VGA_SWITCHEROO_OFF;
212         return 0;
213 }
214
215 /* stage one happens before delay */
216 static int vga_switchto_stage1(struct vga_switcheroo_client *new_client)
217 {
218         int ret;
219         int i;
220         struct vga_switcheroo_client *active = NULL;
221
222         for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
223                 if (vgasr_priv.clients[i].active == true) {
224                         active = &vgasr_priv.clients[i];
225                         break;
226                 }
227         }
228         if (!active)
229                 return 0;
230
231         /* power up the first device */
232         ret = pci_enable_device(new_client->pdev);
233         if (ret)
234                 return ret;
235
236         if (new_client->pwr_state == VGA_SWITCHEROO_OFF)
237                 vga_switchon(new_client);
238
239         /* swap shadow resource to denote boot VGA device has changed so X starts on new device */
240         active->pdev->resource[PCI_ROM_RESOURCE].flags &= ~IORESOURCE_ROM_SHADOW;
241         new_client->pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW;
242         return 0;
243 }
244
245 /* post delay */
246 static int vga_switchto_stage2(struct vga_switcheroo_client *new_client)
247 {
248         int ret;
249         int i;
250         struct vga_switcheroo_client *active = NULL;
251
252         for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
253                 if (vgasr_priv.clients[i].active == true) {
254                         active = &vgasr_priv.clients[i];
255                         break;
256                 }
257         }
258         if (!active)
259                 return 0;
260
261         active->active = false;
262
263         if (new_client->fb_info) {
264                 struct fb_event event;
265                 event.info = new_client->fb_info;
266                 fb_notifier_call_chain(FB_EVENT_REMAP_ALL_CONSOLE, &event);
267         }
268
269         ret = vgasr_priv.handler->switchto(new_client->id);
270         if (ret)
271                 return ret;
272
273         if (new_client->reprobe)
274                 new_client->reprobe(new_client->pdev);
275
276         if (active->pwr_state == VGA_SWITCHEROO_ON)
277                 vga_switchoff(active);
278
279         new_client->active = true;
280         return 0;
281 }
282
283 static ssize_t
284 vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf,
285                              size_t cnt, loff_t *ppos)
286 {
287         char usercmd[64];
288         const char *pdev_name;
289         int i, ret;
290         bool delay = false, can_switch;
291         bool just_mux = false;
292         int client_id = -1;
293         struct vga_switcheroo_client *client = NULL;
294
295         if (cnt > 63)
296                 cnt = 63;
297
298         if (copy_from_user(usercmd, ubuf, cnt))
299                 return -EFAULT;
300
301         mutex_lock(&vgasr_mutex);
302
303         if (!vgasr_priv.active) {
304                 cnt = -EINVAL;
305                 goto out;
306         }
307
308         /* pwr off the device not in use */
309         if (strncmp(usercmd, "OFF", 3) == 0) {
310                 for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
311                         if (vgasr_priv.clients[i].active)
312                                 continue;
313                         if (vgasr_priv.clients[i].pwr_state == VGA_SWITCHEROO_ON)
314                                 vga_switchoff(&vgasr_priv.clients[i]);
315                 }
316                 goto out;
317         }
318         /* pwr on the device not in use */
319         if (strncmp(usercmd, "ON", 2) == 0) {
320                 for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
321                         if (vgasr_priv.clients[i].active)
322                                 continue;
323                         if (vgasr_priv.clients[i].pwr_state == VGA_SWITCHEROO_OFF)
324                                 vga_switchon(&vgasr_priv.clients[i]);
325                 }
326                 goto out;
327         }
328
329         /* request a delayed switch - test can we switch now */
330         if (strncmp(usercmd, "DIGD", 4) == 0) {
331                 client_id = VGA_SWITCHEROO_IGD;
332                 delay = true;
333         }
334
335         if (strncmp(usercmd, "DDIS", 4) == 0) {
336                 client_id = VGA_SWITCHEROO_DIS;
337                 delay = true;
338         }
339
340         if (strncmp(usercmd, "IGD", 3) == 0)
341                 client_id = VGA_SWITCHEROO_IGD;
342
343         if (strncmp(usercmd, "DIS", 3) == 0)
344                 client_id = VGA_SWITCHEROO_DIS;
345
346         if (strncmp(usercmd, "MIGD", 4) == 0) {
347                 just_mux = true;
348                 client_id = VGA_SWITCHEROO_IGD;
349         }
350         if (strncmp(usercmd, "MDIS", 4) == 0) {
351                 just_mux = true;
352                 client_id = VGA_SWITCHEROO_DIS;
353         }
354
355         if (client_id == -1)
356                 goto out;
357
358         for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
359                 if (vgasr_priv.clients[i].id == client_id) {
360                         client = &vgasr_priv.clients[i];
361                         break;
362                 }
363         }
364
365         vgasr_priv.delayed_switch_active = false;
366
367         if (just_mux) {
368                 ret = vgasr_priv.handler->switchto(client_id);
369                 goto out;
370         }
371
372         if (client->active == true)
373                 goto out;
374
375         /* okay we want a switch - test if devices are willing to switch */
376         can_switch = true;
377         for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
378                 can_switch = vgasr_priv.clients[i].can_switch(vgasr_priv.clients[i].pdev);
379                 if (can_switch == false) {
380                         printk(KERN_ERR "vga_switcheroo: client %d refused switch\n", i);
381                         break;
382                 }
383         }
384
385         if (can_switch == false && delay == false)
386                 goto out;
387
388         if (can_switch == true) {
389                 pdev_name = pci_name(client->pdev);
390                 ret = vga_switchto_stage1(client);
391                 if (ret)
392                         printk(KERN_ERR "vga_switcheroo: switching failed stage 1 %d\n", ret);
393
394                 ret = vga_switchto_stage2(client);
395                 if (ret)
396                         printk(KERN_ERR "vga_switcheroo: switching failed stage 2 %d\n", ret);
397
398         } else {
399                 printk(KERN_INFO "vga_switcheroo: setting delayed switch to client %d\n", client->id);
400                 vgasr_priv.delayed_switch_active = true;
401                 vgasr_priv.delayed_client_id = client_id;
402
403                 ret = vga_switchto_stage1(client);
404                 if (ret)
405                         printk(KERN_ERR "vga_switcheroo: delayed switching stage 1 failed %d\n", ret);
406         }
407
408 out:
409         mutex_unlock(&vgasr_mutex);
410         return cnt;
411 }
412
413 static const struct file_operations vga_switcheroo_debugfs_fops = {
414         .owner = THIS_MODULE,
415         .open = vga_switcheroo_debugfs_open,
416         .write = vga_switcheroo_debugfs_write,
417         .read = seq_read,
418         .llseek = seq_lseek,
419         .release = single_release,
420 };
421
422 static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv)
423 {
424         if (priv->switch_file) {
425                 debugfs_remove(priv->switch_file);
426                 priv->switch_file = NULL;
427         }
428         if (priv->debugfs_root) {
429                 debugfs_remove(priv->debugfs_root);
430                 priv->debugfs_root = NULL;
431         }
432 }
433
434 static int vga_switcheroo_debugfs_init(struct vgasr_priv *priv)
435 {
436         /* already initialised */
437         if (priv->debugfs_root)
438                 return 0;
439         priv->debugfs_root = debugfs_create_dir("vgaswitcheroo", NULL);
440
441         if (!priv->debugfs_root) {
442                 printk(KERN_ERR "vga_switcheroo: Cannot create /sys/kernel/debug/vgaswitcheroo\n");
443                 goto fail;
444         }
445
446         priv->switch_file = debugfs_create_file("switch", 0644,
447                                                 priv->debugfs_root, NULL, &vga_switcheroo_debugfs_fops);
448         if (!priv->switch_file) {
449                 printk(KERN_ERR "vga_switcheroo: cannot create /sys/kernel/debug/vgaswitcheroo/switch\n");
450                 goto fail;
451         }
452         return 0;
453 fail:
454         vga_switcheroo_debugfs_fini(priv);
455         return -1;
456 }
457
458 int vga_switcheroo_process_delayed_switch(void)
459 {
460         struct vga_switcheroo_client *client = NULL;
461         const char *pdev_name;
462         bool can_switch = true;
463         int i;
464         int ret;
465         int err = -EINVAL;
466
467         mutex_lock(&vgasr_mutex);
468         if (!vgasr_priv.delayed_switch_active)
469                 goto err;
470
471         printk(KERN_INFO "vga_switcheroo: processing delayed switch to %d\n", vgasr_priv.delayed_client_id);
472
473         for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
474                 if (vgasr_priv.clients[i].id == vgasr_priv.delayed_client_id)
475                         client = &vgasr_priv.clients[i];
476                 can_switch = vgasr_priv.clients[i].can_switch(vgasr_priv.clients[i].pdev);
477                 if (can_switch == false) {
478                         printk(KERN_ERR "vga_switcheroo: client %d refused switch\n", i);
479                         break;
480                 }
481         }
482
483         if (can_switch == false || client == NULL)
484                 goto err;
485
486         pdev_name = pci_name(client->pdev);
487         ret = vga_switchto_stage2(client);
488         if (ret)
489                 printk(KERN_ERR "vga_switcheroo: delayed switching failed stage 2 %d\n", ret);
490
491         vgasr_priv.delayed_switch_active = false;
492         err = 0;
493 err:
494         mutex_unlock(&vgasr_mutex);
495         return err;
496 }
497 EXPORT_SYMBOL(vga_switcheroo_process_delayed_switch);
498