/*
* Copyright 2012 by Oracle Inc
* Author: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
*
* This code borrows ideas from https://lkml.org/lkml/2011/11/30/249
* so many thanks go to Kevin Tian <kevin.tian@intel.com>
* and Yu Ke <ke.yu@intel.com>.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/cpumask.h>
#include <linux/cpufreq.h>
#include <linux/freezer.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/acpi.h>
#include <acpi/processor.h>
#include <xen/xen.h>
#include <xen/xen-ops.h>
#include <xen/interface/platform.h>
#include <asm/xen/hypercall.h>
static int no_hypercall;
MODULE_PARM_DESC(off, "Inhibit the hypercall.");
module_param_named(off, no_hypercall, int, 0400);
/*
* Note: Do not convert the acpi_id* below to cpumask_var_t or use cpumask_bit
* - as those shrink to nr_cpu_bits (which is dependent on possible_cpu), which
* can be less than what we want to put in. Instead use the 'nr_acpi_bits'
* which is dynamically computed based on the MADT or x2APIC table.
*/
static unsigned int nr_acpi_bits;
/* Mutex to protect the acpi_ids_done - for CPU hotplug use. */
static DEFINE_MUTEX(acpi_ids_mutex);
/* Which ACPI ID we have processed from 'struct acpi_processor'. */
static unsigned long *acpi_ids_done;
/* Which ACPI ID exist in the SSDT/DSDT processor definitions. */
static unsigned long *acpi_id_present;
/* And if there is an _CST definition (or a PBLK) for the ACPI IDs */
static unsigned long *acpi_id_cst_present;
static int push_cxx_to_hypervisor(struct acpi_processor *_pr)
{
struct xen_platform_op op = {
.cmd = XENPF_set_processor_pminfo,
.interface_version = XENPF_INTERFACE_VERSION,
.u.set_pminfo.id = _pr->acpi_id,
.u.set_pminfo.type = XEN_PM_CX,
};
struct xen_processor_cx *dst_cx, *dst_cx_states = NULL;
struct acpi_processor_cx *cx;
unsigned int i, ok;
int ret = 0;
dst_cx_states = kcalloc(_pr->power.count,
sizeof(struct xen_processor_cx), GFP_KERNEL);
if (!dst_cx_states)
return -ENOMEM;
for (ok = 0, i = 1; i <= _pr->power.count; i++) {
cx = &_pr->power.states[i];
if (!cx->valid)
continue;
dst_cx = &(dst_cx_states[ok++]);
dst_cx->reg.space_id = ACPI_ADR_SPACE_SYSTEM_IO;
if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
dst_cx->reg.bit_width = 8;
dst_cx->reg.bit_offset = 0;
dst_cx->reg.access_size = 1;
} else {
dst_cx->reg.space_id = ACPI_ADR_SPACE_FIXED_HARDWARE;
if (cx->entry_method == ACPI_CSTATE_FFH) {
/* NATIVE_CSTATE_BEYOND_HALT */
dst_cx->reg.bit_offset = 2;
dst_cx->reg.bit_width = 1; /* VENDOR_INTEL */
}
dst_cx->reg.access_size = 0;
}
dst_cx->reg.address = cx->address;
dst_cx->type = cx->type;
dst_cx->latency = cx->latency;
dst_cx->dpcnt = 0;
set_xen_guest_handle(dst_cx->dp, NULL);
}
if (!ok) {
pr_debug("No _Cx for ACPI CPU %u\n", _pr->acpi_id);
kfree(dst_cx_states);
return -EINVAL;
}
op.u.set_pminfo.power.count = ok;
op.u.set_pminfo.power.flags.bm_control = _pr->flags.bm_control;
op.u.set_pminfo.power.flags.bm_check = _pr->flags.bm_check;
op.u.set_pminfo.power.flags.has_cst = _pr->flags.has_cst;
op.u.set_pminfo.power.flags.power_setup_done =
_pr->flags.power_setup_done;
set_xen_guest_handle(op.u.set_pminfo.power.states, dst_cx_states);
if (!no_hypercall)
ret = HYPERVISOR_dom0_op(&op);
if (!ret) {
pr_debug("ACPI CPU%u - C-states uploaded.\n", _pr->acpi_id);
for (i = 1; i <= _pr->power.count; i++) {
cx = &_pr->power.states[i];
if (!cx->valid)
continue;
pr_debug(" C%d: %s %d uS\n",
cx->type, cx->desc, (u32)cx->latency);
}
} else if (ret != -EINVAL)
/* EINVAL means the ACPI ID is incorrect - meaning the ACPI
* table is referencing a non-existing CPU - which can happen
* with broken ACPI tables. */
pr_err("(CX): Hypervisor error (%d) for ACPI CPU%u\n",
ret, _pr->acpi_id);
kfree(dst_cx_states);
return ret;
}
static struct xen_processor_px *
xen_copy_pss_data(struct acpi_processor *_pr,
struct xen_processor_performance *dst_perf)
{
struct xen_processor_px *dst_states = NULL;
unsigned int i;
BUILD_BUG_ON(sizeof(struct xen_processor_px) !=
sizeof(struct acpi_processor_px));
dst_states = kcalloc(_pr->performance->state_count,
sizeof(struct xen_processor_px), GFP_KERNEL);
if (!dst_states)
return ERR_PTR(-ENOMEM);
dst_perf->state_count = _pr->performance->state_count;
for (i = 0; i < _pr->performance->state_count; i++) {
/* Fortunatly for us, they are both the same size */
memcpy(&(dst_states[i]), &(_pr->performance->states[i]),
sizeof(struct acpi_processor_px));
}
return dst_states;
}
static int xen_copy_psd_data(struct acpi_processor *_pr,
struct xen_processor_performance *dst)
{
struct acpi_psd_package *pdomain;
BUILD_BUG_ON(sizeof(struct xen_psd_package) !=
sizeof(struct acpi_psd_package));
/* This information is enumerated only if acpi_processor_preregister_performance
* has been called.
*/
dst->shared_type = _pr->performance->shared_type;
pdomain = &(_pr->performance->domain_info);
/* 'acpi_processor_preregister_performance' does not parse if the
* num_processors <= 1, but Xen still requires it. Do it manually here.
*/
if (pdomain->num_processors <= 1) {
if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL)
dst->shared_type = CPUFREQ_SHARED_TYPE_ALL;
else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL)
dst->shared_type = CPUFREQ_SHARED_TYPE_HW;
else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY)
dst->shared_type = CPUFREQ_SHARED_TYPE_ANY;
}
memcpy(&(dst->domain_info), pdomain, sizeof(struct acpi_psd_package));
return 0;
}
static int xen_copy_pct_data(struct acpi_pct_register *pct,
struct xen_pct_register *dst_pct)
{
/* It would be nice if you could just do 'memcpy(pct, dst_pct') but
* sadly the Xen structure did not have the proper padding so the
* descriptor field takes two (dst_pct) bytes instead of one (pct).
*/
dst_pct->descriptor = pct->descriptor;
dst_pct->length = pct->length;
dst_pct->space_id = pct->space_id;
dst_pct->bit_width = pct->bit_width;
dst_pct->bit_offset = pct->bit_offset;
dst_pct->reserved = pct->reserved;
dst_pct->address = pct->address;
return 0;
}
static int push_pxx_to_hypervisor(struct acpi_processor *_pr)
{
int ret = 0;
struct xen_platform_op op = {
.cmd = XENPF_set_processor_pminfo,
.interface_version = XENPF_INTERFACE_VERSION,
.u.set_pminfo.id = _pr->acpi_id,
.u.set_pminfo.type = XEN_PM_PX,
};
struct xen_processor_performance *dst_perf;
struct xen_processor_px *dst_states = NULL;
dst_perf = &op.u.set_pminfo.perf;
dst_perf->platform_limit = _pr->performance_platform_limit;
dst_perf->flags |= XEN_PX_PPC;
xen_copy_pct_data(&(_pr->performance->control_register),
&dst_perf->control_register);
xen_copy_pct_data(&(_pr->performance->status_register),
&dst_perf->status_register);
dst_perf->flags |= XEN_PX_PCT;
dst_states = xen_copy_pss_data(_pr, dst_perf);
if (!IS_ERR_OR_NULL(dst_states)) {
set_xen_guest_handle(dst_perf->states, dst_states);
dst_perf->flags |= XEN_PX_PSS;
}
if (!xen_copy_psd_data(_pr, dst_perf))
dst_perf->flags |= XEN_PX_PSD;
if (dst_perf->flags != (XEN_PX_PSD | XEN_PX_PSS | XEN_PX_PCT | XEN_PX_PPC)) {
pr_warn("ACPI CPU%u missing some P-state data (%x), skipping\n",
_pr->acpi_id, dst_perf->flags);
ret = -ENODEV;
goto err_free;
}
if (!no_hypercall)
ret = HYPERVISOR_dom0_op(&op);
if (!ret) {
struct acpi_processor_performance *perf;
unsigned int i;
perf = _pr->performance;
pr_debug("ACPI CPU%u - P-states uploaded.\n", _pr->acpi_id);
for (i = 0; i < perf->state_count; i++) {
pr_debug(" %cP%d: %d MHz, %d mW, %d uS\n",
(i == perf->state ? '*' : ' '), i,
(u32) perf->states[i].core_frequency,
(u32) perf->states[i].power,
(u32) perf->states[i].transition_latency);
}
} else if (ret != -EINVAL)
/* EINVAL means the ACPI ID is incorrect - meaning the ACPI
* table is referencing a non-existing CPU - which can happen
* with broken ACPI tables. */
pr_warn("(_PXX): Hypervisor error (%d) for ACPI CPU%u\n",
ret, _pr->acpi_id);
err_free:
if (!IS_ERR_OR_NULL(dst_states))
kfree(dst_states);
return ret;
}
static int upload_pm_data(struct acpi_processor *_pr)
{
int err = 0;
mutex_lock(&acpi_ids_mutex);
if (__test_and_set_bit(_pr->acpi_id, acpi_ids_done)) {
mutex_unlock(&acpi_ids_mutex);
return -EBUSY;
}
if (_pr->flags.power)
err = push_cxx_to_hypervisor(_pr);
if (_pr->performance && _pr->performance->states)
err |= push_pxx_to_hypervisor(_pr);
mutex_unlock(&acpi_ids_mutex);
return err;
}
static unsigned int __init get_max_acpi_id(void)
{
struct xenpf_pcpuinfo *info;
struct xen_platform_op op = {
.cmd = XENPF_get_cpuinfo,
.interface_version = XENPF_INTERFACE_VERSION,
};
int ret = 0;
unsigned int i, last_cpu, max_acpi_id = 0;
info = &op.u.pcpu_info;
info->xen_cpuid = 0;
ret = HYPERVISOR_dom0_op(&op);
if (ret)
return NR_CPUS;
/* The max_present is the same irregardless of the xen_cpuid */
last_cpu = op.u.pcpu_info.max_present;
for (i = 0; i <= last_cpu; i++) {
info->xen_cpuid = i;
ret = HYPERVISOR_dom0_op(&op);
if (ret)
continue;
max_acpi_id = max(info->acpi_id, max_acpi_id);
}
max_acpi_id *= 2; /* Slack for CPU hotplug support. */
pr_debug("Max ACPI ID: %u\n", max_acpi_id);
return max_acpi_id;
}
/*
* The read_acpi_id and check_acpi_ids are there to support the Xen
* oddity of virtual CPUs != physical CPUs in the initial domain.
* The user can supply 'xen_max_vcpus=X' on the Xen hypervisor line
* which will band the amount of CPUs the initial domain can see.
* In general that is OK, except it plays havoc with any of the
* for_each_[present|online]_cpu macros which are banded to the virtual
* CPU amount.
*/
static acpi_status
read_acpi_id(acpi_handle handle, u32 lvl, void *context, void **rv)
{
u32 acpi_id;
acpi_status status;
acpi_object_type acpi_type;
unsigned long long tmp;
union acpi_object object = { 0 };
struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
acpi_io_address pblk = 0;
status = acpi_get_type(handle, &acpi_type);
if (ACPI_FAILURE(status))
return AE_OK;
switch (acpi_type) {
case ACPI_TYPE_PROCESSOR:
status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
if (ACPI_FAILURE(status))
return AE_OK;
acpi_id = object.processor.proc_id;
pblk = object.processor.pblk_address;
break;
case ACPI_TYPE_DEVICE:
status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
if (ACPI_FAILURE(status))
return AE_OK;
acpi_id = tmp;
break;
default:
return AE_OK;
}
/* There are more ACPI Processor objects than in x2APIC or MADT.
* This can happen with incorrect ACPI SSDT declerations. */
if (acpi_id > nr_acpi_bits) {
pr_debug("We only have %u, trying to set %u\n",
nr_acpi_bits, acpi_id);
return AE_OK;
}
/* OK, There is a ACPI Processor object */
__set_bit(acpi_id, acpi_id_present);
pr_debug("ACPI CPU%u w/ PBLK:0x%lx\n", acpi_id, (unsigned long)pblk);
status = acpi_evaluate_object(handle, "_CST", NULL, &buffer);
if (ACPI_FAILURE(status)) {
if (!pblk)
return AE_OK;
}
/* .. and it has a C-state */
__set_bit(acpi_id, acpi_id_cst_present);
return AE_OK;
}
static int check_acpi_ids(struct acpi_processor *pr_backup)
{
if (!pr_backup)
return -ENODEV;
if (acpi_id_present && acpi_id_cst_present)
/* OK, done this once .. skip to uploading */
goto upload;
/* All online CPUs have been processed at this stage. Now verify
* whether in fact "online CPUs" == physical CPUs.
*/
acpi_id_present = kcalloc(BITS_TO_LONGS(nr_acpi_bits), sizeof(unsigned long), GFP_KERNEL);
if (!acpi_id_present)
return -ENOMEM;
acpi_id_cst_present = kcalloc(BITS_TO_LONGS(nr_acpi_bits), sizeof(unsigned long), GFP_KERNEL);
if (!acpi_id_cst_present) {
kfree(acpi_id_present);
return -ENOMEM;
}
acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
ACPI_UINT32_MAX,
read_acpi_id, NULL, NULL, NULL);
acpi_get_devices("ACPI0007", read_acpi_id, NULL, NULL);
upload:
if (!bitmap_equal(acpi_id_present, acpi_ids_done, nr_acpi_bits)) {
unsigned int i;
for_each_set_bit(i, acpi_id_present, nr_acpi_bits) {
pr_backup->acpi_id = i;
/* Mask out C-states if there are no _CST or PBLK */
pr_backup->flags.power = test_bit(i, acpi_id_cst_present);
(void)upload_pm_data(pr_backup);
}
}
return 0;
}
static int __init check_prereq(void)
{
struct cpuinfo_x86 *c = &cpu_data(0);
if (!xen_initial_domain())
return -ENODEV;
if (!acpi_gbl_FADT.smi_command)
return -ENODEV;
if (c->x86_vendor == X86_VENDOR_INTEL) {
if (!cpu_has(c, X86_FEATURE_EST))
return -ENODEV;
return 0;
}
if (c->x86_vendor == X86_VENDOR_AMD) {
/* Copied from powernow-k8.h, can't include ../cpufreq/powernow
* as we get compile warnings for the static functions.
*/
#define CPUID_FREQ_VOLT_CAPABILITIES 0x80000007
#define USE_HW_PSTATE 0x00000080
u32 eax, ebx, ecx, edx;
cpuid(CPUID_FREQ_VOLT_CAPABILITIES, &eax, &ebx, &ecx, &edx);
if ((edx & USE_HW_PSTATE) != USE_HW_PSTATE)
return -ENODEV;
return 0;
}
return -ENODEV;
}
/* acpi_perf_data is a pointer to percpu data. */
static struct acpi_processor_performance __percpu *acpi_perf_data;
static void free_acpi_perf_data(void)
{
unsigned int i;
/* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
for_each_possible_cpu(i)
free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
->shared_cpu_map);
free_percpu(acpi_perf_data);
}
static int xen_upload_processor_pm_data(void)
{
struct acpi_processor *pr_backup = NULL;
unsigned int i;
int rc = 0;
pr_info("Uploading Xen processor PM info\n");
for_each_possible_cpu(i) {
struct acpi_processor *_pr;
_pr = per_cpu(processors, i /* APIC ID */);
if (!_pr)
continue;
if (!pr_backup) {
pr_backup = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
if (pr_backup)
memcpy(pr_backup, _pr, sizeof(struct acpi_processor));
}
(void)upload_pm_data(_pr);
}
rc = check_acpi_ids(pr_backup);
kfree(pr_backup);
return rc;
}
static int xen_acpi_processor_resume(struct notifier_block *nb,
unsigned long action, void *data)
{
bitmap_zero(acpi_ids_done, nr_acpi_bits);
return xen_upload_processor_pm_data();
}
struct notifier_block xen_acpi_processor_resume_nb = {
.notifier_call = xen_acpi_processor_resume,
};
static int __init xen_acpi_processor_init(void)
{
unsigned int i;
int rc = check_prereq();
if (rc)
return rc;
nr_acpi_bits = get_max_acpi_id() + 1;
acpi_ids_done = kcalloc(BITS_TO_LONGS(nr_acpi_bits), sizeof(unsigned long), GFP_KERNEL);
if (!acpi_ids_done)
return -ENOMEM;
acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
if (!acpi_perf_data) {
pr_debug("Memory allocation error for acpi_perf_data\n");
kfree(acpi_ids_done);
return -ENOMEM;
}
for_each_possible_cpu(i) {
if (!zalloc_cpumask_var_node(
&per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
GFP_KERNEL, cpu_to_node(i))) {
rc = -ENOMEM;
goto err_out;
}
}
/* Do initialization in ACPI core. It is OK to fail here. */
(void)acpi_processor_preregister_performance(acpi_perf_data);
for_each_possible_cpu(i) {
struct acpi_processor *pr;
struct acpi_processor_performance *perf;
pr = per_cpu(processors, i);
perf = per_cpu_ptr(acpi_perf_data, i);
if (!pr)
continue;
pr->performance = perf;
rc = acpi_processor_get_performance_info(pr);
if (rc)
goto err_out;
}
rc = xen_upload_processor_pm_data();
if (rc)
goto err_unregister;
xen_resume_notifier_register(&xen_acpi_processor_resume_nb);
return 0;
err_unregister:
for_each_possible_cpu(i) {
struct acpi_processor_performance *perf;
perf = per_cpu_ptr(acpi_perf_data, i);
acpi_processor_unregister_performance(perf, i);
}
err_out:
/* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
free_acpi_perf_data();
kfree(acpi_ids_done);
return rc;
}
static void __exit xen_acpi_processor_exit(void)
{
int i;
xen_resume_notifier_unregister(&xen_acpi_processor_resume_nb);
kfree(acpi_ids_done);
kfree(acpi_id_present);
kfree(acpi_id_cst_present);
for_each_possible_cpu(i) {
struct acpi_processor_performance *perf;
perf = per_cpu_ptr(acpi_perf_data, i);
acpi_processor_unregister_performance(perf, i);
}
free_acpi_perf_data();
}
MODULE_AUTHOR("Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>");
MODULE_DESCRIPTION("Xen ACPI Processor P-states (and Cx) driver which uploads PM data to Xen hypervisor");
MODULE_LICENSE("GPL");
/* We want to be loaded before the CPU freq scaling drivers are loaded.
* They are loaded in late_initcall. */
device_initcall(xen_acpi_processor_init);
module_exit(xen_acpi_processor_exit);
