1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * fam15h_power.c - AMD Family 15h processor power monitoring
4 *
5 * Copyright (c) 2011-2016 Advanced Micro Devices, Inc.
6 * Author: Andreas Herrmann <herrmann.der.user@googlemail.com>
7 */
8
9#include <linux/err.h>
10#include <linux/hwmon.h>
11#include <linux/hwmon-sysfs.h>
12#include <linux/init.h>
13#include <linux/module.h>
14#include <linux/pci.h>
15#include <linux/bitops.h>
16#include <linux/cpu.h>
17#include <linux/cpumask.h>
18#include <linux/time.h>
19#include <linux/sched.h>
20#include <asm/processor.h>
21#include <asm/msr.h>
22
23MODULE_DESCRIPTION("AMD Family 15h CPU processor power monitor");
24MODULE_AUTHOR("Andreas Herrmann <herrmann.der.user@googlemail.com>");
25MODULE_LICENSE("GPL");
26
27/* D18F3 */
28#define REG_NORTHBRIDGE_CAP		0xe8
29
30/* D18F4 */
31#define REG_PROCESSOR_TDP		0x1b8
32
33/* D18F5 */
34#define REG_TDP_RUNNING_AVERAGE		0xe0
35#define REG_TDP_LIMIT3			0xe8
36
37#define FAM15H_MIN_NUM_ATTRS		2
38#define FAM15H_NUM_GROUPS		2
39#define MAX_CUS				8
40
41/* set maximum interval as 1 second */
42#define MAX_INTERVAL			1000
43
44#define PCI_DEVICE_ID_AMD_15H_M70H_NB_F4 0x15b4
45
46struct fam15h_power_data {
47	struct pci_dev *pdev;
48	unsigned int tdp_to_watts;
49	unsigned int base_tdp;
50	unsigned int processor_pwr_watts;
51	unsigned int cpu_pwr_sample_ratio;
52	const struct attribute_group *groups[FAM15H_NUM_GROUPS];
53	struct attribute_group group;
54	/* maximum accumulated power of a compute unit */
55	u64 max_cu_acc_power;
56	/* accumulated power of the compute units */
57	u64 cu_acc_power[MAX_CUS];
58	/* performance timestamp counter */
59	u64 cpu_sw_pwr_ptsc[MAX_CUS];
60	/* online/offline status of current compute unit */
61	int cu_on[MAX_CUS];
62	unsigned long power_period;
63};
64
65static bool is_carrizo_or_later(void)
66{
67	return boot_cpu_data.x86 == 0x15 && boot_cpu_data.x86_model >= 0x60;
68}
69
70static ssize_t power1_input_show(struct device *dev,
71				 struct device_attribute *attr, char *buf)
72{
73	u32 val, tdp_limit, running_avg_range;
74	s32 running_avg_capture;
75	u64 curr_pwr_watts;
76	struct fam15h_power_data *data = dev_get_drvdata(dev);
77	struct pci_dev *f4 = data->pdev;
78
79	pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
80				  REG_TDP_RUNNING_AVERAGE, &val);
81
82	/*
83	 * On Carrizo and later platforms, TdpRunAvgAccCap bit field
84	 * is extended to 4:31 from 4:25.
85	 */
86	if (is_carrizo_or_later()) {
87		running_avg_capture = val >> 4;
88		running_avg_capture = sign_extend32(running_avg_capture, 27);
89	} else {
90		running_avg_capture = (val >> 4) & 0x3fffff;
91		running_avg_capture = sign_extend32(running_avg_capture, 21);
92	}
93
94	running_avg_range = (val & 0xf) + 1;
95
96	pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
97				  REG_TDP_LIMIT3, &val);
98
99	/*
100	 * On Carrizo and later platforms, ApmTdpLimit bit field
101	 * is extended to 16:31 from 16:28.
102	 */
103	if (is_carrizo_or_later())
104		tdp_limit = val >> 16;
105	else
106		tdp_limit = (val >> 16) & 0x1fff;
107
108	curr_pwr_watts = ((u64)(tdp_limit +
109				data->base_tdp)) << running_avg_range;
110	curr_pwr_watts -= running_avg_capture;
111	curr_pwr_watts *= data->tdp_to_watts;
112
113	/*
114	 * Convert to microWatt
115	 *
116	 * power is in Watt provided as fixed point integer with
117	 * scaling factor 1/(2^16).  For conversion we use
118	 * (10^6)/(2^16) = 15625/(2^10)
119	 */
120	curr_pwr_watts = (curr_pwr_watts * 15625) >> (10 + running_avg_range);
121	return sprintf(buf, "%u\n", (unsigned int) curr_pwr_watts);
122}
123static DEVICE_ATTR_RO(power1_input);
124
125static ssize_t power1_crit_show(struct device *dev,
126				struct device_attribute *attr, char *buf)
127{
128	struct fam15h_power_data *data = dev_get_drvdata(dev);
129
130	return sprintf(buf, "%u\n", data->processor_pwr_watts);
131}
132static DEVICE_ATTR_RO(power1_crit);
133
134static void do_read_registers_on_cu(void *_data)
135{
136	struct fam15h_power_data *data = _data;
137	int cpu, cu;
138
139	cpu = smp_processor_id();
140
141	/*
142	 * With the new x86 topology modelling, cpu core id actually
143	 * is compute unit id.
144	 */
145	cu = cpu_data(cpu).cpu_core_id;
146
147	rdmsrl_safe(MSR_F15H_CU_PWR_ACCUMULATOR, &data->cu_acc_power[cu]);
148	rdmsrl_safe(MSR_F15H_PTSC, &data->cpu_sw_pwr_ptsc[cu]);
149
150	data->cu_on[cu] = 1;
151}
152
153/*
154 * This function is only able to be called when CPUID
155 * Fn8000_0007:EDX[12] is set.
156 */
157static int read_registers(struct fam15h_power_data *data)
158{
159	int core, this_core;
160	cpumask_var_t mask;
161	int ret, cpu;
162
163	ret = zalloc_cpumask_var(&mask, GFP_KERNEL);
164	if (!ret)
165		return -ENOMEM;
166
167	memset(data->cu_on, 0, sizeof(int) * MAX_CUS);
168
169	cpus_read_lock();
170
171	/*
172	 * Choose the first online core of each compute unit, and then
173	 * read their MSR value of power and ptsc in a single IPI,
174	 * because the MSR value of CPU core represent the compute
175	 * unit's.
176	 */
177	core = -1;
178
179	for_each_online_cpu(cpu) {
180		this_core = topology_core_id(cpu);
181
182		if (this_core == core)
183			continue;
184
185		core = this_core;
186
187		/* get any CPU on this compute unit */
188		cpumask_set_cpu(cpumask_any(topology_sibling_cpumask(cpu)), mask);
189	}
190
191	on_each_cpu_mask(mask, do_read_registers_on_cu, data, true);
192
193	cpus_read_unlock();
194	free_cpumask_var(mask);
195
196	return 0;
197}
198
199static ssize_t power1_average_show(struct device *dev,
200				   struct device_attribute *attr, char *buf)
201{
202	struct fam15h_power_data *data = dev_get_drvdata(dev);
203	u64 prev_cu_acc_power[MAX_CUS], prev_ptsc[MAX_CUS],
204	    jdelta[MAX_CUS];
205	u64 tdelta, avg_acc;
206	int cu, cu_num, ret;
207	signed long leftover;
208
209	/*
210	 * With the new x86 topology modelling, x86_max_cores is the
211	 * compute unit number.
212	 */
213	cu_num = boot_cpu_data.x86_max_cores;
214
215	ret = read_registers(data);
216	if (ret)
217		return 0;
218
219	for (cu = 0; cu < cu_num; cu++) {
220		prev_cu_acc_power[cu] = data->cu_acc_power[cu];
221		prev_ptsc[cu] = data->cpu_sw_pwr_ptsc[cu];
222	}
223
224	leftover = schedule_timeout_interruptible(msecs_to_jiffies(data->power_period));
225	if (leftover)
226		return 0;
227
228	ret = read_registers(data);
229	if (ret)
230		return 0;
231
232	for (cu = 0, avg_acc = 0; cu < cu_num; cu++) {
233		/* check if current compute unit is online */
234		if (data->cu_on[cu] == 0)
235			continue;
236
237		if (data->cu_acc_power[cu] < prev_cu_acc_power[cu]) {
238			jdelta[cu] = data->max_cu_acc_power + data->cu_acc_power[cu];
239			jdelta[cu] -= prev_cu_acc_power[cu];
240		} else {
241			jdelta[cu] = data->cu_acc_power[cu] - prev_cu_acc_power[cu];
242		}
243		tdelta = data->cpu_sw_pwr_ptsc[cu] - prev_ptsc[cu];
244		jdelta[cu] *= data->cpu_pwr_sample_ratio * 1000;
245		do_div(jdelta[cu], tdelta);
246
247		/* the unit is microWatt */
248		avg_acc += jdelta[cu];
249	}
250
251	return sprintf(buf, "%llu\n", (unsigned long long)avg_acc);
252}
253static DEVICE_ATTR_RO(power1_average);
254
255static ssize_t power1_average_interval_show(struct device *dev,
256					    struct device_attribute *attr,
257					    char *buf)
258{
259	struct fam15h_power_data *data = dev_get_drvdata(dev);
260
261	return sprintf(buf, "%lu\n", data->power_period);
262}
263
264static ssize_t power1_average_interval_store(struct device *dev,
265					     struct device_attribute *attr,
266					     const char *buf, size_t count)
267{
268	struct fam15h_power_data *data = dev_get_drvdata(dev);
269	unsigned long temp;
270	int ret;
271
272	ret = kstrtoul(buf, 10, &temp);
273	if (ret)
274		return ret;
275
276	if (temp > MAX_INTERVAL)
277		return -EINVAL;
278
279	/* the interval value should be greater than 0 */
280	if (temp <= 0)
281		return -EINVAL;
282
283	data->power_period = temp;
284
285	return count;
286}
287static DEVICE_ATTR_RW(power1_average_interval);
288
289static int fam15h_power_init_attrs(struct pci_dev *pdev,
290				   struct fam15h_power_data *data)
291{
292	int n = FAM15H_MIN_NUM_ATTRS;
293	struct attribute **fam15h_power_attrs;
294	struct cpuinfo_x86 *c = &boot_cpu_data;
295
296	if (c->x86 == 0x15 &&
297	    (c->x86_model <= 0xf ||
298	     (c->x86_model >= 0x60 && c->x86_model <= 0x7f)))
299		n += 1;
300
301	/* check if processor supports accumulated power */
302	if (boot_cpu_has(X86_FEATURE_ACC_POWER))
303		n += 2;
304
305	fam15h_power_attrs = devm_kcalloc(&pdev->dev, n,
306					  sizeof(*fam15h_power_attrs),
307					  GFP_KERNEL);
308
309	if (!fam15h_power_attrs)
310		return -ENOMEM;
311
312	n = 0;
313	fam15h_power_attrs[n++] = &dev_attr_power1_crit.attr;
314	if (c->x86 == 0x15 &&
315	    (c->x86_model <= 0xf ||
316	     (c->x86_model >= 0x60 && c->x86_model <= 0x7f)))
317		fam15h_power_attrs[n++] = &dev_attr_power1_input.attr;
318
319	if (boot_cpu_has(X86_FEATURE_ACC_POWER)) {
320		fam15h_power_attrs[n++] = &dev_attr_power1_average.attr;
321		fam15h_power_attrs[n++] = &dev_attr_power1_average_interval.attr;
322	}
323
324	data->group.attrs = fam15h_power_attrs;
325
326	return 0;
327}
328
329static bool should_load_on_this_node(struct pci_dev *f4)
330{
331	u32 val;
332
333	pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 3),
334				  REG_NORTHBRIDGE_CAP, &val);
335	if ((val & BIT(29)) && ((val >> 30) & 3))
336		return false;
337
338	return true;
339}
340
341/*
342 * Newer BKDG versions have an updated recommendation on how to properly
343 * initialize the running average range (was: 0xE, now: 0x9). This avoids
344 * counter saturations resulting in bogus power readings.
345 * We correct this value ourselves to cope with older BIOSes.
346 */
347static const struct pci_device_id affected_device[] = {
348	{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
349	{ 0 }
350};
351
352static void tweak_runavg_range(struct pci_dev *pdev)
353{
354	u32 val;
355
356	/*
357	 * let this quirk apply only to the current version of the
358	 * northbridge, since future versions may change the behavior
359	 */
360	if (!pci_match_id(affected_device, pdev))
361		return;
362
363	pci_bus_read_config_dword(pdev->bus,
364		PCI_DEVFN(PCI_SLOT(pdev->devfn), 5),
365		REG_TDP_RUNNING_AVERAGE, &val);
366	if ((val & 0xf) != 0xe)
367		return;
368
369	val &= ~0xf;
370	val |=  0x9;
371	pci_bus_write_config_dword(pdev->bus,
372		PCI_DEVFN(PCI_SLOT(pdev->devfn), 5),
373		REG_TDP_RUNNING_AVERAGE, val);
374}
375
376#ifdef CONFIG_PM
377static int fam15h_power_resume(struct pci_dev *pdev)
378{
379	tweak_runavg_range(pdev);
380	return 0;
381}
382#else
383#define fam15h_power_resume NULL
384#endif
385
386static int fam15h_power_init_data(struct pci_dev *f4,
387				  struct fam15h_power_data *data)
388{
389	u32 val;
390	u64 tmp;
391	int ret;
392
393	pci_read_config_dword(f4, REG_PROCESSOR_TDP, &val);
394	data->base_tdp = val >> 16;
395	tmp = val & 0xffff;
396
397	pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
398				  REG_TDP_LIMIT3, &val);
399
400	data->tdp_to_watts = ((val & 0x3ff) << 6) | ((val >> 10) & 0x3f);
401	tmp *= data->tdp_to_watts;
402
403	/* result not allowed to be >= 256W */
404	if ((tmp >> 16) >= 256)
405		dev_warn(&f4->dev,
406			 "Bogus value for ProcessorPwrWatts (processor_pwr_watts>=%u)\n",
407			 (unsigned int) (tmp >> 16));
408
409	/* convert to microWatt */
410	data->processor_pwr_watts = (tmp * 15625) >> 10;
411
412	ret = fam15h_power_init_attrs(f4, data);
413	if (ret)
414		return ret;
415
416
417	/* CPUID Fn8000_0007:EDX[12] indicates to support accumulated power */
418	if (!boot_cpu_has(X86_FEATURE_ACC_POWER))
419		return 0;
420
421	/*
422	 * determine the ratio of the compute unit power accumulator
423	 * sample period to the PTSC counter period by executing CPUID
424	 * Fn8000_0007:ECX
425	 */
426	data->cpu_pwr_sample_ratio = cpuid_ecx(0x80000007);
427
428	if (rdmsrl_safe(MSR_F15H_CU_MAX_PWR_ACCUMULATOR, &tmp)) {
429		pr_err("Failed to read max compute unit power accumulator MSR\n");
430		return -ENODEV;
431	}
432
433	data->max_cu_acc_power = tmp;
434
435	/*
436	 * Milliseconds are a reasonable interval for the measurement.
437	 * But it shouldn't set too long here, because several seconds
438	 * would cause the read function to hang. So set default
439	 * interval as 10 ms.
440	 */
441	data->power_period = 10;
442
443	return read_registers(data);
444}
445
446static int fam15h_power_probe(struct pci_dev *pdev,
447			      const struct pci_device_id *id)
448{
449	struct fam15h_power_data *data;
450	struct device *dev = &pdev->dev;
451	struct device *hwmon_dev;
452	int ret;
453
454	/*
455	 * though we ignore every other northbridge, we still have to
456	 * do the tweaking on _each_ node in MCM processors as the counters
457	 * are working hand-in-hand
458	 */
459	tweak_runavg_range(pdev);
460
461	if (!should_load_on_this_node(pdev))
462		return -ENODEV;
463
464	data = devm_kzalloc(dev, sizeof(struct fam15h_power_data), GFP_KERNEL);
465	if (!data)
466		return -ENOMEM;
467
468	ret = fam15h_power_init_data(pdev, data);
469	if (ret)
470		return ret;
471
472	data->pdev = pdev;
473
474	data->groups[0] = &data->group;
475
476	hwmon_dev = devm_hwmon_device_register_with_groups(dev, "fam15h_power",
477							   data,
478							   &data->groups[0]);
479	return PTR_ERR_OR_ZERO(hwmon_dev);
480}
481
482static const struct pci_device_id fam15h_power_id_table[] = {
483	{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
484	{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_M30H_NB_F4) },
485	{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_M60H_NB_F4) },
486	{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_M70H_NB_F4) },
487	{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_16H_NB_F4) },
488	{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_16H_M30H_NB_F4) },
489	{}
490};
491MODULE_DEVICE_TABLE(pci, fam15h_power_id_table);
492
493static struct pci_driver fam15h_power_driver = {
494	.name = "fam15h_power",
495	.id_table = fam15h_power_id_table,
496	.probe = fam15h_power_probe,
497	.resume = fam15h_power_resume,
498};
499
500module_pci_driver(fam15h_power_driver);
501