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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * pmi backend for the cbe_cpufreq driver4 *5 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005-20076 *7 * Author: Christian Krafft <krafft@de.ibm.com>8 */9 10#include <linux/kernel.h>11#include <linux/types.h>12#include <linux/timer.h>13#include <linux/init.h>14#include <linux/pm_qos.h>15#include <linux/slab.h>16 17#include <asm/processor.h>18#include <asm/pmi.h>19#include <asm/cell-regs.h>20 21#ifdef DEBUG22#include <asm/time.h>23#endif24 25#include "ppc_cbe_cpufreq.h"26 27bool cbe_cpufreq_has_pmi = false;28EXPORT_SYMBOL_GPL(cbe_cpufreq_has_pmi);29 30/*31 * hardware specific functions32 */33 34int cbe_cpufreq_set_pmode_pmi(int cpu, unsigned int pmode)35{36 int ret;37 pmi_message_t pmi_msg;38#ifdef DEBUG39 long time;40#endif41 pmi_msg.type = PMI_TYPE_FREQ_CHANGE;42 pmi_msg.data1 = cbe_cpu_to_node(cpu);43 pmi_msg.data2 = pmode;44 45#ifdef DEBUG46 time = jiffies;47#endif48 pmi_send_message(pmi_msg);49 50#ifdef DEBUG51 time = jiffies - time;52 time = jiffies_to_msecs(time);53 pr_debug("had to wait %lu ms for a transition using " \54 "PMI\n", time);55#endif56 ret = pmi_msg.data2;57 pr_debug("PMI returned slow mode %d\n", ret);58 59 return ret;60}61EXPORT_SYMBOL_GPL(cbe_cpufreq_set_pmode_pmi);62 63 64static void cbe_cpufreq_handle_pmi(pmi_message_t pmi_msg)65{66 struct cpufreq_policy *policy;67 struct freq_qos_request *req;68 u8 node, slow_mode;69 int cpu, ret;70 71 BUG_ON(pmi_msg.type != PMI_TYPE_FREQ_CHANGE);72 73 node = pmi_msg.data1;74 slow_mode = pmi_msg.data2;75 76 cpu = cbe_node_to_cpu(node);77 78 pr_debug("cbe_handle_pmi: node: %d max_freq: %d\n", node, slow_mode);79 80 policy = cpufreq_cpu_get(cpu);81 if (!policy) {82 pr_warn("cpufreq policy not found cpu%d\n", cpu);83 return;84 }85 86 req = policy->driver_data;87 88 ret = freq_qos_update_request(req,89 policy->freq_table[slow_mode].frequency);90 if (ret < 0)91 pr_warn("Failed to update freq constraint: %d\n", ret);92 else93 pr_debug("limiting node %d to slow mode %d\n", node, slow_mode);94 95 cpufreq_cpu_put(policy);96}97 98static struct pmi_handler cbe_pmi_handler = {99 .type = PMI_TYPE_FREQ_CHANGE,100 .handle_pmi_message = cbe_cpufreq_handle_pmi,101};102 103void cbe_cpufreq_pmi_policy_init(struct cpufreq_policy *policy)104{105 struct freq_qos_request *req;106 int ret;107 108 if (!cbe_cpufreq_has_pmi)109 return;110 111 req = kzalloc(sizeof(*req), GFP_KERNEL);112 if (!req)113 return;114 115 ret = freq_qos_add_request(&policy->constraints, req, FREQ_QOS_MAX,116 policy->freq_table[0].frequency);117 if (ret < 0) {118 pr_err("Failed to add freq constraint (%d)\n", ret);119 kfree(req);120 return;121 }122 123 policy->driver_data = req;124}125EXPORT_SYMBOL_GPL(cbe_cpufreq_pmi_policy_init);126 127void cbe_cpufreq_pmi_policy_exit(struct cpufreq_policy *policy)128{129 struct freq_qos_request *req = policy->driver_data;130 131 if (cbe_cpufreq_has_pmi) {132 freq_qos_remove_request(req);133 kfree(req);134 }135}136EXPORT_SYMBOL_GPL(cbe_cpufreq_pmi_policy_exit);137 138void cbe_cpufreq_pmi_init(void)139{140 if (!pmi_register_handler(&cbe_pmi_handler))141 cbe_cpufreq_has_pmi = true;142}143EXPORT_SYMBOL_GPL(cbe_cpufreq_pmi_init);144 145void cbe_cpufreq_pmi_exit(void)146{147 pmi_unregister_handler(&cbe_pmi_handler);148 cbe_cpufreq_has_pmi = false;149}150EXPORT_SYMBOL_GPL(cbe_cpufreq_pmi_exit);151