Root/drivers/xen/xen-acpi-processor.c

1/*
2 * Copyright 2012 by Oracle Inc
3 * Author: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
4 *
5 * This code borrows ideas from https://lkml.org/lkml/2011/11/30/249
6 * so many thanks go to Kevin Tian <kevin.tian@intel.com>
7 * and Yu Ke <ke.yu@intel.com>.
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms and conditions of the GNU General Public License,
11 * version 2, as published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope it will be useful, but WITHOUT
14 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
16 * more details.
17 *
18 */
19
20#include <linux/cpumask.h>
21#include <linux/cpufreq.h>
22#include <linux/freezer.h>
23#include <linux/kernel.h>
24#include <linux/kthread.h>
25#include <linux/init.h>
26#include <linux/module.h>
27#include <linux/types.h>
28#include <acpi/acpi_bus.h>
29#include <acpi/acpi_drivers.h>
30#include <acpi/processor.h>
31
32#include <xen/xen.h>
33#include <xen/interface/platform.h>
34#include <asm/xen/hypercall.h>
35
36#define DRV_NAME "xen-acpi-processor: "
37
38static int no_hypercall;
39MODULE_PARM_DESC(off, "Inhibit the hypercall.");
40module_param_named(off, no_hypercall, int, 0400);
41
42/*
43 * Note: Do not convert the acpi_id* below to cpumask_var_t or use cpumask_bit
44 * - as those shrink to nr_cpu_bits (which is dependent on possible_cpu), which
45 * can be less than what we want to put in. Instead use the 'nr_acpi_bits'
46 * which is dynamically computed based on the MADT or x2APIC table.
47 */
48static unsigned int nr_acpi_bits;
49/* Mutex to protect the acpi_ids_done - for CPU hotplug use. */
50static DEFINE_MUTEX(acpi_ids_mutex);
51/* Which ACPI ID we have processed from 'struct acpi_processor'. */
52static unsigned long *acpi_ids_done;
53/* Which ACPI ID exist in the SSDT/DSDT processor definitions. */
54static unsigned long __initdata *acpi_id_present;
55/* And if there is an _CST definition (or a PBLK) for the ACPI IDs */
56static unsigned long __initdata *acpi_id_cst_present;
57
58static int push_cxx_to_hypervisor(struct acpi_processor *_pr)
59{
60    struct xen_platform_op op = {
61        .cmd = XENPF_set_processor_pminfo,
62        .interface_version = XENPF_INTERFACE_VERSION,
63        .u.set_pminfo.id = _pr->acpi_id,
64        .u.set_pminfo.type = XEN_PM_CX,
65    };
66    struct xen_processor_cx *dst_cx, *dst_cx_states = NULL;
67    struct acpi_processor_cx *cx;
68    unsigned int i, ok;
69    int ret = 0;
70
71    dst_cx_states = kcalloc(_pr->power.count,
72                sizeof(struct xen_processor_cx), GFP_KERNEL);
73    if (!dst_cx_states)
74        return -ENOMEM;
75
76    for (ok = 0, i = 1; i <= _pr->power.count; i++) {
77        cx = &_pr->power.states[i];
78        if (!cx->valid)
79            continue;
80
81        dst_cx = &(dst_cx_states[ok++]);
82
83        dst_cx->reg.space_id = ACPI_ADR_SPACE_SYSTEM_IO;
84        if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
85            dst_cx->reg.bit_width = 8;
86            dst_cx->reg.bit_offset = 0;
87            dst_cx->reg.access_size = 1;
88        } else {
89            dst_cx->reg.space_id = ACPI_ADR_SPACE_FIXED_HARDWARE;
90            if (cx->entry_method == ACPI_CSTATE_FFH) {
91                /* NATIVE_CSTATE_BEYOND_HALT */
92                dst_cx->reg.bit_offset = 2;
93                dst_cx->reg.bit_width = 1; /* VENDOR_INTEL */
94            }
95            dst_cx->reg.access_size = 0;
96        }
97        dst_cx->reg.address = cx->address;
98
99        dst_cx->type = cx->type;
100        dst_cx->latency = cx->latency;
101        dst_cx->power = cx->power;
102
103        dst_cx->dpcnt = 0;
104        set_xen_guest_handle(dst_cx->dp, NULL);
105    }
106    if (!ok) {
107        pr_debug(DRV_NAME "No _Cx for ACPI CPU %u\n", _pr->acpi_id);
108        kfree(dst_cx_states);
109        return -EINVAL;
110    }
111    op.u.set_pminfo.power.count = ok;
112    op.u.set_pminfo.power.flags.bm_control = _pr->flags.bm_control;
113    op.u.set_pminfo.power.flags.bm_check = _pr->flags.bm_check;
114    op.u.set_pminfo.power.flags.has_cst = _pr->flags.has_cst;
115    op.u.set_pminfo.power.flags.power_setup_done =
116        _pr->flags.power_setup_done;
117
118    set_xen_guest_handle(op.u.set_pminfo.power.states, dst_cx_states);
119
120    if (!no_hypercall)
121        ret = HYPERVISOR_dom0_op(&op);
122
123    if (!ret) {
124        pr_debug("ACPI CPU%u - C-states uploaded.\n", _pr->acpi_id);
125        for (i = 1; i <= _pr->power.count; i++) {
126            cx = &_pr->power.states[i];
127            if (!cx->valid)
128                continue;
129            pr_debug(" C%d: %s %d uS\n",
130                 cx->type, cx->desc, (u32)cx->latency);
131        }
132    } else if (ret != -EINVAL)
133        /* EINVAL means the ACPI ID is incorrect - meaning the ACPI
134         * table is referencing a non-existing CPU - which can happen
135         * with broken ACPI tables. */
136        pr_err(DRV_NAME "(CX): Hypervisor error (%d) for ACPI CPU%u\n",
137               ret, _pr->acpi_id);
138
139    kfree(dst_cx_states);
140
141    return ret;
142}
143static struct xen_processor_px *
144xen_copy_pss_data(struct acpi_processor *_pr,
145          struct xen_processor_performance *dst_perf)
146{
147    struct xen_processor_px *dst_states = NULL;
148    unsigned int i;
149
150    BUILD_BUG_ON(sizeof(struct xen_processor_px) !=
151             sizeof(struct acpi_processor_px));
152
153    dst_states = kcalloc(_pr->performance->state_count,
154                 sizeof(struct xen_processor_px), GFP_KERNEL);
155    if (!dst_states)
156        return ERR_PTR(-ENOMEM);
157
158    dst_perf->state_count = _pr->performance->state_count;
159    for (i = 0; i < _pr->performance->state_count; i++) {
160        /* Fortunatly for us, they are both the same size */
161        memcpy(&(dst_states[i]), &(_pr->performance->states[i]),
162               sizeof(struct acpi_processor_px));
163    }
164    return dst_states;
165}
166static int xen_copy_psd_data(struct acpi_processor *_pr,
167                 struct xen_processor_performance *dst)
168{
169    struct acpi_psd_package *pdomain;
170
171    BUILD_BUG_ON(sizeof(struct xen_psd_package) !=
172             sizeof(struct acpi_psd_package));
173
174    /* This information is enumerated only if acpi_processor_preregister_performance
175     * has been called.
176     */
177    dst->shared_type = _pr->performance->shared_type;
178
179    pdomain = &(_pr->performance->domain_info);
180
181    /* 'acpi_processor_preregister_performance' does not parse if the
182     * num_processors <= 1, but Xen still requires it. Do it manually here.
183     */
184    if (pdomain->num_processors <= 1) {
185        if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL)
186            dst->shared_type = CPUFREQ_SHARED_TYPE_ALL;
187        else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL)
188            dst->shared_type = CPUFREQ_SHARED_TYPE_HW;
189        else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY)
190            dst->shared_type = CPUFREQ_SHARED_TYPE_ANY;
191
192    }
193    memcpy(&(dst->domain_info), pdomain, sizeof(struct acpi_psd_package));
194    return 0;
195}
196static int xen_copy_pct_data(struct acpi_pct_register *pct,
197                 struct xen_pct_register *dst_pct)
198{
199    /* It would be nice if you could just do 'memcpy(pct, dst_pct') but
200     * sadly the Xen structure did not have the proper padding so the
201     * descriptor field takes two (dst_pct) bytes instead of one (pct).
202     */
203    dst_pct->descriptor = pct->descriptor;
204    dst_pct->length = pct->length;
205    dst_pct->space_id = pct->space_id;
206    dst_pct->bit_width = pct->bit_width;
207    dst_pct->bit_offset = pct->bit_offset;
208    dst_pct->reserved = pct->reserved;
209    dst_pct->address = pct->address;
210    return 0;
211}
212static int push_pxx_to_hypervisor(struct acpi_processor *_pr)
213{
214    int ret = 0;
215    struct xen_platform_op op = {
216        .cmd = XENPF_set_processor_pminfo,
217        .interface_version = XENPF_INTERFACE_VERSION,
218        .u.set_pminfo.id = _pr->acpi_id,
219        .u.set_pminfo.type = XEN_PM_PX,
220    };
221    struct xen_processor_performance *dst_perf;
222    struct xen_processor_px *dst_states = NULL;
223
224    dst_perf = &op.u.set_pminfo.perf;
225
226    dst_perf->platform_limit = _pr->performance_platform_limit;
227    dst_perf->flags |= XEN_PX_PPC;
228    xen_copy_pct_data(&(_pr->performance->control_register),
229              &dst_perf->control_register);
230    xen_copy_pct_data(&(_pr->performance->status_register),
231              &dst_perf->status_register);
232    dst_perf->flags |= XEN_PX_PCT;
233    dst_states = xen_copy_pss_data(_pr, dst_perf);
234    if (!IS_ERR_OR_NULL(dst_states)) {
235        set_xen_guest_handle(dst_perf->states, dst_states);
236        dst_perf->flags |= XEN_PX_PSS;
237    }
238    if (!xen_copy_psd_data(_pr, dst_perf))
239        dst_perf->flags |= XEN_PX_PSD;
240
241    if (dst_perf->flags != (XEN_PX_PSD | XEN_PX_PSS | XEN_PX_PCT | XEN_PX_PPC)) {
242        pr_warn(DRV_NAME "ACPI CPU%u missing some P-state data (%x), skipping.\n",
243            _pr->acpi_id, dst_perf->flags);
244        ret = -ENODEV;
245        goto err_free;
246    }
247
248    if (!no_hypercall)
249        ret = HYPERVISOR_dom0_op(&op);
250
251    if (!ret) {
252        struct acpi_processor_performance *perf;
253        unsigned int i;
254
255        perf = _pr->performance;
256        pr_debug("ACPI CPU%u - P-states uploaded.\n", _pr->acpi_id);
257        for (i = 0; i < perf->state_count; i++) {
258            pr_debug(" %cP%d: %d MHz, %d mW, %d uS\n",
259            (i == perf->state ? '*' : ' '), i,
260            (u32) perf->states[i].core_frequency,
261            (u32) perf->states[i].power,
262            (u32) perf->states[i].transition_latency);
263        }
264    } else if (ret != -EINVAL)
265        /* EINVAL means the ACPI ID is incorrect - meaning the ACPI
266         * table is referencing a non-existing CPU - which can happen
267         * with broken ACPI tables. */
268        pr_warn(DRV_NAME "(_PXX): Hypervisor error (%d) for ACPI CPU%u\n",
269               ret, _pr->acpi_id);
270err_free:
271    if (!IS_ERR_OR_NULL(dst_states))
272        kfree(dst_states);
273
274    return ret;
275}
276static int upload_pm_data(struct acpi_processor *_pr)
277{
278    int err = 0;
279
280    mutex_lock(&acpi_ids_mutex);
281    if (__test_and_set_bit(_pr->acpi_id, acpi_ids_done)) {
282        mutex_unlock(&acpi_ids_mutex);
283        return -EBUSY;
284    }
285    if (_pr->flags.power)
286        err = push_cxx_to_hypervisor(_pr);
287
288    if (_pr->performance && _pr->performance->states)
289        err |= push_pxx_to_hypervisor(_pr);
290
291    mutex_unlock(&acpi_ids_mutex);
292    return err;
293}
294static unsigned int __init get_max_acpi_id(void)
295{
296    struct xenpf_pcpuinfo *info;
297    struct xen_platform_op op = {
298        .cmd = XENPF_get_cpuinfo,
299        .interface_version = XENPF_INTERFACE_VERSION,
300    };
301    int ret = 0;
302    unsigned int i, last_cpu, max_acpi_id = 0;
303
304    info = &op.u.pcpu_info;
305    info->xen_cpuid = 0;
306
307    ret = HYPERVISOR_dom0_op(&op);
308    if (ret)
309        return NR_CPUS;
310
311    /* The max_present is the same irregardless of the xen_cpuid */
312    last_cpu = op.u.pcpu_info.max_present;
313    for (i = 0; i <= last_cpu; i++) {
314        info->xen_cpuid = i;
315        ret = HYPERVISOR_dom0_op(&op);
316        if (ret)
317            continue;
318        max_acpi_id = max(info->acpi_id, max_acpi_id);
319    }
320    max_acpi_id *= 2; /* Slack for CPU hotplug support. */
321    pr_debug(DRV_NAME "Max ACPI ID: %u\n", max_acpi_id);
322    return max_acpi_id;
323}
324/*
325 * The read_acpi_id and check_acpi_ids are there to support the Xen
326 * oddity of virtual CPUs != physical CPUs in the initial domain.
327 * The user can supply 'xen_max_vcpus=X' on the Xen hypervisor line
328 * which will band the amount of CPUs the initial domain can see.
329 * In general that is OK, except it plays havoc with any of the
330 * for_each_[present|online]_cpu macros which are banded to the virtual
331 * CPU amount.
332 */
333static acpi_status __init
334read_acpi_id(acpi_handle handle, u32 lvl, void *context, void **rv)
335{
336    u32 acpi_id;
337    acpi_status status;
338    acpi_object_type acpi_type;
339    unsigned long long tmp;
340    union acpi_object object = { 0 };
341    struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
342    acpi_io_address pblk = 0;
343
344    status = acpi_get_type(handle, &acpi_type);
345    if (ACPI_FAILURE(status))
346        return AE_OK;
347
348    switch (acpi_type) {
349    case ACPI_TYPE_PROCESSOR:
350        status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
351        if (ACPI_FAILURE(status))
352            return AE_OK;
353        acpi_id = object.processor.proc_id;
354        pblk = object.processor.pblk_address;
355        break;
356    case ACPI_TYPE_DEVICE:
357        status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
358        if (ACPI_FAILURE(status))
359            return AE_OK;
360        acpi_id = tmp;
361        break;
362    default:
363        return AE_OK;
364    }
365    /* There are more ACPI Processor objects than in x2APIC or MADT.
366     * This can happen with incorrect ACPI SSDT declerations. */
367    if (acpi_id > nr_acpi_bits) {
368        pr_debug(DRV_NAME "We only have %u, trying to set %u\n",
369             nr_acpi_bits, acpi_id);
370        return AE_OK;
371    }
372    /* OK, There is a ACPI Processor object */
373    __set_bit(acpi_id, acpi_id_present);
374
375    pr_debug(DRV_NAME "ACPI CPU%u w/ PBLK:0x%lx\n", acpi_id,
376         (unsigned long)pblk);
377
378    status = acpi_evaluate_object(handle, "_CST", NULL, &buffer);
379    if (ACPI_FAILURE(status)) {
380        if (!pblk)
381            return AE_OK;
382    }
383    /* .. and it has a C-state */
384    __set_bit(acpi_id, acpi_id_cst_present);
385
386    return AE_OK;
387}
388static int __init check_acpi_ids(struct acpi_processor *pr_backup)
389{
390
391    if (!pr_backup)
392        return -ENODEV;
393
394    /* All online CPUs have been processed at this stage. Now verify
395     * whether in fact "online CPUs" == physical CPUs.
396     */
397    acpi_id_present = kcalloc(BITS_TO_LONGS(nr_acpi_bits), sizeof(unsigned long), GFP_KERNEL);
398    if (!acpi_id_present)
399        return -ENOMEM;
400
401    acpi_id_cst_present = kcalloc(BITS_TO_LONGS(nr_acpi_bits), sizeof(unsigned long), GFP_KERNEL);
402    if (!acpi_id_cst_present) {
403        kfree(acpi_id_present);
404        return -ENOMEM;
405    }
406
407    acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
408                ACPI_UINT32_MAX,
409                read_acpi_id, NULL, NULL, NULL);
410    acpi_get_devices("ACPI0007", read_acpi_id, NULL, NULL);
411
412    if (!bitmap_equal(acpi_id_present, acpi_ids_done, nr_acpi_bits)) {
413        unsigned int i;
414        for_each_set_bit(i, acpi_id_present, nr_acpi_bits) {
415            pr_backup->acpi_id = i;
416            /* Mask out C-states if there are no _CST or PBLK */
417            pr_backup->flags.power = test_bit(i, acpi_id_cst_present);
418            (void)upload_pm_data(pr_backup);
419        }
420    }
421    kfree(acpi_id_present);
422    acpi_id_present = NULL;
423    kfree(acpi_id_cst_present);
424    acpi_id_cst_present = NULL;
425    return 0;
426}
427static int __init check_prereq(void)
428{
429    struct cpuinfo_x86 *c = &cpu_data(0);
430
431    if (!xen_initial_domain())
432        return -ENODEV;
433
434    if (!acpi_gbl_FADT.smi_command)
435        return -ENODEV;
436
437    if (c->x86_vendor == X86_VENDOR_INTEL) {
438        if (!cpu_has(c, X86_FEATURE_EST))
439            return -ENODEV;
440
441        return 0;
442    }
443    if (c->x86_vendor == X86_VENDOR_AMD) {
444        /* Copied from powernow-k8.h, can't include ../cpufreq/powernow
445         * as we get compile warnings for the static functions.
446         */
447#define CPUID_FREQ_VOLT_CAPABILITIES 0x80000007
448#define USE_HW_PSTATE 0x00000080
449        u32 eax, ebx, ecx, edx;
450        cpuid(CPUID_FREQ_VOLT_CAPABILITIES, &eax, &ebx, &ecx, &edx);
451        if ((edx & USE_HW_PSTATE) != USE_HW_PSTATE)
452            return -ENODEV;
453        return 0;
454    }
455    return -ENODEV;
456}
457/* acpi_perf_data is a pointer to percpu data. */
458static struct acpi_processor_performance __percpu *acpi_perf_data;
459
460static void free_acpi_perf_data(void)
461{
462    unsigned int i;
463
464    /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
465    for_each_possible_cpu(i)
466        free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
467                 ->shared_cpu_map);
468    free_percpu(acpi_perf_data);
469}
470
471static int __init xen_acpi_processor_init(void)
472{
473    struct acpi_processor *pr_backup = NULL;
474    unsigned int i;
475    int rc = check_prereq();
476
477    if (rc)
478        return rc;
479
480    nr_acpi_bits = get_max_acpi_id() + 1;
481    acpi_ids_done = kcalloc(BITS_TO_LONGS(nr_acpi_bits), sizeof(unsigned long), GFP_KERNEL);
482    if (!acpi_ids_done)
483        return -ENOMEM;
484
485    acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
486    if (!acpi_perf_data) {
487        pr_debug(DRV_NAME "Memory allocation error for acpi_perf_data.\n");
488        kfree(acpi_ids_done);
489        return -ENOMEM;
490    }
491    for_each_possible_cpu(i) {
492        if (!zalloc_cpumask_var_node(
493            &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
494            GFP_KERNEL, cpu_to_node(i))) {
495            rc = -ENOMEM;
496            goto err_out;
497        }
498    }
499
500    /* Do initialization in ACPI core. It is OK to fail here. */
501    (void)acpi_processor_preregister_performance(acpi_perf_data);
502
503    for_each_possible_cpu(i) {
504        struct acpi_processor_performance *perf;
505
506        perf = per_cpu_ptr(acpi_perf_data, i);
507        rc = acpi_processor_register_performance(perf, i);
508        if (rc)
509            goto err_out;
510    }
511    rc = acpi_processor_notify_smm(THIS_MODULE);
512    if (rc)
513        goto err_unregister;
514
515    for_each_possible_cpu(i) {
516        struct acpi_processor *_pr;
517        _pr = per_cpu(processors, i /* APIC ID */);
518        if (!_pr)
519            continue;
520
521        if (!pr_backup) {
522            pr_backup = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
523            if (pr_backup)
524                memcpy(pr_backup, _pr, sizeof(struct acpi_processor));
525        }
526        (void)upload_pm_data(_pr);
527    }
528    rc = check_acpi_ids(pr_backup);
529
530    kfree(pr_backup);
531    pr_backup = NULL;
532
533    if (rc)
534        goto err_unregister;
535
536    return 0;
537err_unregister:
538    for_each_possible_cpu(i) {
539        struct acpi_processor_performance *perf;
540        perf = per_cpu_ptr(acpi_perf_data, i);
541        acpi_processor_unregister_performance(perf, i);
542    }
543err_out:
544    /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
545    free_acpi_perf_data();
546    kfree(acpi_ids_done);
547    return rc;
548}
549static void __exit xen_acpi_processor_exit(void)
550{
551    int i;
552
553    kfree(acpi_ids_done);
554    for_each_possible_cpu(i) {
555        struct acpi_processor_performance *perf;
556        perf = per_cpu_ptr(acpi_perf_data, i);
557        acpi_processor_unregister_performance(perf, i);
558    }
559    free_acpi_perf_data();
560}
561
562MODULE_AUTHOR("Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>");
563MODULE_DESCRIPTION("Xen ACPI Processor P-states (and Cx) driver which uploads PM data to Xen hypervisor");
564MODULE_LICENSE("GPL");
565
566/* We want to be loaded before the CPU freq scaling drivers are loaded.
567 * They are loaded in late_initcall. */
568device_initcall(xen_acpi_processor_init);
569module_exit(xen_acpi_processor_exit);
570

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