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path: root/drivers/pci/pcie/aspm.c
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Diffstat (limited to 'drivers/pci/pcie/aspm.c')
-rw-r--r--drivers/pci/pcie/aspm.c811
1 files changed, 811 insertions, 0 deletions
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
new file mode 100644
index 00000000000..61fedb2448b
--- /dev/null
+++ b/drivers/pci/pcie/aspm.c
@@ -0,0 +1,811 @@
1/*
2 * File: drivers/pci/pcie/aspm.c
3 * Enabling PCIE link L0s/L1 state and Clock Power Management
4 *
5 * Copyright (C) 2007 Intel
6 * Copyright (C) Zhang Yanmin (yanmin.zhang@intel.com)
7 * Copyright (C) Shaohua Li (shaohua.li@intel.com)
8 */
9
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/moduleparam.h>
13#include <linux/pci.h>
14#include <linux/pci_regs.h>
15#include <linux/errno.h>
16#include <linux/pm.h>
17#include <linux/init.h>
18#include <linux/slab.h>
19#include <linux/pci-aspm.h>
20#include "../pci.h"
21
22#ifdef MODULE_PARAM_PREFIX
23#undef MODULE_PARAM_PREFIX
24#endif
25#define MODULE_PARAM_PREFIX "pcie_aspm."
26
27struct endpoint_state {
28 unsigned int l0s_acceptable_latency;
29 unsigned int l1_acceptable_latency;
30};
31
32struct pcie_link_state {
33 struct list_head sibiling;
34 struct pci_dev *pdev;
35
36 /* ASPM state */
37 unsigned int support_state;
38 unsigned int enabled_state;
39 unsigned int bios_aspm_state;
40 /* upstream component */
41 unsigned int l0s_upper_latency;
42 unsigned int l1_upper_latency;
43 /* downstream component */
44 unsigned int l0s_down_latency;
45 unsigned int l1_down_latency;
46 /* Clock PM state*/
47 unsigned int clk_pm_capable;
48 unsigned int clk_pm_enabled;
49 unsigned int bios_clk_state;
50
51 /*
52 * A pcie downstream port only has one slot under it, so at most there
53 * are 8 functions
54 */
55 struct endpoint_state endpoints[8];
56};
57
58static int aspm_disabled;
59static DEFINE_MUTEX(aspm_lock);
60static LIST_HEAD(link_list);
61
62#define POLICY_DEFAULT 0 /* BIOS default setting */
63#define POLICY_PERFORMANCE 1 /* high performance */
64#define POLICY_POWERSAVE 2 /* high power saving */
65static int aspm_policy;
66static const char *policy_str[] = {
67 [POLICY_DEFAULT] = "default",
68 [POLICY_PERFORMANCE] = "performance",
69 [POLICY_POWERSAVE] = "powersave"
70};
71
72static int policy_to_aspm_state(struct pci_dev *pdev)
73{
74 struct pcie_link_state *link_state = pdev->link_state;
75
76 switch (aspm_policy) {
77 case POLICY_PERFORMANCE:
78 /* Disable ASPM and Clock PM */
79 return 0;
80 case POLICY_POWERSAVE:
81 /* Enable ASPM L0s/L1 */
82 return PCIE_LINK_STATE_L0S|PCIE_LINK_STATE_L1;
83 case POLICY_DEFAULT:
84 return link_state->bios_aspm_state;
85 }
86 return 0;
87}
88
89static int policy_to_clkpm_state(struct pci_dev *pdev)
90{
91 struct pcie_link_state *link_state = pdev->link_state;
92
93 switch (aspm_policy) {
94 case POLICY_PERFORMANCE:
95 /* Disable ASPM and Clock PM */
96 return 0;
97 case POLICY_POWERSAVE:
98 /* Disable Clock PM */
99 return 1;
100 case POLICY_DEFAULT:
101 return link_state->bios_clk_state;
102 }
103 return 0;
104}
105
106static void pcie_set_clock_pm(struct pci_dev *pdev, int enable)
107{
108 struct pci_dev *child_dev;
109 int pos;
110 u16 reg16;
111 struct pcie_link_state *link_state = pdev->link_state;
112
113 list_for_each_entry(child_dev, &pdev->subordinate->devices, bus_list) {
114 pos = pci_find_capability(child_dev, PCI_CAP_ID_EXP);
115 if (!pos)
116 return;
117 pci_read_config_word(child_dev, pos + PCI_EXP_LNKCTL, &reg16);
118 if (enable)
119 reg16 |= PCI_EXP_LNKCTL_CLKREQ_EN;
120 else
121 reg16 &= ~PCI_EXP_LNKCTL_CLKREQ_EN;
122 pci_write_config_word(child_dev, pos + PCI_EXP_LNKCTL, reg16);
123 }
124 link_state->clk_pm_enabled = !!enable;
125}
126
127static void pcie_check_clock_pm(struct pci_dev *pdev)
128{
129 int pos;
130 u32 reg32;
131 u16 reg16;
132 int capable = 1, enabled = 1;
133 struct pci_dev *child_dev;
134 struct pcie_link_state *link_state = pdev->link_state;
135
136 /* All functions should have the same cap and state, take the worst */
137 list_for_each_entry(child_dev, &pdev->subordinate->devices, bus_list) {
138 pos = pci_find_capability(child_dev, PCI_CAP_ID_EXP);
139 if (!pos)
140 return;
141 pci_read_config_dword(child_dev, pos + PCI_EXP_LNKCAP, &reg32);
142 if (!(reg32 & PCI_EXP_LNKCAP_CLKPM)) {
143 capable = 0;
144 enabled = 0;
145 break;
146 }
147 pci_read_config_word(child_dev, pos + PCI_EXP_LNKCTL, &reg16);
148 if (!(reg16 & PCI_EXP_LNKCTL_CLKREQ_EN))
149 enabled = 0;
150 }
151 link_state->clk_pm_capable = capable;
152 link_state->clk_pm_enabled = enabled;
153 link_state->bios_clk_state = enabled;
154 pcie_set_clock_pm(pdev, policy_to_clkpm_state(pdev));
155}
156
157/*
158 * pcie_aspm_configure_common_clock: check if the 2 ends of a link
159 * could use common clock. If they are, configure them to use the
160 * common clock. That will reduce the ASPM state exit latency.
161 */
162static void pcie_aspm_configure_common_clock(struct pci_dev *pdev)
163{
164 int pos, child_pos;
165 u16 reg16 = 0;
166 struct pci_dev *child_dev;
167 int same_clock = 1;
168
169 /*
170 * all functions of a slot should have the same Slot Clock
171 * Configuration, so just check one function
172 * */
173 child_dev = list_entry(pdev->subordinate->devices.next, struct pci_dev,
174 bus_list);
175 BUG_ON(!child_dev->is_pcie);
176
177 /* Check downstream component if bit Slot Clock Configuration is 1 */
178 child_pos = pci_find_capability(child_dev, PCI_CAP_ID_EXP);
179 pci_read_config_word(child_dev, child_pos + PCI_EXP_LNKSTA, &reg16);
180 if (!(reg16 & PCI_EXP_LNKSTA_SLC))
181 same_clock = 0;
182
183 /* Check upstream component if bit Slot Clock Configuration is 1 */
184 pos = pci_find_capability(pdev, PCI_CAP_ID_EXP);
185 pci_read_config_word(pdev, pos + PCI_EXP_LNKSTA, &reg16);
186 if (!(reg16 & PCI_EXP_LNKSTA_SLC))
187 same_clock = 0;
188
189 /* Configure downstream component, all functions */
190 list_for_each_entry(child_dev, &pdev->subordinate->devices, bus_list) {
191 child_pos = pci_find_capability(child_dev, PCI_CAP_ID_EXP);
192 pci_read_config_word(child_dev, child_pos + PCI_EXP_LNKCTL,
193 &reg16);
194 if (same_clock)
195 reg16 |= PCI_EXP_LNKCTL_CCC;
196 else
197 reg16 &= ~PCI_EXP_LNKCTL_CCC;
198 pci_write_config_word(child_dev, child_pos + PCI_EXP_LNKCTL,
199 reg16);
200 }
201
202 /* Configure upstream component */
203 pci_read_config_word(pdev, pos + PCI_EXP_LNKCTL, &reg16);
204 if (same_clock)
205 reg16 |= PCI_EXP_LNKCTL_CCC;
206 else
207 reg16 &= ~PCI_EXP_LNKCTL_CCC;
208 pci_write_config_word(pdev, pos + PCI_EXP_LNKCTL, reg16);
209
210 /* retrain link */
211 reg16 |= PCI_EXP_LNKCTL_RL;
212 pci_write_config_word(pdev, pos + PCI_EXP_LNKCTL, reg16);
213
214 /* Wait for link training end */
215 while (1) {
216 pci_read_config_word(pdev, pos + PCI_EXP_LNKSTA, &reg16);
217 if (!(reg16 & PCI_EXP_LNKSTA_LT))
218 break;
219 cpu_relax();
220 }
221}
222
223/*
224 * calc_L0S_latency: Convert L0s latency encoding to ns
225 */
226static unsigned int calc_L0S_latency(unsigned int latency_encoding, int ac)
227{
228 unsigned int ns = 64;
229
230 if (latency_encoding == 0x7) {
231 if (ac)
232 ns = -1U;
233 else
234 ns = 5*1000; /* > 4us */
235 } else
236 ns *= (1 << latency_encoding);
237 return ns;
238}
239
240/*
241 * calc_L1_latency: Convert L1 latency encoding to ns
242 */
243static unsigned int calc_L1_latency(unsigned int latency_encoding, int ac)
244{
245 unsigned int ns = 1000;
246
247 if (latency_encoding == 0x7) {
248 if (ac)
249 ns = -1U;
250 else
251 ns = 65*1000; /* > 64us */
252 } else
253 ns *= (1 << latency_encoding);
254 return ns;
255}
256
257static void pcie_aspm_get_cap_device(struct pci_dev *pdev, u32 *state,
258 unsigned int *l0s, unsigned int *l1, unsigned int *enabled)
259{
260 int pos;
261 u16 reg16;
262 u32 reg32;
263 unsigned int latency;
264
265 pos = pci_find_capability(pdev, PCI_CAP_ID_EXP);
266 pci_read_config_dword(pdev, pos + PCI_EXP_LNKCAP, &reg32);
267 *state = (reg32 & PCI_EXP_LNKCAP_ASPMS) >> 10;
268 if (*state != PCIE_LINK_STATE_L0S &&
269 *state != (PCIE_LINK_STATE_L1|PCIE_LINK_STATE_L0S))
270 *state = 0;
271 if (*state == 0)
272 return;
273
274 latency = (reg32 & PCI_EXP_LNKCAP_L0SEL) >> 12;
275 *l0s = calc_L0S_latency(latency, 0);
276 if (*state & PCIE_LINK_STATE_L1) {
277 latency = (reg32 & PCI_EXP_LNKCAP_L1EL) >> 15;
278 *l1 = calc_L1_latency(latency, 0);
279 }
280 pci_read_config_word(pdev, pos + PCI_EXP_LNKCTL, &reg16);
281 *enabled = reg16 & (PCIE_LINK_STATE_L0S|PCIE_LINK_STATE_L1);
282}
283
284static void pcie_aspm_cap_init(struct pci_dev *pdev)
285{
286 struct pci_dev *child_dev;
287 u32 state, tmp;
288 struct pcie_link_state *link_state = pdev->link_state;
289
290 /* upstream component states */
291 pcie_aspm_get_cap_device(pdev, &link_state->support_state,
292 &link_state->l0s_upper_latency,
293 &link_state->l1_upper_latency,
294 &link_state->enabled_state);
295 /* downstream component states, all functions have the same setting */
296 child_dev = list_entry(pdev->subordinate->devices.next, struct pci_dev,
297 bus_list);
298 pcie_aspm_get_cap_device(child_dev, &state,
299 &link_state->l0s_down_latency,
300 &link_state->l1_down_latency,
301 &tmp);
302 link_state->support_state &= state;
303 if (!link_state->support_state)
304 return;
305 link_state->enabled_state &= link_state->support_state;
306 link_state->bios_aspm_state = link_state->enabled_state;
307
308 /* ENDPOINT states*/
309 list_for_each_entry(child_dev, &pdev->subordinate->devices, bus_list) {
310 int pos;
311 u32 reg32;
312 unsigned int latency;
313 struct endpoint_state *ep_state =
314 &link_state->endpoints[PCI_FUNC(child_dev->devfn)];
315
316 if (child_dev->pcie_type != PCI_EXP_TYPE_ENDPOINT &&
317 child_dev->pcie_type != PCI_EXP_TYPE_LEG_END)
318 continue;
319
320 pos = pci_find_capability(child_dev, PCI_CAP_ID_EXP);
321 pci_read_config_dword(child_dev, pos + PCI_EXP_DEVCAP, &reg32);
322 latency = (reg32 & PCI_EXP_DEVCAP_L0S) >> 6;
323 latency = calc_L0S_latency(latency, 1);
324 ep_state->l0s_acceptable_latency = latency;
325 if (link_state->support_state & PCIE_LINK_STATE_L1) {
326 latency = (reg32 & PCI_EXP_DEVCAP_L1) >> 9;
327 latency = calc_L1_latency(latency, 1);
328 ep_state->l1_acceptable_latency = latency;
329 }
330 }
331}
332
333static unsigned int __pcie_aspm_check_state_one(struct pci_dev *pdev,
334 unsigned int state)
335{
336 struct pci_dev *parent_dev, *tmp_dev;
337 unsigned int latency, l1_latency = 0;
338 struct pcie_link_state *link_state;
339 struct endpoint_state *ep_state;
340
341 parent_dev = pdev->bus->self;
342 link_state = parent_dev->link_state;
343 state &= link_state->support_state;
344 if (state == 0)
345 return 0;
346 ep_state = &link_state->endpoints[PCI_FUNC(pdev->devfn)];
347
348 /*
349 * Check latency for endpoint device.
350 * TBD: The latency from the endpoint to root complex vary per
351 * switch's upstream link state above the device. Here we just do a
352 * simple check which assumes all links above the device can be in L1
353 * state, that is we just consider the worst case. If switch's upstream
354 * link can't be put into L0S/L1, then our check is too strictly.
355 */
356 tmp_dev = pdev;
357 while (state & (PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1)) {
358 parent_dev = tmp_dev->bus->self;
359 link_state = parent_dev->link_state;
360 if (state & PCIE_LINK_STATE_L0S) {
361 latency = max_t(unsigned int,
362 link_state->l0s_upper_latency,
363 link_state->l0s_down_latency);
364 if (latency > ep_state->l0s_acceptable_latency)
365 state &= ~PCIE_LINK_STATE_L0S;
366 }
367 if (state & PCIE_LINK_STATE_L1) {
368 latency = max_t(unsigned int,
369 link_state->l1_upper_latency,
370 link_state->l1_down_latency);
371 if (latency + l1_latency >
372 ep_state->l1_acceptable_latency)
373 state &= ~PCIE_LINK_STATE_L1;
374 }
375 if (!parent_dev->bus->self) /* parent_dev is a root port */
376 break;
377 else {
378 /*
379 * parent_dev is the downstream port of a switch, make
380 * tmp_dev the upstream port of the switch
381 */
382 tmp_dev = parent_dev->bus->self;
383 /*
384 * every switch on the path to root complex need 1 more
385 * microsecond for L1. Spec doesn't mention L0S.
386 */
387 if (state & PCIE_LINK_STATE_L1)
388 l1_latency += 1000;
389 }
390 }
391 return state;
392}
393
394static unsigned int pcie_aspm_check_state(struct pci_dev *pdev,
395 unsigned int state)
396{
397 struct pci_dev *child_dev;
398
399 /* If no child, disable the link */
400 if (list_empty(&pdev->subordinate->devices))
401 return 0;
402 list_for_each_entry(child_dev, &pdev->subordinate->devices, bus_list) {
403 if (child_dev->pcie_type == PCI_EXP_TYPE_PCI_BRIDGE) {
404 /*
405 * If downstream component of a link is pci bridge, we
406 * disable ASPM for now for the link
407 * */
408 state = 0;
409 break;
410 }
411 if ((child_dev->pcie_type != PCI_EXP_TYPE_ENDPOINT &&
412 child_dev->pcie_type != PCI_EXP_TYPE_LEG_END))
413 continue;
414 /* Device not in D0 doesn't need check latency */
415 if (child_dev->current_state == PCI_D1 ||
416 child_dev->current_state == PCI_D2 ||
417 child_dev->current_state == PCI_D3hot ||
418 child_dev->current_state == PCI_D3cold)
419 continue;
420 state = __pcie_aspm_check_state_one(child_dev, state);
421 }
422 return state;
423}
424
425static void __pcie_aspm_config_one_dev(struct pci_dev *pdev, unsigned int state)
426{
427 u16 reg16;
428 int pos = pci_find_capability(pdev, PCI_CAP_ID_EXP);
429
430 pci_read_config_word(pdev, pos + PCI_EXP_LNKCTL, &reg16);
431 reg16 &= ~0x3;
432 reg16 |= state;
433 pci_write_config_word(pdev, pos + PCI_EXP_LNKCTL, reg16);
434}
435
436static void __pcie_aspm_config_link(struct pci_dev *pdev, unsigned int state)
437{
438 struct pci_dev *child_dev;
439 int valid = 1;
440 struct pcie_link_state *link_state = pdev->link_state;
441
442 /*
443 * if the downstream component has pci bridge function, don't do ASPM
444 * now
445 */
446 list_for_each_entry(child_dev, &pdev->subordinate->devices, bus_list) {
447 if (child_dev->pcie_type == PCI_EXP_TYPE_PCI_BRIDGE) {
448 valid = 0;
449 break;
450 }
451 }
452 if (!valid)
453 return;
454
455 /*
456 * spec 2.0 suggests all functions should be configured the same
457 * setting for ASPM. Enabling ASPM L1 should be done in upstream
458 * component first and then downstream, and vice versa for disabling
459 * ASPM L1. Spec doesn't mention L0S.
460 */
461 if (state & PCIE_LINK_STATE_L1)
462 __pcie_aspm_config_one_dev(pdev, state);
463
464 list_for_each_entry(child_dev, &pdev->subordinate->devices, bus_list)
465 __pcie_aspm_config_one_dev(child_dev, state);
466
467 if (!(state & PCIE_LINK_STATE_L1))
468 __pcie_aspm_config_one_dev(pdev, state);
469
470 link_state->enabled_state = state;
471}
472
473static void __pcie_aspm_configure_link_state(struct pci_dev *pdev,
474 unsigned int state)
475{
476 struct pcie_link_state *link_state = pdev->link_state;
477
478 if (link_state->support_state == 0)
479 return;
480 state &= PCIE_LINK_STATE_L0S|PCIE_LINK_STATE_L1;
481
482 /* state 0 means disabling aspm */
483 state = pcie_aspm_check_state(pdev, state);
484 if (link_state->enabled_state == state)
485 return;
486 __pcie_aspm_config_link(pdev, state);
487}
488
489/*
490 * pcie_aspm_configure_link_state: enable/disable PCI express link state
491 * @pdev: the root port or switch downstream port
492 */
493static void pcie_aspm_configure_link_state(struct pci_dev *pdev,
494 unsigned int state)
495{
496 down_read(&pci_bus_sem);
497 mutex_lock(&aspm_lock);
498 __pcie_aspm_configure_link_state(pdev, state);
499 mutex_unlock(&aspm_lock);
500 up_read(&pci_bus_sem);
501}
502
503static void free_link_state(struct pci_dev *pdev)
504{
505 kfree(pdev->link_state);
506 pdev->link_state = NULL;
507}
508
509/*
510 * pcie_aspm_init_link_state: Initiate PCI express link state.
511 * It is called after the pcie and its children devices are scaned.
512 * @pdev: the root port or switch downstream port
513 */
514void pcie_aspm_init_link_state(struct pci_dev *pdev)
515{
516 unsigned int state;
517 struct pcie_link_state *link_state;
518 int error = 0;
519
520 if (aspm_disabled || !pdev->is_pcie || pdev->link_state)
521 return;
522 if (pdev->pcie_type != PCI_EXP_TYPE_ROOT_PORT &&
523 pdev->pcie_type != PCI_EXP_TYPE_DOWNSTREAM)
524 return;
525 down_read(&pci_bus_sem);
526 if (list_empty(&pdev->subordinate->devices))
527 goto out;
528
529 mutex_lock(&aspm_lock);
530
531 link_state = kzalloc(sizeof(*link_state), GFP_KERNEL);
532 if (!link_state)
533 goto unlock_out;
534 pdev->link_state = link_state;
535
536 pcie_aspm_configure_common_clock(pdev);
537
538 pcie_aspm_cap_init(pdev);
539
540 /* config link state to avoid BIOS error */
541 state = pcie_aspm_check_state(pdev, policy_to_aspm_state(pdev));
542 __pcie_aspm_config_link(pdev, state);
543
544 pcie_check_clock_pm(pdev);
545
546 link_state->pdev = pdev;
547 list_add(&link_state->sibiling, &link_list);
548
549unlock_out:
550 if (error)
551 free_link_state(pdev);
552 mutex_unlock(&aspm_lock);
553out:
554 up_read(&pci_bus_sem);
555}
556
557/* @pdev: the endpoint device */
558void pcie_aspm_exit_link_state(struct pci_dev *pdev)
559{
560 struct pci_dev *parent = pdev->bus->self;
561 struct pcie_link_state *link_state = parent->link_state;
562
563 if (aspm_disabled || !pdev->is_pcie || !parent || !link_state)
564 return;
565 if (parent->pcie_type != PCI_EXP_TYPE_ROOT_PORT &&
566 parent->pcie_type != PCI_EXP_TYPE_DOWNSTREAM)
567 return;
568 down_read(&pci_bus_sem);
569 mutex_lock(&aspm_lock);
570
571 /*
572 * All PCIe functions are in one slot, remove one function will remove
573 * the the whole slot, so just wait
574 */
575 if (!list_empty(&parent->subordinate->devices))
576 goto out;
577
578 /* All functions are removed, so just disable ASPM for the link */
579 __pcie_aspm_config_one_dev(parent, 0);
580 list_del(&link_state->sibiling);
581 /* Clock PM is for endpoint device */
582
583 free_link_state(parent);
584out:
585 mutex_unlock(&aspm_lock);
586 up_read(&pci_bus_sem);
587}
588
589/* @pdev: the root port or switch downstream port */
590void pcie_aspm_pm_state_change(struct pci_dev *pdev)
591{
592 struct pcie_link_state *link_state = pdev->link_state;
593
594 if (aspm_disabled || !pdev->is_pcie || !pdev->link_state)
595 return;
596 if (pdev->pcie_type != PCI_EXP_TYPE_ROOT_PORT &&
597 pdev->pcie_type != PCI_EXP_TYPE_DOWNSTREAM)
598 return;
599 /*
600 * devices changed PM state, we should recheck if latency meets all
601 * functions' requirement
602 */
603 pcie_aspm_configure_link_state(pdev, link_state->enabled_state);
604}
605
606/*
607 * pci_disable_link_state - disable pci device's link state, so the link will
608 * never enter specific states
609 */
610void pci_disable_link_state(struct pci_dev *pdev, int state)
611{
612 struct pci_dev *parent = pdev->bus->self;
613 struct pcie_link_state *link_state;
614
615 if (aspm_disabled || !pdev->is_pcie)
616 return;
617 if (pdev->pcie_type == PCI_EXP_TYPE_ROOT_PORT ||
618 pdev->pcie_type == PCI_EXP_TYPE_DOWNSTREAM)
619 parent = pdev;
620 if (!parent || !parent->link_state)
621 return;
622
623 down_read(&pci_bus_sem);
624 mutex_lock(&aspm_lock);
625 link_state = parent->link_state;
626 link_state->support_state &=
627 ~(state & (PCIE_LINK_STATE_L0S|PCIE_LINK_STATE_L1));
628 if (state & PCIE_LINK_STATE_CLKPM)
629 link_state->clk_pm_capable = 0;
630
631 __pcie_aspm_configure_link_state(parent, link_state->enabled_state);
632 if (!link_state->clk_pm_capable && link_state->clk_pm_enabled)
633 pcie_set_clock_pm(parent, 0);
634 mutex_unlock(&aspm_lock);
635 up_read(&pci_bus_sem);
636}
637EXPORT_SYMBOL(pci_disable_link_state);
638
639static int pcie_aspm_set_policy(const char *val, struct kernel_param *kp)
640{
641 int i;
642 struct pci_dev *pdev;
643 struct pcie_link_state *link_state;
644
645 for (i = 0; i < ARRAY_SIZE(policy_str); i++)
646 if (!strncmp(val, policy_str[i], strlen(policy_str[i])))
647 break;
648 if (i >= ARRAY_SIZE(policy_str))
649 return -EINVAL;
650 if (i == aspm_policy)
651 return 0;
652
653 down_read(&pci_bus_sem);
654 mutex_lock(&aspm_lock);
655 aspm_policy = i;
656 list_for_each_entry(link_state, &link_list, sibiling) {
657 pdev = link_state->pdev;
658 __pcie_aspm_configure_link_state(pdev,
659 policy_to_aspm_state(pdev));
660 if (link_state->clk_pm_capable &&
661 link_state->clk_pm_enabled != policy_to_clkpm_state(pdev))
662 pcie_set_clock_pm(pdev, policy_to_clkpm_state(pdev));
663
664 }
665 mutex_unlock(&aspm_lock);
666 up_read(&pci_bus_sem);
667 return 0;
668}
669
670static int pcie_aspm_get_policy(char *buffer, struct kernel_param *kp)
671{
672 int i, cnt = 0;
673 for (i = 0; i < ARRAY_SIZE(policy_str); i++)
674 if (i == aspm_policy)
675 cnt += sprintf(buffer + cnt, "[%s] ", policy_str[i]);
676 else
677 cnt += sprintf(buffer + cnt, "%s ", policy_str[i]);
678 return cnt;
679}
680
681module_param_call(policy, pcie_aspm_set_policy, pcie_aspm_get_policy,
682 NULL, 0644);
683
684#ifdef CONFIG_PCIEASPM_DEBUG
685static ssize_t link_state_show(struct device *dev,
686 struct device_attribute *attr,
687 char *buf)
688{
689 struct pci_dev *pci_device = to_pci_dev(dev);
690 struct pcie_link_state *link_state = pci_device->link_state;
691
692 return sprintf(buf, "%d\n", link_state->enabled_state);
693}
694
695static ssize_t link_state_store(struct device *dev,
696 struct device_attribute *attr,
697 const char *buf,
698 size_t n)
699{
700 struct pci_dev *pci_device = to_pci_dev(dev);
701 int state;
702
703 if (n < 1)
704 return -EINVAL;
705 state = buf[0]-'0';
706 if (state >= 0 && state <= 3) {
707 /* setup link aspm state */
708 pcie_aspm_configure_link_state(pci_device, state);
709 return n;
710 }
711
712 return -EINVAL;
713}
714
715static ssize_t clk_ctl_show(struct device *dev,
716 struct device_attribute *attr,
717 char *buf)
718{
719 struct pci_dev *pci_device = to_pci_dev(dev);
720 struct pcie_link_state *link_state = pci_device->link_state;
721
722 return sprintf(buf, "%d\n", link_state->clk_pm_enabled);
723}
724
725static ssize_t clk_ctl_store(struct device *dev,
726 struct device_attribute *attr,
727 const char *buf,
728 size_t n)
729{
730 struct pci_dev *pci_device = to_pci_dev(dev);
731 int state;
732
733 if (n < 1)
734 return -EINVAL;
735 state = buf[0]-'0';
736
737 down_read(&pci_bus_sem);
738 mutex_lock(&aspm_lock);
739 pcie_set_clock_pm(pci_device, !!state);
740 mutex_unlock(&aspm_lock);
741 up_read(&pci_bus_sem);
742
743 return n;
744}
745
746static DEVICE_ATTR(link_state, 0644, link_state_show, link_state_store);
747static DEVICE_ATTR(clk_ctl, 0644, clk_ctl_show, clk_ctl_store);
748
749static char power_group[] = "power";
750void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev)
751{
752 struct pcie_link_state *link_state = pdev->link_state;
753
754 if (!pdev->is_pcie || (pdev->pcie_type != PCI_EXP_TYPE_ROOT_PORT &&
755 pdev->pcie_type != PCI_EXP_TYPE_DOWNSTREAM) || !link_state)
756 return;
757
758 if (link_state->support_state)
759 sysfs_add_file_to_group(&pdev->dev.kobj,
760 &dev_attr_link_state.attr, power_group);
761 if (link_state->clk_pm_capable)
762 sysfs_add_file_to_group(&pdev->dev.kobj,
763 &dev_attr_clk_ctl.attr, power_group);
764}
765
766void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev)
767{
768 struct pcie_link_state *link_state = pdev->link_state;
769
770 if (!pdev->is_pcie || (pdev->pcie_type != PCI_EXP_TYPE_ROOT_PORT &&
771 pdev->pcie_type != PCI_EXP_TYPE_DOWNSTREAM) || !link_state)
772 return;
773
774 if (link_state->support_state)
775 sysfs_remove_file_from_group(&pdev->dev.kobj,
776 &dev_attr_link_state.attr, power_group);
777 if (link_state->clk_pm_capable)
778 sysfs_remove_file_from_group(&pdev->dev.kobj,
779 &dev_attr_clk_ctl.attr, power_group);
780}
781#endif
782
783static int __init pcie_aspm_disable(char *str)
784{
785 aspm_disabled = 1;
786 return 1;
787}
788
789__setup("pcie_noaspm", pcie_aspm_disable);
790
791#ifdef CONFIG_ACPI
792#include <acpi/acpi_bus.h>
793#include <linux/pci-acpi.h>
794static void pcie_aspm_platform_init(void)
795{
796 pcie_osc_support_set(OSC_ACTIVE_STATE_PWR_SUPPORT|
797 OSC_CLOCK_PWR_CAPABILITY_SUPPORT);
798}
799#else
800static inline void pcie_aspm_platform_init(void) { }
801#endif
802
803static int __init pcie_aspm_init(void)
804{
805 if (aspm_disabled)
806 return 0;
807 pcie_aspm_platform_init();
808 return 0;
809}
810
811fs_initcall(pcie_aspm_init);
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-22 06:20:37 -0500