linux/drivers/cpufreq/cppc_cpufreq.c
Viresh Kumar 1eb5dde674 cpufreq: CPPC: Add support for frequency invariance
The Frequency Invariance Engine (FIE) is providing a frequency scaling
correction factor that helps achieve more accurate load-tracking.

Normally, this scaling factor can be obtained directly with the help of
the cpufreq drivers as they know the exact frequency the hardware is
running at. But that isn't the case for CPPC cpufreq driver.

Another way of obtaining that is using the arch specific counter
support, which is already present in kernel, but that hardware is
optional for platforms.

This patch updates the CPPC driver to register itself with the topology
core to provide its own implementation (cppc_scale_freq_tick()) of
topology_scale_freq_tick() which gets called by the scheduler on every
tick. Note that the arch specific counters have higher priority than
CPPC counters, if available, though the CPPC driver doesn't need to have
any special handling for that.

On an invocation of cppc_scale_freq_tick(), we schedule an irq work
(since we reach here from hard-irq context), which then schedules a
normal work item and cppc_scale_freq_workfn() updates the per_cpu
arch_freq_scale variable based on the counter updates since the last
tick.

To allow platforms to disable this CPPC counter-based frequency
invariance support, this is all done under CONFIG_ACPI_CPPC_CPUFREQ_FIE,
which is enabled by default.

This also exports sched_setattr_nocheck() as the CPPC driver can be
built as a module.

Cc: linux-acpi@vger.kernel.org
Tested-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com>
Tested-by: Qian Cai <quic_qiancai@quicinc.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-07-01 07:32:14 +05:30

789 lines
20 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* CPPC (Collaborative Processor Performance Control) driver for
* interfacing with the CPUfreq layer and governors. See
* cppc_acpi.c for CPPC specific methods.
*
* (C) Copyright 2014, 2015 Linaro Ltd.
* Author: Ashwin Chaugule <ashwin.chaugule@linaro.org>
*/
#define pr_fmt(fmt) "CPPC Cpufreq:" fmt
#include <linux/arch_topology.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/dmi.h>
#include <linux/irq_work.h>
#include <linux/kthread.h>
#include <linux/time.h>
#include <linux/vmalloc.h>
#include <uapi/linux/sched/types.h>
#include <asm/unaligned.h>
#include <acpi/cppc_acpi.h>
/* Minimum struct length needed for the DMI processor entry we want */
#define DMI_ENTRY_PROCESSOR_MIN_LENGTH 48
/* Offset in the DMI processor structure for the max frequency */
#define DMI_PROCESSOR_MAX_SPEED 0x14
/*
* This list contains information parsed from per CPU ACPI _CPC and _PSD
* structures: e.g. the highest and lowest supported performance, capabilities,
* desired performance, level requested etc. Depending on the share_type, not
* all CPUs will have an entry in the list.
*/
static LIST_HEAD(cpu_data_list);
static bool boost_supported;
struct cppc_workaround_oem_info {
char oem_id[ACPI_OEM_ID_SIZE + 1];
char oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1];
u32 oem_revision;
};
static struct cppc_workaround_oem_info wa_info[] = {
{
.oem_id = "HISI ",
.oem_table_id = "HIP07 ",
.oem_revision = 0,
}, {
.oem_id = "HISI ",
.oem_table_id = "HIP08 ",
.oem_revision = 0,
}
};
#ifdef CONFIG_ACPI_CPPC_CPUFREQ_FIE
/* Frequency invariance support */
struct cppc_freq_invariance {
int cpu;
struct irq_work irq_work;
struct kthread_work work;
struct cppc_perf_fb_ctrs prev_perf_fb_ctrs;
struct cppc_cpudata *cpu_data;
};
static DEFINE_PER_CPU(struct cppc_freq_invariance, cppc_freq_inv);
static struct kthread_worker *kworker_fie;
static struct cpufreq_driver cppc_cpufreq_driver;
static unsigned int hisi_cppc_cpufreq_get_rate(unsigned int cpu);
static int cppc_perf_from_fbctrs(struct cppc_cpudata *cpu_data,
struct cppc_perf_fb_ctrs *fb_ctrs_t0,
struct cppc_perf_fb_ctrs *fb_ctrs_t1);
/**
* cppc_scale_freq_workfn - CPPC arch_freq_scale updater for frequency invariance
* @work: The work item.
*
* The CPPC driver register itself with the topology core to provide its own
* implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which
* gets called by the scheduler on every tick.
*
* Note that the arch specific counters have higher priority than CPPC counters,
* if available, though the CPPC driver doesn't need to have any special
* handling for that.
*
* On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we
* reach here from hard-irq context), which then schedules a normal work item
* and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable
* based on the counter updates since the last tick.
*/
static void cppc_scale_freq_workfn(struct kthread_work *work)
{
struct cppc_freq_invariance *cppc_fi;
struct cppc_perf_fb_ctrs fb_ctrs = {0};
struct cppc_cpudata *cpu_data;
unsigned long local_freq_scale;
u64 perf;
cppc_fi = container_of(work, struct cppc_freq_invariance, work);
cpu_data = cppc_fi->cpu_data;
if (cppc_get_perf_ctrs(cppc_fi->cpu, &fb_ctrs)) {
pr_warn("%s: failed to read perf counters\n", __func__);
return;
}
perf = cppc_perf_from_fbctrs(cpu_data, &cppc_fi->prev_perf_fb_ctrs,
&fb_ctrs);
cppc_fi->prev_perf_fb_ctrs = fb_ctrs;
perf <<= SCHED_CAPACITY_SHIFT;
local_freq_scale = div64_u64(perf, cpu_data->perf_caps.highest_perf);
/* This can happen due to counter's overflow */
if (unlikely(local_freq_scale > 1024))
local_freq_scale = 1024;
per_cpu(arch_freq_scale, cppc_fi->cpu) = local_freq_scale;
}
static void cppc_irq_work(struct irq_work *irq_work)
{
struct cppc_freq_invariance *cppc_fi;
cppc_fi = container_of(irq_work, struct cppc_freq_invariance, irq_work);
kthread_queue_work(kworker_fie, &cppc_fi->work);
}
static void cppc_scale_freq_tick(void)
{
struct cppc_freq_invariance *cppc_fi = &per_cpu(cppc_freq_inv, smp_processor_id());
/*
* cppc_get_perf_ctrs() can potentially sleep, call that from the right
* context.
*/
irq_work_queue(&cppc_fi->irq_work);
}
static struct scale_freq_data cppc_sftd = {
.source = SCALE_FREQ_SOURCE_CPPC,
.set_freq_scale = cppc_scale_freq_tick,
};
static void cppc_cpufreq_cpu_fie_init(struct cpufreq_policy *policy)
{
struct cppc_freq_invariance *cppc_fi;
int cpu, ret;
if (cppc_cpufreq_driver.get == hisi_cppc_cpufreq_get_rate)
return;
for_each_cpu(cpu, policy->cpus) {
cppc_fi = &per_cpu(cppc_freq_inv, cpu);
cppc_fi->cpu = cpu;
cppc_fi->cpu_data = policy->driver_data;
kthread_init_work(&cppc_fi->work, cppc_scale_freq_workfn);
init_irq_work(&cppc_fi->irq_work, cppc_irq_work);
ret = cppc_get_perf_ctrs(cpu, &cppc_fi->prev_perf_fb_ctrs);
if (ret) {
pr_warn("%s: failed to read perf counters for cpu:%d: %d\n",
__func__, cpu, ret);
/*
* Don't abort if the CPU was offline while the driver
* was getting registered.
*/
if (cpu_online(cpu))
return;
}
}
/* Register for freq-invariance */
topology_set_scale_freq_source(&cppc_sftd, policy->cpus);
}
/*
* We free all the resources on policy's removal and not on CPU removal as the
* irq-work are per-cpu and the hotplug core takes care of flushing the pending
* irq-works (hint: smpcfd_dying_cpu()) on CPU hotplug. Even if the kthread-work
* fires on another CPU after the concerned CPU is removed, it won't harm.
*
* We just need to make sure to remove them all on policy->exit().
*/
static void cppc_cpufreq_cpu_fie_exit(struct cpufreq_policy *policy)
{
struct cppc_freq_invariance *cppc_fi;
int cpu;
if (cppc_cpufreq_driver.get == hisi_cppc_cpufreq_get_rate)
return;
/* policy->cpus will be empty here, use related_cpus instead */
topology_clear_scale_freq_source(SCALE_FREQ_SOURCE_CPPC, policy->related_cpus);
for_each_cpu(cpu, policy->related_cpus) {
cppc_fi = &per_cpu(cppc_freq_inv, cpu);
irq_work_sync(&cppc_fi->irq_work);
kthread_cancel_work_sync(&cppc_fi->work);
}
}
static void __init cppc_freq_invariance_init(void)
{
struct sched_attr attr = {
.size = sizeof(struct sched_attr),
.sched_policy = SCHED_DEADLINE,
.sched_nice = 0,
.sched_priority = 0,
/*
* Fake (unused) bandwidth; workaround to "fix"
* priority inheritance.
*/
.sched_runtime = 1000000,
.sched_deadline = 10000000,
.sched_period = 10000000,
};
int ret;
if (cppc_cpufreq_driver.get == hisi_cppc_cpufreq_get_rate)
return;
kworker_fie = kthread_create_worker(0, "cppc_fie");
if (IS_ERR(kworker_fie))
return;
ret = sched_setattr_nocheck(kworker_fie->task, &attr);
if (ret) {
pr_warn("%s: failed to set SCHED_DEADLINE: %d\n", __func__,
ret);
kthread_destroy_worker(kworker_fie);
return;
}
}
static void cppc_freq_invariance_exit(void)
{
if (cppc_cpufreq_driver.get == hisi_cppc_cpufreq_get_rate)
return;
kthread_destroy_worker(kworker_fie);
kworker_fie = NULL;
}
#else
static inline void cppc_cpufreq_cpu_fie_init(struct cpufreq_policy *policy)
{
}
static inline void cppc_cpufreq_cpu_fie_exit(struct cpufreq_policy *policy)
{
}
static inline void cppc_freq_invariance_init(void)
{
}
static inline void cppc_freq_invariance_exit(void)
{
}
#endif /* CONFIG_ACPI_CPPC_CPUFREQ_FIE */
/* Callback function used to retrieve the max frequency from DMI */
static void cppc_find_dmi_mhz(const struct dmi_header *dm, void *private)
{
const u8 *dmi_data = (const u8 *)dm;
u16 *mhz = (u16 *)private;
if (dm->type == DMI_ENTRY_PROCESSOR &&
dm->length >= DMI_ENTRY_PROCESSOR_MIN_LENGTH) {
u16 val = (u16)get_unaligned((const u16 *)
(dmi_data + DMI_PROCESSOR_MAX_SPEED));
*mhz = val > *mhz ? val : *mhz;
}
}
/* Look up the max frequency in DMI */
static u64 cppc_get_dmi_max_khz(void)
{
u16 mhz = 0;
dmi_walk(cppc_find_dmi_mhz, &mhz);
/*
* Real stupid fallback value, just in case there is no
* actual value set.
*/
mhz = mhz ? mhz : 1;
return (1000 * mhz);
}
/*
* If CPPC lowest_freq and nominal_freq registers are exposed then we can
* use them to convert perf to freq and vice versa
*
* If the perf/freq point lies between Nominal and Lowest, we can treat
* (Low perf, Low freq) and (Nom Perf, Nom freq) as 2D co-ordinates of a line
* and extrapolate the rest
* For perf/freq > Nominal, we use the ratio perf:freq at Nominal for conversion
*/
static unsigned int cppc_cpufreq_perf_to_khz(struct cppc_cpudata *cpu_data,
unsigned int perf)
{
struct cppc_perf_caps *caps = &cpu_data->perf_caps;
static u64 max_khz;
u64 mul, div;
if (caps->lowest_freq && caps->nominal_freq) {
if (perf >= caps->nominal_perf) {
mul = caps->nominal_freq;
div = caps->nominal_perf;
} else {
mul = caps->nominal_freq - caps->lowest_freq;
div = caps->nominal_perf - caps->lowest_perf;
}
} else {
if (!max_khz)
max_khz = cppc_get_dmi_max_khz();
mul = max_khz;
div = caps->highest_perf;
}
return (u64)perf * mul / div;
}
static unsigned int cppc_cpufreq_khz_to_perf(struct cppc_cpudata *cpu_data,
unsigned int freq)
{
struct cppc_perf_caps *caps = &cpu_data->perf_caps;
static u64 max_khz;
u64 mul, div;
if (caps->lowest_freq && caps->nominal_freq) {
if (freq >= caps->nominal_freq) {
mul = caps->nominal_perf;
div = caps->nominal_freq;
} else {
mul = caps->lowest_perf;
div = caps->lowest_freq;
}
} else {
if (!max_khz)
max_khz = cppc_get_dmi_max_khz();
mul = caps->highest_perf;
div = max_khz;
}
return (u64)freq * mul / div;
}
static int cppc_cpufreq_set_target(struct cpufreq_policy *policy,
unsigned int target_freq,
unsigned int relation)
{
struct cppc_cpudata *cpu_data = policy->driver_data;
unsigned int cpu = policy->cpu;
struct cpufreq_freqs freqs;
u32 desired_perf;
int ret = 0;
desired_perf = cppc_cpufreq_khz_to_perf(cpu_data, target_freq);
/* Return if it is exactly the same perf */
if (desired_perf == cpu_data->perf_ctrls.desired_perf)
return ret;
cpu_data->perf_ctrls.desired_perf = desired_perf;
freqs.old = policy->cur;
freqs.new = target_freq;
cpufreq_freq_transition_begin(policy, &freqs);
ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls);
cpufreq_freq_transition_end(policy, &freqs, ret != 0);
if (ret)
pr_debug("Failed to set target on CPU:%d. ret:%d\n",
cpu, ret);
return ret;
}
static int cppc_verify_policy(struct cpufreq_policy_data *policy)
{
cpufreq_verify_within_cpu_limits(policy);
return 0;
}
/*
* The PCC subspace describes the rate at which platform can accept commands
* on the shared PCC channel (including READs which do not count towards freq
* transition requests), so ideally we need to use the PCC values as a fallback
* if we don't have a platform specific transition_delay_us
*/
#ifdef CONFIG_ARM64
#include <asm/cputype.h>
static unsigned int cppc_cpufreq_get_transition_delay_us(unsigned int cpu)
{
unsigned long implementor = read_cpuid_implementor();
unsigned long part_num = read_cpuid_part_number();
switch (implementor) {
case ARM_CPU_IMP_QCOM:
switch (part_num) {
case QCOM_CPU_PART_FALKOR_V1:
case QCOM_CPU_PART_FALKOR:
return 10000;
}
}
return cppc_get_transition_latency(cpu) / NSEC_PER_USEC;
}
#else
static unsigned int cppc_cpufreq_get_transition_delay_us(unsigned int cpu)
{
return cppc_get_transition_latency(cpu) / NSEC_PER_USEC;
}
#endif
static struct cppc_cpudata *cppc_cpufreq_get_cpu_data(unsigned int cpu)
{
struct cppc_cpudata *cpu_data;
int ret;
cpu_data = kzalloc(sizeof(struct cppc_cpudata), GFP_KERNEL);
if (!cpu_data)
goto out;
if (!zalloc_cpumask_var(&cpu_data->shared_cpu_map, GFP_KERNEL))
goto free_cpu;
ret = acpi_get_psd_map(cpu, cpu_data);
if (ret) {
pr_debug("Err parsing CPU%d PSD data: ret:%d\n", cpu, ret);
goto free_mask;
}
ret = cppc_get_perf_caps(cpu, &cpu_data->perf_caps);
if (ret) {
pr_debug("Err reading CPU%d perf caps: ret:%d\n", cpu, ret);
goto free_mask;
}
/* Convert the lowest and nominal freq from MHz to KHz */
cpu_data->perf_caps.lowest_freq *= 1000;
cpu_data->perf_caps.nominal_freq *= 1000;
list_add(&cpu_data->node, &cpu_data_list);
return cpu_data;
free_mask:
free_cpumask_var(cpu_data->shared_cpu_map);
free_cpu:
kfree(cpu_data);
out:
return NULL;
}
static void cppc_cpufreq_put_cpu_data(struct cpufreq_policy *policy)
{
struct cppc_cpudata *cpu_data = policy->driver_data;
list_del(&cpu_data->node);
free_cpumask_var(cpu_data->shared_cpu_map);
kfree(cpu_data);
policy->driver_data = NULL;
}
static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
unsigned int cpu = policy->cpu;
struct cppc_cpudata *cpu_data;
struct cppc_perf_caps *caps;
int ret;
cpu_data = cppc_cpufreq_get_cpu_data(cpu);
if (!cpu_data) {
pr_err("Error in acquiring _CPC/_PSD data for CPU%d.\n", cpu);
return -ENODEV;
}
caps = &cpu_data->perf_caps;
policy->driver_data = cpu_data;
/*
* Set min to lowest nonlinear perf to avoid any efficiency penalty (see
* Section 8.4.7.1.1.5 of ACPI 6.1 spec)
*/
policy->min = cppc_cpufreq_perf_to_khz(cpu_data,
caps->lowest_nonlinear_perf);
policy->max = cppc_cpufreq_perf_to_khz(cpu_data,
caps->nominal_perf);
/*
* Set cpuinfo.min_freq to Lowest to make the full range of performance
* available if userspace wants to use any perf between lowest & lowest
* nonlinear perf
*/
policy->cpuinfo.min_freq = cppc_cpufreq_perf_to_khz(cpu_data,
caps->lowest_perf);
policy->cpuinfo.max_freq = cppc_cpufreq_perf_to_khz(cpu_data,
caps->nominal_perf);
policy->transition_delay_us = cppc_cpufreq_get_transition_delay_us(cpu);
policy->shared_type = cpu_data->shared_type;
switch (policy->shared_type) {
case CPUFREQ_SHARED_TYPE_HW:
case CPUFREQ_SHARED_TYPE_NONE:
/* Nothing to be done - we'll have a policy for each CPU */
break;
case CPUFREQ_SHARED_TYPE_ANY:
/*
* All CPUs in the domain will share a policy and all cpufreq
* operations will use a single cppc_cpudata structure stored
* in policy->driver_data.
*/
cpumask_copy(policy->cpus, cpu_data->shared_cpu_map);
break;
default:
pr_debug("Unsupported CPU co-ord type: %d\n",
policy->shared_type);
ret = -EFAULT;
goto out;
}
/*
* If 'highest_perf' is greater than 'nominal_perf', we assume CPU Boost
* is supported.
*/
if (caps->highest_perf > caps->nominal_perf)
boost_supported = true;
/* Set policy->cur to max now. The governors will adjust later. */
policy->cur = cppc_cpufreq_perf_to_khz(cpu_data, caps->highest_perf);
cpu_data->perf_ctrls.desired_perf = caps->highest_perf;
ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls);
if (ret) {
pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
caps->highest_perf, cpu, ret);
goto out;
}
cppc_cpufreq_cpu_fie_init(policy);
return 0;
out:
cppc_cpufreq_put_cpu_data(policy);
return ret;
}
static int cppc_cpufreq_cpu_exit(struct cpufreq_policy *policy)
{
struct cppc_cpudata *cpu_data = policy->driver_data;
struct cppc_perf_caps *caps = &cpu_data->perf_caps;
unsigned int cpu = policy->cpu;
int ret;
cppc_cpufreq_cpu_fie_exit(policy);
cpu_data->perf_ctrls.desired_perf = caps->lowest_perf;
ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls);
if (ret)
pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
caps->lowest_perf, cpu, ret);
cppc_cpufreq_put_cpu_data(policy);
return 0;
}
static inline u64 get_delta(u64 t1, u64 t0)
{
if (t1 > t0 || t0 > ~(u32)0)
return t1 - t0;
return (u32)t1 - (u32)t0;
}
static int cppc_perf_from_fbctrs(struct cppc_cpudata *cpu_data,
struct cppc_perf_fb_ctrs *fb_ctrs_t0,
struct cppc_perf_fb_ctrs *fb_ctrs_t1)
{
u64 delta_reference, delta_delivered;
u64 reference_perf;
reference_perf = fb_ctrs_t0->reference_perf;
delta_reference = get_delta(fb_ctrs_t1->reference,
fb_ctrs_t0->reference);
delta_delivered = get_delta(fb_ctrs_t1->delivered,
fb_ctrs_t0->delivered);
/* Check to avoid divide-by zero and invalid delivered_perf */
if (!delta_reference || !delta_delivered)
return cpu_data->perf_ctrls.desired_perf;
return (reference_perf * delta_delivered) / delta_reference;
}
static unsigned int cppc_cpufreq_get_rate(unsigned int cpu)
{
struct cppc_perf_fb_ctrs fb_ctrs_t0 = {0}, fb_ctrs_t1 = {0};
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
struct cppc_cpudata *cpu_data = policy->driver_data;
u64 delivered_perf;
int ret;
cpufreq_cpu_put(policy);
ret = cppc_get_perf_ctrs(cpu, &fb_ctrs_t0);
if (ret)
return ret;
udelay(2); /* 2usec delay between sampling */
ret = cppc_get_perf_ctrs(cpu, &fb_ctrs_t1);
if (ret)
return ret;
delivered_perf = cppc_perf_from_fbctrs(cpu_data, &fb_ctrs_t0,
&fb_ctrs_t1);
return cppc_cpufreq_perf_to_khz(cpu_data, delivered_perf);
}
static int cppc_cpufreq_set_boost(struct cpufreq_policy *policy, int state)
{
struct cppc_cpudata *cpu_data = policy->driver_data;
struct cppc_perf_caps *caps = &cpu_data->perf_caps;
int ret;
if (!boost_supported) {
pr_err("BOOST not supported by CPU or firmware\n");
return -EINVAL;
}
if (state)
policy->max = cppc_cpufreq_perf_to_khz(cpu_data,
caps->highest_perf);
else
policy->max = cppc_cpufreq_perf_to_khz(cpu_data,
caps->nominal_perf);
policy->cpuinfo.max_freq = policy->max;
ret = freq_qos_update_request(policy->max_freq_req, policy->max);
if (ret < 0)
return ret;
return 0;
}
static ssize_t show_freqdomain_cpus(struct cpufreq_policy *policy, char *buf)
{
struct cppc_cpudata *cpu_data = policy->driver_data;
return cpufreq_show_cpus(cpu_data->shared_cpu_map, buf);
}
cpufreq_freq_attr_ro(freqdomain_cpus);
static struct freq_attr *cppc_cpufreq_attr[] = {
&freqdomain_cpus,
NULL,
};
static struct cpufreq_driver cppc_cpufreq_driver = {
.flags = CPUFREQ_CONST_LOOPS,
.verify = cppc_verify_policy,
.target = cppc_cpufreq_set_target,
.get = cppc_cpufreq_get_rate,
.init = cppc_cpufreq_cpu_init,
.exit = cppc_cpufreq_cpu_exit,
.set_boost = cppc_cpufreq_set_boost,
.attr = cppc_cpufreq_attr,
.name = "cppc_cpufreq",
};
/*
* HISI platform does not support delivered performance counter and
* reference performance counter. It can calculate the performance using the
* platform specific mechanism. We reuse the desired performance register to
* store the real performance calculated by the platform.
*/
static unsigned int hisi_cppc_cpufreq_get_rate(unsigned int cpu)
{
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
struct cppc_cpudata *cpu_data = policy->driver_data;
u64 desired_perf;
int ret;
cpufreq_cpu_put(policy);
ret = cppc_get_desired_perf(cpu, &desired_perf);
if (ret < 0)
return -EIO;
return cppc_cpufreq_perf_to_khz(cpu_data, desired_perf);
}
static void cppc_check_hisi_workaround(void)
{
struct acpi_table_header *tbl;
acpi_status status = AE_OK;
int i;
status = acpi_get_table(ACPI_SIG_PCCT, 0, &tbl);
if (ACPI_FAILURE(status) || !tbl)
return;
for (i = 0; i < ARRAY_SIZE(wa_info); i++) {
if (!memcmp(wa_info[i].oem_id, tbl->oem_id, ACPI_OEM_ID_SIZE) &&
!memcmp(wa_info[i].oem_table_id, tbl->oem_table_id, ACPI_OEM_TABLE_ID_SIZE) &&
wa_info[i].oem_revision == tbl->oem_revision) {
/* Overwrite the get() callback */
cppc_cpufreq_driver.get = hisi_cppc_cpufreq_get_rate;
break;
}
}
acpi_put_table(tbl);
}
static int __init cppc_cpufreq_init(void)
{
int ret;
if ((acpi_disabled) || !acpi_cpc_valid())
return -ENODEV;
INIT_LIST_HEAD(&cpu_data_list);
cppc_check_hisi_workaround();
cppc_freq_invariance_init();
ret = cpufreq_register_driver(&cppc_cpufreq_driver);
if (ret)
cppc_freq_invariance_exit();
return ret;
}
static inline void free_cpu_data(void)
{
struct cppc_cpudata *iter, *tmp;
list_for_each_entry_safe(iter, tmp, &cpu_data_list, node) {
free_cpumask_var(iter->shared_cpu_map);
list_del(&iter->node);
kfree(iter);
}
}
static void __exit cppc_cpufreq_exit(void)
{
cpufreq_unregister_driver(&cppc_cpufreq_driver);
cppc_freq_invariance_exit();
free_cpu_data();
}
module_exit(cppc_cpufreq_exit);
MODULE_AUTHOR("Ashwin Chaugule");
MODULE_DESCRIPTION("CPUFreq driver based on the ACPI CPPC v5.0+ spec");
MODULE_LICENSE("GPL");
late_initcall(cppc_cpufreq_init);
static const struct acpi_device_id cppc_acpi_ids[] __used = {
{ACPI_PROCESSOR_DEVICE_HID, },
{}
};
MODULE_DEVICE_TABLE(acpi, cppc_acpi_ids);