1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * thermal support for the cell processor
4 *
5 * This module adds some sysfs attributes to cpu and spu nodes.
6 * Base for measurements are the digital thermal sensors (DTS)
7 * located on the chip.
8 * The accuracy is 2 degrees, starting from 65 up to 125 degrees celsius
9 * The attributes can be found under
10 * /sys/devices/system/cpu/cpuX/thermal
11 * /sys/devices/system/spu/spuX/thermal
12 *
13 * The following attributes are added for each node:
14 * temperature:
15 * contains the current temperature measured by the DTS
16 * throttle_begin:
17 * throttling begins when temperature is greater or equal to
18 * throttle_begin. Setting this value to 125 prevents throttling.
19 * throttle_end:
20 * throttling is being ceased, if the temperature is lower than
21 * throttle_end. Due to a delay between applying throttling and
22 * a reduced temperature this value should be less than throttle_begin.
23 * A value equal to throttle_begin provides only a very little hysteresis.
24 * throttle_full_stop:
25 * If the temperatrue is greater or equal to throttle_full_stop,
26 * full throttling is applied to the cpu or spu. This value should be
27 * greater than throttle_begin and throttle_end. Setting this value to
28 * 65 prevents the unit from running code at all.
29 *
30 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
31 *
32 * Author: Christian Krafft <krafft@de.ibm.com>
33 */
34
35 #include <linux/module.h>
36 #include <linux/device.h>
37 #include <linux/kernel.h>
38 #include <linux/cpu.h>
39 #include <linux/stringify.h>
40 #include <asm/spu.h>
41 #include <asm/io.h>
42 #include <asm/cell-regs.h>
43
44 #include "spu_priv1_mmio.h"
45
46 #define TEMP_MIN 65
47 #define TEMP_MAX 125
48
49 #define DEVICE_PREFIX_ATTR(_prefix,_name,_mode) \
50 struct device_attribute attr_ ## _prefix ## _ ## _name = { \
51 .attr = { .name = __stringify(_name), .mode = _mode }, \
52 .show = _prefix ## _show_ ## _name, \
53 .store = _prefix ## _store_ ## _name, \
54 };
55
56 static inline u8 reg_to_temp(u8 reg_value)
57 {
58 return ((reg_value & 0x3f) << 1) + TEMP_MIN;
59 }
60
61 static inline u8 temp_to_reg(u8 temp)
62 {
63 return ((temp - TEMP_MIN) >> 1) & 0x3f;
64 }
65
66 static struct cbe_pmd_regs __iomem *get_pmd_regs(struct device *dev)
67 {
68 struct spu *spu;
69
70 spu = container_of(dev, struct spu, dev);
71
72 return cbe_get_pmd_regs(spu_devnode(spu));
73 }
74
75 /* returns the value for a given spu in a given register */
76 static u8 spu_read_register_value(struct device *dev, union spe_reg __iomem *reg)
77 {
78 union spe_reg value;
79 struct spu *spu;
80
81 spu = container_of(dev, struct spu, dev);
82 value.val = in_be64(®->val);
83
84 return value.spe[spu->spe_id];
85 }
86
87 static ssize_t spu_show_temp(struct device *dev, struct device_attribute *attr,
88 char *buf)
89 {
90 u8 value;
91 struct cbe_pmd_regs __iomem *pmd_regs;
92
93 pmd_regs = get_pmd_regs(dev);
94
95 value = spu_read_register_value(dev, &pmd_regs->ts_ctsr1);
96
97 return sprintf(buf, "%d\n", reg_to_temp(value));
98 }
99
100 static ssize_t show_throttle(struct cbe_pmd_regs __iomem *pmd_regs, char *buf, int pos)
101 {
102 u64 value;
103
104 value = in_be64(&pmd_regs->tm_tpr.val);
105 /* access the corresponding byte */
106 value >>= pos;
107 value &= 0x3F;
108
109 return sprintf(buf, "%d\n", reg_to_temp(value));
110 }
111
112 static ssize_t store_throttle(struct cbe_pmd_regs __iomem *pmd_regs, const char *buf, size_t size, int pos)
113 {
114 u64 reg_value;
115 unsigned int temp;
116 u64 new_value;
117 int ret;
118
119 ret = sscanf(buf, "%u", &temp);
120
121 if (ret != 1 || temp < TEMP_MIN || temp > TEMP_MAX)
122 return -EINVAL;
123
124 new_value = temp_to_reg(temp);
125
126 reg_value = in_be64(&pmd_regs->tm_tpr.val);
127
128 /* zero out bits for new value */
129 reg_value &= ~(0xffull << pos);
130 /* set bits to new value */
131 reg_value |= new_value << pos;
132
133 out_be64(&pmd_regs->tm_tpr.val, reg_value);
134 return size;
135 }
136
137 static ssize_t spu_show_throttle_end(struct device *dev,
138 struct device_attribute *attr, char *buf)
139 {
140 return show_throttle(get_pmd_regs(dev), buf, 0);
141 }
142
143 static ssize_t spu_show_throttle_begin(struct device *dev,
144 struct device_attribute *attr, char *buf)
145 {
146 return show_throttle(get_pmd_regs(dev), buf, 8);
147 }
148
149 static ssize_t spu_show_throttle_full_stop(struct device *dev,
150 struct device_attribute *attr, char *buf)
151 {
152 return show_throttle(get_pmd_regs(dev), buf, 16);
153 }
154
155 static ssize_t spu_store_throttle_end(struct device *dev,
156 struct device_attribute *attr, const char *buf, size_t size)
157 {
158 return store_throttle(get_pmd_regs(dev), buf, size, 0);
159 }
160
161 static ssize_t spu_store_throttle_begin(struct device *dev,
162 struct device_attribute *attr, const char *buf, size_t size)
163 {
164 return store_throttle(get_pmd_regs(dev), buf, size, 8);
165 }
166
167 static ssize_t spu_store_throttle_full_stop(struct device *dev,
168 struct device_attribute *attr, const char *buf, size_t size)
169 {
170 return store_throttle(get_pmd_regs(dev), buf, size, 16);
171 }
172
173 static ssize_t ppe_show_temp(struct device *dev, char *buf, int pos)
174 {
175 struct cbe_pmd_regs __iomem *pmd_regs;
176 u64 value;
177
178 pmd_regs = cbe_get_cpu_pmd_regs(dev->id);
179 value = in_be64(&pmd_regs->ts_ctsr2);
180
181 value = (value >> pos) & 0x3f;
182
183 return sprintf(buf, "%d\n", reg_to_temp(value));
184 }
185
186
187 /* shows the temperature of the DTS on the PPE,
188 * located near the linear thermal sensor */
189 static ssize_t ppe_show_temp0(struct device *dev,
190 struct device_attribute *attr, char *buf)
191 {
192 return ppe_show_temp(dev, buf, 32);
193 }
194
195 /* shows the temperature of the second DTS on the PPE */
196 static ssize_t ppe_show_temp1(struct device *dev,
197 struct device_attribute *attr, char *buf)
198 {
199 return ppe_show_temp(dev, buf, 0);
200 }
201
202 static ssize_t ppe_show_throttle_end(struct device *dev,
203 struct device_attribute *attr, char *buf)
204 {
205 return show_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, 32);
206 }
207
208 static ssize_t ppe_show_throttle_begin(struct device *dev,
209 struct device_attribute *attr, char *buf)
210 {
211 return show_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, 40);
212 }
213
214 static ssize_t ppe_show_throttle_full_stop(struct device *dev,
215 struct device_attribute *attr, char *buf)
216 {
217 return show_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, 48);
218 }
219
220 static ssize_t ppe_store_throttle_end(struct device *dev,
221 struct device_attribute *attr, const char *buf, size_t size)
222 {
223 return store_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, size, 32);
224 }
225
226 static ssize_t ppe_store_throttle_begin(struct device *dev,
227 struct device_attribute *attr, const char *buf, size_t size)
228 {
229 return store_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, size, 40);
230 }
231
232 static ssize_t ppe_store_throttle_full_stop(struct device *dev,
233 struct device_attribute *attr, const char *buf, size_t size)
234 {
235 return store_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, size, 48);
236 }
237
238
239 static struct device_attribute attr_spu_temperature = {
240 .attr = {.name = "temperature", .mode = 0400 },
241 .show = spu_show_temp,
242 };
243
244 static DEVICE_PREFIX_ATTR(spu, throttle_end, 0600);
245 static DEVICE_PREFIX_ATTR(spu, throttle_begin, 0600);
246 static DEVICE_PREFIX_ATTR(spu, throttle_full_stop, 0600);
247
248
249 static struct attribute *spu_attributes[] = {
250 &attr_spu_temperature.attr,
251 &attr_spu_throttle_end.attr,
252 &attr_spu_throttle_begin.attr,
253 &attr_spu_throttle_full_stop.attr,
254 NULL,
255 };
256
257 static const struct attribute_group spu_attribute_group = {
258 .name = "thermal",
259 .attrs = spu_attributes,
260 };
261
262 static struct device_attribute attr_ppe_temperature0 = {
263 .attr = {.name = "temperature0", .mode = 0400 },
264 .show = ppe_show_temp0,
265 };
266
267 static struct device_attribute attr_ppe_temperature1 = {
268 .attr = {.name = "temperature1", .mode = 0400 },
269 .show = ppe_show_temp1,
270 };
271
272 static DEVICE_PREFIX_ATTR(ppe, throttle_end, 0600);
273 static DEVICE_PREFIX_ATTR(ppe, throttle_begin, 0600);
274 static DEVICE_PREFIX_ATTR(ppe, throttle_full_stop, 0600);
275
276 static struct attribute *ppe_attributes[] = {
277 &attr_ppe_temperature0.attr,
278 &attr_ppe_temperature1.attr,
279 &attr_ppe_throttle_end.attr,
280 &attr_ppe_throttle_begin.attr,
281 &attr_ppe_throttle_full_stop.attr,
282 NULL,
283 };
284
285 static struct attribute_group ppe_attribute_group = {
286 .name = "thermal",
287 .attrs = ppe_attributes,
288 };
289
290 /*
291 * initialize throttling with default values
292 */
293 static int __init init_default_values(void)
294 {
295 int cpu;
296 struct cbe_pmd_regs __iomem *pmd_regs;
297 struct device *dev;
298 union ppe_spe_reg tpr;
299 union spe_reg str1;
300 u64 str2;
301 union spe_reg cr1;
302 u64 cr2;
303
304 /* TPR defaults */
305 /* ppe
306 * 1F - no full stop
307 * 08 - dynamic throttling starts if over 80 degrees
308 * 03 - dynamic throttling ceases if below 70 degrees */
309 tpr.ppe = 0x1F0803;
310 /* spe
311 * 10 - full stopped when over 96 degrees
312 * 08 - dynamic throttling starts if over 80 degrees
313 * 03 - dynamic throttling ceases if below 70 degrees
314 */
315 tpr.spe = 0x100803;
316
317 /* STR defaults */
318 /* str1
319 * 10 - stop 16 of 32 cycles
320 */
321 str1.val = 0x1010101010101010ull;
322 /* str2
323 * 10 - stop 16 of 32 cycles
324 */
325 str2 = 0x10;
326
327 /* CR defaults */
328 /* cr1
329 * 4 - normal operation
330 */
331 cr1.val = 0x0404040404040404ull;
332 /* cr2
333 * 4 - normal operation
334 */
335 cr2 = 0x04;
336
337 for_each_possible_cpu (cpu) {
338 pr_debug("processing cpu %d\n", cpu);
339 dev = get_cpu_device(cpu);
340
341 if (!dev) {
342 pr_info("invalid dev pointer for cbe_thermal\n");
343 return -EINVAL;
344 }
345
346 pmd_regs = cbe_get_cpu_pmd_regs(dev->id);
347
348 if (!pmd_regs) {
349 pr_info("invalid CBE regs pointer for cbe_thermal\n");
350 return -EINVAL;
351 }
352
353 out_be64(&pmd_regs->tm_str2, str2);
354 out_be64(&pmd_regs->tm_str1.val, str1.val);
355 out_be64(&pmd_regs->tm_tpr.val, tpr.val);
356 out_be64(&pmd_regs->tm_cr1.val, cr1.val);
357 out_be64(&pmd_regs->tm_cr2, cr2);
358 }
359
360 return 0;
361 }
362
363
364 static int __init thermal_init(void)
365 {
366 int rc = init_default_values();
367
368 if (rc == 0) {
369 spu_add_dev_attr_group(&spu_attribute_group);
370 cpu_add_dev_attr_group(&ppe_attribute_group);
371 }
372
373 return rc;
374 }
375 module_init(thermal_init);
376
377 static void __exit thermal_exit(void)
378 {
379 spu_remove_dev_attr_group(&spu_attribute_group);
380 cpu_remove_dev_attr_group(&ppe_attribute_group);
381 }
382 module_exit(thermal_exit);
383
384 MODULE_DESCRIPTION("Cell processor thermal driver");
385 MODULE_LICENSE("GPL");
386 MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");
387
388
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