[net-next-2.6.git] / arch / sparc / kernel / us3_cpufreq.c

/* us3_cpufreq.c: UltraSPARC-III cpu frequency support
 *
 * Copyright (C) 2003 David S. Miller (davem@redhat.com)
 *
 * Many thanks to Dominik Brodowski for fixing up the cpufreq
 * infrastructure in order to make this driver easier to implement.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/cpufreq.h>
#include <linux/threads.h>
#include <linux/slab.h>
#include <linux/init.h>

#include <asm/head.h>
#include <asm/timer.h>

static struct cpufreq_driver *cpufreq_us3_driver;

struct us3_freq_percpu_info {
	struct cpufreq_frequency_table table[4];
};

/* Indexed by cpu number. */
static struct us3_freq_percpu_info *us3_freq_table;

/* UltraSPARC-III has three dividers: 1, 2, and 32.  These are controlled
 * in the Safari config register.
 */
#define SAFARI_CFG_DIV_1	0x0000000000000000UL
#define SAFARI_CFG_DIV_2	0x0000000040000000UL
#define SAFARI_CFG_DIV_32	0x0000000080000000UL
#define SAFARI_CFG_DIV_MASK	0x00000000C0000000UL

static unsigned long read_safari_cfg(void)
{
	unsigned long ret;

	__asm__ __volatile__("ldxa	[%%g0] %1, %0"
			     : "=&r" (ret)
			     : "i" (ASI_SAFARI_CONFIG));
	return ret;
}

static void write_safari_cfg(unsigned long val)
{
	__asm__ __volatile__("stxa	%0, [%%g0] %1\n\t"
			     "membar	#Sync"
			     : /* no outputs */
			     : "r" (val), "i" (ASI_SAFARI_CONFIG)
			     : "memory");
}

static unsigned long get_current_freq(unsigned int cpu, unsigned long safari_cfg)
{
	unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
	unsigned long ret;

	switch (safari_cfg & SAFARI_CFG_DIV_MASK) {
	case SAFARI_CFG_DIV_1:
		ret = clock_tick / 1;
		break;
	case SAFARI_CFG_DIV_2:
		ret = clock_tick / 2;
		break;
	case SAFARI_CFG_DIV_32:
		ret = clock_tick / 32;
		break;
	default:
		BUG();
	};

	return ret;
}

static unsigned int us3_freq_get(unsigned int cpu)
{
	cpumask_t cpus_allowed;
	unsigned long reg;
	unsigned int ret;

	if (!cpu_online(cpu))
		return 0;

	cpus_allowed = current->cpus_allowed;
	set_cpus_allowed_ptr(current, cpumask_of(cpu));

	reg = read_safari_cfg();
	ret = get_current_freq(cpu, reg);

	set_cpus_allowed_ptr(current, &cpus_allowed);

	return ret;
}

static void us3_set_cpu_divider_index(unsigned int cpu, unsigned int index)
{
	unsigned long new_bits, new_freq, reg;
	cpumask_t cpus_allowed;
	struct cpufreq_freqs freqs;

	if (!cpu_online(cpu))
		return;

	cpus_allowed = current->cpus_allowed;
	set_cpus_allowed_ptr(current, cpumask_of(cpu));

	new_freq = sparc64_get_clock_tick(cpu) / 1000;
	switch (index) {
	case 0:
		new_bits = SAFARI_CFG_DIV_1;
		new_freq /= 1;
		break;
	case 1:
		new_bits = SAFARI_CFG_DIV_2;
		new_freq /= 2;
		break;
	case 2:
		new_bits = SAFARI_CFG_DIV_32;
		new_freq /= 32;
		break;

	default:
		BUG();
	};

	reg = read_safari_cfg();

	freqs.old = get_current_freq(cpu, reg);
	freqs.new = new_freq;
	freqs.cpu = cpu;
	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

	reg &= ~SAFARI_CFG_DIV_MASK;
	reg |= new_bits;
	write_safari_cfg(reg);

	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);

	set_cpus_allowed_ptr(current, &cpus_allowed);
}

static int us3_freq_target(struct cpufreq_policy *policy,
			  unsigned int target_freq,
			  unsigned int relation)
{
	unsigned int new_index = 0;

	if (cpufreq_frequency_table_target(policy,
					   &us3_freq_table[policy->cpu].table[0],
					   target_freq,
					   relation,
					   &new_index))
		return -EINVAL;

	us3_set_cpu_divider_index(policy->cpu, new_index);

	return 0;
}

static int us3_freq_verify(struct cpufreq_policy *policy)
{
	return cpufreq_frequency_table_verify(policy,
					      &us3_freq_table[policy->cpu].table[0]);
}

static int __init us3_freq_cpu_init(struct cpufreq_policy *policy)
{
	unsigned int cpu = policy->cpu;
	unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
	struct cpufreq_frequency_table *table =
		&us3_freq_table[cpu].table[0];

	table[0].index = 0;
	table[0].frequency = clock_tick / 1;
	table[1].index = 1;
	table[1].frequency = clock_tick / 2;
	table[2].index = 2;
	table[2].frequency = clock_tick / 32;
	table[3].index = 0;
	table[3].frequency = CPUFREQ_TABLE_END;

	policy->cpuinfo.transition_latency = 0;
	policy->cur = clock_tick;

	return cpufreq_frequency_table_cpuinfo(policy, table);
}

static int us3_freq_cpu_exit(struct cpufreq_policy *policy)
{
	if (cpufreq_us3_driver)
		us3_set_cpu_divider_index(policy->cpu, 0);

	return 0;
}

static int __init us3_freq_init(void)
{
	unsigned long manuf, impl, ver;
	int ret;

	if (tlb_type != cheetah && tlb_type != cheetah_plus)
		return -ENODEV;

	__asm__("rdpr %%ver, %0" : "=r" (ver));
	manuf = ((ver >> 48) & 0xffff);
	impl  = ((ver >> 32) & 0xffff);

	if (manuf == CHEETAH_MANUF &&
	    (impl == CHEETAH_IMPL ||
	     impl == CHEETAH_PLUS_IMPL ||
	     impl == JAGUAR_IMPL ||
	     impl == PANTHER_IMPL)) {
		struct cpufreq_driver *driver;

		ret = -ENOMEM;
		driver = kzalloc(sizeof(struct cpufreq_driver), GFP_KERNEL);
		if (!driver)
			goto err_out;

		us3_freq_table = kzalloc(
			(NR_CPUS * sizeof(struct us3_freq_percpu_info)),
			GFP_KERNEL);
		if (!us3_freq_table)
			goto err_out;

		driver->init = us3_freq_cpu_init;
		driver->verify = us3_freq_verify;
		driver->target = us3_freq_target;
		driver->get = us3_freq_get;
		driver->exit = us3_freq_cpu_exit;
		driver->owner = THIS_MODULE,
		strcpy(driver->name, "UltraSPARC-III");

		cpufreq_us3_driver = driver;
		ret = cpufreq_register_driver(driver);
		if (ret)
			goto err_out;

		return 0;

err_out:
		if (driver) {
			kfree(driver);
			cpufreq_us3_driver = NULL;
		}
		kfree(us3_freq_table);
		us3_freq_table = NULL;
		return ret;
	}

	return -ENODEV;
}

static void __exit us3_freq_exit(void)
{
	if (cpufreq_us3_driver) {
		cpufreq_unregister_driver(cpufreq_us3_driver);
		kfree(cpufreq_us3_driver);
		cpufreq_us3_driver = NULL;
		kfree(us3_freq_table);
		us3_freq_table = NULL;
	}
}

MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
MODULE_DESCRIPTION("cpufreq driver for UltraSPARC-III");
MODULE_LICENSE("GPL");

module_init(us3_freq_init);
module_exit(us3_freq_exit);
Commit	Line	Data
1da177e4 LT	1	/* us3_cpufreq.c: UltraSPARC-III cpu frequency support
	2	*
	3	* Copyright (C) 2003 David S. Miller (davem@redhat.com)
	4	*
	5	* Many thanks to Dominik Brodowski for fixing up the cpufreq
	6	* infrastructure in order to make this driver easier to implement.
	7	*/
	8
	9	#include <linux/kernel.h>
	10	#include <linux/module.h>
	11	#include <linux/sched.h>
	12	#include <linux/smp.h>
	13	#include <linux/cpufreq.h>
	14	#include <linux/threads.h>
	15	#include <linux/slab.h>
	16	#include <linux/init.h>
	17
	18	#include <asm/head.h>
	19	#include <asm/timer.h>
	20
	21	static struct cpufreq_driver *cpufreq_us3_driver;
	22
	23	struct us3_freq_percpu_info {
	24	struct cpufreq_frequency_table table[4];
	25	};
	26
	27	/* Indexed by cpu number. */
	28	static struct us3_freq_percpu_info *us3_freq_table;
	29
	30	/* UltraSPARC-III has three dividers: 1, 2, and 32. These are controlled
	31	* in the Safari config register.
	32	*/
	33	#define SAFARI_CFG_DIV_1 0x0000000000000000UL
	34	#define SAFARI_CFG_DIV_2 0x0000000040000000UL
	35	#define SAFARI_CFG_DIV_32 0x0000000080000000UL
	36	#define SAFARI_CFG_DIV_MASK 0x00000000C0000000UL
	37
	38	static unsigned long read_safari_cfg(void)
	39	{
	40	unsigned long ret;
	41
	42	__asm__ __volatile__("ldxa [%%g0] %1, %0"
	43	: "=&r" (ret)
	44	: "i" (ASI_SAFARI_CONFIG));
	45	return ret;
	46	}
	47
	48	static void write_safari_cfg(unsigned long val)
	49	{
	50	__asm__ __volatile__("stxa %0, [%%g0] %1\n\t"
	51	"membar #Sync"
	52	: /* no outputs */
	53	: "r" (val), "i" (ASI_SAFARI_CONFIG)
	54	: "memory");
	55	}
	56
	57	static unsigned long get_current_freq(unsigned int cpu, unsigned long safari_cfg)
	58	{
2cab224d	59	unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
1da177e4 LT	60	unsigned long ret;
	61
	62	switch (safari_cfg & SAFARI_CFG_DIV_MASK) {
	63	case SAFARI_CFG_DIV_1:
	64	ret = clock_tick / 1;
	65	break;
	66	case SAFARI_CFG_DIV_2:
	67	ret = clock_tick / 2;
	68	break;
	69	case SAFARI_CFG_DIV_32:
	70	ret = clock_tick / 32;
	71	break;
	72	default:
	73	BUG();
	74	};
	75
	76	return ret;
	77	}
	78
2cab224d DM	79	static unsigned int us3_freq_get(unsigned int cpu)
	80	{
	81	cpumask_t cpus_allowed;
	82	unsigned long reg;
	83	unsigned int ret;
	84
	85	if (!cpu_online(cpu))
	86	return 0;
	87
	88	cpus_allowed = current->cpus_allowed;
d2566af8	89	set_cpus_allowed_ptr(current, cpumask_of(cpu));
2cab224d DM	90
	91	reg = read_safari_cfg();
	92	ret = get_current_freq(cpu, reg);
	93
d2566af8	94	set_cpus_allowed_ptr(current, &cpus_allowed);
2cab224d DM	95
	96	return ret;
	97	}
	98
1da177e4 LT	99	static void us3_set_cpu_divider_index(unsigned int cpu, unsigned int index)
	100	{
	101	unsigned long new_bits, new_freq, reg;
	102	cpumask_t cpus_allowed;
	103	struct cpufreq_freqs freqs;
	104
	105	if (!cpu_online(cpu))
	106	return;
	107
	108	cpus_allowed = current->cpus_allowed;
d2566af8	109	set_cpus_allowed_ptr(current, cpumask_of(cpu));
1da177e4	110
2cab224d	111	new_freq = sparc64_get_clock_tick(cpu) / 1000;
1da177e4 LT	112	switch (index) {
	113	case 0:
	114	new_bits = SAFARI_CFG_DIV_1;
	115	new_freq /= 1;
	116	break;
	117	case 1:
	118	new_bits = SAFARI_CFG_DIV_2;
	119	new_freq /= 2;
	120	break;
	121	case 2:
	122	new_bits = SAFARI_CFG_DIV_32;
	123	new_freq /= 32;
	124	break;
	125
	126	default:
	127	BUG();
	128	};
	129
	130	reg = read_safari_cfg();
	131
	132	freqs.old = get_current_freq(cpu, reg);
	133	freqs.new = new_freq;
	134	freqs.cpu = cpu;
	135	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
	136
	137	reg &= ~SAFARI_CFG_DIV_MASK;
	138	reg \|= new_bits;
	139	write_safari_cfg(reg);
	140
	141	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
	142
d2566af8	143	set_cpus_allowed_ptr(current, &cpus_allowed);
1da177e4 LT	144	}
	145
	146	static int us3_freq_target(struct cpufreq_policy *policy,
	147	unsigned int target_freq,
	148	unsigned int relation)
	149	{
	150	unsigned int new_index = 0;
	151
	152	if (cpufreq_frequency_table_target(policy,
	153	&us3_freq_table[policy->cpu].table[0],
	154	target_freq,
	155	relation,
	156	&new_index))
	157	return -EINVAL;
	158
	159	us3_set_cpu_divider_index(policy->cpu, new_index);
	160
	161	return 0;
	162	}
	163
	164	static int us3_freq_verify(struct cpufreq_policy *policy)
	165	{
	166	return cpufreq_frequency_table_verify(policy,
	167	&us3_freq_table[policy->cpu].table[0]);
	168	}
	169
	170	static int __init us3_freq_cpu_init(struct cpufreq_policy *policy)
	171	{
	172	unsigned int cpu = policy->cpu;
2cab224d	173	unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
1da177e4 LT	174	struct cpufreq_frequency_table *table =
	175	&us3_freq_table[cpu].table[0];
	176
	177	table[0].index = 0;
	178	table[0].frequency = clock_tick / 1;
	179	table[1].index = 1;
	180	table[1].frequency = clock_tick / 2;
	181	table[2].index = 2;
	182	table[2].frequency = clock_tick / 32;
	183	table[3].index = 0;
	184	table[3].frequency = CPUFREQ_TABLE_END;
	185
1da177e4 LT	186	policy->cpuinfo.transition_latency = 0;
	187	policy->cur = clock_tick;
	188
	189	return cpufreq_frequency_table_cpuinfo(policy, table);
	190	}
	191
	192	static int us3_freq_cpu_exit(struct cpufreq_policy *policy)
	193	{
	194	if (cpufreq_us3_driver)
	195	us3_set_cpu_divider_index(policy->cpu, 0);
	196
	197	return 0;
	198	}
	199
	200	static int __init us3_freq_init(void)
	201	{
	202	unsigned long manuf, impl, ver;
	203	int ret;
	204
d82ace7d DM	205	if (tlb_type != cheetah && tlb_type != cheetah_plus)
	206	return -ENODEV;
	207
1da177e4 LT	208	__asm__("rdpr %%ver, %0" : "=r" (ver));
	209	manuf = ((ver >> 48) & 0xffff);
	210	impl = ((ver >> 32) & 0xffff);
	211
	212	if (manuf == CHEETAH_MANUF &&
d2212bc7 DM	213	(impl == CHEETAH_IMPL \|\|
	214	impl == CHEETAH_PLUS_IMPL \|\|
	215	impl == JAGUAR_IMPL \|\|
	216	impl == PANTHER_IMPL)) {
1da177e4 LT	217	struct cpufreq_driver *driver;
	218
	219	ret = -ENOMEM;
9132983a	220	driver = kzalloc(sizeof(struct cpufreq_driver), GFP_KERNEL);
1da177e4 LT	221	if (!driver)
1da177e4 LT	222	goto err_out;
1da177e4	223
9132983a	224	us3_freq_table = kzalloc(
1da177e4 LT	225	(NR_CPUS * sizeof(struct us3_freq_percpu_info)),
	226	GFP_KERNEL);
	227	if (!us3_freq_table)
	228	goto err_out;
	229
2cab224d	230	driver->init = us3_freq_cpu_init;
1da177e4 LT	231	driver->verify = us3_freq_verify;
1da177e4 LT	232	driver->target = us3_freq_target;
2cab224d	233	driver->get = us3_freq_get;
1da177e4 LT	234	driver->exit = us3_freq_cpu_exit;
	235	driver->owner = THIS_MODULE,
	236	strcpy(driver->name, "UltraSPARC-III");
	237
	238	cpufreq_us3_driver = driver;
	239	ret = cpufreq_register_driver(driver);
	240	if (ret)
	241	goto err_out;
	242
	243	return 0;
	244
	245	err_out:
	246	if (driver) {
	247	kfree(driver);
	248	cpufreq_us3_driver = NULL;
	249	}
b2325fe1 JJ	250	kfree(us3_freq_table);
b2325fe1 JJ	251	us3_freq_table = NULL;
1da177e4 LT	252	return ret;
	253	}
	254
	255	return -ENODEV;
	256	}
	257
	258	static void __exit us3_freq_exit(void)
	259	{
	260	if (cpufreq_us3_driver) {
	261	cpufreq_unregister_driver(cpufreq_us3_driver);
1da177e4 LT	262	kfree(cpufreq_us3_driver);
	263	cpufreq_us3_driver = NULL;
	264	kfree(us3_freq_table);
	265	us3_freq_table = NULL;
	266	}
	267	}
	268
	269	MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
	270	MODULE_DESCRIPTION("cpufreq driver for UltraSPARC-III");
	271	MODULE_LICENSE("GPL");
	272
	273	module_init(us3_freq_init);
	274	module_exit(us3_freq_exit);