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-rw-r--r--drivers/pci/pci-sysfs.c5
-rw-r--r--drivers/pci/pci.c4
-rw-r--r--drivers/pci/pcie/Kconfig20
-rw-r--r--drivers/pci/pcie/Makefile3
-rw-r--r--drivers/pci/pcie/aspm.c802
-rw-r--r--drivers/pci/probe.c5
-rw-r--r--drivers/pci/remove.c4
-rw-r--r--include/linux/aspm.h44
-rw-r--r--include/linux/pci.h5
-rw-r--r--include/linux/pci_regs.h8
10 files changed, 900 insertions, 0 deletions
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 7d1877341aad..d05c1b252386 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -21,6 +21,7 @@
21#include <linux/topology.h> 21#include <linux/topology.h>
22#include <linux/mm.h> 22#include <linux/mm.h>
23#include <linux/capability.h> 23#include <linux/capability.h>
24#include <linux/aspm.h>
24#include "pci.h" 25#include "pci.h"
25 26
26static int sysfs_initialized; /* = 0 */ 27static int sysfs_initialized; /* = 0 */
@@ -650,6 +651,8 @@ int __must_check pci_create_sysfs_dev_files (struct pci_dev *pdev)
650 if (pcibios_add_platform_entries(pdev)) 651 if (pcibios_add_platform_entries(pdev))
651 goto err_rom_file; 652 goto err_rom_file;
652 653
654 pcie_aspm_create_sysfs_dev_files(pdev);
655
653 return 0; 656 return 0;
654 657
655err_rom_file: 658err_rom_file:
@@ -679,6 +682,8 @@ void pci_remove_sysfs_dev_files(struct pci_dev *pdev)
679 if (!sysfs_initialized) 682 if (!sysfs_initialized)
680 return; 683 return;
681 684
685 pcie_aspm_remove_sysfs_dev_files(pdev);
686
682 if (pdev->cfg_size < 4096) 687 if (pdev->cfg_size < 4096)
683 sysfs_remove_bin_file(&pdev->dev.kobj, &pci_config_attr); 688 sysfs_remove_bin_file(&pdev->dev.kobj, &pci_config_attr);
684 else 689 else
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 35f78f1628fc..1f1693161956 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -18,6 +18,7 @@
18#include <linux/spinlock.h> 18#include <linux/spinlock.h>
19#include <linux/string.h> 19#include <linux/string.h>
20#include <linux/log2.h> 20#include <linux/log2.h>
21#include <linux/aspm.h>
21#include <asm/dma.h> /* isa_dma_bridge_buggy */ 22#include <asm/dma.h> /* isa_dma_bridge_buggy */
22#include "pci.h" 23#include "pci.h"
23 24
@@ -519,6 +520,9 @@ pci_set_power_state(struct pci_dev *dev, pci_power_t state)
519 if (need_restore) 520 if (need_restore)
520 pci_restore_bars(dev); 521 pci_restore_bars(dev);
521 522
523 if (dev->bus->self)
524 pcie_aspm_pm_state_change(dev->bus->self);
525
522 return 0; 526 return 0;
523} 527}
524 528
diff --git a/drivers/pci/pcie/Kconfig b/drivers/pci/pcie/Kconfig
index 287a9311716c..60104cf98796 100644
--- a/drivers/pci/pcie/Kconfig
+++ b/drivers/pci/pcie/Kconfig
@@ -26,3 +26,23 @@ config HOTPLUG_PCI_PCIE
26 When in doubt, say N. 26 When in doubt, say N.
27 27
28source "drivers/pci/pcie/aer/Kconfig" 28source "drivers/pci/pcie/aer/Kconfig"
29
30#
31# PCI Express ASPM
32#
33config PCIEASPM
34 bool "PCI Express ASPM support(Experimental)"
35 depends on PCI && EXPERIMENTAL
36 default y
37 help
38 This enables PCI Express ASPM (Active State Power Management) and
39 Clock Power Management. ASPM supports state L0/L0s/L1.
40
41 When in doubt, say N.
42config PCIEASPM_DEBUG
43 bool "Debug PCI Express ASPM"
44 depends on PCIEASPM
45 default n
46 help
47 This enables PCI Express ASPM debug support. It will add per-device
48 interface to control ASPM.
diff --git a/drivers/pci/pcie/Makefile b/drivers/pci/pcie/Makefile
index e00fb99acf44..11f6bb1eae24 100644
--- a/drivers/pci/pcie/Makefile
+++ b/drivers/pci/pcie/Makefile
@@ -2,6 +2,9 @@
2# Makefile for PCI-Express PORT Driver 2# Makefile for PCI-Express PORT Driver
3# 3#
4 4
5# Build PCI Express ASPM if needed
6obj-$(CONFIG_PCIEASPM) += aspm.o
7
5pcieportdrv-y := portdrv_core.o portdrv_pci.o portdrv_bus.o 8pcieportdrv-y := portdrv_core.o portdrv_pci.o portdrv_bus.o
6 9
7obj-$(CONFIG_PCIEPORTBUS) += pcieportdrv.o 10obj-$(CONFIG_PCIEPORTBUS) += pcieportdrv.o
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
new file mode 100644
index 000000000000..1a5adeb10c95
--- /dev/null
+++ b/drivers/pci/pcie/aspm.c
@@ -0,0 +1,802 @@
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/aspm.h>
20#include <acpi/acpi_bus.h>
21#include <linux/pci-acpi.h>
22#include "../pci.h"
23
24#ifdef MODULE_PARAM_PREFIX
25#undef MODULE_PARAM_PREFIX
26#endif
27#define MODULE_PARAM_PREFIX "pcie_aspm."
28
29struct endpoint_state {
30 unsigned int l0s_acceptable_latency;
31 unsigned int l1_acceptable_latency;
32};
33
34struct pcie_link_state {
35 struct list_head sibiling;
36 struct pci_dev *pdev;
37
38 /* ASPM state */
39 unsigned int support_state;
40 unsigned int enabled_state;
41 unsigned int bios_aspm_state;
42 /* upstream component */
43 unsigned int l0s_upper_latency;
44 unsigned int l1_upper_latency;
45 /* downstream component */
46 unsigned int l0s_down_latency;
47 unsigned int l1_down_latency;
48 /* Clock PM state*/
49 unsigned int clk_pm_capable;
50 unsigned int clk_pm_enabled;
51 unsigned int bios_clk_state;
52
53 /*
54 * A pcie downstream port only has one slot under it, so at most there
55 * are 8 functions
56 */
57 struct endpoint_state endpoints[8];
58};
59
60static int aspm_disabled;
61static DEFINE_MUTEX(aspm_lock);
62static LIST_HEAD(link_list);
63
64#define POLICY_DEFAULT 0 /* BIOS default setting */
65#define POLICY_PERFORMANCE 1 /* high performance */
66#define POLICY_POWERSAVE 2 /* high power saving */
67static int aspm_policy;
68static const char *policy_str[] = {
69 [POLICY_DEFAULT] = "default",
70 [POLICY_PERFORMANCE] = "performance",
71 [POLICY_POWERSAVE] = "powersave"
72};
73
74static int policy_to_aspm_state(struct pci_dev *pdev)
75{
76 struct pcie_link_state *link_state = pdev->link_state;
77
78 switch (aspm_policy) {
79 case POLICY_PERFORMANCE:
80 /* Disable ASPM and Clock PM */
81 return 0;
82 case POLICY_POWERSAVE:
83 /* Enable ASPM L0s/L1 */
84 return PCIE_LINK_STATE_L0S|PCIE_LINK_STATE_L1;
85 case POLICY_DEFAULT:
86 return link_state->bios_aspm_state;
87 }
88 return 0;
89}
90
91static int policy_to_clkpm_state(struct pci_dev *pdev)
92{
93 struct pcie_link_state *link_state = pdev->link_state;
94
95 switch (aspm_policy) {
96 case POLICY_PERFORMANCE:
97 /* Disable ASPM and Clock PM */
98 return 0;
99 case POLICY_POWERSAVE:
100 /* Disable Clock PM */
101 return 1;
102 case POLICY_DEFAULT:
103 return link_state->bios_clk_state;
104 }
105 return 0;
106}
107
108static void pcie_set_clock_pm(struct pci_dev *pdev, int enable)
109{
110 struct pci_dev *child_dev;
111 int pos;
112 u16 reg16;
113 struct pcie_link_state *link_state = pdev->link_state;
114
115 list_for_each_entry(child_dev, &pdev->subordinate->devices, bus_list) {
116 pos = pci_find_capability(child_dev, PCI_CAP_ID_EXP);
117 if (!pos)
118 return;
119 pci_read_config_word(child_dev, pos + PCI_EXP_LNKCTL, &reg16);
120 if (enable)
121 reg16 |= PCI_EXP_LNKCTL_CLKREQ_EN;
122 else
123 reg16 &= ~PCI_EXP_LNKCTL_CLKREQ_EN;
124 pci_write_config_word(child_dev, pos + PCI_EXP_LNKCTL, reg16);
125 }
126 link_state->clk_pm_enabled = !!enable;
127}
128
129static void pcie_check_clock_pm(struct pci_dev *pdev)
130{
131 int pos;
132 u32 reg32;
133 u16 reg16;
134 int capable = 1, enabled = 1;
135 struct pci_dev *child_dev;
136 struct pcie_link_state *link_state = pdev->link_state;
137
138 /* All functions should have the same cap and state, take the worst */
139 list_for_each_entry(child_dev, &pdev->subordinate->devices, bus_list) {
140 pos = pci_find_capability(child_dev, PCI_CAP_ID_EXP);
141 if (!pos)
142 return;
143 pci_read_config_dword(child_dev, pos + PCI_EXP_LNKCAP, &reg32);
144 if (!(reg32 & PCI_EXP_LNKCAP_CLKPM)) {
145 capable = 0;
146 enabled = 0;
147 break;
148 }
149 pci_read_config_word(child_dev, pos + PCI_EXP_LNKCTL, &reg16);
150 if (!(reg16 & PCI_EXP_LNKCTL_CLKREQ_EN))
151 enabled = 0;
152 }
153 link_state->clk_pm_capable = capable;
154 link_state->clk_pm_enabled = enabled;
155 link_state->bios_clk_state = enabled;
156 pcie_set_clock_pm(pdev, policy_to_clkpm_state(pdev));
157}
158
159/*
160 * pcie_aspm_configure_common_clock: check if the 2 ends of a link
161 * could use common clock. If they are, configure them to use the
162 * common clock. That will reduce the ASPM state exit latency.
163 */
164static void pcie_aspm_configure_common_clock(struct pci_dev *pdev)
165{
166 int pos, child_pos;
167 u16 reg16 = 0;
168 struct pci_dev *child_dev;
169 int same_clock = 1;
170
171 /*
172 * all functions of a slot should have the same Slot Clock
173 * Configuration, so just check one function
174 * */
175 child_dev = list_entry(pdev->subordinate->devices.next, struct pci_dev,
176 bus_list);
177 BUG_ON(!child_dev->is_pcie);
178
179 /* Check downstream component if bit Slot Clock Configuration is 1 */
180 child_pos = pci_find_capability(child_dev, PCI_CAP_ID_EXP);
181 pci_read_config_word(child_dev, child_pos + PCI_EXP_LNKSTA, &reg16);
182 if (!(reg16 & PCI_EXP_LNKSTA_SLC))
183 same_clock = 0;
184
185 /* Check upstream component if bit Slot Clock Configuration is 1 */
186 pos = pci_find_capability(pdev, PCI_CAP_ID_EXP);
187 pci_read_config_word(pdev, pos + PCI_EXP_LNKSTA, &reg16);
188 if (!(reg16 & PCI_EXP_LNKSTA_SLC))
189 same_clock = 0;
190
191 /* Configure downstream component, all functions */
192 list_for_each_entry(child_dev, &pdev->subordinate->devices, bus_list) {
193 child_pos = pci_find_capability(child_dev, PCI_CAP_ID_EXP);
194 pci_read_config_word(child_dev, child_pos + PCI_EXP_LNKCTL,
195 &reg16);
196 if (same_clock)
197 reg16 |= PCI_EXP_LNKCTL_CCC;
198 else
199 reg16 &= ~PCI_EXP_LNKCTL_CCC;
200 pci_write_config_word(child_dev, child_pos + PCI_EXP_LNKCTL,
201 reg16);
202 }
203
204 /* Configure upstream component */
205 pci_read_config_word(pdev, pos + PCI_EXP_LNKCTL, &reg16);
206 if (same_clock)
207 reg16 |= PCI_EXP_LNKCTL_CCC;
208 else
209 reg16 &= ~PCI_EXP_LNKCTL_CCC;
210 pci_write_config_word(pdev, pos + PCI_EXP_LNKCTL, reg16);
211
212 /* retrain link */
213 reg16 |= PCI_EXP_LNKCTL_RL;
214 pci_write_config_word(pdev, pos + PCI_EXP_LNKCTL, reg16);
215
216 /* Wait for link training end */
217 while (1) {
218 pci_read_config_word(pdev, pos + PCI_EXP_LNKSTA, &reg16);
219 if (!(reg16 & PCI_EXP_LNKSTA_LT))
220 break;
221 cpu_relax();
222 }
223}
224
225/*
226 * calc_L0S_latency: Convert L0s latency encoding to ns
227 */
228static unsigned int calc_L0S_latency(unsigned int latency_encoding, int ac)
229{
230 unsigned int ns = 64;
231
232 if (latency_encoding == 0x7) {
233 if (ac)
234 ns = -1U;
235 else
236 ns = 5*1000; /* > 4us */
237 } else
238 ns *= (1 << latency_encoding);
239 return ns;
240}
241
242/*
243 * calc_L1_latency: Convert L1 latency encoding to ns
244 */
245static unsigned int calc_L1_latency(unsigned int latency_encoding, int ac)
246{
247 unsigned int ns = 1000;
248
249 if (latency_encoding == 0x7) {
250 if (ac)
251 ns = -1U;
252 else
253 ns = 65*1000; /* > 64us */
254 } else
255 ns *= (1 << latency_encoding);
256 return ns;
257}
258
259static void pcie_aspm_get_cap_device(struct pci_dev *pdev, u32 *state,
260 unsigned int *l0s, unsigned int *l1, unsigned int *enabled)
261{
262 int pos;
263 u16 reg16;
264 u32 reg32;
265 unsigned int latency;
266
267 pos = pci_find_capability(pdev, PCI_CAP_ID_EXP);
268 pci_read_config_dword(pdev, pos + PCI_EXP_LNKCAP, &reg32);
269 *state = (reg32 & PCI_EXP_LNKCAP_ASPMS) >> 10;
270 if (*state != PCIE_LINK_STATE_L0S &&
271 *state != (PCIE_LINK_STATE_L1|PCIE_LINK_STATE_L0S))
272 * state = 0;
273 if (*state == 0)
274 return;
275
276 latency = (reg32 & PCI_EXP_LNKCAP_L0SEL) >> 12;
277 *l0s = calc_L0S_latency(latency, 0);
278 if (*state & PCIE_LINK_STATE_L1) {
279 latency = (reg32 & PCI_EXP_LNKCAP_L1EL) >> 15;
280 *l1 = calc_L1_latency(latency, 0);
281 }
282 pci_read_config_word(pdev, pos + PCI_EXP_LNKCTL, &reg16);
283 *enabled = reg16 & (PCIE_LINK_STATE_L0S|PCIE_LINK_STATE_L1);
284}
285
286static void pcie_aspm_cap_init(struct pci_dev *pdev)
287{
288 struct pci_dev *child_dev;
289 u32 state, tmp;
290 struct pcie_link_state *link_state = pdev->link_state;
291
292 /* upstream component states */
293 pcie_aspm_get_cap_device(pdev, &link_state->support_state,
294 &link_state->l0s_upper_latency,
295 &link_state->l1_upper_latency,
296 &link_state->enabled_state);
297 /* downstream component states, all functions have the same setting */
298 child_dev = list_entry(pdev->subordinate->devices.next, struct pci_dev,
299 bus_list);
300 pcie_aspm_get_cap_device(child_dev, &state,
301 &link_state->l0s_down_latency,
302 &link_state->l1_down_latency,
303 &tmp);
304 link_state->support_state &= state;
305 if (!link_state->support_state)
306 return;
307 link_state->enabled_state &= link_state->support_state;
308 link_state->bios_aspm_state = link_state->enabled_state;
309
310 /* ENDPOINT states*/
311 list_for_each_entry(child_dev, &pdev->subordinate->devices, bus_list) {
312 int pos;
313 u32 reg32;
314 unsigned int latency;
315 struct endpoint_state *ep_state =
316 &link_state->endpoints[PCI_FUNC(child_dev->devfn)];
317
318 if (child_dev->pcie_type != PCI_EXP_TYPE_ENDPOINT &&
319 child_dev->pcie_type != PCI_EXP_TYPE_LEG_END)
320 continue;
321
322 pos = pci_find_capability(child_dev, PCI_CAP_ID_EXP);
323 pci_read_config_dword(child_dev, pos + PCI_EXP_DEVCAP, &reg32);
324 latency = (reg32 & PCI_EXP_DEVCAP_L0S) >> 6;
325 latency = calc_L0S_latency(latency, 1);
326 ep_state->l0s_acceptable_latency = latency;
327 if (link_state->support_state & PCIE_LINK_STATE_L1) {
328 latency = (reg32 & PCI_EXP_DEVCAP_L1) >> 9;
329 latency = calc_L1_latency(latency, 1);
330 ep_state->l1_acceptable_latency = latency;
331 }
332 }
333}
334
335static unsigned int __pcie_aspm_check_state_one(struct pci_dev *pdev,
336 unsigned int state)
337{
338 struct pci_dev *parent_dev, *tmp_dev;
339 unsigned int latency, l1_latency = 0;
340 struct pcie_link_state *link_state;
341 struct endpoint_state *ep_state;
342
343 parent_dev = pdev->bus->self;
344 link_state = parent_dev->link_state;
345 state &= link_state->support_state;
346 if (state == 0)
347 return 0;
348 ep_state = &link_state->endpoints[PCI_FUNC(pdev->devfn)];
349
350 /*
351 * Check latency for endpoint device.
352 * TBD: The latency from the endpoint to root complex vary per
353 * switch's upstream link state above the device. Here we just do a
354 * simple check which assumes all links above the device can be in L1
355 * state, that is we just consider the worst case. If switch's upstream
356 * link can't be put into L0S/L1, then our check is too strictly.
357 */
358 tmp_dev = pdev;
359 while (state & (PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1)) {
360 parent_dev = tmp_dev->bus->self;
361 link_state = parent_dev->link_state;
362 if (state & PCIE_LINK_STATE_L0S) {
363 latency = max_t(unsigned int,
364 link_state->l0s_upper_latency,
365 link_state->l0s_down_latency);
366 if (latency > ep_state->l0s_acceptable_latency)
367 state &= ~PCIE_LINK_STATE_L0S;
368 }
369 if (state & PCIE_LINK_STATE_L1) {
370 latency = max_t(unsigned int,
371 link_state->l1_upper_latency,
372 link_state->l1_down_latency);
373 if (latency + l1_latency >
374 ep_state->l1_acceptable_latency)
375 state &= ~PCIE_LINK_STATE_L1;
376 }
377 if (!parent_dev->bus->self) /* parent_dev is a root port */
378 break;
379 else {
380 /*
381 * parent_dev is the downstream port of a switch, make
382 * tmp_dev the upstream port of the switch
383 */
384 tmp_dev = parent_dev->bus->self;
385 /*
386 * every switch on the path to root complex need 1 more
387 * microsecond for L1. Spec doesn't mention L0S.
388 */
389 if (state & PCIE_LINK_STATE_L1)
390 l1_latency += 1000;
391 }
392 }
393 return state;
394}
395
396static unsigned int pcie_aspm_check_state(struct pci_dev *pdev,
397 unsigned int state)
398{
399 struct pci_dev *child_dev;
400
401 /* If no child, disable the link */
402 if (list_empty(&pdev->subordinate->devices))
403 return 0;
404 list_for_each_entry(child_dev, &pdev->subordinate->devices, bus_list) {
405 if (child_dev->pcie_type == PCI_EXP_TYPE_PCI_BRIDGE) {
406 /*
407 * If downstream component of a link is pci bridge, we
408 * disable ASPM for now for the link
409 * */
410 state = 0;
411 break;
412 }
413 if ((child_dev->pcie_type != PCI_EXP_TYPE_ENDPOINT &&
414 child_dev->pcie_type != PCI_EXP_TYPE_LEG_END))
415 continue;
416 /* Device not in D0 doesn't need check latency */
417 if (child_dev->current_state == PCI_D1 ||
418 child_dev->current_state == PCI_D2 ||
419 child_dev->current_state == PCI_D3hot ||
420 child_dev->current_state == PCI_D3cold)
421 continue;
422 state = __pcie_aspm_check_state_one(child_dev, state);
423 }
424 return state;
425}
426
427static void __pcie_aspm_config_one_dev(struct pci_dev *pdev, unsigned int state)
428{
429 u16 reg16;
430 int pos = pci_find_capability(pdev, PCI_CAP_ID_EXP);
431
432 pci_read_config_word(pdev, pos + PCI_EXP_LNKCTL, &reg16);
433 reg16 &= ~0x3;
434 reg16 |= state;
435 pci_write_config_word(pdev, pos + PCI_EXP_LNKCTL, reg16);
436}
437
438static void __pcie_aspm_config_link(struct pci_dev *pdev, unsigned int state)
439{
440 struct pci_dev *child_dev;
441 int valid = 1;
442 struct pcie_link_state *link_state = pdev->link_state;
443
444 /*
445 * if the downstream component has pci bridge function, don't do ASPM
446 * now
447 */
448 list_for_each_entry(child_dev, &pdev->subordinate->devices, bus_list) {
449 if (child_dev->pcie_type == PCI_EXP_TYPE_PCI_BRIDGE) {
450 valid = 0;
451 break;
452 }
453 }
454 if (!valid)
455 return;
456
457 /*
458 * spec 2.0 suggests all functions should be configured the same
459 * setting for ASPM. Enabling ASPM L1 should be done in upstream
460 * component first and then downstream, and vice versa for disabling
461 * ASPM L1. Spec doesn't mention L0S.
462 */
463 if (state & PCIE_LINK_STATE_L1)
464 __pcie_aspm_config_one_dev(pdev, state);
465
466 list_for_each_entry(child_dev, &pdev->subordinate->devices, bus_list)
467 __pcie_aspm_config_one_dev(child_dev, state);
468
469 if (!(state & PCIE_LINK_STATE_L1))
470 __pcie_aspm_config_one_dev(pdev, state);
471
472 link_state->enabled_state = state;
473}
474
475static void __pcie_aspm_configure_link_state(struct pci_dev *pdev,
476 unsigned int state)
477{
478 struct pcie_link_state *link_state = pdev->link_state;
479
480 if (link_state->support_state == 0)
481 return;
482 state &= PCIE_LINK_STATE_L0S|PCIE_LINK_STATE_L1;
483
484 /* state 0 means disabling aspm */
485 state = pcie_aspm_check_state(pdev, state);
486 if (link_state->enabled_state == state)
487 return;
488 __pcie_aspm_config_link(pdev, state);
489}
490
491/*
492 * pcie_aspm_configure_link_state: enable/disable PCI express link state
493 * @pdev: the root port or switch downstream port
494 */
495static void pcie_aspm_configure_link_state(struct pci_dev *pdev,
496 unsigned int state)
497{
498 down_read(&pci_bus_sem);
499 mutex_lock(&aspm_lock);
500 __pcie_aspm_configure_link_state(pdev, state);
501 mutex_unlock(&aspm_lock);
502 up_read(&pci_bus_sem);
503}
504
505static void free_link_state(struct pci_dev *pdev)
506{
507 kfree(pdev->link_state);
508 pdev->link_state = NULL;
509}
510
511/*
512 * pcie_aspm_init_link_state: Initiate PCI express link state.
513 * It is called after the pcie and its children devices are scaned.
514 * @pdev: the root port or switch downstream port
515 */
516void pcie_aspm_init_link_state(struct pci_dev *pdev)
517{
518 unsigned int state;
519 struct pcie_link_state *link_state;
520 int error = 0;
521
522 if (aspm_disabled || !pdev->is_pcie || pdev->link_state)
523 return;
524 if (pdev->pcie_type != PCI_EXP_TYPE_ROOT_PORT &&
525 pdev->pcie_type != PCI_EXP_TYPE_DOWNSTREAM)
526 return;
527 down_read(&pci_bus_sem);
528 if (list_empty(&pdev->subordinate->devices))
529 goto out;
530
531 mutex_lock(&aspm_lock);
532
533 link_state = kzalloc(sizeof(*link_state), GFP_KERNEL);
534 if (!link_state)
535 goto unlock_out;
536 pdev->link_state = link_state;
537
538 pcie_aspm_configure_common_clock(pdev);
539
540 pcie_aspm_cap_init(pdev);
541
542 /* config link state to avoid BIOS error */
543 state = pcie_aspm_check_state(pdev, policy_to_aspm_state(pdev));
544 __pcie_aspm_config_link(pdev, state);
545
546 pcie_check_clock_pm(pdev);
547
548 link_state->pdev = pdev;
549 list_add(&link_state->sibiling, &link_list);
550
551unlock_out:
552 if (error)
553 free_link_state(pdev);
554 mutex_unlock(&aspm_lock);
555out:
556 up_read(&pci_bus_sem);
557}
558
559/* @pdev: the endpoint device */
560void pcie_aspm_exit_link_state(struct pci_dev *pdev)
561{
562 struct pci_dev *parent = pdev->bus->self;
563 struct pcie_link_state *link_state = parent->link_state;
564
565 if (aspm_disabled || !pdev->is_pcie || !parent || !link_state)
566 return;
567 if (parent->pcie_type != PCI_EXP_TYPE_ROOT_PORT &&
568 parent->pcie_type != PCI_EXP_TYPE_DOWNSTREAM)
569 return;
570 down_read(&pci_bus_sem);
571 mutex_lock(&aspm_lock);
572
573 /*
574 * All PCIe functions are in one slot, remove one function will remove
575 * the the whole slot, so just wait
576 */
577 if (!list_empty(&parent->subordinate->devices))
578 goto out;
579
580 /* All functions are removed, so just disable ASPM for the link */
581 __pcie_aspm_config_one_dev(parent, 0);
582 list_del(&link_state->sibiling);
583 /* Clock PM is for endpoint device */
584
585 free_link_state(parent);
586out:
587 mutex_unlock(&aspm_lock);
588 up_read(&pci_bus_sem);
589}
590
591/* @pdev: the root port or switch downstream port */
592void pcie_aspm_pm_state_change(struct pci_dev *pdev)
593{
594 struct pcie_link_state *link_state = pdev->link_state;
595
596 if (aspm_disabled || !pdev->is_pcie || !pdev->link_state)
597 return;
598 if (pdev->pcie_type != PCI_EXP_TYPE_ROOT_PORT &&
599 pdev->pcie_type != PCI_EXP_TYPE_DOWNSTREAM)
600 return;
601 /*
602 * devices changed PM state, we should recheck if latency meets all
603 * functions' requirement
604 */
605 pcie_aspm_configure_link_state(pdev, link_state->enabled_state);
606}
607
608/*
609 * pci_disable_link_state - disable pci device's link state, so the link will
610 * never enter specific states
611 */
612void pci_disable_link_state(struct pci_dev *pdev, int state)
613{
614 struct pci_dev *parent = pdev->bus->self;
615 struct pcie_link_state *link_state;
616
617 if (aspm_disabled || !pdev->is_pcie)
618 return;
619 if (pdev->pcie_type == PCI_EXP_TYPE_ROOT_PORT ||
620 pdev->pcie_type == PCI_EXP_TYPE_DOWNSTREAM)
621 parent = pdev;
622 if (!parent)
623 return;
624
625 down_read(&pci_bus_sem);
626 mutex_lock(&aspm_lock);
627 link_state = parent->link_state;
628 link_state->support_state &=
629 ~(state & (PCIE_LINK_STATE_L0S|PCIE_LINK_STATE_L1));
630 if (state & PCIE_LINK_STATE_CLKPM)
631 link_state->clk_pm_capable = 0;
632
633 __pcie_aspm_configure_link_state(parent, link_state->enabled_state);
634 if (!link_state->clk_pm_capable && link_state->clk_pm_enabled)
635 pcie_set_clock_pm(parent, 0);
636 mutex_unlock(&aspm_lock);
637 up_read(&pci_bus_sem);
638}
639EXPORT_SYMBOL(pci_disable_link_state);
640
641static int pcie_aspm_set_policy(const char *val, struct kernel_param *kp)
642{
643 int i;
644 struct pci_dev *pdev;
645 struct pcie_link_state *link_state;
646
647 for (i = 0; i < ARRAY_SIZE(policy_str); i++)
648 if (!strncmp(val, policy_str[i], strlen(policy_str[i])))
649 break;
650 if (i >= ARRAY_SIZE(policy_str))
651 return -EINVAL;
652 if (i == aspm_policy)
653 return 0;
654
655 down_read(&pci_bus_sem);
656 mutex_lock(&aspm_lock);
657 aspm_policy = i;
658 list_for_each_entry(link_state, &link_list, sibiling) {
659 pdev = link_state->pdev;
660 __pcie_aspm_configure_link_state(pdev,
661 policy_to_aspm_state(pdev));
662 if (link_state->clk_pm_capable &&
663 link_state->clk_pm_enabled != policy_to_clkpm_state(pdev))
664 pcie_set_clock_pm(pdev, policy_to_clkpm_state(pdev));
665
666 }
667 mutex_unlock(&aspm_lock);
668 up_read(&pci_bus_sem);
669 return 0;
670}
671
672static int pcie_aspm_get_policy(char *buffer, struct kernel_param *kp)
673{
674 int i, cnt = 0;
675 for (i = 0; i < ARRAY_SIZE(policy_str); i++)
676 if (i == aspm_policy)
677 cnt += sprintf(buffer + cnt, "[%s] ", policy_str[i]);
678 else
679 cnt += sprintf(buffer + cnt, "%s ", policy_str[i]);
680 return cnt;
681}
682
683module_param_call(policy, pcie_aspm_set_policy, pcie_aspm_get_policy,
684 NULL, 0644);
685
686#ifdef CONFIG_PCIEASPM_DEBUG
687static ssize_t link_state_show(struct device *dev,
688 struct device_attribute *attr,
689 char *buf)
690{
691 struct pci_dev *pci_device = to_pci_dev(dev);
692 struct pcie_link_state *link_state = pci_device->link_state;
693
694 return sprintf(buf, "%d\n", link_state->enabled_state);
695}
696
697static ssize_t link_state_store(struct device *dev,
698 struct device_attribute *attr,
699 const char *buf,
700 size_t n)
701{
702 struct pci_dev *pci_device = to_pci_dev(dev);
703 int state;
704
705 if (n < 1)
706 return -EINVAL;
707 state = buf[0]-'0';
708 if (state >= 0 && state <= 3) {
709 /* setup link aspm state */
710 pcie_aspm_configure_link_state(pci_device, state);
711 return n;
712 }
713
714 return -EINVAL;
715}
716
717static ssize_t clk_ctl_show(struct device *dev,
718 struct device_attribute *attr,
719 char *buf)
720{
721 struct pci_dev *pci_device = to_pci_dev(dev);
722 struct pcie_link_state *link_state = pci_device->link_state;
723
724 return sprintf(buf, "%d\n", link_state->clk_pm_enabled);
725}
726
727static ssize_t clk_ctl_store(struct device *dev,
728 struct device_attribute *attr,
729 const char *buf,
730 size_t n)
731{
732 struct pci_dev *pci_device = to_pci_dev(dev);
733 int state;
734
735 if (n < 1)
736 return -EINVAL;
737 state = buf[0]-'0';
738
739 down_read(&pci_bus_sem);
740 mutex_lock(&aspm_lock);
741 pcie_set_clock_pm(pci_device, !!state);
742 mutex_unlock(&aspm_lock);
743 up_read(&pci_bus_sem);
744
745 return n;
746}
747
748static DEVICE_ATTR(link_state, 0644, link_state_show, link_state_store);
749static DEVICE_ATTR(clk_ctl, 0644, clk_ctl_show, clk_ctl_store);
750
751static char power_group[] = "power";
752void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev)
753{
754 struct pcie_link_state *link_state = pdev->link_state;
755
756 if (!pdev->is_pcie || (pdev->pcie_type != PCI_EXP_TYPE_ROOT_PORT &&
757 pdev->pcie_type != PCI_EXP_TYPE_DOWNSTREAM))
758 return;
759
760 if (link_state->support_state)
761 sysfs_add_file_to_group(&pdev->dev.kobj,
762 &dev_attr_link_state.attr, power_group);
763 if (link_state->clk_pm_capable)
764 sysfs_add_file_to_group(&pdev->dev.kobj,
765 &dev_attr_clk_ctl.attr, power_group);
766}
767
768void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev)
769{
770 struct pcie_link_state *link_state = pdev->link_state;
771
772 if (!pdev->is_pcie || (pdev->pcie_type != PCI_EXP_TYPE_ROOT_PORT &&
773 pdev->pcie_type != PCI_EXP_TYPE_DOWNSTREAM))
774 return;
775
776 if (link_state->support_state)
777 sysfs_remove_file_from_group(&pdev->dev.kobj,
778 &dev_attr_link_state.attr, power_group);
779 if (link_state->clk_pm_capable)
780 sysfs_remove_file_from_group(&pdev->dev.kobj,
781 &dev_attr_clk_ctl.attr, power_group);
782}
783#endif
784
785static int __init pcie_aspm_disable(char *str)
786{
787 aspm_disabled = 1;
788 return 1;
789}
790
791__setup("pcie_noaspm", pcie_aspm_disable);
792
793static int __init pcie_aspm_init(void)
794{
795 if (aspm_disabled)
796 return 0;
797 pci_osc_support_set(OSC_ACTIVE_STATE_PWR_SUPPORT|
798 OSC_CLOCK_PWR_CAPABILITY_SUPPORT);
799 return 0;
800}
801
802fs_initcall(pcie_aspm_init);
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 4262dfec5676..9b4673df27e7 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -9,6 +9,7 @@
9#include <linux/slab.h> 9#include <linux/slab.h>
10#include <linux/module.h> 10#include <linux/module.h>
11#include <linux/cpumask.h> 11#include <linux/cpumask.h>
12#include <linux/aspm.h>
12#include "pci.h" 13#include "pci.h"
13 14
14#define CARDBUS_LATENCY_TIMER 176 /* secondary latency timer */ 15#define CARDBUS_LATENCY_TIMER 176 /* secondary latency timer */
@@ -1010,6 +1011,10 @@ int pci_scan_slot(struct pci_bus *bus, int devfn)
1010 break; 1011 break;
1011 } 1012 }
1012 } 1013 }
1014
1015 if (bus->self)
1016 pcie_aspm_init_link_state(bus->self);
1017
1013 return nr; 1018 return nr;
1014} 1019}
1015 1020
diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
index 430281b2e921..05c9ad2a7f8b 100644
--- a/drivers/pci/remove.c
+++ b/drivers/pci/remove.c
@@ -1,5 +1,6 @@
1#include <linux/pci.h> 1#include <linux/pci.h>
2#include <linux/module.h> 2#include <linux/module.h>
3#include <linux/aspm.h>
3#include "pci.h" 4#include "pci.h"
4 5
5static void pci_free_resources(struct pci_dev *dev) 6static void pci_free_resources(struct pci_dev *dev)
@@ -30,6 +31,9 @@ static void pci_stop_dev(struct pci_dev *dev)
30 dev->global_list.next = dev->global_list.prev = NULL; 31 dev->global_list.next = dev->global_list.prev = NULL;
31 up_write(&pci_bus_sem); 32 up_write(&pci_bus_sem);
32 } 33 }
34
35 if (dev->bus->self)
36 pcie_aspm_exit_link_state(dev);
33} 37}
34 38
35static void pci_destroy_dev(struct pci_dev *dev) 39static void pci_destroy_dev(struct pci_dev *dev)
diff --git a/include/linux/aspm.h b/include/linux/aspm.h
new file mode 100644
index 000000000000..f41a69895485
--- /dev/null
+++ b/include/linux/aspm.h
@@ -0,0 +1,44 @@
1/*
2 * aspm.h
3 *
4 * PCI Express ASPM defines and function prototypes
5 *
6 * Copyright (C) 2007 Intel Corp.
7 * Zhang Yanmin (yanmin.zhang@intel.com)
8 * Shaohua Li (shaohua.li@intel.com)
9 *
10 * For more information, please consult the following manuals (look at
11 * http://www.pcisig.com/ for how to get them):
12 *
13 * PCI Express Specification
14 */
15
16#ifndef LINUX_ASPM_H
17#define LINUX_ASPM_H
18
19#include <linux/pci.h>
20
21#define PCIE_LINK_STATE_L0S 1
22#define PCIE_LINK_STATE_L1 2
23#define PCIE_LINK_STATE_CLKPM 4
24
25#ifdef CONFIG_PCIEASPM
26extern void pcie_aspm_init_link_state(struct pci_dev *pdev);
27extern void pcie_aspm_exit_link_state(struct pci_dev *pdev);
28extern void pcie_aspm_pm_state_change(struct pci_dev *pdev);
29extern void pci_disable_link_state(struct pci_dev *pdev, int state);
30#else
31#define pcie_aspm_init_link_state(pdev) do {} while (0)
32#define pcie_aspm_exit_link_state(pdev) do {} while (0)
33#define pcie_aspm_pm_state_change(pdev) do {} while (0)
34#define pci_disable_link_state(pdev, state) do {} while (0)
35#endif
36
37#ifdef CONFIG_PCIEASPM_DEBUG /* this depends on CONFIG_PCIEASPM */
38extern void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev);
39extern void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev);
40#else
41#define pcie_aspm_create_sysfs_dev_files(pdev) do {} while (0)
42#define pcie_aspm_remove_sysfs_dev_files(pdev) do {} while (0)
43#endif
44#endif /* LINUX_ASPM_H */
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 13813b0592fc..163b45241729 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -128,6 +128,7 @@ struct pci_cap_saved_state {
128 u32 data[0]; 128 u32 data[0];
129}; 129};
130 130
131struct pcie_link_state;
131/* 132/*
132 * The pci_dev structure is used to describe PCI devices. 133 * The pci_dev structure is used to describe PCI devices.
133 */ 134 */
@@ -163,6 +164,10 @@ struct pci_dev {
163 this is D0-D3, D0 being fully functional, 164 this is D0-D3, D0 being fully functional,
164 and D3 being off. */ 165 and D3 being off. */
165 166
167#ifdef CONFIG_PCIEASPM
168 struct pcie_link_state *link_state; /* ASPM link state. */
169#endif
170
166 pci_channel_state_t error_state; /* current connectivity state */ 171 pci_channel_state_t error_state; /* current connectivity state */
167 struct device dev; /* Generic device interface */ 172 struct device dev; /* Generic device interface */
168 173
diff --git a/include/linux/pci_regs.h b/include/linux/pci_regs.h
index c1914a8b94a9..c0c1223c9194 100644
--- a/include/linux/pci_regs.h
+++ b/include/linux/pci_regs.h
@@ -395,9 +395,17 @@
395#define PCI_EXP_DEVSTA_AUXPD 0x10 /* AUX Power Detected */ 395#define PCI_EXP_DEVSTA_AUXPD 0x10 /* AUX Power Detected */
396#define PCI_EXP_DEVSTA_TRPND 0x20 /* Transactions Pending */ 396#define PCI_EXP_DEVSTA_TRPND 0x20 /* Transactions Pending */
397#define PCI_EXP_LNKCAP 12 /* Link Capabilities */ 397#define PCI_EXP_LNKCAP 12 /* Link Capabilities */
398#define PCI_EXP_LNKCAP_ASPMS 0xc00 /* ASPM Support */
399#define PCI_EXP_LNKCAP_L0SEL 0x7000 /* L0s Exit Latency */
400#define PCI_EXP_LNKCAP_L1EL 0x38000 /* L1 Exit Latency */
401#define PCI_EXP_LNKCAP_CLKPM 0x40000 /* L1 Clock Power Management */
398#define PCI_EXP_LNKCTL 16 /* Link Control */ 402#define PCI_EXP_LNKCTL 16 /* Link Control */
403#define PCI_EXP_LNKCTL_RL 0x20 /* Retrain Link */
404#define PCI_EXP_LNKCTL_CCC 0x40 /* Common Clock COnfiguration */
399#define PCI_EXP_LNKCTL_CLKREQ_EN 0x100 /* Enable clkreq */ 405#define PCI_EXP_LNKCTL_CLKREQ_EN 0x100 /* Enable clkreq */
400#define PCI_EXP_LNKSTA 18 /* Link Status */ 406#define PCI_EXP_LNKSTA 18 /* Link Status */
407#define PCI_EXP_LNKSTA_LT 0x800 /* Link Training */
408#define PCI_EXP_LNKSTA_SLC 0x1000 /* Slot Clock Configuration */
401#define PCI_EXP_SLTCAP 20 /* Slot Capabilities */ 409#define PCI_EXP_SLTCAP 20 /* Slot Capabilities */
402#define PCI_EXP_SLTCTL 24 /* Slot Control */ 410#define PCI_EXP_SLTCTL 24 /* Slot Control */
403#define PCI_EXP_SLTSTA 26 /* Slot Status */ 411#define PCI_EXP_SLTSTA 26 /* Slot Status */
generated by cgit v1.2.2 (git 2.25.0) at 2025-11-21 16:37:27 -0500