powernow-k7.c

linux 内核源代码

			 (u32) state->power,
			 (u32) state->transition_latency,
			 (u32) state->control,
			 pc.bits.sgtc);

		vid = pc.bits.vid;
		fid = pc.bits.fid;

		powernow_table[i].frequency = fsb * fid_codes[fid] / 10;
		powernow_table[i].index = fid; /* lower 8 bits */
		powernow_table[i].index |= (vid << 8); /* upper 8 bits */

		speed = powernow_table[i].frequency;
		speed_mhz = speed / 1000;

		/* processor_perflib will multiply the MHz value by 1000 to
		 * get a KHz value (e.g. 1266000). However, powernow-k7 works
		 * with true KHz values (e.g. 1266768). To ensure that all
		 * powernow frequencies are available, we must ensure that
		 * ACPI doesn't restrict them, so we round up the MHz value
		 * to ensure that perflib's computed KHz value is greater than
		 * or equal to powernow's KHz value.
		 */
		if (speed % 1000 > 0)
			speed_mhz++;

		if ((fid_codes[fid] % 10)==5) {
			if (have_a0 == 1)
				powernow_table[i].frequency = CPUFREQ_ENTRY_INVALID;
		}

		dprintk ("   FID: 0x%x (%d.%dx [%dMHz])  "
			 "VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10,
			 fid_codes[fid] % 10, speed_mhz, vid,
			 mobile_vid_table[vid]/1000,
			 mobile_vid_table[vid]%1000);

		if (state->core_frequency != speed_mhz) {
			state->core_frequency = speed_mhz;
			dprintk("   Corrected ACPI frequency to %d\n",
				speed_mhz);
		}

		if (latency < pc.bits.sgtc)
			latency = pc.bits.sgtc;

		if (speed < minimum_speed)
			minimum_speed = speed;
		if (speed > maximum_speed)
			maximum_speed = speed;
	}

	powernow_table[i].frequency = CPUFREQ_TABLE_END;
	powernow_table[i].index = 0;

	/* notify BIOS that we exist */
	acpi_processor_notify_smm(THIS_MODULE);

	return 0;

err2:
	acpi_processor_unregister_performance(acpi_processor_perf, 0);
err1:
	kfree(acpi_processor_perf);
err0:
	printk(KERN_WARNING PFX "ACPI perflib can not be used in this platform\n");
	acpi_processor_perf = NULL;
	return retval;
}
#else
static int powernow_acpi_init(void)
{
	printk(KERN_INFO PFX "no support for ACPI processor found."
	       "  Please recompile your kernel with ACPI processor\n");
	return -EINVAL;
}
#endif

static int powernow_decode_bios (int maxfid, int startvid)
{
	struct psb_s *psb;
	struct pst_s *pst;
	unsigned int i, j;
	unsigned char *p;
	unsigned int etuple;
	unsigned int ret;

	etuple = cpuid_eax(0x80000001);

	for (i=0xC0000; i < 0xffff0 ; i+=16) {

		p = phys_to_virt(i);

		if (memcmp(p, "AMDK7PNOW!",  10) == 0){
			dprintk ("Found PSB header at %p\n", p);
			psb = (struct psb_s *) p;
			dprintk ("Table version: 0x%x\n", psb->tableversion);
			if (psb->tableversion != 0x12) {
				printk (KERN_INFO PFX "Sorry, only v1.2 tables supported right now\n");
				return -ENODEV;
			}

			dprintk ("Flags: 0x%x\n", psb->flags);
			if ((psb->flags & 1)==0) {
				dprintk ("Mobile voltage regulator\n");
			} else {
				dprintk ("Desktop voltage regulator\n");
			}

			latency = psb->settlingtime;
			if (latency < 100) {
				printk (KERN_INFO PFX "BIOS set settling time to %d microseconds."
						"Should be at least 100. Correcting.\n", latency);
				latency = 100;
			}
			dprintk ("Settling Time: %d microseconds.\n", psb->settlingtime);
			dprintk ("Has %d PST tables. (Only dumping ones relevant to this CPU).\n", psb->numpst);

			p += sizeof (struct psb_s);

			pst = (struct pst_s *) p;

			for (j=0; j<psb->numpst; j++) {
				pst = (struct pst_s *) p;
				number_scales = pst->numpstates;

				if ((etuple == pst->cpuid) && check_fsb(pst->fsbspeed) &&
				    (maxfid==pst->maxfid) && (startvid==pst->startvid))
				{
					dprintk ("PST:%d (@%p)\n", j, pst);
					dprintk (" cpuid: 0x%x  fsb: %d  maxFID: 0x%x  startvid: 0x%x\n",
						 pst->cpuid, pst->fsbspeed, pst->maxfid, pst->startvid);

					ret = get_ranges ((char *) pst + sizeof (struct pst_s));
					return ret;
				} else {
					unsigned int k;
					p = (char *) pst + sizeof (struct pst_s);
					for (k=0; k<number_scales; k++)
						p+=2;
				}
			}
			printk (KERN_INFO PFX "No PST tables match this cpuid (0x%x)\n", etuple);
			printk (KERN_INFO PFX "This is indicative of a broken BIOS.\n");

			return -EINVAL;
		}
		p++;
	}

	return -ENODEV;
}


static int powernow_target (struct cpufreq_policy *policy,
			    unsigned int target_freq,
			    unsigned int relation)
{
	unsigned int newstate;

	if (cpufreq_frequency_table_target(policy, powernow_table, target_freq, relation, &newstate))
		return -EINVAL;

	change_speed(newstate);

	return 0;
}


static int powernow_verify (struct cpufreq_policy *policy)
{
	return cpufreq_frequency_table_verify(policy, powernow_table);
}

/*
 * We use the fact that the bus frequency is somehow
 * a multiple of 100000/3 khz, then we compute sgtc according
 * to this multiple.
 * That way, we match more how AMD thinks all of that work.
 * We will then get the same kind of behaviour already tested under
 * the "well-known" other OS.
 */
static int __init fixup_sgtc(void)
{
	unsigned int sgtc;
	unsigned int m;

	m = fsb / 3333;
	if ((m % 10) >= 5)
		m += 5;

	m /= 10;

	sgtc = 100 * m * latency;
	sgtc = sgtc / 3;
	if (sgtc > 0xfffff) {
		printk(KERN_WARNING PFX "SGTC too large %d\n", sgtc);
		sgtc = 0xfffff;
	}
	return sgtc;
}

static unsigned int powernow_get(unsigned int cpu)
{
	union msr_fidvidstatus fidvidstatus;
	unsigned int cfid;

	if (cpu)
		return 0;
	rdmsrl (MSR_K7_FID_VID_STATUS, fidvidstatus.val);
	cfid = fidvidstatus.bits.CFID;

	return (fsb * fid_codes[cfid] / 10);
}


static int __init acer_cpufreq_pst(const struct dmi_system_id *d)
{
	printk(KERN_WARNING "%s laptop with broken PST tables in BIOS detected.\n", d->ident);
	printk(KERN_WARNING "You need to downgrade to 3A21 (09/09/2002), or try a newer BIOS than 3A71 (01/20/2003)\n");
	printk(KERN_WARNING "cpufreq scaling has been disabled as a result of this.\n");
	return 0;
}

/*
 * Some Athlon laptops have really fucked PST tables.
 * A BIOS update is all that can save them.
 * Mention this, and disable cpufreq.
 */
static struct dmi_system_id __initdata powernow_dmi_table[] = {
	{
		.callback = acer_cpufreq_pst,
		.ident = "Acer Aspire",
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Insyde Software"),
			DMI_MATCH(DMI_BIOS_VERSION, "3A71"),
		},
	},
	{ }
};

static int __init powernow_cpu_init (struct cpufreq_policy *policy)
{
	union msr_fidvidstatus fidvidstatus;
	int result;

	if (policy->cpu != 0)
		return -ENODEV;

	rdmsrl (MSR_K7_FID_VID_STATUS, fidvidstatus.val);

	recalibrate_cpu_khz();

	fsb = (10 * cpu_khz) / fid_codes[fidvidstatus.bits.CFID];
	if (!fsb) {
		printk(KERN_WARNING PFX "can not determine bus frequency\n");
		return -EINVAL;
	}
	dprintk("FSB: %3dMHz\n", fsb/1000);

	if (dmi_check_system(powernow_dmi_table) || acpi_force) {
		printk (KERN_INFO PFX "PSB/PST known to be broken.  Trying ACPI instead\n");
		result = powernow_acpi_init();
	} else {
		result = powernow_decode_bios(fidvidstatus.bits.MFID, fidvidstatus.bits.SVID);
		if (result) {
			printk (KERN_INFO PFX "Trying ACPI perflib\n");
			maximum_speed = 0;
			minimum_speed = -1;
			latency = 0;
			result = powernow_acpi_init();
			if (result) {
				printk (KERN_INFO PFX "ACPI and legacy methods failed\n");
				printk (KERN_INFO PFX "See http://www.codemonkey.org.uk/projects/cpufreq/powernow-k7.html\n");
			}
		} else {
			/* SGTC use the bus clock as timer */
			latency = fixup_sgtc();
			printk(KERN_INFO PFX "SGTC: %d\n", latency);
		}
	}

	if (result)
		return result;

	printk (KERN_INFO PFX "Minimum speed %d MHz. Maximum speed %d MHz.\n",
				minimum_speed/1000, maximum_speed/1000);

	policy->cpuinfo.transition_latency = cpufreq_scale(2000000UL, fsb, latency);

	policy->cur = powernow_get(0);

	cpufreq_frequency_table_get_attr(powernow_table, policy->cpu);

	return cpufreq_frequency_table_cpuinfo(policy, powernow_table);
}

static int powernow_cpu_exit (struct cpufreq_policy *policy) {
	cpufreq_frequency_table_put_attr(policy->cpu);

#ifdef CONFIG_X86_POWERNOW_K7_ACPI
	if (acpi_processor_perf) {
		acpi_processor_unregister_performance(acpi_processor_perf, 0);
		kfree(acpi_processor_perf);
	}
#endif

	kfree(powernow_table);
	return 0;
}

static struct freq_attr* powernow_table_attr[] = {
	&cpufreq_freq_attr_scaling_available_freqs,
	NULL,
};

static struct cpufreq_driver powernow_driver = {
	.verify	= powernow_verify,
	.target	= powernow_target,
	.get	= powernow_get,
	.init	= powernow_cpu_init,
	.exit	= powernow_cpu_exit,
	.name	= "powernow-k7",
	.owner	= THIS_MODULE,
	.attr	= powernow_table_attr,
};

static int __init powernow_init (void)
{
	if (check_powernow()==0)
		return -ENODEV;
	return cpufreq_register_driver(&powernow_driver);
}


static void __exit powernow_exit (void)
{
	cpufreq_unregister_driver(&powernow_driver);
}

module_param(acpi_force,  int, 0444);
MODULE_PARM_DESC(acpi_force, "Force ACPI to be used.");

MODULE_AUTHOR ("Dave Jones <[e-mail]>");
MODULE_DESCRIPTION ("Powernow driver for AMD K7 processors.");
MODULE_LICENSE ("GPL");

late_initcall(powernow_init);
module_exit(powernow_exit);