diff options
Diffstat (limited to 'drivers/idle')
-rw-r--r-- | drivers/idle/Kconfig | 17 | ||||
-rw-r--r-- | drivers/idle/Makefile | 2 | ||||
-rw-r--r-- | drivers/idle/i7300_idle.c | 609 |
3 files changed, 628 insertions, 0 deletions
diff --git a/drivers/idle/Kconfig b/drivers/idle/Kconfig new file mode 100644 index 000000000000..108264de0ac9 --- /dev/null +++ b/drivers/idle/Kconfig | |||
@@ -0,0 +1,17 @@ | |||
1 | |||
2 | menu "Memory power savings" | ||
3 | |||
4 | config I7300_IDLE_IOAT_CHANNEL | ||
5 | bool | ||
6 | |||
7 | config I7300_IDLE | ||
8 | tristate "Intel chipset idle memory power saving driver" | ||
9 | select I7300_IDLE_IOAT_CHANNEL | ||
10 | depends on X86_64 && EXPERIMENTAL | ||
11 | help | ||
12 | Enable memory power savings when idle with certain Intel server | ||
13 | chipsets. The chipset must have I/O AT support, such as the | ||
14 | Intel 7300. The power savings depends on the type and quantity of | ||
15 | DRAM devices. | ||
16 | |||
17 | endmenu | ||
diff --git a/drivers/idle/Makefile b/drivers/idle/Makefile new file mode 100644 index 000000000000..5f68fc377e21 --- /dev/null +++ b/drivers/idle/Makefile | |||
@@ -0,0 +1,2 @@ | |||
1 | obj-$(CONFIG_I7300_IDLE) += i7300_idle.o | ||
2 | |||
diff --git a/drivers/idle/i7300_idle.c b/drivers/idle/i7300_idle.c new file mode 100644 index 000000000000..fb176f6ef9f8 --- /dev/null +++ b/drivers/idle/i7300_idle.c | |||
@@ -0,0 +1,609 @@ | |||
1 | /* | ||
2 | * (C) Copyright 2008 Intel Corporation | ||
3 | * Authors: | ||
4 | * Andy Henroid <andrew.d.henroid@intel.com> | ||
5 | * Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> | ||
6 | */ | ||
7 | |||
8 | /* | ||
9 | * Save DIMM power on Intel 7300-based platforms when all CPUs/cores | ||
10 | * are idle, using the DIMM thermal throttling capability. | ||
11 | * | ||
12 | * This driver depends on the Intel integrated DMA controller (I/O AT). | ||
13 | * If the driver for I/O AT (drivers/dma/ioatdma*) is also enabled, | ||
14 | * this driver should work cooperatively. | ||
15 | */ | ||
16 | |||
17 | /* #define DEBUG */ | ||
18 | |||
19 | #include <linux/module.h> | ||
20 | #include <linux/pci.h> | ||
21 | #include <linux/sched.h> | ||
22 | #include <linux/notifier.h> | ||
23 | #include <linux/cpumask.h> | ||
24 | #include <linux/ktime.h> | ||
25 | #include <linux/delay.h> | ||
26 | #include <linux/debugfs.h> | ||
27 | #include <linux/stop_machine.h> | ||
28 | #include <linux/i7300_idle.h> | ||
29 | |||
30 | #include <asm/idle.h> | ||
31 | |||
32 | #include "../dma/ioatdma_hw.h" | ||
33 | #include "../dma/ioatdma_registers.h" | ||
34 | |||
35 | #define I7300_IDLE_DRIVER_VERSION "1.55" | ||
36 | #define I7300_PRINT "i7300_idle:" | ||
37 | |||
38 | #define MAX_STOP_RETRIES 10 | ||
39 | |||
40 | static int debug; | ||
41 | module_param_named(debug, debug, uint, 0644); | ||
42 | MODULE_PARM_DESC(debug, "Enable debug printks in this driver"); | ||
43 | |||
44 | #define dprintk(fmt, arg...) \ | ||
45 | do { if (debug) printk(KERN_INFO I7300_PRINT fmt, ##arg); } while (0) | ||
46 | |||
47 | /* | ||
48 | * Value to set THRTLOW to when initiating throttling | ||
49 | * 0 = No throttling | ||
50 | * 1 = Throttle when > 4 activations per eval window (Maximum throttling) | ||
51 | * 2 = Throttle when > 8 activations | ||
52 | * 168 = Throttle when > 672 activations (Minimum throttling) | ||
53 | */ | ||
54 | #define MAX_THROTTLE_LOW_LIMIT 168 | ||
55 | static uint throttle_low_limit = 1; | ||
56 | module_param_named(throttle_low_limit, throttle_low_limit, uint, 0644); | ||
57 | MODULE_PARM_DESC(throttle_low_limit, | ||
58 | "Value for THRTLOWLM activation field " | ||
59 | "(0 = disable throttle, 1 = Max throttle, 168 = Min throttle)"); | ||
60 | |||
61 | /* | ||
62 | * simple invocation and duration statistics | ||
63 | */ | ||
64 | static unsigned long total_starts; | ||
65 | static unsigned long total_us; | ||
66 | |||
67 | #ifdef DEBUG | ||
68 | static unsigned long past_skip; | ||
69 | #endif | ||
70 | |||
71 | static struct pci_dev *fbd_dev; | ||
72 | |||
73 | static spinlock_t i7300_idle_lock; | ||
74 | static int i7300_idle_active; | ||
75 | |||
76 | static u8 i7300_idle_thrtctl_saved; | ||
77 | static u8 i7300_idle_thrtlow_saved; | ||
78 | static u32 i7300_idle_mc_saved; | ||
79 | |||
80 | static cpumask_t idle_cpumask; | ||
81 | static ktime_t start_ktime; | ||
82 | static unsigned long avg_idle_us; | ||
83 | |||
84 | static struct dentry *debugfs_dir; | ||
85 | |||
86 | /* Begin: I/O AT Helper routines */ | ||
87 | |||
88 | #define IOAT_CHANBASE(ioat_ctl, chan) (ioat_ctl + 0x80 + 0x80 * chan) | ||
89 | /* Snoop control (disable snoops when coherency is not important) */ | ||
90 | #define IOAT_DESC_SADDR_SNP_CTL (1UL << 1) | ||
91 | #define IOAT_DESC_DADDR_SNP_CTL (1UL << 2) | ||
92 | |||
93 | static struct pci_dev *ioat_dev; | ||
94 | static struct ioat_dma_descriptor *ioat_desc; /* I/O AT desc & data (1 page) */ | ||
95 | static unsigned long ioat_desc_phys; | ||
96 | static u8 *ioat_iomap; /* I/O AT memory-mapped control regs (aka CB_BAR) */ | ||
97 | static u8 *ioat_chanbase; | ||
98 | |||
99 | /* Start I/O AT memory copy */ | ||
100 | static int i7300_idle_ioat_start(void) | ||
101 | { | ||
102 | u32 err; | ||
103 | /* Clear error (due to circular descriptor pointer) */ | ||
104 | err = readl(ioat_chanbase + IOAT_CHANERR_OFFSET); | ||
105 | if (err) | ||
106 | writel(err, ioat_chanbase + IOAT_CHANERR_OFFSET); | ||
107 | |||
108 | writeb(IOAT_CHANCMD_START, ioat_chanbase + IOAT1_CHANCMD_OFFSET); | ||
109 | return 0; | ||
110 | } | ||
111 | |||
112 | /* Stop I/O AT memory copy */ | ||
113 | static void i7300_idle_ioat_stop(void) | ||
114 | { | ||
115 | int i; | ||
116 | u64 sts; | ||
117 | |||
118 | for (i = 0; i < MAX_STOP_RETRIES; i++) { | ||
119 | writeb(IOAT_CHANCMD_RESET, | ||
120 | ioat_chanbase + IOAT1_CHANCMD_OFFSET); | ||
121 | |||
122 | udelay(10); | ||
123 | |||
124 | sts = readq(ioat_chanbase + IOAT1_CHANSTS_OFFSET) & | ||
125 | IOAT_CHANSTS_DMA_TRANSFER_STATUS; | ||
126 | |||
127 | if (sts != IOAT_CHANSTS_DMA_TRANSFER_STATUS_ACTIVE) | ||
128 | break; | ||
129 | |||
130 | } | ||
131 | |||
132 | if (i == MAX_STOP_RETRIES) { | ||
133 | dprintk("failed to stop I/O AT after %d retries\n", | ||
134 | MAX_STOP_RETRIES); | ||
135 | } | ||
136 | } | ||
137 | |||
138 | /* Test I/O AT by copying 1024 byte from 2k to 1k */ | ||
139 | static int __init i7300_idle_ioat_selftest(u8 *ctl, | ||
140 | struct ioat_dma_descriptor *desc, unsigned long desc_phys) | ||
141 | { | ||
142 | u64 chan_sts; | ||
143 | |||
144 | memset(desc, 0, 2048); | ||
145 | memset((u8 *) desc + 2048, 0xab, 1024); | ||
146 | |||
147 | desc[0].size = 1024; | ||
148 | desc[0].ctl = 0; | ||
149 | desc[0].src_addr = desc_phys + 2048; | ||
150 | desc[0].dst_addr = desc_phys + 1024; | ||
151 | desc[0].next = 0; | ||
152 | |||
153 | writeb(IOAT_CHANCMD_RESET, ioat_chanbase + IOAT1_CHANCMD_OFFSET); | ||
154 | writeb(IOAT_CHANCMD_START, ioat_chanbase + IOAT1_CHANCMD_OFFSET); | ||
155 | |||
156 | udelay(1000); | ||
157 | |||
158 | chan_sts = readq(ioat_chanbase + IOAT1_CHANSTS_OFFSET) & | ||
159 | IOAT_CHANSTS_DMA_TRANSFER_STATUS; | ||
160 | |||
161 | if (chan_sts != IOAT_CHANSTS_DMA_TRANSFER_STATUS_DONE) { | ||
162 | /* Not complete, reset the channel */ | ||
163 | writeb(IOAT_CHANCMD_RESET, | ||
164 | ioat_chanbase + IOAT1_CHANCMD_OFFSET); | ||
165 | return -1; | ||
166 | } | ||
167 | |||
168 | if (*(u32 *) ((u8 *) desc + 3068) != 0xabababab || | ||
169 | *(u32 *) ((u8 *) desc + 2044) != 0xabababab) { | ||
170 | dprintk("Data values src 0x%x, dest 0x%x, memset 0x%x\n", | ||
171 | *(u32 *) ((u8 *) desc + 2048), | ||
172 | *(u32 *) ((u8 *) desc + 1024), | ||
173 | *(u32 *) ((u8 *) desc + 3072)); | ||
174 | return -1; | ||
175 | } | ||
176 | return 0; | ||
177 | } | ||
178 | |||
179 | static struct device dummy_dma_dev = { | ||
180 | .bus_id = "fallback device", | ||
181 | .coherent_dma_mask = DMA_64BIT_MASK, | ||
182 | .dma_mask = &dummy_dma_dev.coherent_dma_mask, | ||
183 | }; | ||
184 | |||
185 | /* Setup and initialize I/O AT */ | ||
186 | /* This driver needs I/O AT as the throttling takes effect only when there is | ||
187 | * some memory activity. We use I/O AT to set up a dummy copy, while all CPUs | ||
188 | * go idle and memory is throttled. | ||
189 | */ | ||
190 | static int __init i7300_idle_ioat_init(void) | ||
191 | { | ||
192 | u8 ver, chan_count, ioat_chan; | ||
193 | u16 chan_ctl; | ||
194 | |||
195 | ioat_iomap = (u8 *) ioremap_nocache(pci_resource_start(ioat_dev, 0), | ||
196 | pci_resource_len(ioat_dev, 0)); | ||
197 | |||
198 | if (!ioat_iomap) { | ||
199 | printk(KERN_ERR I7300_PRINT "failed to map I/O AT registers\n"); | ||
200 | goto err_ret; | ||
201 | } | ||
202 | |||
203 | ver = readb(ioat_iomap + IOAT_VER_OFFSET); | ||
204 | if (ver != IOAT_VER_1_2) { | ||
205 | printk(KERN_ERR I7300_PRINT "unknown I/O AT version (%u.%u)\n", | ||
206 | ver >> 4, ver & 0xf); | ||
207 | goto err_unmap; | ||
208 | } | ||
209 | |||
210 | chan_count = readb(ioat_iomap + IOAT_CHANCNT_OFFSET); | ||
211 | if (!chan_count) { | ||
212 | printk(KERN_ERR I7300_PRINT "unexpected # of I/O AT channels " | ||
213 | "(%u)\n", | ||
214 | chan_count); | ||
215 | goto err_unmap; | ||
216 | } | ||
217 | |||
218 | ioat_chan = chan_count - 1; | ||
219 | ioat_chanbase = IOAT_CHANBASE(ioat_iomap, ioat_chan); | ||
220 | |||
221 | chan_ctl = readw(ioat_chanbase + IOAT_CHANCTRL_OFFSET); | ||
222 | if (chan_ctl & IOAT_CHANCTRL_CHANNEL_IN_USE) { | ||
223 | printk(KERN_ERR I7300_PRINT "channel %d in use\n", ioat_chan); | ||
224 | goto err_unmap; | ||
225 | } | ||
226 | |||
227 | writew(IOAT_CHANCTRL_CHANNEL_IN_USE, | ||
228 | ioat_chanbase + IOAT_CHANCTRL_OFFSET); | ||
229 | |||
230 | ioat_desc = (struct ioat_dma_descriptor *)dma_alloc_coherent( | ||
231 | &dummy_dma_dev, 4096, | ||
232 | (dma_addr_t *)&ioat_desc_phys, GFP_KERNEL); | ||
233 | if (!ioat_desc) { | ||
234 | printk(KERN_ERR I7300_PRINT "failed to allocate I/O AT desc\n"); | ||
235 | goto err_mark_unused; | ||
236 | } | ||
237 | |||
238 | writel(ioat_desc_phys & 0xffffffffUL, | ||
239 | ioat_chanbase + IOAT1_CHAINADDR_OFFSET_LOW); | ||
240 | writel(ioat_desc_phys >> 32, | ||
241 | ioat_chanbase + IOAT1_CHAINADDR_OFFSET_HIGH); | ||
242 | |||
243 | if (i7300_idle_ioat_selftest(ioat_iomap, ioat_desc, ioat_desc_phys)) { | ||
244 | printk(KERN_ERR I7300_PRINT "I/O AT self-test failed\n"); | ||
245 | goto err_free; | ||
246 | } | ||
247 | |||
248 | /* Setup circular I/O AT descriptor chain */ | ||
249 | ioat_desc[0].ctl = IOAT_DESC_SADDR_SNP_CTL | IOAT_DESC_DADDR_SNP_CTL; | ||
250 | ioat_desc[0].src_addr = ioat_desc_phys + 2048; | ||
251 | ioat_desc[0].dst_addr = ioat_desc_phys + 3072; | ||
252 | ioat_desc[0].size = 128; | ||
253 | ioat_desc[0].next = ioat_desc_phys + sizeof(struct ioat_dma_descriptor); | ||
254 | |||
255 | ioat_desc[1].ctl = ioat_desc[0].ctl; | ||
256 | ioat_desc[1].src_addr = ioat_desc[0].src_addr; | ||
257 | ioat_desc[1].dst_addr = ioat_desc[0].dst_addr; | ||
258 | ioat_desc[1].size = ioat_desc[0].size; | ||
259 | ioat_desc[1].next = ioat_desc_phys; | ||
260 | |||
261 | return 0; | ||
262 | |||
263 | err_free: | ||
264 | dma_free_coherent(&dummy_dma_dev, 4096, (void *)ioat_desc, 0); | ||
265 | err_mark_unused: | ||
266 | writew(0, ioat_chanbase + IOAT_CHANCTRL_OFFSET); | ||
267 | err_unmap: | ||
268 | iounmap(ioat_iomap); | ||
269 | err_ret: | ||
270 | return -ENODEV; | ||
271 | } | ||
272 | |||
273 | /* Cleanup I/O AT */ | ||
274 | static void __exit i7300_idle_ioat_exit(void) | ||
275 | { | ||
276 | int i; | ||
277 | u64 chan_sts; | ||
278 | |||
279 | i7300_idle_ioat_stop(); | ||
280 | |||
281 | /* Wait for a while for the channel to halt before releasing */ | ||
282 | for (i = 0; i < MAX_STOP_RETRIES; i++) { | ||
283 | writeb(IOAT_CHANCMD_RESET, | ||
284 | ioat_chanbase + IOAT1_CHANCMD_OFFSET); | ||
285 | |||
286 | chan_sts = readq(ioat_chanbase + IOAT1_CHANSTS_OFFSET) & | ||
287 | IOAT_CHANSTS_DMA_TRANSFER_STATUS; | ||
288 | |||
289 | if (chan_sts != IOAT_CHANSTS_DMA_TRANSFER_STATUS_ACTIVE) { | ||
290 | writew(0, ioat_chanbase + IOAT_CHANCTRL_OFFSET); | ||
291 | break; | ||
292 | } | ||
293 | udelay(1000); | ||
294 | } | ||
295 | |||
296 | chan_sts = readq(ioat_chanbase + IOAT1_CHANSTS_OFFSET) & | ||
297 | IOAT_CHANSTS_DMA_TRANSFER_STATUS; | ||
298 | |||
299 | /* | ||
300 | * We tried to reset multiple times. If IO A/T channel is still active | ||
301 | * flag an error and return without cleanup. Memory leak is better | ||
302 | * than random corruption in that extreme error situation. | ||
303 | */ | ||
304 | if (chan_sts == IOAT_CHANSTS_DMA_TRANSFER_STATUS_ACTIVE) { | ||
305 | printk(KERN_ERR I7300_PRINT "Unable to stop IO A/T channels." | ||
306 | " Not freeing resources\n"); | ||
307 | return; | ||
308 | } | ||
309 | |||
310 | dma_free_coherent(&dummy_dma_dev, 4096, (void *)ioat_desc, 0); | ||
311 | iounmap(ioat_iomap); | ||
312 | } | ||
313 | |||
314 | /* End: I/O AT Helper routines */ | ||
315 | |||
316 | #define DIMM_THRTLOW 0x64 | ||
317 | #define DIMM_THRTCTL 0x67 | ||
318 | #define DIMM_THRTCTL_THRMHUNT (1UL << 0) | ||
319 | #define DIMM_MC 0x40 | ||
320 | #define DIMM_GTW_MODE (1UL << 17) | ||
321 | #define DIMM_GBLACT 0x60 | ||
322 | |||
323 | /* | ||
324 | * Keep track of an exponential-decaying average of recent idle durations. | ||
325 | * The latest duration gets DURATION_WEIGHT_PCT percentage weight | ||
326 | * in this average, with the old average getting the remaining weight. | ||
327 | * | ||
328 | * High weights emphasize recent history, low weights include long history. | ||
329 | */ | ||
330 | #define DURATION_WEIGHT_PCT 55 | ||
331 | |||
332 | /* | ||
333 | * When the decaying average of recent durations or the predicted duration | ||
334 | * of the next timer interrupt is shorter than duration_threshold, the | ||
335 | * driver will decline to throttle. | ||
336 | */ | ||
337 | #define DURATION_THRESHOLD_US 100 | ||
338 | |||
339 | |||
340 | /* Store DIMM thermal throttle configuration */ | ||
341 | static int i7300_idle_thrt_save(void) | ||
342 | { | ||
343 | u32 new_mc_val; | ||
344 | u8 gblactlm; | ||
345 | |||
346 | pci_read_config_byte(fbd_dev, DIMM_THRTCTL, &i7300_idle_thrtctl_saved); | ||
347 | pci_read_config_byte(fbd_dev, DIMM_THRTLOW, &i7300_idle_thrtlow_saved); | ||
348 | pci_read_config_dword(fbd_dev, DIMM_MC, &i7300_idle_mc_saved); | ||
349 | /* | ||
350 | * Make sure we have Global Throttling Window Mode set to have a | ||
351 | * "short" window. This (mostly) works around an issue where | ||
352 | * throttling persists until the end of the global throttling window | ||
353 | * size. On the tested system, this was resulting in a maximum of | ||
354 | * 64 ms to exit throttling (average 32 ms). The actual numbers | ||
355 | * depends on system frequencies. Setting the short window reduces | ||
356 | * this by a factor of 4096. | ||
357 | * | ||
358 | * We will only do this only if the system is set for | ||
359 | * unlimited-activations while in open-loop throttling (i.e., when | ||
360 | * Global Activation Throttle Limit is zero). | ||
361 | */ | ||
362 | pci_read_config_byte(fbd_dev, DIMM_GBLACT, &gblactlm); | ||
363 | dprintk("thrtctl_saved = 0x%02x, thrtlow_saved = 0x%02x\n", | ||
364 | i7300_idle_thrtctl_saved, | ||
365 | i7300_idle_thrtlow_saved); | ||
366 | dprintk("mc_saved = 0x%08x, gblactlm = 0x%02x\n", | ||
367 | i7300_idle_mc_saved, | ||
368 | gblactlm); | ||
369 | if (gblactlm == 0) { | ||
370 | new_mc_val = i7300_idle_mc_saved | DIMM_GTW_MODE; | ||
371 | pci_write_config_dword(fbd_dev, DIMM_MC, new_mc_val); | ||
372 | return 0; | ||
373 | } else { | ||
374 | dprintk("could not set GTW_MODE = 1 (OLTT enabled)\n"); | ||
375 | return -ENODEV; | ||
376 | } | ||
377 | } | ||
378 | |||
379 | /* Restore DIMM thermal throttle configuration */ | ||
380 | static void i7300_idle_thrt_restore(void) | ||
381 | { | ||
382 | pci_write_config_dword(fbd_dev, DIMM_MC, i7300_idle_mc_saved); | ||
383 | pci_write_config_byte(fbd_dev, DIMM_THRTLOW, i7300_idle_thrtlow_saved); | ||
384 | pci_write_config_byte(fbd_dev, DIMM_THRTCTL, i7300_idle_thrtctl_saved); | ||
385 | } | ||
386 | |||
387 | /* Enable DIMM thermal throttling */ | ||
388 | static void i7300_idle_start(void) | ||
389 | { | ||
390 | u8 new_ctl; | ||
391 | u8 limit; | ||
392 | |||
393 | new_ctl = i7300_idle_thrtctl_saved & ~DIMM_THRTCTL_THRMHUNT; | ||
394 | pci_write_config_byte(fbd_dev, DIMM_THRTCTL, new_ctl); | ||
395 | |||
396 | limit = throttle_low_limit; | ||
397 | if (unlikely(limit > MAX_THROTTLE_LOW_LIMIT)) | ||
398 | limit = MAX_THROTTLE_LOW_LIMIT; | ||
399 | |||
400 | pci_write_config_byte(fbd_dev, DIMM_THRTLOW, limit); | ||
401 | |||
402 | new_ctl = i7300_idle_thrtctl_saved | DIMM_THRTCTL_THRMHUNT; | ||
403 | pci_write_config_byte(fbd_dev, DIMM_THRTCTL, new_ctl); | ||
404 | } | ||
405 | |||
406 | /* Disable DIMM thermal throttling */ | ||
407 | static void i7300_idle_stop(void) | ||
408 | { | ||
409 | u8 new_ctl; | ||
410 | u8 got_ctl; | ||
411 | |||
412 | new_ctl = i7300_idle_thrtctl_saved & ~DIMM_THRTCTL_THRMHUNT; | ||
413 | pci_write_config_byte(fbd_dev, DIMM_THRTCTL, new_ctl); | ||
414 | |||
415 | pci_write_config_byte(fbd_dev, DIMM_THRTLOW, i7300_idle_thrtlow_saved); | ||
416 | pci_write_config_byte(fbd_dev, DIMM_THRTCTL, i7300_idle_thrtctl_saved); | ||
417 | pci_read_config_byte(fbd_dev, DIMM_THRTCTL, &got_ctl); | ||
418 | WARN_ON_ONCE(got_ctl != i7300_idle_thrtctl_saved); | ||
419 | } | ||
420 | |||
421 | |||
422 | /* | ||
423 | * i7300_avg_duration_check() | ||
424 | * return 0 if the decaying average of recent idle durations is | ||
425 | * more than DURATION_THRESHOLD_US | ||
426 | */ | ||
427 | static int i7300_avg_duration_check(void) | ||
428 | { | ||
429 | if (avg_idle_us >= DURATION_THRESHOLD_US) | ||
430 | return 0; | ||
431 | |||
432 | #ifdef DEBUG | ||
433 | past_skip++; | ||
434 | #endif | ||
435 | return 1; | ||
436 | } | ||
437 | |||
438 | /* Idle notifier to look at idle CPUs */ | ||
439 | static int i7300_idle_notifier(struct notifier_block *nb, unsigned long val, | ||
440 | void *data) | ||
441 | { | ||
442 | unsigned long flags; | ||
443 | ktime_t now_ktime; | ||
444 | static ktime_t idle_begin_time; | ||
445 | static int time_init = 1; | ||
446 | |||
447 | if (!throttle_low_limit) | ||
448 | return 0; | ||
449 | |||
450 | if (unlikely(time_init)) { | ||
451 | time_init = 0; | ||
452 | idle_begin_time = ktime_get(); | ||
453 | } | ||
454 | |||
455 | spin_lock_irqsave(&i7300_idle_lock, flags); | ||
456 | if (val == IDLE_START) { | ||
457 | |||
458 | cpu_set(smp_processor_id(), idle_cpumask); | ||
459 | |||
460 | if (cpus_weight(idle_cpumask) != num_online_cpus()) | ||
461 | goto end; | ||
462 | |||
463 | now_ktime = ktime_get(); | ||
464 | idle_begin_time = now_ktime; | ||
465 | |||
466 | if (i7300_avg_duration_check()) | ||
467 | goto end; | ||
468 | |||
469 | i7300_idle_active = 1; | ||
470 | total_starts++; | ||
471 | start_ktime = now_ktime; | ||
472 | |||
473 | i7300_idle_start(); | ||
474 | i7300_idle_ioat_start(); | ||
475 | |||
476 | } else if (val == IDLE_END) { | ||
477 | cpu_clear(smp_processor_id(), idle_cpumask); | ||
478 | if (cpus_weight(idle_cpumask) == (num_online_cpus() - 1)) { | ||
479 | /* First CPU coming out of idle */ | ||
480 | u64 idle_duration_us; | ||
481 | |||
482 | now_ktime = ktime_get(); | ||
483 | |||
484 | idle_duration_us = ktime_to_us(ktime_sub | ||
485 | (now_ktime, idle_begin_time)); | ||
486 | |||
487 | avg_idle_us = | ||
488 | ((100 - DURATION_WEIGHT_PCT) * avg_idle_us + | ||
489 | DURATION_WEIGHT_PCT * idle_duration_us) / 100; | ||
490 | |||
491 | if (i7300_idle_active) { | ||
492 | ktime_t idle_ktime; | ||
493 | |||
494 | idle_ktime = ktime_sub(now_ktime, start_ktime); | ||
495 | total_us += ktime_to_us(idle_ktime); | ||
496 | |||
497 | i7300_idle_ioat_stop(); | ||
498 | i7300_idle_stop(); | ||
499 | i7300_idle_active = 0; | ||
500 | } | ||
501 | } | ||
502 | } | ||
503 | end: | ||
504 | spin_unlock_irqrestore(&i7300_idle_lock, flags); | ||
505 | return 0; | ||
506 | } | ||
507 | |||
508 | static struct notifier_block i7300_idle_nb = { | ||
509 | .notifier_call = i7300_idle_notifier, | ||
510 | }; | ||
511 | |||
512 | MODULE_DEVICE_TABLE(pci, pci_tbl); | ||
513 | |||
514 | int stats_open_generic(struct inode *inode, struct file *fp) | ||
515 | { | ||
516 | fp->private_data = inode->i_private; | ||
517 | return 0; | ||
518 | } | ||
519 | |||
520 | static ssize_t stats_read_ul(struct file *fp, char __user *ubuf, size_t count, | ||
521 | loff_t *off) | ||
522 | { | ||
523 | unsigned long *p = fp->private_data; | ||
524 | char buf[32]; | ||
525 | int len; | ||
526 | |||
527 | len = snprintf(buf, 32, "%lu\n", *p); | ||
528 | return simple_read_from_buffer(ubuf, count, off, buf, len); | ||
529 | } | ||
530 | |||
531 | static const struct file_operations idle_fops = { | ||
532 | .open = stats_open_generic, | ||
533 | .read = stats_read_ul, | ||
534 | }; | ||
535 | |||
536 | struct debugfs_file_info { | ||
537 | void *ptr; | ||
538 | char name[32]; | ||
539 | struct dentry *file; | ||
540 | } debugfs_file_list[] = { | ||
541 | {&total_starts, "total_starts", NULL}, | ||
542 | {&total_us, "total_us", NULL}, | ||
543 | #ifdef DEBUG | ||
544 | {&past_skip, "past_skip", NULL}, | ||
545 | #endif | ||
546 | {NULL, "", NULL} | ||
547 | }; | ||
548 | |||
549 | static int __init i7300_idle_init(void) | ||
550 | { | ||
551 | spin_lock_init(&i7300_idle_lock); | ||
552 | cpus_clear(idle_cpumask); | ||
553 | total_us = 0; | ||
554 | |||
555 | if (i7300_idle_platform_probe(&fbd_dev, &ioat_dev)) | ||
556 | return -ENODEV; | ||
557 | |||
558 | if (i7300_idle_thrt_save()) | ||
559 | return -ENODEV; | ||
560 | |||
561 | if (i7300_idle_ioat_init()) | ||
562 | return -ENODEV; | ||
563 | |||
564 | debugfs_dir = debugfs_create_dir("i7300_idle", NULL); | ||
565 | if (debugfs_dir) { | ||
566 | int i = 0; | ||
567 | |||
568 | while (debugfs_file_list[i].ptr != NULL) { | ||
569 | debugfs_file_list[i].file = debugfs_create_file( | ||
570 | debugfs_file_list[i].name, | ||
571 | S_IRUSR, | ||
572 | debugfs_dir, | ||
573 | debugfs_file_list[i].ptr, | ||
574 | &idle_fops); | ||
575 | i++; | ||
576 | } | ||
577 | } | ||
578 | |||
579 | idle_notifier_register(&i7300_idle_nb); | ||
580 | |||
581 | printk(KERN_INFO "i7300_idle: loaded v%s\n", I7300_IDLE_DRIVER_VERSION); | ||
582 | return 0; | ||
583 | } | ||
584 | |||
585 | static void __exit i7300_idle_exit(void) | ||
586 | { | ||
587 | idle_notifier_unregister(&i7300_idle_nb); | ||
588 | |||
589 | if (debugfs_dir) { | ||
590 | int i = 0; | ||
591 | |||
592 | while (debugfs_file_list[i].file != NULL) { | ||
593 | debugfs_remove(debugfs_file_list[i].file); | ||
594 | i++; | ||
595 | } | ||
596 | |||
597 | debugfs_remove(debugfs_dir); | ||
598 | } | ||
599 | i7300_idle_thrt_restore(); | ||
600 | i7300_idle_ioat_exit(); | ||
601 | } | ||
602 | |||
603 | module_init(i7300_idle_init); | ||
604 | module_exit(i7300_idle_exit); | ||
605 | |||
606 | MODULE_AUTHOR("Andy Henroid <andrew.d.henroid@intel.com>"); | ||
607 | MODULE_DESCRIPTION("Intel Chipset DIMM Idle Power Saving Driver v" | ||
608 | I7300_IDLE_DRIVER_VERSION); | ||
609 | MODULE_LICENSE("GPL"); | ||