linux/drivers/cpufreq/pcc-cpufreq.c
Lenny Szubowicz 7e7e8fe698 cpufreq: pcc: Enable autoload of pcc-cpufreq for ACPI processors
The pcc-cpufreq driver is not automatically loaded on systems where
the platform's power management setting requires this driver.
Instead, on those systems no CPU frequency driver is registered and
active.

Make the autoloading matching criteria for loading the pcc-cpufreq
driver the same as done in acpi-cpufreq by commit c655affbd5
("ACPI / cpufreq: Add ACPI processor device IDs to acpi-cpufreq").

x86 CPU frequency drivers are now typically autoloaded by specifying
MODULE_DEVICE_TABLE entries and x86cpu model specific matching.
But pcc-cpufreq was omitted when acpi-cpufreq and other drivers were
changed to use this approach.

Both acpi-cpufreq and pcc-cpufreq depend on a distinct and mutually
exclusive set of ACPI methods which are not directly tied to specific
processor model numbers. Both of these drivers have init routines
which look for their required ACPI methods. As a result, only the
appropriate driver registers as the cpu frequency driver and the other
one ends up being unloaded.

Tested on various systems where acpi-cpufreq, intel_pstate, and
pcc-cpufreq are the expected cpu frequency drivers.

Signed-off-by: Lenny Szubowicz <lszubowi@redhat.com>
Signed-off-by: Joseph Szczypek <joseph.szczypek@hp.com>
Reported-by: Trinh Dao <trinh.dao@hp.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-11-14 00:16:25 +01:00

620 lines
15 KiB
C

/*
* pcc-cpufreq.c - Processor Clocking Control firmware cpufreq interface
*
* Copyright (C) 2009 Red Hat, Matthew Garrett <mjg@redhat.com>
* Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
* Nagananda Chumbalkar <nagananda.chumbalkar@hp.com>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or NON
* INFRINGEMENT. See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/sched.h>
#include <linux/cpufreq.h>
#include <linux/compiler.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <linux/io.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include <acpi/processor.h>
#define PCC_VERSION "1.10.00"
#define POLL_LOOPS 300
#define CMD_COMPLETE 0x1
#define CMD_GET_FREQ 0x0
#define CMD_SET_FREQ 0x1
#define BUF_SZ 4
struct pcc_register_resource {
u8 descriptor;
u16 length;
u8 space_id;
u8 bit_width;
u8 bit_offset;
u8 access_size;
u64 address;
} __attribute__ ((packed));
struct pcc_memory_resource {
u8 descriptor;
u16 length;
u8 space_id;
u8 resource_usage;
u8 type_specific;
u64 granularity;
u64 minimum;
u64 maximum;
u64 translation_offset;
u64 address_length;
} __attribute__ ((packed));
static struct cpufreq_driver pcc_cpufreq_driver;
struct pcc_header {
u32 signature;
u16 length;
u8 major;
u8 minor;
u32 features;
u16 command;
u16 status;
u32 latency;
u32 minimum_time;
u32 maximum_time;
u32 nominal;
u32 throttled_frequency;
u32 minimum_frequency;
};
static void __iomem *pcch_virt_addr;
static struct pcc_header __iomem *pcch_hdr;
static DEFINE_SPINLOCK(pcc_lock);
static struct acpi_generic_address doorbell;
static u64 doorbell_preserve;
static u64 doorbell_write;
static u8 OSC_UUID[16] = {0x9F, 0x2C, 0x9B, 0x63, 0x91, 0x70, 0x1f, 0x49,
0xBB, 0x4F, 0xA5, 0x98, 0x2F, 0xA1, 0xB5, 0x46};
struct pcc_cpu {
u32 input_offset;
u32 output_offset;
};
static struct pcc_cpu __percpu *pcc_cpu_info;
static int pcc_cpufreq_verify(struct cpufreq_policy *policy)
{
cpufreq_verify_within_cpu_limits(policy);
return 0;
}
static inline void pcc_cmd(void)
{
u64 doorbell_value;
int i;
acpi_read(&doorbell_value, &doorbell);
acpi_write((doorbell_value & doorbell_preserve) | doorbell_write,
&doorbell);
for (i = 0; i < POLL_LOOPS; i++) {
if (ioread16(&pcch_hdr->status) & CMD_COMPLETE)
break;
}
}
static inline void pcc_clear_mapping(void)
{
if (pcch_virt_addr)
iounmap(pcch_virt_addr);
pcch_virt_addr = NULL;
}
static unsigned int pcc_get_freq(unsigned int cpu)
{
struct pcc_cpu *pcc_cpu_data;
unsigned int curr_freq;
unsigned int freq_limit;
u16 status;
u32 input_buffer;
u32 output_buffer;
spin_lock(&pcc_lock);
pr_debug("get: get_freq for CPU %d\n", cpu);
pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
input_buffer = 0x1;
iowrite32(input_buffer,
(pcch_virt_addr + pcc_cpu_data->input_offset));
iowrite16(CMD_GET_FREQ, &pcch_hdr->command);
pcc_cmd();
output_buffer =
ioread32(pcch_virt_addr + pcc_cpu_data->output_offset);
/* Clear the input buffer - we are done with the current command */
memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
status = ioread16(&pcch_hdr->status);
if (status != CMD_COMPLETE) {
pr_debug("get: FAILED: for CPU %d, status is %d\n",
cpu, status);
goto cmd_incomplete;
}
iowrite16(0, &pcch_hdr->status);
curr_freq = (((ioread32(&pcch_hdr->nominal) * (output_buffer & 0xff))
/ 100) * 1000);
pr_debug("get: SUCCESS: (virtual) output_offset for cpu %d is "
"0x%p, contains a value of: 0x%x. Speed is: %d MHz\n",
cpu, (pcch_virt_addr + pcc_cpu_data->output_offset),
output_buffer, curr_freq);
freq_limit = (output_buffer >> 8) & 0xff;
if (freq_limit != 0xff) {
pr_debug("get: frequency for cpu %d is being temporarily"
" capped at %d\n", cpu, curr_freq);
}
spin_unlock(&pcc_lock);
return curr_freq;
cmd_incomplete:
iowrite16(0, &pcch_hdr->status);
spin_unlock(&pcc_lock);
return 0;
}
static int pcc_cpufreq_target(struct cpufreq_policy *policy,
unsigned int target_freq,
unsigned int relation)
{
struct pcc_cpu *pcc_cpu_data;
struct cpufreq_freqs freqs;
u16 status;
u32 input_buffer;
int cpu;
cpu = policy->cpu;
pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
pr_debug("target: CPU %d should go to target freq: %d "
"(virtual) input_offset is 0x%p\n",
cpu, target_freq,
(pcch_virt_addr + pcc_cpu_data->input_offset));
freqs.old = policy->cur;
freqs.new = target_freq;
cpufreq_freq_transition_begin(policy, &freqs);
spin_lock(&pcc_lock);
input_buffer = 0x1 | (((target_freq * 100)
/ (ioread32(&pcch_hdr->nominal) * 1000)) << 8);
iowrite32(input_buffer,
(pcch_virt_addr + pcc_cpu_data->input_offset));
iowrite16(CMD_SET_FREQ, &pcch_hdr->command);
pcc_cmd();
/* Clear the input buffer - we are done with the current command */
memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
status = ioread16(&pcch_hdr->status);
iowrite16(0, &pcch_hdr->status);
cpufreq_freq_transition_end(policy, &freqs, status != CMD_COMPLETE);
spin_unlock(&pcc_lock);
if (status != CMD_COMPLETE) {
pr_debug("target: FAILED for cpu %d, with status: 0x%x\n",
cpu, status);
return -EINVAL;
}
pr_debug("target: was SUCCESSFUL for cpu %d\n", cpu);
return 0;
}
static int pcc_get_offset(int cpu)
{
acpi_status status;
struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
union acpi_object *pccp, *offset;
struct pcc_cpu *pcc_cpu_data;
struct acpi_processor *pr;
int ret = 0;
pr = per_cpu(processors, cpu);
pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
if (!pr)
return -ENODEV;
status = acpi_evaluate_object(pr->handle, "PCCP", NULL, &buffer);
if (ACPI_FAILURE(status))
return -ENODEV;
pccp = buffer.pointer;
if (!pccp || pccp->type != ACPI_TYPE_PACKAGE) {
ret = -ENODEV;
goto out_free;
};
offset = &(pccp->package.elements[0]);
if (!offset || offset->type != ACPI_TYPE_INTEGER) {
ret = -ENODEV;
goto out_free;
}
pcc_cpu_data->input_offset = offset->integer.value;
offset = &(pccp->package.elements[1]);
if (!offset || offset->type != ACPI_TYPE_INTEGER) {
ret = -ENODEV;
goto out_free;
}
pcc_cpu_data->output_offset = offset->integer.value;
memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
memset_io((pcch_virt_addr + pcc_cpu_data->output_offset), 0, BUF_SZ);
pr_debug("pcc_get_offset: for CPU %d: pcc_cpu_data "
"input_offset: 0x%x, pcc_cpu_data output_offset: 0x%x\n",
cpu, pcc_cpu_data->input_offset, pcc_cpu_data->output_offset);
out_free:
kfree(buffer.pointer);
return ret;
}
static int __init pcc_cpufreq_do_osc(acpi_handle *handle)
{
acpi_status status;
struct acpi_object_list input;
struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
union acpi_object in_params[4];
union acpi_object *out_obj;
u32 capabilities[2];
u32 errors;
u32 supported;
int ret = 0;
input.count = 4;
input.pointer = in_params;
in_params[0].type = ACPI_TYPE_BUFFER;
in_params[0].buffer.length = 16;
in_params[0].buffer.pointer = OSC_UUID;
in_params[1].type = ACPI_TYPE_INTEGER;
in_params[1].integer.value = 1;
in_params[2].type = ACPI_TYPE_INTEGER;
in_params[2].integer.value = 2;
in_params[3].type = ACPI_TYPE_BUFFER;
in_params[3].buffer.length = 8;
in_params[3].buffer.pointer = (u8 *)&capabilities;
capabilities[0] = OSC_QUERY_ENABLE;
capabilities[1] = 0x1;
status = acpi_evaluate_object(*handle, "_OSC", &input, &output);
if (ACPI_FAILURE(status))
return -ENODEV;
if (!output.length)
return -ENODEV;
out_obj = output.pointer;
if (out_obj->type != ACPI_TYPE_BUFFER) {
ret = -ENODEV;
goto out_free;
}
errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
if (errors) {
ret = -ENODEV;
goto out_free;
}
supported = *((u32 *)(out_obj->buffer.pointer + 4));
if (!(supported & 0x1)) {
ret = -ENODEV;
goto out_free;
}
kfree(output.pointer);
capabilities[0] = 0x0;
capabilities[1] = 0x1;
status = acpi_evaluate_object(*handle, "_OSC", &input, &output);
if (ACPI_FAILURE(status))
return -ENODEV;
if (!output.length)
return -ENODEV;
out_obj = output.pointer;
if (out_obj->type != ACPI_TYPE_BUFFER) {
ret = -ENODEV;
goto out_free;
}
errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
if (errors) {
ret = -ENODEV;
goto out_free;
}
supported = *((u32 *)(out_obj->buffer.pointer + 4));
if (!(supported & 0x1)) {
ret = -ENODEV;
goto out_free;
}
out_free:
kfree(output.pointer);
return ret;
}
static int __init pcc_cpufreq_probe(void)
{
acpi_status status;
struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
struct pcc_memory_resource *mem_resource;
struct pcc_register_resource *reg_resource;
union acpi_object *out_obj, *member;
acpi_handle handle, osc_handle;
int ret = 0;
status = acpi_get_handle(NULL, "\\_SB", &handle);
if (ACPI_FAILURE(status))
return -ENODEV;
if (!acpi_has_method(handle, "PCCH"))
return -ENODEV;
status = acpi_get_handle(handle, "_OSC", &osc_handle);
if (ACPI_SUCCESS(status)) {
ret = pcc_cpufreq_do_osc(&osc_handle);
if (ret)
pr_debug("probe: _OSC evaluation did not succeed\n");
/* Firmware's use of _OSC is optional */
ret = 0;
}
status = acpi_evaluate_object(handle, "PCCH", NULL, &output);
if (ACPI_FAILURE(status))
return -ENODEV;
out_obj = output.pointer;
if (out_obj->type != ACPI_TYPE_PACKAGE) {
ret = -ENODEV;
goto out_free;
}
member = &out_obj->package.elements[0];
if (member->type != ACPI_TYPE_BUFFER) {
ret = -ENODEV;
goto out_free;
}
mem_resource = (struct pcc_memory_resource *)member->buffer.pointer;
pr_debug("probe: mem_resource descriptor: 0x%x,"
" length: %d, space_id: %d, resource_usage: %d,"
" type_specific: %d, granularity: 0x%llx,"
" minimum: 0x%llx, maximum: 0x%llx,"
" translation_offset: 0x%llx, address_length: 0x%llx\n",
mem_resource->descriptor, mem_resource->length,
mem_resource->space_id, mem_resource->resource_usage,
mem_resource->type_specific, mem_resource->granularity,
mem_resource->minimum, mem_resource->maximum,
mem_resource->translation_offset,
mem_resource->address_length);
if (mem_resource->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) {
ret = -ENODEV;
goto out_free;
}
pcch_virt_addr = ioremap_nocache(mem_resource->minimum,
mem_resource->address_length);
if (pcch_virt_addr == NULL) {
pr_debug("probe: could not map shared mem region\n");
ret = -ENOMEM;
goto out_free;
}
pcch_hdr = pcch_virt_addr;
pr_debug("probe: PCCH header (virtual) addr: 0x%p\n", pcch_hdr);
pr_debug("probe: PCCH header is at physical address: 0x%llx,"
" signature: 0x%x, length: %d bytes, major: %d, minor: %d,"
" supported features: 0x%x, command field: 0x%x,"
" status field: 0x%x, nominal latency: %d us\n",
mem_resource->minimum, ioread32(&pcch_hdr->signature),
ioread16(&pcch_hdr->length), ioread8(&pcch_hdr->major),
ioread8(&pcch_hdr->minor), ioread32(&pcch_hdr->features),
ioread16(&pcch_hdr->command), ioread16(&pcch_hdr->status),
ioread32(&pcch_hdr->latency));
pr_debug("probe: min time between commands: %d us,"
" max time between commands: %d us,"
" nominal CPU frequency: %d MHz,"
" minimum CPU frequency: %d MHz,"
" minimum CPU frequency without throttling: %d MHz\n",
ioread32(&pcch_hdr->minimum_time),
ioread32(&pcch_hdr->maximum_time),
ioread32(&pcch_hdr->nominal),
ioread32(&pcch_hdr->throttled_frequency),
ioread32(&pcch_hdr->minimum_frequency));
member = &out_obj->package.elements[1];
if (member->type != ACPI_TYPE_BUFFER) {
ret = -ENODEV;
goto pcch_free;
}
reg_resource = (struct pcc_register_resource *)member->buffer.pointer;
doorbell.space_id = reg_resource->space_id;
doorbell.bit_width = reg_resource->bit_width;
doorbell.bit_offset = reg_resource->bit_offset;
doorbell.access_width = 64;
doorbell.address = reg_resource->address;
pr_debug("probe: doorbell: space_id is %d, bit_width is %d, "
"bit_offset is %d, access_width is %d, address is 0x%llx\n",
doorbell.space_id, doorbell.bit_width, doorbell.bit_offset,
doorbell.access_width, reg_resource->address);
member = &out_obj->package.elements[2];
if (member->type != ACPI_TYPE_INTEGER) {
ret = -ENODEV;
goto pcch_free;
}
doorbell_preserve = member->integer.value;
member = &out_obj->package.elements[3];
if (member->type != ACPI_TYPE_INTEGER) {
ret = -ENODEV;
goto pcch_free;
}
doorbell_write = member->integer.value;
pr_debug("probe: doorbell_preserve: 0x%llx,"
" doorbell_write: 0x%llx\n",
doorbell_preserve, doorbell_write);
pcc_cpu_info = alloc_percpu(struct pcc_cpu);
if (!pcc_cpu_info) {
ret = -ENOMEM;
goto pcch_free;
}
printk(KERN_DEBUG "pcc-cpufreq: (v%s) driver loaded with frequency"
" limits: %d MHz, %d MHz\n", PCC_VERSION,
ioread32(&pcch_hdr->minimum_frequency),
ioread32(&pcch_hdr->nominal));
kfree(output.pointer);
return ret;
pcch_free:
pcc_clear_mapping();
out_free:
kfree(output.pointer);
return ret;
}
static int pcc_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
unsigned int cpu = policy->cpu;
unsigned int result = 0;
if (!pcch_virt_addr) {
result = -1;
goto out;
}
result = pcc_get_offset(cpu);
if (result) {
pr_debug("init: PCCP evaluation failed\n");
goto out;
}
policy->max = policy->cpuinfo.max_freq =
ioread32(&pcch_hdr->nominal) * 1000;
policy->min = policy->cpuinfo.min_freq =
ioread32(&pcch_hdr->minimum_frequency) * 1000;
pr_debug("init: policy->max is %d, policy->min is %d\n",
policy->max, policy->min);
out:
return result;
}
static int pcc_cpufreq_cpu_exit(struct cpufreq_policy *policy)
{
return 0;
}
static struct cpufreq_driver pcc_cpufreq_driver = {
.flags = CPUFREQ_CONST_LOOPS,
.get = pcc_get_freq,
.verify = pcc_cpufreq_verify,
.target = pcc_cpufreq_target,
.init = pcc_cpufreq_cpu_init,
.exit = pcc_cpufreq_cpu_exit,
.name = "pcc-cpufreq",
};
static int __init pcc_cpufreq_init(void)
{
int ret;
if (acpi_disabled)
return 0;
ret = pcc_cpufreq_probe();
if (ret) {
pr_debug("pcc_cpufreq_init: PCCH evaluation failed\n");
return ret;
}
ret = cpufreq_register_driver(&pcc_cpufreq_driver);
return ret;
}
static void __exit pcc_cpufreq_exit(void)
{
cpufreq_unregister_driver(&pcc_cpufreq_driver);
pcc_clear_mapping();
free_percpu(pcc_cpu_info);
}
static const struct acpi_device_id processor_device_ids[] = {
{ACPI_PROCESSOR_OBJECT_HID, },
{ACPI_PROCESSOR_DEVICE_HID, },
{},
};
MODULE_DEVICE_TABLE(acpi, processor_device_ids);
MODULE_AUTHOR("Matthew Garrett, Naga Chumbalkar");
MODULE_VERSION(PCC_VERSION);
MODULE_DESCRIPTION("Processor Clocking Control interface driver");
MODULE_LICENSE("GPL");
late_initcall(pcc_cpufreq_init);
module_exit(pcc_cpufreq_exit);