[deliverable/linux.git] / drivers / cpufreq / pcc-cpufreq.c

/*
 *  pcc-cpufreq.c - Processor Clocking Control firmware cpufreq interface
 *
 *  Copyright (C) 2009 Red Hat, Matthew Garrett <mjg@redhat.com>
 *  Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
 *	Nagananda Chumbalkar <nagananda.chumbalkar@hp.com>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; version 2 of the License.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or NON
 *  INFRINGEMENT. See the GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

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

#include <linux/acpi.h>
#include <linux/io.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>

#include <acpi/processor.h>

#define PCC_VERSION	"1.10.00"
#define POLL_LOOPS 	300

#define CMD_COMPLETE 	0x1
#define CMD_GET_FREQ 	0x0
#define CMD_SET_FREQ 	0x1

#define BUF_SZ		4

struct pcc_register_resource {
	u8 descriptor;
	u16 length;
	u8 space_id;
	u8 bit_width;
	u8 bit_offset;
	u8 access_size;
	u64 address;
} __attribute__ ((packed));

struct pcc_memory_resource {
	u8 descriptor;
	u16 length;
	u8 space_id;
	u8 resource_usage;
	u8 type_specific;
	u64 granularity;
	u64 minimum;
	u64 maximum;
	u64 translation_offset;
	u64 address_length;
} __attribute__ ((packed));

static struct cpufreq_driver pcc_cpufreq_driver;

struct pcc_header {
	u32 signature;
	u16 length;
	u8 major;
	u8 minor;
	u32 features;
	u16 command;
	u16 status;
	u32 latency;
	u32 minimum_time;
	u32 maximum_time;
	u32 nominal;
	u32 throttled_frequency;
	u32 minimum_frequency;
};

static void __iomem *pcch_virt_addr;
static struct pcc_header __iomem *pcch_hdr;

static DEFINE_SPINLOCK(pcc_lock);

static struct acpi_generic_address doorbell;

static u64 doorbell_preserve;
static u64 doorbell_write;

static u8 OSC_UUID[16] = {0x9F, 0x2C, 0x9B, 0x63, 0x91, 0x70, 0x1f, 0x49,
			  0xBB, 0x4F, 0xA5, 0x98, 0x2F, 0xA1, 0xB5, 0x46};

struct pcc_cpu {
	u32 input_offset;
	u32 output_offset;
};

static struct pcc_cpu __percpu *pcc_cpu_info;

static int pcc_cpufreq_verify(struct cpufreq_policy *policy)
{
	cpufreq_verify_within_cpu_limits(policy);
	return 0;
}

static inline void pcc_cmd(void)
{
	u64 doorbell_value;
	int i;

	acpi_read(&doorbell_value, &doorbell);
	acpi_write((doorbell_value & doorbell_preserve) | doorbell_write,
		   &doorbell);

	for (i = 0; i < POLL_LOOPS; i++) {
		if (ioread16(&pcch_hdr->status) & CMD_COMPLETE)
			break;
	}
}

static inline void pcc_clear_mapping(void)
{
	if (pcch_virt_addr)
		iounmap(pcch_virt_addr);
	pcch_virt_addr = NULL;
}

static unsigned int pcc_get_freq(unsigned int cpu)
{
	struct pcc_cpu *pcc_cpu_data;
	unsigned int curr_freq;
	unsigned int freq_limit;
	u16 status;
	u32 input_buffer;
	u32 output_buffer;

	spin_lock(&pcc_lock);

	pr_debug("get: get_freq for CPU %d\n", cpu);
	pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);

	input_buffer = 0x1;
	iowrite32(input_buffer,
			(pcch_virt_addr + pcc_cpu_data->input_offset));
	iowrite16(CMD_GET_FREQ, &pcch_hdr->command);

	pcc_cmd();

	output_buffer =
		ioread32(pcch_virt_addr + pcc_cpu_data->output_offset);

	/* Clear the input buffer - we are done with the current command */
	memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);

	status = ioread16(&pcch_hdr->status);
	if (status != CMD_COMPLETE) {
		pr_debug("get: FAILED: for CPU %d, status is %d\n",
			cpu, status);
		goto cmd_incomplete;
	}
	iowrite16(0, &pcch_hdr->status);
	curr_freq = (((ioread32(&pcch_hdr->nominal) * (output_buffer & 0xff))
			/ 100) * 1000);

	pr_debug("get: SUCCESS: (virtual) output_offset for cpu %d is "
		"0x%p, contains a value of: 0x%x. Speed is: %d MHz\n",
		cpu, (pcch_virt_addr + pcc_cpu_data->output_offset),
		output_buffer, curr_freq);

	freq_limit = (output_buffer >> 8) & 0xff;
	if (freq_limit != 0xff) {
		pr_debug("get: frequency for cpu %d is being temporarily"
			" capped at %d\n", cpu, curr_freq);
	}

	spin_unlock(&pcc_lock);
	return curr_freq;

cmd_incomplete:
	iowrite16(0, &pcch_hdr->status);
	spin_unlock(&pcc_lock);
	return 0;
}

static int pcc_cpufreq_target(struct cpufreq_policy *policy,
			      unsigned int target_freq,
			      unsigned int relation)
{
	struct pcc_cpu *pcc_cpu_data;
	struct cpufreq_freqs freqs;
	u16 status;
	u32 input_buffer;
	int cpu;

	spin_lock(&pcc_lock);
	cpu = policy->cpu;
	pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);

	pr_debug("target: CPU %d should go to target freq: %d "
		"(virtual) input_offset is 0x%p\n",
		cpu, target_freq,
		(pcch_virt_addr + pcc_cpu_data->input_offset));

	freqs.new = target_freq;
	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);

	input_buffer = 0x1 | (((target_freq * 100)
			       / (ioread32(&pcch_hdr->nominal) * 1000)) << 8);
	iowrite32(input_buffer,
			(pcch_virt_addr + pcc_cpu_data->input_offset));
	iowrite16(CMD_SET_FREQ, &pcch_hdr->command);

	pcc_cmd();

	/* Clear the input buffer - we are done with the current command */
	memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);

	status = ioread16(&pcch_hdr->status);
	if (status != CMD_COMPLETE) {
		pr_debug("target: FAILED for cpu %d, with status: 0x%x\n",
			cpu, status);
		goto cmd_incomplete;
	}
	iowrite16(0, &pcch_hdr->status);

	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
	pr_debug("target: was SUCCESSFUL for cpu %d\n", cpu);
	spin_unlock(&pcc_lock);

	return 0;

cmd_incomplete:
	freqs.new = freqs.old;
	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
	iowrite16(0, &pcch_hdr->status);
	spin_unlock(&pcc_lock);
	return -EINVAL;
}

static int pcc_get_offset(int cpu)
{
	acpi_status status;
	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
	union acpi_object *pccp, *offset;
	struct pcc_cpu *pcc_cpu_data;
	struct acpi_processor *pr;
	int ret = 0;

	pr = per_cpu(processors, cpu);
	pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);

	if (!pr)
		return -ENODEV;

	status = acpi_evaluate_object(pr->handle, "PCCP", NULL, &buffer);
	if (ACPI_FAILURE(status))
		return -ENODEV;

	pccp = buffer.pointer;
	if (!pccp || pccp->type != ACPI_TYPE_PACKAGE) {
		ret = -ENODEV;
		goto out_free;
	};

	offset = &(pccp->package.elements[0]);
	if (!offset || offset->type != ACPI_TYPE_INTEGER) {
		ret = -ENODEV;
		goto out_free;
	}

	pcc_cpu_data->input_offset = offset->integer.value;

	offset = &(pccp->package.elements[1]);
	if (!offset || offset->type != ACPI_TYPE_INTEGER) {
		ret = -ENODEV;
		goto out_free;
	}

	pcc_cpu_data->output_offset = offset->integer.value;

	memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
	memset_io((pcch_virt_addr + pcc_cpu_data->output_offset), 0, BUF_SZ);

	pr_debug("pcc_get_offset: for CPU %d: pcc_cpu_data "
		"input_offset: 0x%x, pcc_cpu_data output_offset: 0x%x\n",
		cpu, pcc_cpu_data->input_offset, pcc_cpu_data->output_offset);
out_free:
	kfree(buffer.pointer);
	return ret;
}

static int __init pcc_cpufreq_do_osc(acpi_handle *handle)
{
	acpi_status status;
	struct acpi_object_list input;
	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
	union acpi_object in_params[4];
	union acpi_object *out_obj;
	u32 capabilities[2];
	u32 errors;
	u32 supported;
	int ret = 0;

	input.count = 4;
	input.pointer = in_params;
	in_params[0].type               = ACPI_TYPE_BUFFER;
	in_params[0].buffer.length      = 16;
	in_params[0].buffer.pointer     = OSC_UUID;
	in_params[1].type               = ACPI_TYPE_INTEGER;
	in_params[1].integer.value      = 1;
	in_params[2].type               = ACPI_TYPE_INTEGER;
	in_params[2].integer.value      = 2;
	in_params[3].type               = ACPI_TYPE_BUFFER;
	in_params[3].buffer.length      = 8;
	in_params[3].buffer.pointer     = (u8 *)&capabilities;

	capabilities[0] = OSC_QUERY_ENABLE;
	capabilities[1] = 0x1;

	status = acpi_evaluate_object(*handle, "_OSC", &input, &output);
	if (ACPI_FAILURE(status))
		return -ENODEV;

	if (!output.length)
		return -ENODEV;

	out_obj = output.pointer;
	if (out_obj->type != ACPI_TYPE_BUFFER) {
		ret = -ENODEV;
		goto out_free;
	}

	errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
	if (errors) {
		ret = -ENODEV;
		goto out_free;
	}

	supported = *((u32 *)(out_obj->buffer.pointer + 4));
	if (!(supported & 0x1)) {
		ret = -ENODEV;
		goto out_free;
	}

	kfree(output.pointer);
	capabilities[0] = 0x0;
	capabilities[1] = 0x1;

	status = acpi_evaluate_object(*handle, "_OSC", &input, &output);
	if (ACPI_FAILURE(status))
		return -ENODEV;

	if (!output.length)
		return -ENODEV;

	out_obj = output.pointer;
	if (out_obj->type != ACPI_TYPE_BUFFER) {
		ret = -ENODEV;
		goto out_free;
	}

	errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
	if (errors) {
		ret = -ENODEV;
		goto out_free;
	}

	supported = *((u32 *)(out_obj->buffer.pointer + 4));
	if (!(supported & 0x1)) {
		ret = -ENODEV;
		goto out_free;
	}

out_free:
	kfree(output.pointer);
	return ret;
}

static int __init pcc_cpufreq_probe(void)
{
	acpi_status status;
	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
	struct pcc_memory_resource *mem_resource;
	struct pcc_register_resource *reg_resource;
	union acpi_object *out_obj, *member;
	acpi_handle handle, osc_handle;
	int ret = 0;

	status = acpi_get_handle(NULL, "\\_SB", &handle);
	if (ACPI_FAILURE(status))
		return -ENODEV;

	if (!acpi_has_method(handle, "PCCH"))
		return -ENODEV;

	status = acpi_get_handle(handle, "_OSC", &osc_handle);
	if (ACPI_SUCCESS(status)) {
		ret = pcc_cpufreq_do_osc(&osc_handle);
		if (ret)
			pr_debug("probe: _OSC evaluation did not succeed\n");
		/* Firmware's use of _OSC is optional */
		ret = 0;
	}

	status = acpi_evaluate_object(handle, "PCCH", NULL, &output);
	if (ACPI_FAILURE(status))
		return -ENODEV;

	out_obj = output.pointer;
	if (out_obj->type != ACPI_TYPE_PACKAGE) {
		ret = -ENODEV;
		goto out_free;
	}

	member = &out_obj->package.elements[0];
	if (member->type != ACPI_TYPE_BUFFER) {
		ret = -ENODEV;
		goto out_free;
	}

	mem_resource = (struct pcc_memory_resource *)member->buffer.pointer;

	pr_debug("probe: mem_resource descriptor: 0x%x,"
		" length: %d, space_id: %d, resource_usage: %d,"
		" type_specific: %d, granularity: 0x%llx,"
		" minimum: 0x%llx, maximum: 0x%llx,"
		" translation_offset: 0x%llx, address_length: 0x%llx\n",
		mem_resource->descriptor, mem_resource->length,
		mem_resource->space_id, mem_resource->resource_usage,
		mem_resource->type_specific, mem_resource->granularity,
		mem_resource->minimum, mem_resource->maximum,
		mem_resource->translation_offset,
		mem_resource->address_length);

	if (mem_resource->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) {
		ret = -ENODEV;
		goto out_free;
	}

	pcch_virt_addr = ioremap_nocache(mem_resource->minimum,
					mem_resource->address_length);
	if (pcch_virt_addr == NULL) {
		pr_debug("probe: could not map shared mem region\n");
		ret = -ENOMEM;
		goto out_free;
	}
	pcch_hdr = pcch_virt_addr;

	pr_debug("probe: PCCH header (virtual) addr: 0x%p\n", pcch_hdr);
	pr_debug("probe: PCCH header is at physical address: 0x%llx,"
		" signature: 0x%x, length: %d bytes, major: %d, minor: %d,"
		" supported features: 0x%x, command field: 0x%x,"
		" status field: 0x%x, nominal latency: %d us\n",
		mem_resource->minimum, ioread32(&pcch_hdr->signature),
		ioread16(&pcch_hdr->length), ioread8(&pcch_hdr->major),
		ioread8(&pcch_hdr->minor), ioread32(&pcch_hdr->features),
		ioread16(&pcch_hdr->command), ioread16(&pcch_hdr->status),
		ioread32(&pcch_hdr->latency));

	pr_debug("probe: min time between commands: %d us,"
		" max time between commands: %d us,"
		" nominal CPU frequency: %d MHz,"
		" minimum CPU frequency: %d MHz,"
		" minimum CPU frequency without throttling: %d MHz\n",
		ioread32(&pcch_hdr->minimum_time),
		ioread32(&pcch_hdr->maximum_time),
		ioread32(&pcch_hdr->nominal),
		ioread32(&pcch_hdr->throttled_frequency),
		ioread32(&pcch_hdr->minimum_frequency));

	member = &out_obj->package.elements[1];
	if (member->type != ACPI_TYPE_BUFFER) {
		ret = -ENODEV;
		goto pcch_free;
	}

	reg_resource = (struct pcc_register_resource *)member->buffer.pointer;

	doorbell.space_id = reg_resource->space_id;
	doorbell.bit_width = reg_resource->bit_width;
	doorbell.bit_offset = reg_resource->bit_offset;
	doorbell.access_width = 64;
	doorbell.address = reg_resource->address;

	pr_debug("probe: doorbell: space_id is %d, bit_width is %d, "
		"bit_offset is %d, access_width is %d, address is 0x%llx\n",
		doorbell.space_id, doorbell.bit_width, doorbell.bit_offset,
		doorbell.access_width, reg_resource->address);

	member = &out_obj->package.elements[2];
	if (member->type != ACPI_TYPE_INTEGER) {
		ret = -ENODEV;
		goto pcch_free;
	}

	doorbell_preserve = member->integer.value;

	member = &out_obj->package.elements[3];
	if (member->type != ACPI_TYPE_INTEGER) {
		ret = -ENODEV;
		goto pcch_free;
	}

	doorbell_write = member->integer.value;

	pr_debug("probe: doorbell_preserve: 0x%llx,"
		" doorbell_write: 0x%llx\n",
		doorbell_preserve, doorbell_write);

	pcc_cpu_info = alloc_percpu(struct pcc_cpu);
	if (!pcc_cpu_info) {
		ret = -ENOMEM;
		goto pcch_free;
	}

	printk(KERN_DEBUG "pcc-cpufreq: (v%s) driver loaded with frequency"
	       " limits: %d MHz, %d MHz\n", PCC_VERSION,
	       ioread32(&pcch_hdr->minimum_frequency),
	       ioread32(&pcch_hdr->nominal));
	kfree(output.pointer);
	return ret;
pcch_free:
	pcc_clear_mapping();
out_free:
	kfree(output.pointer);
	return ret;
}

static int pcc_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
	unsigned int cpu = policy->cpu;
	unsigned int result = 0;

	if (!pcch_virt_addr) {
		result = -1;
		goto out;
	}

	result = pcc_get_offset(cpu);
	if (result) {
		pr_debug("init: PCCP evaluation failed\n");
		goto out;
	}

	policy->max = policy->cpuinfo.max_freq =
		ioread32(&pcch_hdr->nominal) * 1000;
	policy->min = policy->cpuinfo.min_freq =
		ioread32(&pcch_hdr->minimum_frequency) * 1000;

	pr_debug("init: policy->max is %d, policy->min is %d\n",
		policy->max, policy->min);
out:
	return result;
}

static int pcc_cpufreq_cpu_exit(struct cpufreq_policy *policy)
{
	return 0;
}

static struct cpufreq_driver pcc_cpufreq_driver = {
	.flags = CPUFREQ_CONST_LOOPS,
	.get = pcc_get_freq,
	.verify = pcc_cpufreq_verify,
	.target = pcc_cpufreq_target,
	.init = pcc_cpufreq_cpu_init,
	.exit = pcc_cpufreq_cpu_exit,
	.name = "pcc-cpufreq",
};

static int __init pcc_cpufreq_init(void)
{
	int ret;

	if (acpi_disabled)
		return 0;

	ret = pcc_cpufreq_probe();
	if (ret) {
		pr_debug("pcc_cpufreq_init: PCCH evaluation failed\n");
		return ret;
	}

	ret = cpufreq_register_driver(&pcc_cpufreq_driver);

	return ret;
}

static void __exit pcc_cpufreq_exit(void)
{
	cpufreq_unregister_driver(&pcc_cpufreq_driver);

	pcc_clear_mapping();

	free_percpu(pcc_cpu_info);
}

MODULE_AUTHOR("Matthew Garrett, Naga Chumbalkar");
MODULE_VERSION(PCC_VERSION);
MODULE_DESCRIPTION("Processor Clocking Control interface driver");
MODULE_LICENSE("GPL");

late_initcall(pcc_cpufreq_init);
module_exit(pcc_cpufreq_exit);
Commit	Line	Data
0f1d683f NC	1	/*
	2	* pcc-cpufreq.c - Processor Clocking Control firmware cpufreq interface
	3	*
	4	* Copyright (C) 2009 Red Hat, Matthew Garrett <mjg@redhat.com>
	5	* Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
	6	* Nagananda Chumbalkar <nagananda.chumbalkar@hp.com>
	7	*
	8	* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License as published by
	12	* the Free Software Foundation; version 2 of the License.
	13	*
	14	* This program is distributed in the hope that it will be useful, but
	15	* WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or NON
	17	* INFRINGEMENT. See the GNU General Public License for more details.
	18	*
	19	* You should have received a copy of the GNU General Public License along
	20	* with this program; if not, write to the Free Software Foundation, Inc.,
	21	* 675 Mass Ave, Cambridge, MA 02139, USA.
	22	*
	23	* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	24	*/
	25
	26	#include <linux/kernel.h>
	27	#include <linux/module.h>
	28	#include <linux/init.h>
	29	#include <linux/smp.h>
	30	#include <linux/sched.h>
	31	#include <linux/cpufreq.h>
	32	#include <linux/compiler.h>
5a0e3ad6	33	#include <linux/slab.h>
0f1d683f NC	34
	35	#include <linux/acpi.h>
	36	#include <linux/io.h>
	37	#include <linux/spinlock.h>
	38	#include <linux/uaccess.h>
	39
	40	#include <acpi/processor.h>
	41
904cc1e6	42	#define PCC_VERSION "1.10.00"
0f1d683f NC	43	#define POLL_LOOPS 300
	44
	45	#define CMD_COMPLETE 0x1
	46	#define CMD_GET_FREQ 0x0
	47	#define CMD_SET_FREQ 0x1
	48
	49	#define BUF_SZ 4
	50
0f1d683f NC	51	struct pcc_register_resource {
	52	u8 descriptor;
	53	u16 length;
	54	u8 space_id;
	55	u8 bit_width;
	56	u8 bit_offset;
	57	u8 access_size;
	58	u64 address;
	59	} __attribute__ ((packed));
	60
	61	struct pcc_memory_resource {
	62	u8 descriptor;
	63	u16 length;
	64	u8 space_id;
	65	u8 resource_usage;
	66	u8 type_specific;
	67	u64 granularity;
	68	u64 minimum;
	69	u64 maximum;
	70	u64 translation_offset;
	71	u64 address_length;
	72	} __attribute__ ((packed));
	73
	74	static struct cpufreq_driver pcc_cpufreq_driver;
	75
	76	struct pcc_header {
	77	u32 signature;
	78	u16 length;
	79	u8 major;
	80	u8 minor;
	81	u32 features;
	82	u16 command;
	83	u16 status;
	84	u32 latency;
	85	u32 minimum_time;
	86	u32 maximum_time;
	87	u32 nominal;
	88	u32 throttled_frequency;
	89	u32 minimum_frequency;
	90	};
	91
	92	static void __iomem *pcch_virt_addr;
	93	static struct pcc_header __iomem *pcch_hdr;
	94
	95	static DEFINE_SPINLOCK(pcc_lock);
	96
	97	static struct acpi_generic_address doorbell;
	98
	99	static u64 doorbell_preserve;
	100	static u64 doorbell_write;
	101
904cc1e6	102	static u8 OSC_UUID[16] = {0x9F, 0x2C, 0x9B, 0x63, 0x91, 0x70, 0x1f, 0x49,
0f1d683f NC	103	0xBB, 0x4F, 0xA5, 0x98, 0x2F, 0xA1, 0xB5, 0x46};
	104
	105	struct pcc_cpu {
	106	u32 input_offset;
	107	u32 output_offset;
	108	};
	109
a3da3234	110	static struct pcc_cpu __percpu *pcc_cpu_info;
0f1d683f NC	111
	112	static int pcc_cpufreq_verify(struct cpufreq_policy *policy)
	113	{
be49e346	114	cpufreq_verify_within_cpu_limits(policy);
0f1d683f NC	115	return 0;
	116	}
	117
	118	static inline void pcc_cmd(void)
	119	{
	120	u64 doorbell_value;
	121	int i;
	122
	123	acpi_read(&doorbell_value, &doorbell);
	124	acpi_write((doorbell_value & doorbell_preserve) \| doorbell_write,
	125	&doorbell);
	126
	127	for (i = 0; i < POLL_LOOPS; i++) {
	128	if (ioread16(&pcch_hdr->status) & CMD_COMPLETE)
	129	break;
	130	}
	131	}
	132
	133	static inline void pcc_clear_mapping(void)
	134	{
	135	if (pcch_virt_addr)
	136	iounmap(pcch_virt_addr);
	137	pcch_virt_addr = NULL;
	138	}
	139
	140	static unsigned int pcc_get_freq(unsigned int cpu)
	141	{
	142	struct pcc_cpu *pcc_cpu_data;
	143	unsigned int curr_freq;
	144	unsigned int freq_limit;
	145	u16 status;
	146	u32 input_buffer;
	147	u32 output_buffer;
	148
	149	spin_lock(&pcc_lock);
	150
2d06d8c4	151	pr_debug("get: get_freq for CPU %d\n", cpu);
0f1d683f NC	152	pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
	153
	154	input_buffer = 0x1;
	155	iowrite32(input_buffer,
	156	(pcch_virt_addr + pcc_cpu_data->input_offset));
	157	iowrite16(CMD_GET_FREQ, &pcch_hdr->command);
	158
	159	pcc_cmd();
	160
	161	output_buffer =
	162	ioread32(pcch_virt_addr + pcc_cpu_data->output_offset);
	163
	164	/* Clear the input buffer - we are done with the current command */
	165	memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
	166
	167	status = ioread16(&pcch_hdr->status);
	168	if (status != CMD_COMPLETE) {
2d06d8c4	169	pr_debug("get: FAILED: for CPU %d, status is %d\n",
0f1d683f NC	170	cpu, status);
	171	goto cmd_incomplete;
	172	}
	173	iowrite16(0, &pcch_hdr->status);
	174	curr_freq = (((ioread32(&pcch_hdr->nominal) * (output_buffer & 0xff))
	175	/ 100) * 1000);
	176
2d06d8c4 DB	177	pr_debug("get: SUCCESS: (virtual) output_offset for cpu %d is "
2d06d8c4 DB	178	"0x%p, contains a value of: 0x%x. Speed is: %d MHz\n",
0f1d683f NC	179	cpu, (pcch_virt_addr + pcc_cpu_data->output_offset),
	180	output_buffer, curr_freq);
	181
	182	freq_limit = (output_buffer >> 8) & 0xff;
	183	if (freq_limit != 0xff) {
2d06d8c4	184	pr_debug("get: frequency for cpu %d is being temporarily"
0f1d683f NC	185	" capped at %d\n", cpu, curr_freq);
	186	}
	187
	188	spin_unlock(&pcc_lock);
	189	return curr_freq;
	190
	191	cmd_incomplete:
	192	iowrite16(0, &pcch_hdr->status);
	193	spin_unlock(&pcc_lock);
1f858ef2	194	return 0;
0f1d683f NC	195	}
	196
	197	static int pcc_cpufreq_target(struct cpufreq_policy *policy,
	198	unsigned int target_freq,
	199	unsigned int relation)
	200	{
	201	struct pcc_cpu *pcc_cpu_data;
	202	struct cpufreq_freqs freqs;
	203	u16 status;
	204	u32 input_buffer;
	205	int cpu;
	206
	207	spin_lock(&pcc_lock);
	208	cpu = policy->cpu;
	209	pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
	210
2d06d8c4 DB	211	pr_debug("target: CPU %d should go to target freq: %d "
2d06d8c4 DB	212	"(virtual) input_offset is 0x%p\n",
0f1d683f NC	213	cpu, target_freq,
	214	(pcch_virt_addr + pcc_cpu_data->input_offset));
	215
	216	freqs.new = target_freq;
b43a7ffb	217	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
0f1d683f NC	218
	219	input_buffer = 0x1 \| (((target_freq * 100)
	220	/ (ioread32(&pcch_hdr->nominal) * 1000)) << 8);
	221	iowrite32(input_buffer,
	222	(pcch_virt_addr + pcc_cpu_data->input_offset));
	223	iowrite16(CMD_SET_FREQ, &pcch_hdr->command);
	224
	225	pcc_cmd();
	226
	227	/* Clear the input buffer - we are done with the current command */
	228	memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
	229
	230	status = ioread16(&pcch_hdr->status);
	231	if (status != CMD_COMPLETE) {
2d06d8c4	232	pr_debug("target: FAILED for cpu %d, with status: 0x%x\n",
0f1d683f NC	233	cpu, status);
	234	goto cmd_incomplete;
	235	}
	236	iowrite16(0, &pcch_hdr->status);
	237
b43a7ffb	238	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
2d06d8c4	239	pr_debug("target: was SUCCESSFUL for cpu %d\n", cpu);
0f1d683f NC	240	spin_unlock(&pcc_lock);
	241
	242	return 0;
	243
	244	cmd_incomplete:
f77f1465 VK	245	freqs.new = freqs.old;
f77f1465 VK	246	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
0f1d683f NC	247	iowrite16(0, &pcch_hdr->status);
	248	spin_unlock(&pcc_lock);
	249	return -EINVAL;
	250	}
	251
	252	static int pcc_get_offset(int cpu)
	253	{
	254	acpi_status status;
	255	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
	256	union acpi_object pccp, offset;
	257	struct pcc_cpu *pcc_cpu_data;
	258	struct acpi_processor *pr;
	259	int ret = 0;
	260
	261	pr = per_cpu(processors, cpu);
	262	pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
	263
e71f5cc4 NC	264	if (!pr)
	265	return -ENODEV;
	266
0f1d683f NC	267	status = acpi_evaluate_object(pr->handle, "PCCP", NULL, &buffer);
	268	if (ACPI_FAILURE(status))
	269	return -ENODEV;
	270
	271	pccp = buffer.pointer;
	272	if (!pccp \|\| pccp->type != ACPI_TYPE_PACKAGE) {
	273	ret = -ENODEV;
	274	goto out_free;
	275	};
	276
	277	offset = &(pccp->package.elements[0]);
	278	if (!offset \|\| offset->type != ACPI_TYPE_INTEGER) {
	279	ret = -ENODEV;
	280	goto out_free;
	281	}
	282
	283	pcc_cpu_data->input_offset = offset->integer.value;
	284
	285	offset = &(pccp->package.elements[1]);
	286	if (!offset \|\| offset->type != ACPI_TYPE_INTEGER) {
	287	ret = -ENODEV;
	288	goto out_free;
	289	}
	290
	291	pcc_cpu_data->output_offset = offset->integer.value;
	292
	293	memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
	294	memset_io((pcch_virt_addr + pcc_cpu_data->output_offset), 0, BUF_SZ);
	295
2d06d8c4	296	pr_debug("pcc_get_offset: for CPU %d: pcc_cpu_data "
0f1d683f NC	297	"input_offset: 0x%x, pcc_cpu_data output_offset: 0x%x\n",
	298	cpu, pcc_cpu_data->input_offset, pcc_cpu_data->output_offset);
	299	out_free:
	300	kfree(buffer.pointer);
	301	return ret;
	302	}
	303
	304	static int __init pcc_cpufreq_do_osc(acpi_handle *handle)
	305	{
	306	acpi_status status;
	307	struct acpi_object_list input;
	308	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
	309	union acpi_object in_params[4];
	310	union acpi_object *out_obj;
	311	u32 capabilities[2];
	312	u32 errors;
	313	u32 supported;
	314	int ret = 0;
	315
0f1d683f NC	316	input.count = 4;
	317	input.pointer = in_params;
	318	in_params[0].type = ACPI_TYPE_BUFFER;
	319	in_params[0].buffer.length = 16;
	320	in_params[0].buffer.pointer = OSC_UUID;
	321	in_params[1].type = ACPI_TYPE_INTEGER;
	322	in_params[1].integer.value = 1;
	323	in_params[2].type = ACPI_TYPE_INTEGER;
	324	in_params[2].integer.value = 2;
	325	in_params[3].type = ACPI_TYPE_BUFFER;
	326	in_params[3].buffer.length = 8;
	327	in_params[3].buffer.pointer = (u8 *)&capabilities;
	328
	329	capabilities[0] = OSC_QUERY_ENABLE;
	330	capabilities[1] = 0x1;
	331
	332	status = acpi_evaluate_object(*handle, "_OSC", &input, &output);
	333	if (ACPI_FAILURE(status))
	334	return -ENODEV;
	335
	336	if (!output.length)
	337	return -ENODEV;
	338
	339	out_obj = output.pointer;
	340	if (out_obj->type != ACPI_TYPE_BUFFER) {
	341	ret = -ENODEV;
	342	goto out_free;
	343	}
	344
	345	errors = ((u32 )out_obj->buffer.pointer) & ~(1 << 0);
	346	if (errors) {
	347	ret = -ENODEV;
	348	goto out_free;
	349	}
	350
	351	supported = ((u32 )(out_obj->buffer.pointer + 4));
	352	if (!(supported & 0x1)) {
	353	ret = -ENODEV;
	354	goto out_free;
	355	}
	356
	357	kfree(output.pointer);
	358	capabilities[0] = 0x0;
	359	capabilities[1] = 0x1;
	360
	361	status = acpi_evaluate_object(*handle, "_OSC", &input, &output);
	362	if (ACPI_FAILURE(status))
	363	return -ENODEV;
	364
	365	if (!output.length)
	366	return -ENODEV;
	367
	368	out_obj = output.pointer;
36829306 PE	369	if (out_obj->type != ACPI_TYPE_BUFFER) {
	370	ret = -ENODEV;
	371	goto out_free;
	372	}
0f1d683f NC	373
0f1d683f NC	374	errors = ((u32 )out_obj->buffer.pointer) & ~(1 << 0);
36829306 PE	375	if (errors) {
	376	ret = -ENODEV;
	377	goto out_free;
	378	}
0f1d683f NC	379
0f1d683f NC	380	supported = ((u32 )(out_obj->buffer.pointer + 4));
36829306 PE	381	if (!(supported & 0x1)) {
	382	ret = -ENODEV;
	383	goto out_free;
	384	}
0f1d683f NC	385
	386	out_free:
	387	kfree(output.pointer);
	388	return ret;
	389	}
	390
	391	static int __init pcc_cpufreq_probe(void)
	392	{
	393	acpi_status status;
	394	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
	395	struct pcc_memory_resource *mem_resource;
	396	struct pcc_register_resource *reg_resource;
	397	union acpi_object out_obj, member;
7ca9b574	398	acpi_handle handle, osc_handle;
0f1d683f NC	399	int ret = 0;
	400
	401	status = acpi_get_handle(NULL, "\\_SB", &handle);
	402	if (ACPI_FAILURE(status))
	403	return -ENODEV;
	404
7ca9b574	405	if (!acpi_has_method(handle, "PCCH"))
47f8bcf3 MG	406	return -ENODEV;
47f8bcf3 MG	407
0f1d683f NC	408	status = acpi_get_handle(handle, "_OSC", &osc_handle);
	409	if (ACPI_SUCCESS(status)) {
	410	ret = pcc_cpufreq_do_osc(&osc_handle);
	411	if (ret)
2d06d8c4	412	pr_debug("probe: _OSC evaluation did not succeed\n");
0f1d683f NC	413	/* Firmware's use of _OSC is optional */
	414	ret = 0;
	415	}
	416
	417	status = acpi_evaluate_object(handle, "PCCH", NULL, &output);
	418	if (ACPI_FAILURE(status))
	419	return -ENODEV;
	420
	421	out_obj = output.pointer;
	422	if (out_obj->type != ACPI_TYPE_PACKAGE) {
	423	ret = -ENODEV;
	424	goto out_free;
	425	}
	426
	427	member = &out_obj->package.elements[0];
	428	if (member->type != ACPI_TYPE_BUFFER) {
	429	ret = -ENODEV;
	430	goto out_free;
	431	}
	432
	433	mem_resource = (struct pcc_memory_resource *)member->buffer.pointer;
	434
2d06d8c4	435	pr_debug("probe: mem_resource descriptor: 0x%x,"
0f1d683f NC	436	" length: %d, space_id: %d, resource_usage: %d,"
	437	" type_specific: %d, granularity: 0x%llx,"
	438	" minimum: 0x%llx, maximum: 0x%llx,"
	439	" translation_offset: 0x%llx, address_length: 0x%llx\n",
	440	mem_resource->descriptor, mem_resource->length,
	441	mem_resource->space_id, mem_resource->resource_usage,
	442	mem_resource->type_specific, mem_resource->granularity,
	443	mem_resource->minimum, mem_resource->maximum,
	444	mem_resource->translation_offset,
	445	mem_resource->address_length);
	446
	447	if (mem_resource->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) {
	448	ret = -ENODEV;
	449	goto out_free;
	450	}
	451
	452	pcch_virt_addr = ioremap_nocache(mem_resource->minimum,
	453	mem_resource->address_length);
	454	if (pcch_virt_addr == NULL) {
2d06d8c4	455	pr_debug("probe: could not map shared mem region\n");
d06a8a4f	456	ret = -ENOMEM;
0f1d683f NC	457	goto out_free;
	458	}
	459	pcch_hdr = pcch_virt_addr;
	460
2d06d8c4 DB	461	pr_debug("probe: PCCH header (virtual) addr: 0x%p\n", pcch_hdr);
2d06d8c4 DB	462	pr_debug("probe: PCCH header is at physical address: 0x%llx,"
0f1d683f NC	463	" signature: 0x%x, length: %d bytes, major: %d, minor: %d,"
	464	" supported features: 0x%x, command field: 0x%x,"
	465	" status field: 0x%x, nominal latency: %d us\n",
	466	mem_resource->minimum, ioread32(&pcch_hdr->signature),
	467	ioread16(&pcch_hdr->length), ioread8(&pcch_hdr->major),
	468	ioread8(&pcch_hdr->minor), ioread32(&pcch_hdr->features),
	469	ioread16(&pcch_hdr->command), ioread16(&pcch_hdr->status),
	470	ioread32(&pcch_hdr->latency));
	471
2d06d8c4	472	pr_debug("probe: min time between commands: %d us,"
0f1d683f NC	473	" max time between commands: %d us,"
	474	" nominal CPU frequency: %d MHz,"
	475	" minimum CPU frequency: %d MHz,"
	476	" minimum CPU frequency without throttling: %d MHz\n",
	477	ioread32(&pcch_hdr->minimum_time),
	478	ioread32(&pcch_hdr->maximum_time),
	479	ioread32(&pcch_hdr->nominal),
	480	ioread32(&pcch_hdr->throttled_frequency),
	481	ioread32(&pcch_hdr->minimum_frequency));
	482
	483	member = &out_obj->package.elements[1];
	484	if (member->type != ACPI_TYPE_BUFFER) {
	485	ret = -ENODEV;
	486	goto pcch_free;
	487	}
	488
	489	reg_resource = (struct pcc_register_resource *)member->buffer.pointer;
	490
	491	doorbell.space_id = reg_resource->space_id;
	492	doorbell.bit_width = reg_resource->bit_width;
	493	doorbell.bit_offset = reg_resource->bit_offset;
	494	doorbell.access_width = 64;
	495	doorbell.address = reg_resource->address;
	496
2d06d8c4	497	pr_debug("probe: doorbell: space_id is %d, bit_width is %d, "
0f1d683f NC	498	"bit_offset is %d, access_width is %d, address is 0x%llx\n",
	499	doorbell.space_id, doorbell.bit_width, doorbell.bit_offset,
	500	doorbell.access_width, reg_resource->address);
	501
	502	member = &out_obj->package.elements[2];
	503	if (member->type != ACPI_TYPE_INTEGER) {
	504	ret = -ENODEV;
	505	goto pcch_free;
	506	}
	507
	508	doorbell_preserve = member->integer.value;
	509
	510	member = &out_obj->package.elements[3];
	511	if (member->type != ACPI_TYPE_INTEGER) {
	512	ret = -ENODEV;
	513	goto pcch_free;
	514	}
	515
	516	doorbell_write = member->integer.value;
	517
2d06d8c4	518	pr_debug("probe: doorbell_preserve: 0x%llx,"
0f1d683f NC	519	" doorbell_write: 0x%llx\n",
	520	doorbell_preserve, doorbell_write);
	521
	522	pcc_cpu_info = alloc_percpu(struct pcc_cpu);
	523	if (!pcc_cpu_info) {
	524	ret = -ENOMEM;
	525	goto pcch_free;
	526	}
	527
	528	printk(KERN_DEBUG "pcc-cpufreq: (v%s) driver loaded with frequency"
	529	" limits: %d MHz, %d MHz\n", PCC_VERSION,
	530	ioread32(&pcch_hdr->minimum_frequency),
	531	ioread32(&pcch_hdr->nominal));
	532	kfree(output.pointer);
	533	return ret;
	534	pcch_free:
	535	pcc_clear_mapping();
	536	out_free:
	537	kfree(output.pointer);
	538	return ret;
	539	}
	540
	541	static int pcc_cpufreq_cpu_init(struct cpufreq_policy *policy)
	542	{
	543	unsigned int cpu = policy->cpu;
	544	unsigned int result = 0;
	545
	546	if (!pcch_virt_addr) {
	547	result = -1;
179ee434	548	goto out;
0f1d683f NC	549	}
	550
	551	result = pcc_get_offset(cpu);
	552	if (result) {
2d06d8c4	553	pr_debug("init: PCCP evaluation failed\n");
179ee434	554	goto out;
0f1d683f NC	555	}
	556
	557	policy->max = policy->cpuinfo.max_freq =
	558	ioread32(&pcch_hdr->nominal) * 1000;
	559	policy->min = policy->cpuinfo.min_freq =
	560	ioread32(&pcch_hdr->minimum_frequency) * 1000;
179ee434	561
2d06d8c4	562	pr_debug("init: policy->max is %d, policy->min is %d\n",
0f1d683f	563	policy->max, policy->min);
179ee434	564	out:
0f1d683f NC	565	return result;
	566	}
	567
	568	static int pcc_cpufreq_cpu_exit(struct cpufreq_policy *policy)
	569	{
	570	return 0;
	571	}
	572
	573	static struct cpufreq_driver pcc_cpufreq_driver = {
	574	.flags = CPUFREQ_CONST_LOOPS,
	575	.get = pcc_get_freq,
	576	.verify = pcc_cpufreq_verify,
	577	.target = pcc_cpufreq_target,
	578	.init = pcc_cpufreq_cpu_init,
	579	.exit = pcc_cpufreq_cpu_exit,
	580	.name = "pcc-cpufreq",
0f1d683f NC	581	};
	582
	583	static int __init pcc_cpufreq_init(void)
	584	{
	585	int ret;
	586
	587	if (acpi_disabled)
	588	return 0;
	589
	590	ret = pcc_cpufreq_probe();
	591	if (ret) {
2d06d8c4	592	pr_debug("pcc_cpufreq_init: PCCH evaluation failed\n");
0f1d683f NC	593	return ret;
	594	}
	595
	596	ret = cpufreq_register_driver(&pcc_cpufreq_driver);
	597
	598	return ret;
	599	}
	600
	601	static void __exit pcc_cpufreq_exit(void)
	602	{
	603	cpufreq_unregister_driver(&pcc_cpufreq_driver);
	604
	605	pcc_clear_mapping();
	606
	607	free_percpu(pcc_cpu_info);
	608	}
	609
	610	MODULE_AUTHOR("Matthew Garrett, Naga Chumbalkar");
	611	MODULE_VERSION(PCC_VERSION);
	612	MODULE_DESCRIPTION("Processor Clocking Control interface driver");
	613	MODULE_LICENSE("GPL");
	614
	615	late_initcall(pcc_cpufreq_init);
	616	module_exit(pcc_cpufreq_exit);