[mirror_ubuntu-bionic-kernel.git] / arch / x86 / kernel / cpu / cpufreq / longrun.c

/*
 * (C) 2002 - 2003  Dominik Brodowski <linux@brodo.de>
 *
 *  Licensed under the terms of the GNU GPL License version 2.
 *
 *  BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous*
 */

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

#include <asm/msr.h>
#include <asm/processor.h>
#include <asm/timex.h>

#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "longrun", msg)

static struct cpufreq_driver	longrun_driver;

/**
 * longrun_{low,high}_freq is needed for the conversion of cpufreq kHz
 * values into per cent values. In TMTA microcode, the following is valid:
 * performance_pctg = (current_freq - low_freq)/(high_freq - low_freq)
 */
static unsigned int longrun_low_freq, longrun_high_freq;


/**
 * longrun_get_policy - get the current LongRun policy
 * @policy: struct cpufreq_policy where current policy is written into
 *
 * Reads the current LongRun policy by access to MSR_TMTA_LONGRUN_FLAGS
 * and MSR_TMTA_LONGRUN_CTRL
 */
static void __init longrun_get_policy(struct cpufreq_policy *policy)
{
	u32 msr_lo, msr_hi;

	rdmsr(MSR_TMTA_LONGRUN_FLAGS, msr_lo, msr_hi);
	dprintk("longrun flags are %x - %x\n", msr_lo, msr_hi);
	if (msr_lo & 0x01)
		policy->policy = CPUFREQ_POLICY_PERFORMANCE;
	else
		policy->policy = CPUFREQ_POLICY_POWERSAVE;

	rdmsr(MSR_TMTA_LONGRUN_CTRL, msr_lo, msr_hi);
	dprintk("longrun ctrl is %x - %x\n", msr_lo, msr_hi);
	msr_lo &= 0x0000007F;
	msr_hi &= 0x0000007F;

	if ( longrun_high_freq <= longrun_low_freq ) {
		/* Assume degenerate Longrun table */
		policy->min = policy->max = longrun_high_freq;
	} else {
		policy->min = longrun_low_freq + msr_lo *
			((longrun_high_freq - longrun_low_freq) / 100);
		policy->max = longrun_low_freq + msr_hi *
			((longrun_high_freq - longrun_low_freq) / 100);
	}
	policy->cpu = 0;
}


/**
 * longrun_set_policy - sets a new CPUFreq policy
 * @policy: new policy
 *
 * Sets a new CPUFreq policy on LongRun-capable processors. This function
 * has to be called with cpufreq_driver locked.
 */
static int longrun_set_policy(struct cpufreq_policy *policy)
{
	u32 msr_lo, msr_hi;
	u32 pctg_lo, pctg_hi;

	if (!policy)
		return -EINVAL;

	if ( longrun_high_freq <= longrun_low_freq ) {
		/* Assume degenerate Longrun table */
		pctg_lo = pctg_hi = 100;
	} else {
		pctg_lo = (policy->min - longrun_low_freq) /
			((longrun_high_freq - longrun_low_freq) / 100);
		pctg_hi = (policy->max - longrun_low_freq) /
			((longrun_high_freq - longrun_low_freq) / 100);
	}

	if (pctg_hi > 100)
		pctg_hi = 100;
	if (pctg_lo > pctg_hi)
		pctg_lo = pctg_hi;

	/* performance or economy mode */
	rdmsr(MSR_TMTA_LONGRUN_FLAGS, msr_lo, msr_hi);
	msr_lo &= 0xFFFFFFFE;
	switch (policy->policy) {
	case CPUFREQ_POLICY_PERFORMANCE:
		msr_lo |= 0x00000001;
		break;
	case CPUFREQ_POLICY_POWERSAVE:
		break;
	}
	wrmsr(MSR_TMTA_LONGRUN_FLAGS, msr_lo, msr_hi);

	/* lower and upper boundary */
	rdmsr(MSR_TMTA_LONGRUN_CTRL, msr_lo, msr_hi);
	msr_lo &= 0xFFFFFF80;
	msr_hi &= 0xFFFFFF80;
	msr_lo |= pctg_lo;
	msr_hi |= pctg_hi;
	wrmsr(MSR_TMTA_LONGRUN_CTRL, msr_lo, msr_hi);

	return 0;
}


/**
 * longrun_verify_poliy - verifies a new CPUFreq policy
 * @policy: the policy to verify
 *
 * Validates a new CPUFreq policy. This function has to be called with
 * cpufreq_driver locked.
 */
static int longrun_verify_policy(struct cpufreq_policy *policy)
{
	if (!policy)
		return -EINVAL;

	policy->cpu = 0;
	cpufreq_verify_within_limits(policy,
		policy->cpuinfo.min_freq,
		policy->cpuinfo.max_freq);

	if ((policy->policy != CPUFREQ_POLICY_POWERSAVE) &&
	    (policy->policy != CPUFREQ_POLICY_PERFORMANCE))
		return -EINVAL;

	return 0;
}

static unsigned int longrun_get(unsigned int cpu)
{
	u32 eax, ebx, ecx, edx;

	if (cpu)
		return 0;

	cpuid(0x80860007, &eax, &ebx, &ecx, &edx);
	dprintk("cpuid eax is %u\n", eax);

	return (eax * 1000);
}

/**
 * longrun_determine_freqs - determines the lowest and highest possible core frequency
 * @low_freq: an int to put the lowest frequency into
 * @high_freq: an int to put the highest frequency into
 *
 * Determines the lowest and highest possible core frequencies on this CPU.
 * This is necessary to calculate the performance percentage according to
 * TMTA rules:
 * performance_pctg = (target_freq - low_freq)/(high_freq - low_freq)
 */
static unsigned int __init longrun_determine_freqs(unsigned int *low_freq,
						   unsigned int *high_freq)
{
	u32 msr_lo, msr_hi;
	u32 save_lo, save_hi;
	u32 eax, ebx, ecx, edx;
	u32 try_hi;
	struct cpuinfo_x86 *c = &cpu_data(0);

	if (!low_freq || !high_freq)
		return -EINVAL;

	if (cpu_has(c, X86_FEATURE_LRTI)) {
		/* if the LongRun Table Interface is present, the
		 * detection is a bit easier:
		 * For minimum frequency, read out the maximum
		 * level (msr_hi), write that into "currently
		 * selected level", and read out the frequency.
		 * For maximum frequency, read out level zero.
		 */
		/* minimum */
		rdmsr(MSR_TMTA_LRTI_READOUT, msr_lo, msr_hi);
		wrmsr(MSR_TMTA_LRTI_READOUT, msr_hi, msr_hi);
		rdmsr(MSR_TMTA_LRTI_VOLT_MHZ, msr_lo, msr_hi);
		*low_freq = msr_lo * 1000; /* to kHz */

		/* maximum */
		wrmsr(MSR_TMTA_LRTI_READOUT, 0, msr_hi);
		rdmsr(MSR_TMTA_LRTI_VOLT_MHZ, msr_lo, msr_hi);
		*high_freq = msr_lo * 1000; /* to kHz */

		dprintk("longrun table interface told %u - %u kHz\n", *low_freq, *high_freq);

		if (*low_freq > *high_freq)
			*low_freq = *high_freq;
		return 0;
	}

	/* set the upper border to the value determined during TSC init */
	*high_freq = (cpu_khz / 1000);
	*high_freq = *high_freq * 1000;
	dprintk("high frequency is %u kHz\n", *high_freq);

	/* get current borders */
	rdmsr(MSR_TMTA_LONGRUN_CTRL, msr_lo, msr_hi);
	save_lo = msr_lo & 0x0000007F;
	save_hi = msr_hi & 0x0000007F;

	/* if current perf_pctg is larger than 90%, we need to decrease the
	 * upper limit to make the calculation more accurate.
	 */
	cpuid(0x80860007, &eax, &ebx, &ecx, &edx);
	/* try decreasing in 10% steps, some processors react only
	 * on some barrier values */
	for (try_hi = 80; try_hi > 0 && ecx > 90; try_hi -=10) {
		/* set to 0 to try_hi perf_pctg */
		msr_lo &= 0xFFFFFF80;
		msr_hi &= 0xFFFFFF80;
		msr_hi |= try_hi;
		wrmsr(MSR_TMTA_LONGRUN_CTRL, msr_lo, msr_hi);

		/* read out current core MHz and current perf_pctg */
		cpuid(0x80860007, &eax, &ebx, &ecx, &edx);

		/* restore values */
		wrmsr(MSR_TMTA_LONGRUN_CTRL, save_lo, save_hi);
	}
	dprintk("percentage is %u %%, freq is %u MHz\n", ecx, eax);

	/* performance_pctg = (current_freq - low_freq)/(high_freq - low_freq)
	 * eqals
	 * low_freq * ( 1 - perf_pctg) = (cur_freq - high_freq * perf_pctg)
	 *
	 * high_freq * perf_pctg is stored tempoarily into "ebx".
	 */
	ebx = (((cpu_khz / 1000) * ecx) / 100); /* to MHz */

	if ((ecx > 95) || (ecx == 0) || (eax < ebx))
		return -EIO;

	edx = ((eax - ebx) * 100) / (100 - ecx);
	*low_freq = edx * 1000; /* back to kHz */

	dprintk("low frequency is %u kHz\n", *low_freq);

	if (*low_freq > *high_freq)
		*low_freq = *high_freq;

	return 0;
}


static int __init longrun_cpu_init(struct cpufreq_policy *policy)
{
	int result = 0;

	/* capability check */
	if (policy->cpu != 0)
		return -ENODEV;

	/* detect low and high frequency */
	result = longrun_determine_freqs(&longrun_low_freq, &longrun_high_freq);
	if (result)
		return result;

	/* cpuinfo and default policy values */
	policy->cpuinfo.min_freq = longrun_low_freq;
	policy->cpuinfo.max_freq = longrun_high_freq;
	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
	longrun_get_policy(policy);

	return 0;
}


static struct cpufreq_driver longrun_driver = {
	.flags		= CPUFREQ_CONST_LOOPS,
	.verify		= longrun_verify_policy,
	.setpolicy	= longrun_set_policy,
	.get		= longrun_get,
	.init		= longrun_cpu_init,
	.name		= "longrun",
	.owner		= THIS_MODULE,
};


/**
 * longrun_init - initializes the Transmeta Crusoe LongRun CPUFreq driver
 *
 * Initializes the LongRun support.
 */
static int __init longrun_init(void)
{
	struct cpuinfo_x86 *c = &cpu_data(0);

	if (c->x86_vendor != X86_VENDOR_TRANSMETA ||
	    !cpu_has(c, X86_FEATURE_LONGRUN))
		return -ENODEV;

	return cpufreq_register_driver(&longrun_driver);
}


/**
 * longrun_exit - unregisters LongRun support
 */
static void __exit longrun_exit(void)
{
	cpufreq_unregister_driver(&longrun_driver);
}


MODULE_AUTHOR ("Dominik Brodowski <linux@brodo.de>");
MODULE_DESCRIPTION ("LongRun driver for Transmeta Crusoe and Efficeon processors.");
MODULE_LICENSE ("GPL");

module_init(longrun_init);
module_exit(longrun_exit);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
	3	*
	4	* Licensed under the terms of the GNU GPL License version 2.
	5	*
	6	* BIG FAT DISCLAIMER: Work in progress code. Possibly dangerous
	7	*/
	8
	9	#include <linux/kernel.h>
	10	#include <linux/module.h>
	11	#include <linux/init.h>
	12	#include <linux/slab.h>
	13	#include <linux/cpufreq.h>
	14
	15	#include <asm/msr.h>
	16	#include <asm/processor.h>
	17	#include <asm/timex.h>
	18
	19	#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "longrun", msg)
	20
221dee28	21	static struct cpufreq_driver longrun_driver;
1da177e4 LT	22
	23	/**
	24	* longrun_{low,high}_freq is needed for the conversion of cpufreq kHz
	25	* values into per cent values. In TMTA microcode, the following is valid:
	26	* performance_pctg = (current_freq - low_freq)/(high_freq - low_freq)
	27	*/
	28	static unsigned int longrun_low_freq, longrun_high_freq;
	29
	30
	31	/**
	32	* longrun_get_policy - get the current LongRun policy
	33	* @policy: struct cpufreq_policy where current policy is written into
	34	*
	35	* Reads the current LongRun policy by access to MSR_TMTA_LONGRUN_FLAGS
	36	* and MSR_TMTA_LONGRUN_CTRL
	37	*/
	38	static void __init longrun_get_policy(struct cpufreq_policy *policy)
	39	{
	40	u32 msr_lo, msr_hi;
	41
	42	rdmsr(MSR_TMTA_LONGRUN_FLAGS, msr_lo, msr_hi);
	43	dprintk("longrun flags are %x - %x\n", msr_lo, msr_hi);
	44	if (msr_lo & 0x01)
	45	policy->policy = CPUFREQ_POLICY_PERFORMANCE;
	46	else
	47	policy->policy = CPUFREQ_POLICY_POWERSAVE;
	48
	49	rdmsr(MSR_TMTA_LONGRUN_CTRL, msr_lo, msr_hi);
	50	dprintk("longrun ctrl is %x - %x\n", msr_lo, msr_hi);
	51	msr_lo &= 0x0000007F;
	52	msr_hi &= 0x0000007F;
	53
	54	if ( longrun_high_freq <= longrun_low_freq ) {
	55	/* Assume degenerate Longrun table */
	56	policy->min = policy->max = longrun_high_freq;
	57	} else {
	58	policy->min = longrun_low_freq + msr_lo *
	59	((longrun_high_freq - longrun_low_freq) / 100);
	60	policy->max = longrun_low_freq + msr_hi *
	61	((longrun_high_freq - longrun_low_freq) / 100);
	62	}
	63	policy->cpu = 0;
	64	}
	65
	66
	67	/**
	68	* longrun_set_policy - sets a new CPUFreq policy
	69	* @policy: new policy
	70	*
	71	* Sets a new CPUFreq policy on LongRun-capable processors. This function
	72	* has to be called with cpufreq_driver locked.
	73	*/
	74	static int longrun_set_policy(struct cpufreq_policy *policy)
	75	{
	76	u32 msr_lo, msr_hi;
	77	u32 pctg_lo, pctg_hi;
	78
	79	if (!policy)
	80	return -EINVAL;
	81
	82	if ( longrun_high_freq <= longrun_low_freq ) {
	83	/* Assume degenerate Longrun table */
	84	pctg_lo = pctg_hi = 100;
	85	} else {
86	pctg_lo = (policy->min - longrun_low_freq) /
87	((longrun_high_freq - longrun_low_freq) / 100);
88	pctg_hi = (policy->max - longrun_low_freq) /
89	((longrun_high_freq - longrun_low_freq) / 100);
90	}
91
92	if (pctg_hi > 100)
93	pctg_hi = 100;
94	if (pctg_lo > pctg_hi)
95	pctg_lo = pctg_hi;
96
97	/* performance or economy mode */
98	rdmsr(MSR_TMTA_LONGRUN_FLAGS, msr_lo, msr_hi);
99	msr_lo &= 0xFFFFFFFE;
100	switch (policy->policy) {
101	case CPUFREQ_POLICY_PERFORMANCE:
102	msr_lo \|= 0x00000001;
103	break;
104	case CPUFREQ_POLICY_POWERSAVE:
105	break;
106	}
107	wrmsr(MSR_TMTA_LONGRUN_FLAGS, msr_lo, msr_hi);
108
109	/* lower and upper boundary */
110	rdmsr(MSR_TMTA_LONGRUN_CTRL, msr_lo, msr_hi);
111	msr_lo &= 0xFFFFFF80;
112	msr_hi &= 0xFFFFFF80;
113	msr_lo \|= pctg_lo;
114	msr_hi \|= pctg_hi;
115	wrmsr(MSR_TMTA_LONGRUN_CTRL, msr_lo, msr_hi);
116
117	return 0;
118	}
119
120
121	/**
122	* longrun_verify_poliy - verifies a new CPUFreq policy
123	* @policy: the policy to verify
124	*
125	* Validates a new CPUFreq policy. This function has to be called with
126	* cpufreq_driver locked.
127	*/
128	static int longrun_verify_policy(struct cpufreq_policy *policy)
129	{
130	if (!policy)
131	return -EINVAL;
132
133	policy->cpu = 0;
134	cpufreq_verify_within_limits(policy,
135	policy->cpuinfo.min_freq,
136	policy->cpuinfo.max_freq);
137
138	if ((policy->policy != CPUFREQ_POLICY_POWERSAVE) &&
139	(policy->policy != CPUFREQ_POLICY_PERFORMANCE))
140	return -EINVAL;
141
142	return 0;
143	}
144
145	static unsigned int longrun_get(unsigned int cpu)
146	{
147	u32 eax, ebx, ecx, edx;
148
149	if (cpu)
150	return 0;
151
152	cpuid(0x80860007, &eax, &ebx, &ecx, &edx);
153	dprintk("cpuid eax is %u\n", eax);
154
155	return (eax * 1000);
156	}
157
158	/**
159	* longrun_determine_freqs - determines the lowest and highest possible core frequency
160	* @low_freq: an int to put the lowest frequency into
161	* @high_freq: an int to put the highest frequency into
162	*
163	* Determines the lowest and highest possible core frequencies on this CPU.
164	* This is necessary to calculate the performance percentage according to
165	* TMTA rules:
166	* performance_pctg = (target_freq - low_freq)/(high_freq - low_freq)
167	*/
168	static unsigned int __init longrun_determine_freqs(unsigned int *low_freq,
169	unsigned int *high_freq)
170	{
171	u32 msr_lo, msr_hi;
172	u32 save_lo, save_hi;
173	u32 eax, ebx, ecx, edx;
174	u32 try_hi;
92cb7612	175	struct cpuinfo_x86 *c = &cpu_data(0);
1da177e4 LT	176
	177	if (!low_freq \|\| !high_freq)
	178	return -EINVAL;
	179
	180	if (cpu_has(c, X86_FEATURE_LRTI)) {
	181	/* if the LongRun Table Interface is present, the
	182	* detection is a bit easier:
	183	* For minimum frequency, read out the maximum
	184	* level (msr_hi), write that into "currently
	185	* selected level", and read out the frequency.
	186	* For maximum frequency, read out level zero.
	187	*/
	188	/* minimum */
	189	rdmsr(MSR_TMTA_LRTI_READOUT, msr_lo, msr_hi);
	190	wrmsr(MSR_TMTA_LRTI_READOUT, msr_hi, msr_hi);
	191	rdmsr(MSR_TMTA_LRTI_VOLT_MHZ, msr_lo, msr_hi);
	192	low_freq = msr_lo 1000; /* to kHz */
	193
	194	/* maximum */
	195	wrmsr(MSR_TMTA_LRTI_READOUT, 0, msr_hi);
	196	rdmsr(MSR_TMTA_LRTI_VOLT_MHZ, msr_lo, msr_hi);
	197	high_freq = msr_lo 1000; /* to kHz */
	198
	199	dprintk("longrun table interface told %u - %u kHz\n", low_freq, high_freq);
	200
	201	if (low_freq > high_freq)
	202	low_freq = high_freq;
	203	return 0;
	204	}
	205
	206	/* set the upper border to the value determined during TSC init */
	207	*high_freq = (cpu_khz / 1000);
	208	high_freq = high_freq * 1000;
	209	dprintk("high frequency is %u kHz\n", *high_freq);
	210
	211	/* get current borders */
	212	rdmsr(MSR_TMTA_LONGRUN_CTRL, msr_lo, msr_hi);
	213	save_lo = msr_lo & 0x0000007F;
	214	save_hi = msr_hi & 0x0000007F;
	215
	216	/* if current perf_pctg is larger than 90%, we need to decrease the
	217	* upper limit to make the calculation more accurate.
	218	*/
	219	cpuid(0x80860007, &eax, &ebx, &ecx, &edx);
	220	/* try decreasing in 10% steps, some processors react only
	221	* on some barrier values */
	222	for (try_hi = 80; try_hi > 0 && ecx > 90; try_hi -=10) {
	223	/* set to 0 to try_hi perf_pctg */
	224	msr_lo &= 0xFFFFFF80;
	225	msr_hi &= 0xFFFFFF80;
1da177e4 LT	226	msr_hi \|= try_hi;
	227	wrmsr(MSR_TMTA_LONGRUN_CTRL, msr_lo, msr_hi);
	228
	229	/* read out current core MHz and current perf_pctg */
	230	cpuid(0x80860007, &eax, &ebx, &ecx, &edx);
	231
	232	/* restore values */
	233	wrmsr(MSR_TMTA_LONGRUN_CTRL, save_lo, save_hi);
	234	}
	235	dprintk("percentage is %u %%, freq is %u MHz\n", ecx, eax);
	236
	237	/* performance_pctg = (current_freq - low_freq)/(high_freq - low_freq)
	238	* eqals
	239	* low_freq * ( 1 - perf_pctg) = (cur_freq - high_freq * perf_pctg)
	240	*
	241	* high_freq * perf_pctg is stored tempoarily into "ebx".
	242	*/
	243	ebx = (((cpu_khz / 1000) * ecx) / 100); /* to MHz */
	244
	245	if ((ecx > 95) \|\| (ecx == 0) \|\| (eax < ebx))
	246	return -EIO;
	247
667ad4f7	248	edx = ((eax - ebx) * 100) / (100 - ecx);
1da177e4 LT	249	low_freq = edx 1000; /* back to kHz */
	250
	251	dprintk("low frequency is %u kHz\n", *low_freq);
	252
	253	if (low_freq > high_freq)
	254	low_freq = high_freq;
	255
	256	return 0;
	257	}
	258
	259
	260	static int __init longrun_cpu_init(struct cpufreq_policy *policy)
	261	{
	262	int result = 0;
	263
	264	/* capability check */
	265	if (policy->cpu != 0)
	266	return -ENODEV;
	267
	268	/* detect low and high frequency */
	269	result = longrun_determine_freqs(&longrun_low_freq, &longrun_high_freq);
	270	if (result)
	271	return result;
	272
	273	/* cpuinfo and default policy values */
	274	policy->cpuinfo.min_freq = longrun_low_freq;
	275	policy->cpuinfo.max_freq = longrun_high_freq;
	276	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
	277	longrun_get_policy(policy);
	278
	279	return 0;
	280	}
	281
	282
221dee28	283	static struct cpufreq_driver longrun_driver = {
1da177e4 LT	284	.flags = CPUFREQ_CONST_LOOPS,
	285	.verify = longrun_verify_policy,
	286	.setpolicy = longrun_set_policy,
	287	.get = longrun_get,
	288	.init = longrun_cpu_init,
	289	.name = "longrun",
	290	.owner = THIS_MODULE,
	291	};
	292
	293
	294	/**
	295	* longrun_init - initializes the Transmeta Crusoe LongRun CPUFreq driver
	296	*
	297	* Initializes the LongRun support.
	298	*/
	299	static int __init longrun_init(void)
	300	{
92cb7612	301	struct cpuinfo_x86 *c = &cpu_data(0);
1da177e4 LT	302
	303	if (c->x86_vendor != X86_VENDOR_TRANSMETA \|\|
	304	!cpu_has(c, X86_FEATURE_LONGRUN))
	305	return -ENODEV;
	306
	307	return cpufreq_register_driver(&longrun_driver);
	308	}
	309
	310
	311	/**
	312	* longrun_exit - unregisters LongRun support
	313	*/
	314	static void __exit longrun_exit(void)
	315	{
	316	cpufreq_unregister_driver(&longrun_driver);
	317	}
	318
	319
	320	MODULE_AUTHOR ("Dominik Brodowski <linux@brodo.de>");
	321	MODULE_DESCRIPTION ("LongRun driver for Transmeta Crusoe and Efficeon processors.");
	322	MODULE_LICENSE ("GPL");
	323
	324	module_init(longrun_init);
	325	module_exit(longrun_exit);