kernel/drivers/cpufreq/ppc_cbe_cpufreq_pmi.c
2024-07-22 17:22:30 +08:00

151 lines
3.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* pmi backend for the cbe_cpufreq driver
*
* (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007
*
* Author: Christian Krafft <krafft@de.ibm.com>
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/init.h>
#include <linux/pm_qos.h>
#include <asm/processor.h>
#include <asm/prom.h>
#include <asm/pmi.h>
#include <asm/cell-regs.h>
#ifdef DEBUG
#include <asm/time.h>
#endif
#include "ppc_cbe_cpufreq.h"
bool cbe_cpufreq_has_pmi = false;
EXPORT_SYMBOL_GPL(cbe_cpufreq_has_pmi);
/*
* hardware specific functions
*/
int cbe_cpufreq_set_pmode_pmi(int cpu, unsigned int pmode)
{
int ret;
pmi_message_t pmi_msg;
#ifdef DEBUG
long time;
#endif
pmi_msg.type = PMI_TYPE_FREQ_CHANGE;
pmi_msg.data1 = cbe_cpu_to_node(cpu);
pmi_msg.data2 = pmode;
#ifdef DEBUG
time = jiffies;
#endif
pmi_send_message(pmi_msg);
#ifdef DEBUG
time = jiffies - time;
time = jiffies_to_msecs(time);
pr_debug("had to wait %lu ms for a transition using " \
"PMI\n", time);
#endif
ret = pmi_msg.data2;
pr_debug("PMI returned slow mode %d\n", ret);
return ret;
}
EXPORT_SYMBOL_GPL(cbe_cpufreq_set_pmode_pmi);
static void cbe_cpufreq_handle_pmi(pmi_message_t pmi_msg)
{
struct cpufreq_policy *policy;
struct freq_qos_request *req;
u8 node, slow_mode;
int cpu, ret;
BUG_ON(pmi_msg.type != PMI_TYPE_FREQ_CHANGE);
node = pmi_msg.data1;
slow_mode = pmi_msg.data2;
cpu = cbe_node_to_cpu(node);
pr_debug("cbe_handle_pmi: node: %d max_freq: %d\n", node, slow_mode);
policy = cpufreq_cpu_get(cpu);
if (!policy) {
pr_warn("cpufreq policy not found cpu%d\n", cpu);
return;
}
req = policy->driver_data;
ret = freq_qos_update_request(req,
policy->freq_table[slow_mode].frequency);
if (ret < 0)
pr_warn("Failed to update freq constraint: %d\n", ret);
else
pr_debug("limiting node %d to slow mode %d\n", node, slow_mode);
cpufreq_cpu_put(policy);
}
static struct pmi_handler cbe_pmi_handler = {
.type = PMI_TYPE_FREQ_CHANGE,
.handle_pmi_message = cbe_cpufreq_handle_pmi,
};
void cbe_cpufreq_pmi_policy_init(struct cpufreq_policy *policy)
{
struct freq_qos_request *req;
int ret;
if (!cbe_cpufreq_has_pmi)
return;
req = kzalloc(sizeof(*req), GFP_KERNEL);
if (!req)
return;
ret = freq_qos_add_request(&policy->constraints, req, FREQ_QOS_MAX,
policy->freq_table[0].frequency);
if (ret < 0) {
pr_err("Failed to add freq constraint (%d)\n", ret);
kfree(req);
return;
}
policy->driver_data = req;
}
EXPORT_SYMBOL_GPL(cbe_cpufreq_pmi_policy_init);
void cbe_cpufreq_pmi_policy_exit(struct cpufreq_policy *policy)
{
struct freq_qos_request *req = policy->driver_data;
if (cbe_cpufreq_has_pmi) {
freq_qos_remove_request(req);
kfree(req);
}
}
EXPORT_SYMBOL_GPL(cbe_cpufreq_pmi_policy_exit);
void cbe_cpufreq_pmi_init(void)
{
if (!pmi_register_handler(&cbe_pmi_handler))
cbe_cpufreq_has_pmi = true;
}
EXPORT_SYMBOL_GPL(cbe_cpufreq_pmi_init);
void cbe_cpufreq_pmi_exit(void)
{
pmi_unregister_handler(&cbe_pmi_handler);
cbe_cpufreq_has_pmi = false;
}
EXPORT_SYMBOL_GPL(cbe_cpufreq_pmi_exit);