longhaul.c

这个linux源代码是很全面的~基本完整了~使用c编译的~由于时间问题我没有亲自测试~但就算用来做参考资料也是非常好的

/*
 *  $Id: longhaul.c,v 1.83 2003/01/02 22:16:26 db Exp $
 *
 *  (C) 2001  Dave Jones. <[e-mail]>
 *  (C) 2002  Padraig Brady. <[e-mail]>
 *
 *  Licensed under the terms of the GNU GPL License version 2.
 *  Based upon datasheets & sample CPUs kindly provided by VIA.
 *
 *  VIA have currently 3 different versions of Longhaul.
 *
 *  +---------------------+----------+---------------------------------+
 *  | Marketing name      | Codename | longhaul version / features.    |
 *  +---------------------+----------+---------------------------------+
 *  |  Samuel/CyrixIII    |   C5A    | v1 : multipliers only           |
 *  |  Samuel2/C3         | C3E/C5B  | v1 : multiplier only            |
 *  |  Ezra               |   C5C    | v2 : multipliers & voltage      |
 *  |  Ezra-T             | C5M/C5N  | v3 : multipliers, voltage & FSB |
 *  +---------------------+----------+---------------------------------+
 *
 *  BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous*
 */

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

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

#define DEBUG

#ifdef DEBUG
#define dprintk(msg...) printk(msg)
#else
#define dprintk(msg...) do { } while(0);
#endif

static int numscales=16, numvscales;
static int minvid, maxvid;
static int can_scale_voltage;
static int can_scale_fsb;
static int vrmrev;


/* Module parameters */
static int dont_scale_voltage;
static int dont_scale_fsb;
static int current_fsb;

#define __hlt()     __asm__ __volatile__("hlt": : :"memory")

/*
 * Clock ratio tables.
 * The eblcr ones specify the ratio read from the CPU.
 * The clock_ratio ones specify what to write to the CPU.
 */

/* VIA C3 Samuel 1  & Samuel 2 (stepping 0)*/
static int __initdata longhaul1_clock_ratio[16] = {
	-1, /* 0000 -> RESERVED */
	30, /* 0001 ->  3.0x */
	40, /* 0010 ->  4.0x */
	-1, /* 0011 -> RESERVED */
	-1, /* 0100 -> RESERVED */
	35, /* 0101 ->  3.5x */
	45, /* 0110 ->  4.5x */
	55, /* 0111 ->  5.5x */
	60, /* 1000 ->  6.0x */
	70, /* 1001 ->  7.0x */
	80, /* 1010 ->  8.0x */
	50, /* 1011 ->  5.0x */
	65, /* 1100 ->  6.5x */
	75, /* 1101 ->  7.5x */
	-1, /* 1110 -> RESERVED */
	-1, /* 1111 -> RESERVED */
};

static int __initdata samuel1_eblcr[16] = {
	50, /* 0000 -> RESERVED */
	30, /* 0001 ->  3.0x */
	40, /* 0010 ->  4.0x */
	-1, /* 0011 -> RESERVED */
	55, /* 0100 ->  5.5x */
	35, /* 0101 ->  3.5x */
	45, /* 0110 ->  4.5x */
	-1, /* 0111 -> RESERVED */
	-1, /* 1000 -> RESERVED */
	70, /* 1001 ->  7.0x */
	80, /* 1010 ->  8.0x */
	60, /* 1011 ->  6.0x */
	-1, /* 1100 -> RESERVED */
	75, /* 1101 ->  7.5x */
	-1, /* 1110 -> RESERVED */
	65, /* 1111 ->  6.5x */
};

/* VIA C3 Samuel2 Stepping 1->15 & VIA C3 Ezra */
static int __initdata longhaul2_clock_ratio[16] = {
	100, /* 0000 -> 10.0x */
	30,  /* 0001 ->  3.0x */
	40,  /* 0010 ->  4.0x */
	90,  /* 0011 ->  9.0x */
	95,  /* 0100 ->  9.5x */
	35,  /* 0101 ->  3.5x */
	45,  /* 0110 ->  4.5x */
	55,  /* 0111 ->  5.5x */
	60,  /* 1000 ->  6.0x */
	70,  /* 1001 ->  7.0x */
	80,  /* 1010 ->  8.0x */
	50,  /* 1011 ->  5.0x */
	65,  /* 1100 ->  6.5x */
	75,  /* 1101 ->  7.5x */
	85,  /* 1110 ->  8.5x */
	120, /* 1111 -> 12.0x */
};

static int __initdata samuel2_eblcr[16] = {
	50,  /* 0000 ->  5.0x */
	30,  /* 0001 ->  3.0x */
	40,  /* 0010 ->  4.0x */
	100, /* 0011 -> 10.0x */
	55,  /* 0100 ->  5.5x */
	35,  /* 0101 ->  3.5x */
	45,  /* 0110 ->  4.5x */
	110, /* 0111 -> 11.0x */
	90,  /* 1000 ->  9.0x */
	70,  /* 1001 ->  7.0x */
	80,  /* 1010 ->  8.0x */
	60,  /* 1011 ->  6.0x */
	120, /* 1100 -> 12.0x */
	75,  /* 1101 ->  7.5x */
	130, /* 1110 -> 13.0x */
	65,  /* 1111 ->  6.5x */
};

static int __initdata ezra_eblcr[16] = {
	50,  /* 0000 ->  5.0x */
	30,  /* 0001 ->  3.0x */
	40,  /* 0010 ->  4.0x */
	100, /* 0011 -> 10.0x */
	55,  /* 0100 ->  5.5x */
	35,  /* 0101 ->  3.5x */
	45,  /* 0110 ->  4.5x */
	95,  /* 0111 ->  9.5x */
	90,  /* 1000 ->  9.0x */
	70,  /* 1001 ->  7.0x */
	80,  /* 1010 ->  8.0x */
	60,  /* 1011 ->  6.0x */
	120, /* 1100 -> 12.0x */
	75,  /* 1101 ->  7.5x */
	85,  /* 1110 ->  8.5x */
	65,  /* 1111 ->  6.5x */
};

/* VIA C5M. */
static int __initdata longhaul3_clock_ratio[32] = {
	100, /* 0000 -> 10.0x */
	30,  /* 0001 ->  3.0x */
	40,  /* 0010 ->  4.0x */
	90,  /* 0011 ->  9.0x */
	95,  /* 0100 ->  9.5x */
	35,  /* 0101 ->  3.5x */
	45,  /* 0110 ->  4.5x */
	55,  /* 0111 ->  5.5x */
	60,  /* 1000 ->  6.0x */
	70,  /* 1001 ->  7.0x */
	80,  /* 1010 ->  8.0x */
	50,  /* 1011 ->  5.0x */
	65,  /* 1100 ->  6.5x */
	75,  /* 1101 ->  7.5x */
	85,  /* 1110 ->  8.5x */
	120, /* 1111 ->  12.0x */

	-1,  /* 0000 -> RESERVED (10.0x) */
	110, /* 0001 -> 11.0x */
	120, /* 0010 -> 12.0x */
	-1,  /* 0011 -> RESERVED (9.0x)*/
	105, /* 0100 -> 10.5x */
	115, /* 0101 -> 11.5x */
	125, /* 0110 -> 12.5x */
	135, /* 0111 -> 13.5x */
	140, /* 1000 -> 14.0x */
	150, /* 1001 -> 15.0x */
	160, /* 1010 -> 16.0x */
	130, /* 1011 -> 13.0x */
	145, /* 1100 -> 14.5x */
	155, /* 1101 -> 15.5x */
	-1,  /* 1110 -> RESERVED (13.0x) */
	-1,  /* 1111 -> RESERVED (12.0x) */
};

static int __initdata c5m_eblcr[32] = {
	50,  /* 0000 ->  5.0x */
	30,  /* 0001 ->  3.0x */
	40,  /* 0010 ->  4.0x */
	100, /* 0011 -> 10.0x */
	55,  /* 0100 ->  5.5x */
	35,  /* 0101 ->  3.5x */
	45,  /* 0110 ->  4.5x */
	95,  /* 0111 ->  9.5x */
	90,  /* 1000 ->  9.0x */
	70,  /* 1001 ->  7.0x */
	80,  /* 1010 ->  8.0x */
	60,  /* 1011 ->  6.0x */
	120, /* 1100 -> 12.0x */
	75,  /* 1101 ->  7.5x */
	85,  /* 1110 ->  8.5x */
	65,  /* 1111 ->  6.5x */

	-1,  /* 0000 -> RESERVED (9.0x) */
	110, /* 0001 -> 11.0x */
	120, /* 0010 -> 12.0x */
	-1,  /* 0011 -> RESERVED (10.0x)*/
	135, /* 0100 -> 13.5x */
	115, /* 0101 -> 11.5x */
	125, /* 0110 -> 12.5x */
	105, /* 0111 -> 10.5x */
	130, /* 1000 -> 13.0x */
	150, /* 1001 -> 15.0x */
	160, /* 1010 -> 16.0x */
	140, /* 1011 -> 14.0x */
	-1,  /* 1100 -> RESERVED (12.0x) */
	155, /* 1101 -> 15.5x */
	-1,  /* 1110 -> RESERVED (13.0x) */
	145, /* 1111 -> 14.5x */
};

/* fsb values as defined in CPU */
static unsigned int eblcr_fsb_table[] = { 66, 133, 100, -1 };
/* fsb values to favour low fsb speed (lower power) */
static unsigned int power_fsb_table[] = { 66, 100, 133, -1 };
/* fsb values to favour high fsb speed (for e.g. if lowering CPU 
   freq because of heat, but want to maintain highest performance possible) */
static unsigned int perf_fsb_table[] = { 133, 100, 66, -1 };
static unsigned int *fsb_search_table;

/* Voltage scales. Div by 1000 to get actual voltage. */
static int __initdata vrm85scales[32] = {
	1250, 1200, 1150, 1100, 1050, 1800, 1750, 1700,
	1650, 1600, 1550, 1500, 1450, 1400, 1350, 1300,
	1275, 1225, 1175, 1125, 1075, 1825, 1775, 1725,
	1675, 1625, 1575, 1525, 1475, 1425, 1375, 1325,
};

static int __initdata mobilevrmscales[32] = {
	2000, 1950, 1900, 1850, 1800, 1750, 1700, 1650,
	1600, 1550, 1500, 1450, 1500, 1350, 1300, -1,
	1275, 1250, 1225, 1200, 1175, 1150, 1125, 1100,
	1075, 1050, 1025, 1000, 975, 950, 925, -1,
};

/* Clock ratios multiplied by 10 */
static int clock_ratio[32];
static int eblcr_table[32];
static int voltage_table[32];
static int highest_speed, lowest_speed; /* kHz */
static int longhaul; /* version. */
static struct cpufreq_driver *longhaul_driver;


static int longhaul_get_cpu_fsb (void)
{
	unsigned long invalue=0,lo, hi;

	if (current_fsb == 0) {
		rdmsr (MSR_IA32_EBL_CR_POWERON, lo, hi);
		invalue = (lo & (1<<18|1<<19)) >>18;
		return eblcr_fsb_table[invalue];
	} else {
		return current_fsb;
	}
}


static int longhaul_get_cpu_mult (void)
{
	unsigned long invalue=0,lo, hi;

	rdmsr (MSR_IA32_EBL_CR_POWERON, lo, hi);
	invalue = (lo & (1<<22|1<<23|1<<24|1<<25)) >>22;
	if (longhaul==3) {
		if (lo & (1<<27))
			invalue+=16;
	}
	return eblcr_table[invalue];
}


/**
 * longhaul_set_cpu_frequency()
 * @clock_ratio_index : index of clock_ratio[] for new frequency
 * @newfsb: the new FSB
 *
 * Sets a new clock ratio, and -if applicable- a new Front Side Bus
 */

static void longhaul_setstate (unsigned int clock_ratio_index, unsigned int newfsb)
{
	unsigned long lo, hi;
	unsigned int bits;
	int revkey;
	int vidindex, i;
	struct cpufreq_freqs freqs;
	
	if (!newfsb || (clock_ratio[clock_ratio_index] == -1))
		return;

	if ((!can_scale_fsb) && (newfsb != current_fsb))
		return;

	if (((clock_ratio[clock_ratio_index] * newfsb * 100) > highest_speed) ||
	    ((clock_ratio[clock_ratio_index] * newfsb * 100) < lowest_speed))
		return;

	freqs.old = longhaul_get_cpu_mult() * longhaul_get_cpu_fsb() * 100;
	freqs.new = clock_ratio[clock_ratio_index] * newfsb * 100;
	freqs.cpu = 0; /* longhaul.c is UP only driver */
	
	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

	dprintk (KERN_INFO "longhaul: New FSB:%d Mult(x10):%d\n",
				newfsb, clock_ratio[clock_ratio_index]);

	bits = clock_ratio_index;
	/* "bits" contains the bitpattern of the new multiplier.
	   we now need to transform it to the desired format. */

	switch (longhaul) {
	case 1:
		rdmsr (MSR_VIA_BCR2, lo, hi);
		revkey = (lo & 0xf)<<4; /* Rev key. */
		lo &= ~(1<<23|1<<24|1<<25|1<<26);
		lo |= (1<<19);		/* Enable software clock multiplier */
		lo |= (bits<<23);	/* desired multiplier */
		lo |= revkey;
		wrmsr (MSR_VIA_BCR2, lo, hi);

		__hlt();

		/* Disable software clock multiplier */
		rdmsr (MSR_VIA_BCR2, lo, hi);
		lo &= ~(1<<19);
		lo |= revkey;
		wrmsr (MSR_VIA_BCR2, lo, hi);
		break;

	case 2:
		rdmsr (MSR_VIA_LONGHAUL, lo, hi);
		revkey = (lo & 0xf)<<4;	/* Rev key. */
		lo &= 0xfff0bf0f;	/* reset [19:16,14](bus ratio) and [7:4](rev key) to 0 */
		lo |= (bits<<16);
		lo |= (1<<8);	/* EnableSoftBusRatio */
		lo |= revkey;

		if (can_scale_voltage) {
			if (can_scale_fsb==1) {
				dprintk (KERN_INFO "longhaul: Voltage scaling + FSB scaling not done yet.\n");
				goto bad_voltage;
			} else {
				/* PB: TODO fix this up */
				vidindex = (((highest_speed-lowest_speed) / (newfsb/2)) -
						((highest_speed-((clock_ratio[clock_ratio_index] * newfsb * 100)/1000)) / (newfsb/2)));
			}
			for (i=0;i<32;i++) {
				dprintk (KERN_INFO "VID hunting. Looking for %d, found %d\n",
						minvid+(vidindex*25), voltage_table[i]);
				if (voltage_table[i]==(minvid + (vidindex * 25)))
					break;
			}
			if (i==32)
				goto bad_voltage;

			dprintk (KERN_INFO "longhaul: Desired vid index=%d\n", i);
#if 0
			lo &= 0xfe0fffff;/* reset [24:20](voltage) to 0 */
			lo |= (i<<20);   /* set voltage */
			lo |= (1<<9);    /* EnableSoftVID */
#endif
		}

bad_voltage:
		wrmsr (MSR_VIA_LONGHAUL, lo, hi);
		__hlt();

		rdmsr (MSR_VIA_LONGHAUL, lo, hi);
		lo &= ~(1<<8);
		if (can_scale_voltage)
			lo &= ~(1<<9);
		lo |= revkey;
		wrmsr (MSR_VIA_LONGHAUL, lo, hi);
		break;

	case 3:
		rdmsr (MSR_VIA_LONGHAUL, lo, hi);
		revkey = (lo & 0xf)<<4;	/* Rev key. */
		lo &= 0xfff0bf0f;	/* reset longhaul[19:16,14] to 0 */
		lo |= (bits<<16);
		lo |= (1<<8);	/* EnableSoftBusRatio */
		lo |= revkey;

		/* Set FSB */
		if (can_scale_fsb==1) {