813f90728e
The pmi driver got simplified by removing support for multiple devices. As there is no more than one pmi device per maschine, there is no need to specify the device for listening and sending messages. This way the caller (cbe_cpufreq) doesn't need to scan the device tree. When registering the handler on a board without a pmi interface, pmi.c will just return -ENODEV. The patch that fixed the breakage of cell_defconfig has been broken out of the earlier version of this patch. So this is the version that applies cleanly on top of it. Signed-off-by: Christian Krafft <krafft@de.ibm.com> Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
351 lines
8.2 KiB
C
351 lines
8.2 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 unsigned int pmi_frequency_limit = 0;
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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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u64 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 = (u64) get_cycles();
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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 = (u64) get_cycles() - time; /* actual cycles (not cpu cycles!) */
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time = 1000000000 * time / CLOCK_TICK_RATE; /* time in ns (10^-9) */
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pr_debug("had to wait %lu ns for a transition\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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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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pr_debug("pm register is mapped at %p\n", &pmd_regs->pmcr);
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pr_debug("mic register is mapped at %p\n", &mic_tm_regs->slow_fast_timer_0);
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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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/* 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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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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#ifdef CONFIG_PPC_PMI
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if (cbe_cpufreq_has_pmi)
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return set_pmode_pmi(cpu, slow_mode);
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#endif
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return set_pmode_reg(cpu, slow_mode);
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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 cpu;
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u8 cbe_pmode_new;
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BUG_ON(pmi_msg.type != PMI_TYPE_FREQ_CHANGE);
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cpu = cbe_node_to_cpu(pmi_msg.data1);
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cbe_pmode_new = pmi_msg.data2;
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pmi_frequency_limit = cbe_freqs[cbe_pmode_new].frequency;
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pr_debug("cbe_handle_pmi: max freq=%d\n", pmi_frequency_limit);
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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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if (event != CPUFREQ_INCOMPATIBLE)
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return 0;
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cpufreq_verify_within_limits(policy, 0, pmi_frequency_limit);
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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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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 correct latency 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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if (cbe_cpufreq_has_pmi) {
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/* frequency might get limited later, initialize limit with max_freq */
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pmi_frequency_limit = max_freq;
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cpufreq_register_notifier(&pmi_notifier_block, CPUFREQ_POLICY_NOTIFIER);
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}
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/* this ensures that policy->cpuinfo_min 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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if (cbe_cpufreq_has_pmi)
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cpufreq_unregister_notifier(&pmi_notifier_block, CPUFREQ_POLICY_NOTIFIER);
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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, 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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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, 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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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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pmi_unregister_handler(&cbe_pmi_handler);
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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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