145 lines
3.3 KiB
C
145 lines
3.3 KiB
C
/*
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* pmi backend for the cbe_cpufreq driver
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*
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* (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007
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*
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* Author: Christian Krafft <krafft@de.ibm.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2, or (at your option)
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* any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <linux/timer.h>
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#include <linux/init.h>
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#include <linux/of_platform.h>
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#include <asm/processor.h>
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#include <asm/prom.h>
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#include <asm/pmi.h>
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#include <asm/cell-regs.h>
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#ifdef DEBUG
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#include <asm/time.h>
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#endif
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#include "ppc_cbe_cpufreq.h"
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static u8 pmi_slow_mode_limit[MAX_CBE];
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bool cbe_cpufreq_has_pmi = false;
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EXPORT_SYMBOL_GPL(cbe_cpufreq_has_pmi);
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/*
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* hardware specific functions
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*/
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int cbe_cpufreq_set_pmode_pmi(int cpu, unsigned int pmode)
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{
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int ret;
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pmi_message_t pmi_msg;
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#ifdef DEBUG
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long time;
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#endif
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pmi_msg.type = PMI_TYPE_FREQ_CHANGE;
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pmi_msg.data1 = cbe_cpu_to_node(cpu);
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pmi_msg.data2 = pmode;
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#ifdef DEBUG
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time = jiffies;
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#endif
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pmi_send_message(pmi_msg);
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#ifdef DEBUG
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time = jiffies - time;
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time = jiffies_to_msecs(time);
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pr_debug("had to wait %lu ms for a transition using " \
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"PMI\n", time);
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#endif
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ret = pmi_msg.data2;
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pr_debug("PMI returned slow mode %d\n", ret);
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return ret;
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}
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EXPORT_SYMBOL_GPL(cbe_cpufreq_set_pmode_pmi);
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static void cbe_cpufreq_handle_pmi(pmi_message_t pmi_msg)
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{
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u8 node, slow_mode;
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BUG_ON(pmi_msg.type != PMI_TYPE_FREQ_CHANGE);
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node = pmi_msg.data1;
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slow_mode = pmi_msg.data2;
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pmi_slow_mode_limit[node] = slow_mode;
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pr_debug("cbe_handle_pmi: node: %d max_freq: %d\n", node, slow_mode);
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}
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static int pmi_notifier(struct notifier_block *nb,
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unsigned long event, void *data)
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{
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struct cpufreq_policy *policy = data;
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struct cpufreq_frequency_table *cbe_freqs = policy->freq_table;
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u8 node;
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/* Should this really be called for CPUFREQ_ADJUST and CPUFREQ_NOTIFY
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* policy events?)
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*/
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if (event == CPUFREQ_START)
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return 0;
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node = cbe_cpu_to_node(policy->cpu);
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pr_debug("got notified, event=%lu, node=%u\n", event, node);
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if (pmi_slow_mode_limit[node] != 0) {
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pr_debug("limiting node %d to slow mode %d\n",
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node, pmi_slow_mode_limit[node]);
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cpufreq_verify_within_limits(policy, 0,
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cbe_freqs[pmi_slow_mode_limit[node]].frequency);
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}
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return 0;
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}
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static struct notifier_block pmi_notifier_block = {
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.notifier_call = pmi_notifier,
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};
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static struct pmi_handler cbe_pmi_handler = {
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.type = PMI_TYPE_FREQ_CHANGE,
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.handle_pmi_message = cbe_cpufreq_handle_pmi,
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};
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static int __init cbe_cpufreq_pmi_init(void)
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{
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cbe_cpufreq_has_pmi = pmi_register_handler(&cbe_pmi_handler) == 0;
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if (!cbe_cpufreq_has_pmi)
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return -ENODEV;
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cpufreq_register_notifier(&pmi_notifier_block, CPUFREQ_POLICY_NOTIFIER);
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return 0;
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}
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device_initcall(cbe_cpufreq_pmi_init);
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