arch/powerpc/platforms/cell/cbe_cpufreq.c - kernel/msm-4.19 - Gitiles

 /*
  * cpufreq driver for the cell processor
  *
  * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
  *
  * Author: Christian Krafft <krafft@de.ibm.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2, or (at your option)
  * any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */

 #include <linux/cpufreq.h>
 #include <linux/timer.h>

 #include <asm/hw_irq.h>
 #include <asm/io.h>
 #include <asm/machdep.h>
 #include <asm/processor.h>
 #include <asm/prom.h>
 #include <asm/time.h>
 #include <asm/pmi.h>
 #include <asm/of_platform.h>

 #include "cbe_regs.h"

 static DEFINE_MUTEX(cbe_switch_mutex);


 /* the CBE supports an 8 step frequency scaling */
 static struct cpufreq_frequency_table cbe_freqs[] = {
 	{1,	0},
 	{2,	0},
 	{3,	0},
 	{4,	0},
 	{5,	0},
 	{6,	0},
 	{8,	0},
 	{10,	0},
 	{0,	CPUFREQ_TABLE_END},
 };

 /* to write to MIC register */
 static u64 MIC_Slow_Fast_Timer_table[] = {
 	[0 ... 7] = 0x007fc00000000000ull,
 };

 /* more values for the MIC */
 static u64 MIC_Slow_Next_Timer_table[] = {
 	0x0000240000000000ull,
 	0x0000268000000000ull,
 	0x000029C000000000ull,
 	0x00002D0000000000ull,
 	0x0000300000000000ull,
 	0x0000334000000000ull,
 	0x000039C000000000ull,
 	0x00003FC000000000ull,
 };

 static u8 pmi_slow_mode_limit[MAX_BE];

 /*
  * hardware specific functions
  */

 static bool cbe_cpufreq_has_pmi;

 #ifdef CONFIG_PPC_PMI
 static int 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);
 	ret = pmi_msg.data2;

 	pr_debug("PMI returned slow mode %d\n", ret);

 #ifdef DEBUG
 	time = jiffies - time; /* actual cycles (not cpu cycles!) */
 	time = jiffies_to_msecs(time);
 	pr_debug("had to wait %lu ms for a transition using PMI.\n", time);
 #endif
 	return ret;
 }
 #endif

 static int get_pmode(int cpu)
 {
 	int ret;
 	struct cbe_pmd_regs __iomem *pmd_regs;

 	pmd_regs = cbe_get_cpu_pmd_regs(cpu);
 	ret = in_be64(&pmd_regs->pmsr) & 0x07;

 	return ret;
 }

 static int set_pmode_reg(int cpu, unsigned int pmode)
 {
 	struct cbe_pmd_regs __iomem *pmd_regs;
 	struct cbe_mic_tm_regs __iomem *mic_tm_regs;
 	u64 flags;
 	u64 value;
 #ifdef DEBUG
 	long time;
 #endif

 	local_irq_save(flags);

 	mic_tm_regs = cbe_get_cpu_mic_tm_regs(cpu);
 	pmd_regs = cbe_get_cpu_pmd_regs(cpu);

 #ifdef DEBUG
 	time = jiffies;
 #endif
 	out_be64(&mic_tm_regs->slow_fast_timer_0, MIC_Slow_Fast_Timer_table[pmode]);
 	out_be64(&mic_tm_regs->slow_fast_timer_1, MIC_Slow_Fast_Timer_table[pmode]);

 	out_be64(&mic_tm_regs->slow_next_timer_0, MIC_Slow_Next_Timer_table[pmode]);
 	out_be64(&mic_tm_regs->slow_next_timer_1, MIC_Slow_Next_Timer_table[pmode]);

 	value = in_be64(&pmd_regs->pmcr);
 	/* set bits to zero */
 	value &= 0xFFFFFFFFFFFFFFF8ull;
 	/* set bits to next pmode */
 	value |= pmode;

 	out_be64(&pmd_regs->pmcr, value);

 #ifdef DEBUG
 	/* wait until new pmode appears in status register */
 	value = in_be64(&pmd_regs->pmsr) & 0x07;
 	while(value != pmode) {
 		cpu_relax();
 		value = in_be64(&pmd_regs->pmsr) & 0x07;
 	}

 	time = jiffies - time;
 	time = jiffies_to_msecs(time);
 	pr_debug("had to wait %lu ms for a transition using " \
 		 "the pervasive unit.\n", time);
 #endif
 	local_irq_restore(flags);

 	return 0;
 }

 static int set_pmode(int cpu, unsigned int slow_mode)
 {
 	int rc;
 #ifdef CONFIG_PPC_PMI
 	if (cbe_cpufreq_has_pmi)
 		rc = set_pmode_pmi(cpu, slow_mode);
 	else
 #endif
 		rc = set_pmode_reg(cpu, slow_mode);

 	pr_debug("register contains slow mode %d\n", get_pmode(cpu));

 	return rc;
 }

 static void cbe_cpufreq_handle_pmi(pmi_message_t pmi_msg)
 {
 	u8 node; slow_mode;

 	BUG_ON(pmi_msg.type != PMI_TYPE_FREQ_CHANGE);

 	node = pmi_msg.data1;
 	slow_mode = pmi_msg.data2;

 	pmi_slow_mode_limit[node] = slow_mode;

 	pr_debug("cbe_handle_pmi: node: %d, max slow_mode=%d\n", slow_mode);
 }

 static int pmi_notifier(struct notifier_block *nb,
 				       unsigned long event, void *data)
 {
 	struct cpufreq_policy *policy = data;
 	u8 node;

 	node = cbe_cpu_to_node(policy->cpu);

 	pr_debug("got notified, event=%lu, node=%u\n", event, node);

 	if (pmi_slow_mode_limit[node] != 0) {
 		pr_debug("limiting node %d to slow mode %d\n",
 			 node, pmi_slow_mode_limit[node]);

 		cpufreq_verify_within_limits(policy, 0,
 			 cbe_freqs[pmi_slow_mode_limit[node]].frequency);
 	}

 	return 0;
 }

 static struct notifier_block pmi_notifier_block = {
 	.notifier_call = pmi_notifier,
 };

 static struct pmi_handler cbe_pmi_handler = {
 	.type			= PMI_TYPE_FREQ_CHANGE,
 	.handle_pmi_message	= cbe_cpufreq_handle_pmi,
 };


 /*
  * cpufreq functions
  */

 static int cbe_cpufreq_cpu_init(struct cpufreq_policy *policy)
 {
 	const u32 *max_freqp;
 	u32 max_freq;
 	int i, cur_pmode;
 	struct device_node *cpu;

 	cpu = of_get_cpu_node(policy->cpu, NULL);

 	if (!cpu)
 		return -ENODEV;

 	pr_debug("init cpufreq on CPU %d\n", policy->cpu);

 	max_freqp = of_get_property(cpu, "clock-frequency", NULL);

 	of_node_put(cpu);

 	if (!max_freqp)
 		return -EINVAL;

 	/* we need the freq in kHz */
 	max_freq = *max_freqp / 1000;

 	pr_debug("max clock-frequency is at %u kHz\n", max_freq);
 	pr_debug("initializing frequency table\n");

 	/* initialize frequency table */
 	for (i=0; cbe_freqs[i].frequency!=CPUFREQ_TABLE_END; i++) {
 		cbe_freqs[i].frequency = max_freq / cbe_freqs[i].index;
 		pr_debug("%d: %d\n", i, cbe_freqs[i].frequency);
 	}

 	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;

 	/* if DEBUG is enabled set_pmode() measures the latency
 	 * of a transition */
 	policy->cpuinfo.transition_latency = 25000;

 	cur_pmode = get_pmode(policy->cpu);
 	pr_debug("current pmode is at %d\n",cur_pmode);

 	policy->cur = cbe_freqs[cur_pmode].frequency;

 #ifdef CONFIG_SMP
 	policy->cpus = cpu_sibling_map[policy->cpu];
 #endif

 	cpufreq_frequency_table_get_attr(cbe_freqs, policy->cpu);

 	/* this ensures that policy->cpuinfo_min
 	 * and policy->cpuinfo_max are set correctly */
 	return cpufreq_frequency_table_cpuinfo(policy, cbe_freqs);
 }

 static int cbe_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 {
 	cpufreq_frequency_table_put_attr(policy->cpu);
 	return 0;
 }

 static int cbe_cpufreq_verify(struct cpufreq_policy *policy)
 {
 	return cpufreq_frequency_table_verify(policy, cbe_freqs);
 }


 static int cbe_cpufreq_target(struct cpufreq_policy *policy,
 			      unsigned int target_freq,
 			      unsigned int relation)
 {
 	int rc;
 	struct cpufreq_freqs freqs;
 	unsigned int cbe_pmode_new;

 	cpufreq_frequency_table_target(policy,
 				       cbe_freqs,
 				       target_freq,
 				       relation,
 				       &cbe_pmode_new);

 	freqs.old = policy->cur;
 	freqs.new = cbe_freqs[cbe_pmode_new].frequency;
 	freqs.cpu = policy->cpu;

 	mutex_lock(&cbe_switch_mutex);
 	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

 	pr_debug("setting frequency for cpu %d to %d kHz, " \
 		 "1/%d of max frequency\n",
 		 policy->cpu,
 		 cbe_freqs[cbe_pmode_new].frequency,
 		 cbe_freqs[cbe_pmode_new].index);

 	rc = set_pmode(policy->cpu, cbe_pmode_new);

 	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 	mutex_unlock(&cbe_switch_mutex);

 	return rc;
 }

 static struct cpufreq_driver cbe_cpufreq_driver = {
 	.verify		= cbe_cpufreq_verify,
 	.target		= cbe_cpufreq_target,
 	.init		= cbe_cpufreq_cpu_init,
 	.exit		= cbe_cpufreq_cpu_exit,
 	.name		= "cbe-cpufreq",
 	.owner		= THIS_MODULE,
 	.flags		= CPUFREQ_CONST_LOOPS,
 };

 /*
  * module init and destoy
  */

 static int __init cbe_cpufreq_init(void)
 {
 	if (!machine_is(cell))
 		return -ENODEV;

 	cbe_cpufreq_has_pmi = pmi_register_handler(&cbe_pmi_handler) == 0;

 	if (cbe_cpufreq_has_pmi)
 		cpufreq_register_notifier(&pmi_notifier_block, CPUFREQ_POLICY_NOTIFIER);

 	return cpufreq_register_driver(&cbe_cpufreq_driver);
 }

 static void __exit cbe_cpufreq_exit(void)
 {
 	cpufreq_unregister_driver(&cbe_cpufreq_driver);

 	if (cbe_cpufreq_has_pmi) {
 		cpufreq_unregister_notifier(&pmi_notifier_block, CPUFREQ_POLICY_NOTIFIER);
 		pmi_unregister_handler(&cbe_pmi_handler);
 	}
 }

 module_init(cbe_cpufreq_init);
 module_exit(cbe_cpufreq_exit);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");
	/*
	* cpufreq driver for the cell processor
	*
	* (C) Copyright IBM Deutschland Entwicklung GmbH 2005
	*
	* Author: Christian Krafft <krafft@de.ibm.com>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2, or (at your option)
	* any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	*/

	#include <linux/cpufreq.h>
	#include <linux/timer.h>

	#include <asm/hw_irq.h>
	#include <asm/io.h>
	#include <asm/machdep.h>
	#include <asm/processor.h>
	#include <asm/prom.h>
	#include <asm/time.h>
	#include <asm/pmi.h>
	#include <asm/of_platform.h>

	#include "cbe_regs.h"

	static DEFINE_MUTEX(cbe_switch_mutex);


	/* the CBE supports an 8 step frequency scaling */
	static struct cpufreq_frequency_table cbe_freqs[] = {
	{1, 0},
	{2, 0},
	{3, 0},
	{4, 0},
	{5, 0},
	{6, 0},
	{8, 0},
	{10, 0},
	{0, CPUFREQ_TABLE_END},
	};

	/* to write to MIC register */
	static u64 MIC_Slow_Fast_Timer_table[] = {
	[0 ... 7] = 0x007fc00000000000ull,
	};

	/* more values for the MIC */
	static u64 MIC_Slow_Next_Timer_table[] = {
	0x0000240000000000ull,
	0x0000268000000000ull,
	0x000029C000000000ull,
	0x00002D0000000000ull,
	0x0000300000000000ull,
	0x0000334000000000ull,
	0x000039C000000000ull,
	0x00003FC000000000ull,
	};

	static u8 pmi_slow_mode_limit[MAX_BE];

	/*
	* hardware specific functions
	*/

	static bool cbe_cpufreq_has_pmi;

	#ifdef CONFIG_PPC_PMI
	static int 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);
	ret = pmi_msg.data2;

	pr_debug("PMI returned slow mode %d\n", ret);

	#ifdef DEBUG
	time = jiffies - time; /* actual cycles (not cpu cycles!) */
	time = jiffies_to_msecs(time);
	pr_debug("had to wait %lu ms for a transition using PMI.\n", time);
	#endif
	return ret;
	}
	#endif

	static int get_pmode(int cpu)
	{
	int ret;
	struct cbe_pmd_regs __iomem *pmd_regs;

	pmd_regs = cbe_get_cpu_pmd_regs(cpu);
	ret = in_be64(&pmd_regs->pmsr) & 0x07;

	return ret;
	}

	static int set_pmode_reg(int cpu, unsigned int pmode)
	{
	struct cbe_pmd_regs __iomem *pmd_regs;
	struct cbe_mic_tm_regs __iomem *mic_tm_regs;
	u64 flags;
	u64 value;
	#ifdef DEBUG
	long time;
	#endif

	local_irq_save(flags);

	mic_tm_regs = cbe_get_cpu_mic_tm_regs(cpu);
	pmd_regs = cbe_get_cpu_pmd_regs(cpu);

	#ifdef DEBUG
	time = jiffies;
	#endif
	out_be64(&mic_tm_regs->slow_fast_timer_0, MIC_Slow_Fast_Timer_table[pmode]);
	out_be64(&mic_tm_regs->slow_fast_timer_1, MIC_Slow_Fast_Timer_table[pmode]);

	out_be64(&mic_tm_regs->slow_next_timer_0, MIC_Slow_Next_Timer_table[pmode]);
	out_be64(&mic_tm_regs->slow_next_timer_1, MIC_Slow_Next_Timer_table[pmode]);

	value = in_be64(&pmd_regs->pmcr);
	/* set bits to zero */
	value &= 0xFFFFFFFFFFFFFFF8ull;
	/* set bits to next pmode */
	value \|= pmode;

	out_be64(&pmd_regs->pmcr, value);

	#ifdef DEBUG
	/* wait until new pmode appears in status register */
	value = in_be64(&pmd_regs->pmsr) & 0x07;
	while(value != pmode) {
	cpu_relax();
	value = in_be64(&pmd_regs->pmsr) & 0x07;
	}

	time = jiffies - time;
	time = jiffies_to_msecs(time);
	pr_debug("had to wait %lu ms for a transition using " \
	"the pervasive unit.\n", time);
	#endif
	local_irq_restore(flags);

	return 0;
	}

	static int set_pmode(int cpu, unsigned int slow_mode)
	{
	int rc;
	#ifdef CONFIG_PPC_PMI
	if (cbe_cpufreq_has_pmi)
	rc = set_pmode_pmi(cpu, slow_mode);
	else
	#endif
	rc = set_pmode_reg(cpu, slow_mode);

	pr_debug("register contains slow mode %d\n", get_pmode(cpu));

	return rc;
	}

	static void cbe_cpufreq_handle_pmi(pmi_message_t pmi_msg)
	{
	u8 node; slow_mode;

	BUG_ON(pmi_msg.type != PMI_TYPE_FREQ_CHANGE);

	node = pmi_msg.data1;
	slow_mode = pmi_msg.data2;

	pmi_slow_mode_limit[node] = slow_mode;

	pr_debug("cbe_handle_pmi: node: %d, max slow_mode=%d\n", slow_mode);
	}

	static int pmi_notifier(struct notifier_block *nb,
	unsigned long event, void *data)
	{
	struct cpufreq_policy *policy = data;
	u8 node;

	node = cbe_cpu_to_node(policy->cpu);

	pr_debug("got notified, event=%lu, node=%u\n", event, node);

	if (pmi_slow_mode_limit[node] != 0) {
	pr_debug("limiting node %d to slow mode %d\n",
	node, pmi_slow_mode_limit[node]);

	cpufreq_verify_within_limits(policy, 0,
	cbe_freqs[pmi_slow_mode_limit[node]].frequency);
	}

	return 0;
	}

	static struct notifier_block pmi_notifier_block = {
	.notifier_call = pmi_notifier,
	};

	static struct pmi_handler cbe_pmi_handler = {
	.type = PMI_TYPE_FREQ_CHANGE,
	.handle_pmi_message = cbe_cpufreq_handle_pmi,
	};


	/*
	* cpufreq functions
	*/

	static int cbe_cpufreq_cpu_init(struct cpufreq_policy *policy)
	{
	const u32 *max_freqp;
	u32 max_freq;
	int i, cur_pmode;
	struct device_node *cpu;

	cpu = of_get_cpu_node(policy->cpu, NULL);

	if (!cpu)
	return -ENODEV;

	pr_debug("init cpufreq on CPU %d\n", policy->cpu);

	max_freqp = of_get_property(cpu, "clock-frequency", NULL);

	of_node_put(cpu);

	if (!max_freqp)
	return -EINVAL;

	/* we need the freq in kHz */
	max_freq = *max_freqp / 1000;

	pr_debug("max clock-frequency is at %u kHz\n", max_freq);
	pr_debug("initializing frequency table\n");

	/* initialize frequency table */
	for (i=0; cbe_freqs[i].frequency!=CPUFREQ_TABLE_END; i++) {
	cbe_freqs[i].frequency = max_freq / cbe_freqs[i].index;
	pr_debug("%d: %d\n", i, cbe_freqs[i].frequency);
	}

	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;

	/* if DEBUG is enabled set_pmode() measures the latency
	* of a transition */
	policy->cpuinfo.transition_latency = 25000;

	cur_pmode = get_pmode(policy->cpu);
	pr_debug("current pmode is at %d\n",cur_pmode);

	policy->cur = cbe_freqs[cur_pmode].frequency;

	#ifdef CONFIG_SMP
	policy->cpus = cpu_sibling_map[policy->cpu];
	#endif

	cpufreq_frequency_table_get_attr(cbe_freqs, policy->cpu);

	/* this ensures that policy->cpuinfo_min
	* and policy->cpuinfo_max are set correctly */
	return cpufreq_frequency_table_cpuinfo(policy, cbe_freqs);
	}

	static int cbe_cpufreq_cpu_exit(struct cpufreq_policy *policy)
	{
	cpufreq_frequency_table_put_attr(policy->cpu);
	return 0;
	}

	static int cbe_cpufreq_verify(struct cpufreq_policy *policy)
	{
	return cpufreq_frequency_table_verify(policy, cbe_freqs);
	}


	static int cbe_cpufreq_target(struct cpufreq_policy *policy,
	unsigned int target_freq,
	unsigned int relation)
	{
	int rc;
	struct cpufreq_freqs freqs;
	unsigned int cbe_pmode_new;

	cpufreq_frequency_table_target(policy,
	cbe_freqs,
	target_freq,
	relation,
	&cbe_pmode_new);

	freqs.old = policy->cur;
	freqs.new = cbe_freqs[cbe_pmode_new].frequency;
	freqs.cpu = policy->cpu;

	mutex_lock(&cbe_switch_mutex);
	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

	pr_debug("setting frequency for cpu %d to %d kHz, " \
	"1/%d of max frequency\n",
	policy->cpu,
	cbe_freqs[cbe_pmode_new].frequency,
	cbe_freqs[cbe_pmode_new].index);

	rc = set_pmode(policy->cpu, cbe_pmode_new);

	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
	mutex_unlock(&cbe_switch_mutex);

	return rc;
	}

	static struct cpufreq_driver cbe_cpufreq_driver = {
	.verify = cbe_cpufreq_verify,
	.target = cbe_cpufreq_target,
	.init = cbe_cpufreq_cpu_init,
	.exit = cbe_cpufreq_cpu_exit,
	.name = "cbe-cpufreq",
	.owner = THIS_MODULE,
	.flags = CPUFREQ_CONST_LOOPS,
	};

	/*
	* module init and destoy
	*/

	static int __init cbe_cpufreq_init(void)
	{
	if (!machine_is(cell))
	return -ENODEV;

	cbe_cpufreq_has_pmi = pmi_register_handler(&cbe_pmi_handler) == 0;

	if (cbe_cpufreq_has_pmi)
	cpufreq_register_notifier(&pmi_notifier_block, CPUFREQ_POLICY_NOTIFIER);

	return cpufreq_register_driver(&cbe_cpufreq_driver);
	}

	static void __exit cbe_cpufreq_exit(void)
	{
	cpufreq_unregister_driver(&cbe_cpufreq_driver);

	if (cbe_cpufreq_has_pmi) {
	cpufreq_unregister_notifier(&pmi_notifier_block, CPUFREQ_POLICY_NOTIFIER);
	pmi_unregister_handler(&cbe_pmi_handler);
	}
	}

	module_init(cbe_cpufreq_init);
	module_exit(cbe_cpufreq_exit);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");