powernow-k8.c

linux-2.6.15.6

				    (powernow_table[i].index != powernow_table[cntlofreq].index)) {
					printk(KERN_ERR PFX "Too many lo freq table entries\n");
					goto err_out_mem;
				}

				dprintk("double low frequency table entry, ignoring it.\n");
				powernow_table[i].frequency = CPUFREQ_ENTRY_INVALID;
				continue;
			} else
				cntlofreq = i;
		}

		if (powernow_table[i].frequency != (data->acpi_data.states[i].core_frequency * 1000)) {
			printk(KERN_INFO PFX "invalid freq entries %u kHz vs. %u kHz\n",
				powernow_table[i].frequency,
				(unsigned int) (data->acpi_data.states[i].core_frequency * 1000));
			powernow_table[i].frequency = CPUFREQ_ENTRY_INVALID;
			continue;
		}
	}

	powernow_table[data->acpi_data.state_count].frequency = CPUFREQ_TABLE_END;
	powernow_table[data->acpi_data.state_count].index = 0;
	data->powernow_table = powernow_table;

	/* fill in data */
	data->numps = data->acpi_data.state_count;
	print_basics(data);
	powernow_k8_acpi_pst_values(data, 0);

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

	return 0;

err_out_mem:
	kfree(powernow_table);

err_out:
	acpi_processor_unregister_performance(&data->acpi_data, data->cpu);

	/* data->acpi_data.state_count informs us at ->exit() whether ACPI was used */
	data->acpi_data.state_count = 0;

	return -ENODEV;
}

static void powernow_k8_cpu_exit_acpi(struct powernow_k8_data *data)
{
	if (data->acpi_data.state_count)
		acpi_processor_unregister_performance(&data->acpi_data, data->cpu);
}

#else
static int powernow_k8_cpu_init_acpi(struct powernow_k8_data *data) { return -ENODEV; }
static void powernow_k8_cpu_exit_acpi(struct powernow_k8_data *data) { return; }
static void powernow_k8_acpi_pst_values(struct powernow_k8_data *data, unsigned int index) { return; }
#endif /* CONFIG_X86_POWERNOW_K8_ACPI */

/* Take a frequency, and issue the fid/vid transition command */
static int transition_frequency(struct powernow_k8_data *data, unsigned int index)
{
	u32 fid;
	u32 vid;
	int res, i;
	struct cpufreq_freqs freqs;

	dprintk("cpu %d transition to index %u\n", smp_processor_id(), index);

	/* fid are the lower 8 bits of the index we stored into
	 * the cpufreq frequency table in find_psb_table, vid are 
	 * the upper 8 bits.
	 */

	fid = data->powernow_table[index].index & 0xFF;
	vid = (data->powernow_table[index].index & 0xFF00) >> 8;

	dprintk("table matched fid 0x%x, giving vid 0x%x\n", fid, vid);

	if (query_current_values_with_pending_wait(data))
		return 1;

	if ((data->currvid == vid) && (data->currfid == fid)) {
		dprintk("target matches current values (fid 0x%x, vid 0x%x)\n",
			fid, vid);
		return 0;
	}

	if ((fid < HI_FID_TABLE_BOTTOM) && (data->currfid < HI_FID_TABLE_BOTTOM)) {
		printk(KERN_ERR PFX
		       "ignoring illegal change in lo freq table-%x to 0x%x\n",
		       data->currfid, fid);
		return 1;
	}

	dprintk("cpu %d, changing to fid 0x%x, vid 0x%x\n",
		smp_processor_id(), fid, vid);

	freqs.cpu = data->cpu;
	freqs.old = find_khz_freq_from_fid(data->currfid);
	freqs.new = find_khz_freq_from_fid(fid);
	for_each_cpu_mask(i, cpu_core_map[data->cpu]) {
		freqs.cpu = i;
		cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
	}

	res = transition_fid_vid(data, fid, vid);

	freqs.new = find_khz_freq_from_fid(data->currfid);
	for_each_cpu_mask(i, cpu_core_map[data->cpu]) {
		freqs.cpu = i;
		cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
        }
	return res;
}

/* Driver entry point to switch to the target frequency */
static int powernowk8_target(struct cpufreq_policy *pol, unsigned targfreq, unsigned relation)
{
	cpumask_t oldmask = CPU_MASK_ALL;
	struct powernow_k8_data *data = powernow_data[pol->cpu];
	u32 checkfid = data->currfid;
	u32 checkvid = data->currvid;
	unsigned int newstate;
	int ret = -EIO;
	int i;

	/* only run on specific CPU from here on */
	oldmask = current->cpus_allowed;
	set_cpus_allowed(current, cpumask_of_cpu(pol->cpu));

	if (smp_processor_id() != pol->cpu) {
		printk(KERN_ERR "limiting to cpu %u failed\n", pol->cpu);
		goto err_out;
	}

	if (pending_bit_stuck()) {
		printk(KERN_ERR PFX "failing targ, change pending bit set\n");
		goto err_out;
	}

	dprintk("targ: cpu %d, %d kHz, min %d, max %d, relation %d\n",
		pol->cpu, targfreq, pol->min, pol->max, relation);

	if (query_current_values_with_pending_wait(data)) {
		ret = -EIO;
		goto err_out;
	}

	dprintk("targ: curr fid 0x%x, vid 0x%x\n",
		data->currfid, data->currvid);

	if ((checkvid != data->currvid) || (checkfid != data->currfid)) {
		printk(KERN_INFO PFX
			"error - out of sync, fix 0x%x 0x%x, vid 0x%x 0x%x\n",
			checkfid, data->currfid, checkvid, data->currvid);
	}

	if (cpufreq_frequency_table_target(pol, data->powernow_table, targfreq, relation, &newstate))
		goto err_out;

	down(&fidvid_sem);

	powernow_k8_acpi_pst_values(data, newstate);

	if (transition_frequency(data, newstate)) {
		printk(KERN_ERR PFX "transition frequency failed\n");
		ret = 1;
		up(&fidvid_sem);
		goto err_out;
	}

	/* Update all the fid/vids of our siblings */
	for_each_cpu_mask(i, cpu_core_map[pol->cpu]) {
		powernow_data[i]->currvid = data->currvid;
		powernow_data[i]->currfid = data->currfid;
	}	
	up(&fidvid_sem);

	pol->cur = find_khz_freq_from_fid(data->currfid);
	ret = 0;

err_out:
	set_cpus_allowed(current, oldmask);
	return ret;
}

/* Driver entry point to verify the policy and range of frequencies */
static int powernowk8_verify(struct cpufreq_policy *pol)
{
	struct powernow_k8_data *data = powernow_data[pol->cpu];

	return cpufreq_frequency_table_verify(pol, data->powernow_table);
}

/* per CPU init entry point to the driver */
static int __init powernowk8_cpu_init(struct cpufreq_policy *pol)
{
	struct powernow_k8_data *data;
	cpumask_t oldmask = CPU_MASK_ALL;
	int rc, i;

	if (!check_supported_cpu(pol->cpu))
		return -ENODEV;

	data = kzalloc(sizeof(struct powernow_k8_data), GFP_KERNEL);
	if (!data) {
		printk(KERN_ERR PFX "unable to alloc powernow_k8_data");
		return -ENOMEM;
	}

	data->cpu = pol->cpu;

	if (powernow_k8_cpu_init_acpi(data)) {
		/*
		 * Use the PSB BIOS structure. This is only availabe on
		 * an UP version, and is deprecated by AMD.
		 */

		if ((num_online_cpus() != 1) || (num_possible_cpus() != 1)) {
			printk(KERN_ERR PFX "MP systems not supported by PSB BIOS structure\n");
			kfree(data);
			return -ENODEV;
		}
		if (pol->cpu != 0) {
			printk(KERN_ERR PFX "init not cpu 0\n");
			kfree(data);
			return -ENODEV;
		}
		rc = find_psb_table(data);
		if (rc) {
			kfree(data);
			return -ENODEV;
		}
	}

	/* only run on specific CPU from here on */
	oldmask = current->cpus_allowed;
	set_cpus_allowed(current, cpumask_of_cpu(pol->cpu));

	if (smp_processor_id() != pol->cpu) {
		printk(KERN_ERR "limiting to cpu %u failed\n", pol->cpu);
		goto err_out;
	}

	if (pending_bit_stuck()) {
		printk(KERN_ERR PFX "failing init, change pending bit set\n");
		goto err_out;
	}

	if (query_current_values_with_pending_wait(data))
		goto err_out;

	fidvid_msr_init();

	/* run on any CPU again */
	set_cpus_allowed(current, oldmask);

	pol->governor = CPUFREQ_DEFAULT_GOVERNOR;
	pol->cpus = cpu_core_map[pol->cpu];

	/* Take a crude guess here. 
	 * That guess was in microseconds, so multiply with 1000 */
	pol->cpuinfo.transition_latency = (((data->rvo + 8) * data->vstable * VST_UNITS_20US)
	    + (3 * (1 << data->irt) * 10)) * 1000;

	pol->cur = find_khz_freq_from_fid(data->currfid);
	dprintk("policy current frequency %d kHz\n", pol->cur);

	/* min/max the cpu is capable of */
	if (cpufreq_frequency_table_cpuinfo(pol, data->powernow_table)) {
		printk(KERN_ERR PFX "invalid powernow_table\n");
		powernow_k8_cpu_exit_acpi(data);
		kfree(data->powernow_table);
		kfree(data);
		return -EINVAL;
	}

	cpufreq_frequency_table_get_attr(data->powernow_table, pol->cpu);

	printk("cpu_init done, current fid 0x%x, vid 0x%x\n",
	       data->currfid, data->currvid);

	for_each_cpu_mask(i, cpu_core_map[pol->cpu]) {
		powernow_data[i] = data;
	}

	return 0;

err_out:
	set_cpus_allowed(current, oldmask);
	powernow_k8_cpu_exit_acpi(data);

	kfree(data);
	return -ENODEV;
}

static int __devexit powernowk8_cpu_exit (struct cpufreq_policy *pol)
{
	struct powernow_k8_data *data = powernow_data[pol->cpu];

	if (!data)
		return -EINVAL;

	powernow_k8_cpu_exit_acpi(data);

	cpufreq_frequency_table_put_attr(pol->cpu);

	kfree(data->powernow_table);
	kfree(data);

	return 0;
}

static unsigned int powernowk8_get (unsigned int cpu)
{
	struct powernow_k8_data *data = powernow_data[cpu];
	cpumask_t oldmask = current->cpus_allowed;
	unsigned int khz = 0;

	set_cpus_allowed(current, cpumask_of_cpu(cpu));
	if (smp_processor_id() != cpu) {
		printk(KERN_ERR PFX "limiting to CPU %d failed in powernowk8_get\n", cpu);
		set_cpus_allowed(current, oldmask);
		return 0;
	}

	if (query_current_values_with_pending_wait(data))
		goto out;

	khz = find_khz_freq_from_fid(data->currfid);

out:
	set_cpus_allowed(current, oldmask);
	return khz;
}

static struct freq_attr* powernow_k8_attr[] = {
	&cpufreq_freq_attr_scaling_available_freqs,
	NULL,
};

static struct cpufreq_driver cpufreq_amd64_driver = {
	.verify = powernowk8_verify,
	.target = powernowk8_target,
	.init = powernowk8_cpu_init,
	.exit = __devexit_p(powernowk8_cpu_exit),
	.get = powernowk8_get,
	.name = "powernow-k8",
	.owner = THIS_MODULE,
	.attr = powernow_k8_attr,
};

/* driver entry point for init */
static int __init powernowk8_init(void)
{
	unsigned int i, supported_cpus = 0;

	for (i=0; i<NR_CPUS; i++) {
		if (!cpu_online(i))
			continue;
		if (check_supported_cpu(i))
			supported_cpus++;
	}

	if (supported_cpus == num_online_cpus()) {
		printk(KERN_INFO PFX "Found %d AMD Athlon 64 / Opteron processors (" VERSION ")\n",
			supported_cpus);
		return cpufreq_register_driver(&cpufreq_amd64_driver);
	}

	return -ENODEV;
}

/* driver entry point for term */
static void __exit powernowk8_exit(void)
{
	dprintk("exit\n");

	cpufreq_unregister_driver(&cpufreq_amd64_driver);
}

MODULE_AUTHOR("Paul Devriendt <[e-mail]> and Mark Langsdorf <[e-mail].");
MODULE_DESCRIPTION("AMD Athlon 64 and Opteron processor frequency driver.");
MODULE_LICENSE("GPL");

late_initcall(powernowk8_init);
module_exit(powernowk8_exit);