1e21fd5af3
Minor issues have been fixed: * added a missing call to of_node_put() * signedness of a function parameter * added some line breaks * changed global pmi_frequency_limit to a per node pmi_slow_mode_limit array Signed-off-by: Christian Krafft <krafft@de.ibm.com> Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
378 lines
8.4 KiB
C
378 lines
8.4 KiB
C
/*
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* cpufreq driver for the cell processor
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*
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* (C) Copyright IBM Deutschland Entwicklung GmbH 2005
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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/cpufreq.h>
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#include <linux/timer.h>
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#include <asm/hw_irq.h>
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#include <asm/io.h>
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#include <asm/machdep.h>
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#include <asm/processor.h>
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#include <asm/prom.h>
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#include <asm/time.h>
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#include <asm/pmi.h>
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#include <asm/of_platform.h>
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#include "cbe_regs.h"
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static DEFINE_MUTEX(cbe_switch_mutex);
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/* the CBE supports an 8 step frequency scaling */
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static struct cpufreq_frequency_table cbe_freqs[] = {
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{1, 0},
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{2, 0},
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{3, 0},
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{4, 0},
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{5, 0},
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{6, 0},
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{8, 0},
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{10, 0},
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{0, CPUFREQ_TABLE_END},
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};
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/* to write to MIC register */
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static u64 MIC_Slow_Fast_Timer_table[] = {
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[0 ... 7] = 0x007fc00000000000ull,
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};
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/* more values for the MIC */
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static u64 MIC_Slow_Next_Timer_table[] = {
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0x0000240000000000ull,
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0x0000268000000000ull,
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0x000029C000000000ull,
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0x00002D0000000000ull,
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0x0000300000000000ull,
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0x0000334000000000ull,
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0x000039C000000000ull,
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0x00003FC000000000ull,
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};
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static u8 pmi_slow_mode_limit[MAX_BE];
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/*
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* hardware specific functions
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*/
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static bool cbe_cpufreq_has_pmi;
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#ifdef CONFIG_PPC_PMI
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static int 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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ret = pmi_msg.data2;
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pr_debug("PMI returned slow mode %d\n", ret);
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#ifdef DEBUG
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time = jiffies - time; /* actual cycles (not cpu cycles!) */
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time = jiffies_to_msecs(time);
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pr_debug("had to wait %lu ms for a transition using PMI.\n", time);
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#endif
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return ret;
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}
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#endif
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static int get_pmode(int cpu)
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{
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int ret;
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struct cbe_pmd_regs __iomem *pmd_regs;
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pmd_regs = cbe_get_cpu_pmd_regs(cpu);
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ret = in_be64(&pmd_regs->pmsr) & 0x07;
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return ret;
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}
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static int set_pmode_reg(int cpu, unsigned int pmode)
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{
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struct cbe_pmd_regs __iomem *pmd_regs;
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struct cbe_mic_tm_regs __iomem *mic_tm_regs;
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u64 flags;
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u64 value;
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#ifdef DEBUG
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long time;
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#endif
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local_irq_save(flags);
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mic_tm_regs = cbe_get_cpu_mic_tm_regs(cpu);
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pmd_regs = cbe_get_cpu_pmd_regs(cpu);
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#ifdef DEBUG
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time = jiffies;
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#endif
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out_be64(&mic_tm_regs->slow_fast_timer_0, MIC_Slow_Fast_Timer_table[pmode]);
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out_be64(&mic_tm_regs->slow_fast_timer_1, MIC_Slow_Fast_Timer_table[pmode]);
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out_be64(&mic_tm_regs->slow_next_timer_0, MIC_Slow_Next_Timer_table[pmode]);
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out_be64(&mic_tm_regs->slow_next_timer_1, MIC_Slow_Next_Timer_table[pmode]);
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value = in_be64(&pmd_regs->pmcr);
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/* set bits to zero */
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value &= 0xFFFFFFFFFFFFFFF8ull;
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/* set bits to next pmode */
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value |= pmode;
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out_be64(&pmd_regs->pmcr, value);
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#ifdef DEBUG
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/* wait until new pmode appears in status register */
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value = in_be64(&pmd_regs->pmsr) & 0x07;
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while(value != pmode) {
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cpu_relax();
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value = in_be64(&pmd_regs->pmsr) & 0x07;
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}
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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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"the pervasive unit.\n", time);
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#endif
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local_irq_restore(flags);
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return 0;
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}
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static int set_pmode(int cpu, unsigned int slow_mode)
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{
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int rc;
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#ifdef CONFIG_PPC_PMI
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if (cbe_cpufreq_has_pmi)
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rc = set_pmode_pmi(cpu, slow_mode);
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else
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#endif
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rc = set_pmode_reg(cpu, slow_mode);
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pr_debug("register contains slow mode %d\n", get_pmode(cpu));
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return rc;
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}
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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 slow_mode=%d\n", 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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u8 node;
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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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/*
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* cpufreq functions
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*/
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static int cbe_cpufreq_cpu_init(struct cpufreq_policy *policy)
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{
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const u32 *max_freqp;
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u32 max_freq;
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int i, cur_pmode;
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struct device_node *cpu;
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cpu = of_get_cpu_node(policy->cpu, NULL);
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if (!cpu)
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return -ENODEV;
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pr_debug("init cpufreq on CPU %d\n", policy->cpu);
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max_freqp = of_get_property(cpu, "clock-frequency", NULL);
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of_node_put(cpu);
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if (!max_freqp)
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return -EINVAL;
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/* we need the freq in kHz */
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max_freq = *max_freqp / 1000;
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pr_debug("max clock-frequency is at %u kHz\n", max_freq);
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pr_debug("initializing frequency table\n");
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/* initialize frequency table */
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for (i=0; cbe_freqs[i].frequency!=CPUFREQ_TABLE_END; i++) {
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cbe_freqs[i].frequency = max_freq / cbe_freqs[i].index;
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pr_debug("%d: %d\n", i, cbe_freqs[i].frequency);
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}
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policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
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/* if DEBUG is enabled set_pmode() measures the latency
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* of a transition */
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policy->cpuinfo.transition_latency = 25000;
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cur_pmode = get_pmode(policy->cpu);
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pr_debug("current pmode is at %d\n",cur_pmode);
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policy->cur = cbe_freqs[cur_pmode].frequency;
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#ifdef CONFIG_SMP
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policy->cpus = cpu_sibling_map[policy->cpu];
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#endif
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cpufreq_frequency_table_get_attr(cbe_freqs, policy->cpu);
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/* this ensures that policy->cpuinfo_min
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* and policy->cpuinfo_max are set correctly */
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return cpufreq_frequency_table_cpuinfo(policy, cbe_freqs);
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}
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static int cbe_cpufreq_cpu_exit(struct cpufreq_policy *policy)
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{
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cpufreq_frequency_table_put_attr(policy->cpu);
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return 0;
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}
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static int cbe_cpufreq_verify(struct cpufreq_policy *policy)
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{
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return cpufreq_frequency_table_verify(policy, cbe_freqs);
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}
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static int cbe_cpufreq_target(struct cpufreq_policy *policy,
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unsigned int target_freq,
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unsigned int relation)
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{
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int rc;
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struct cpufreq_freqs freqs;
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unsigned int cbe_pmode_new;
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cpufreq_frequency_table_target(policy,
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cbe_freqs,
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target_freq,
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relation,
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&cbe_pmode_new);
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freqs.old = policy->cur;
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freqs.new = cbe_freqs[cbe_pmode_new].frequency;
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freqs.cpu = policy->cpu;
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mutex_lock(&cbe_switch_mutex);
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cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
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pr_debug("setting frequency for cpu %d to %d kHz, " \
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"1/%d of max frequency\n",
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policy->cpu,
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cbe_freqs[cbe_pmode_new].frequency,
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cbe_freqs[cbe_pmode_new].index);
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rc = set_pmode(policy->cpu, cbe_pmode_new);
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cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
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mutex_unlock(&cbe_switch_mutex);
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return rc;
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}
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static struct cpufreq_driver cbe_cpufreq_driver = {
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.verify = cbe_cpufreq_verify,
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.target = cbe_cpufreq_target,
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.init = cbe_cpufreq_cpu_init,
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.exit = cbe_cpufreq_cpu_exit,
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.name = "cbe-cpufreq",
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.owner = THIS_MODULE,
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.flags = CPUFREQ_CONST_LOOPS,
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};
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/*
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* module init and destoy
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*/
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static int __init cbe_cpufreq_init(void)
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{
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if (!machine_is(cell))
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return -ENODEV;
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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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cpufreq_register_notifier(&pmi_notifier_block, CPUFREQ_POLICY_NOTIFIER);
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return cpufreq_register_driver(&cbe_cpufreq_driver);
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}
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static void __exit cbe_cpufreq_exit(void)
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{
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cpufreq_unregister_driver(&cbe_cpufreq_driver);
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if (cbe_cpufreq_has_pmi) {
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cpufreq_unregister_notifier(&pmi_notifier_block, CPUFREQ_POLICY_NOTIFIER);
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pmi_unregister_handler(&cbe_pmi_handler);
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}
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}
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module_init(cbe_cpufreq_init);
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module_exit(cbe_cpufreq_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");
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