[mirror_ubuntu-zesty-kernel.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;

	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.old = policy->cur;
	freqs.new = target_freq;
	cpufreq_freq_transition_begin(policy, &freqs);
	spin_lock(&pcc_lock);

	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);
	iowrite16(0, &pcch_hdr->status);

	cpufreq_freq_transition_end(policy, &freqs, status != CMD_COMPLETE);
	spin_unlock(&pcc_lock);

	if (status != CMD_COMPLETE) {
		pr_debug("target: FAILED for cpu %d, with status: 0x%x\n",
			cpu, status);
		return -EINVAL;
	}

	pr_debug("target: was SUCCESSFUL for cpu %d\n", cpu);

	return 0;
}

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 = 4;
	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);
}

static const struct acpi_device_id processor_device_ids[] = {
	{ACPI_PROCESSOR_OBJECT_HID, },
	{ACPI_PROCESSOR_DEVICE_HID, },
	{},
};
MODULE_DEVICE_TABLE(acpi, processor_device_ids);

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
0f1d683f NC	207	cpu = policy->cpu;
	208	pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
	209
2d06d8c4 DB	210	pr_debug("target: CPU %d should go to target freq: %d "
2d06d8c4 DB	211	"(virtual) input_offset is 0x%p\n",
0f1d683f NC	212	cpu, target_freq,
	213	(pcch_virt_addr + pcc_cpu_data->input_offset));
	214
ab1b1c4e	215	freqs.old = policy->cur;
0f1d683f	216	freqs.new = target_freq;
8fec051e	217	cpufreq_freq_transition_begin(policy, &freqs);
e65b5ddb	218	spin_lock(&pcc_lock);
0f1d683f NC	219
	220	input_buffer = 0x1 \| (((target_freq * 100)
	221	/ (ioread32(&pcch_hdr->nominal) * 1000)) << 8);
	222	iowrite32(input_buffer,
	223	(pcch_virt_addr + pcc_cpu_data->input_offset));
	224	iowrite16(CMD_SET_FREQ, &pcch_hdr->command);
	225
	226	pcc_cmd();
	227
	228	/* Clear the input buffer - we are done with the current command */
	229	memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
	230
	231	status = ioread16(&pcch_hdr->status);
ab1b1c4e VK	232	iowrite16(0, &pcch_hdr->status);
ab1b1c4e VK	233
8fec051e	234	cpufreq_freq_transition_end(policy, &freqs, status != CMD_COMPLETE);
ab1b1c4e VK	235	spin_unlock(&pcc_lock);
ab1b1c4e VK	236
0f1d683f	237	if (status != CMD_COMPLETE) {
2d06d8c4	238	pr_debug("target: FAILED for cpu %d, with status: 0x%x\n",
0f1d683f	239	cpu, status);
ab1b1c4e	240	return -EINVAL;
0f1d683f	241	}
0f1d683f	242
2d06d8c4	243	pr_debug("target: was SUCCESSFUL for cpu %d\n", cpu);
0f1d683f NC	244
0f1d683f NC	245	return 0;
0f1d683f NC	246	}
	247
	248	static int pcc_get_offset(int cpu)
	249	{
	250	acpi_status status;
	251	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
	252	union acpi_object pccp, offset;
	253	struct pcc_cpu *pcc_cpu_data;
	254	struct acpi_processor *pr;
	255	int ret = 0;
	256
	257	pr = per_cpu(processors, cpu);
	258	pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
	259
e71f5cc4 NC	260	if (!pr)
	261	return -ENODEV;
	262
0f1d683f NC	263	status = acpi_evaluate_object(pr->handle, "PCCP", NULL, &buffer);
	264	if (ACPI_FAILURE(status))
	265	return -ENODEV;
	266
	267	pccp = buffer.pointer;
	268	if (!pccp \|\| pccp->type != ACPI_TYPE_PACKAGE) {
	269	ret = -ENODEV;
	270	goto out_free;
	271	};
	272
	273	offset = &(pccp->package.elements[0]);
	274	if (!offset \|\| offset->type != ACPI_TYPE_INTEGER) {
	275	ret = -ENODEV;
	276	goto out_free;
	277	}
	278
	279	pcc_cpu_data->input_offset = offset->integer.value;
	280
	281	offset = &(pccp->package.elements[1]);
	282	if (!offset \|\| offset->type != ACPI_TYPE_INTEGER) {
	283	ret = -ENODEV;
	284	goto out_free;
	285	}
	286
	287	pcc_cpu_data->output_offset = offset->integer.value;
	288
	289	memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
	290	memset_io((pcch_virt_addr + pcc_cpu_data->output_offset), 0, BUF_SZ);
	291
2d06d8c4	292	pr_debug("pcc_get_offset: for CPU %d: pcc_cpu_data "
0f1d683f NC	293	"input_offset: 0x%x, pcc_cpu_data output_offset: 0x%x\n",
	294	cpu, pcc_cpu_data->input_offset, pcc_cpu_data->output_offset);
	295	out_free:
	296	kfree(buffer.pointer);
	297	return ret;
	298	}
	299
	300	static int __init pcc_cpufreq_do_osc(acpi_handle *handle)
	301	{
	302	acpi_status status;
	303	struct acpi_object_list input;
	304	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
	305	union acpi_object in_params[4];
	306	union acpi_object *out_obj;
	307	u32 capabilities[2];
	308	u32 errors;
	309	u32 supported;
	310	int ret = 0;
	311
0f1d683f NC	312	input.count = 4;
	313	input.pointer = in_params;
	314	in_params[0].type = ACPI_TYPE_BUFFER;
	315	in_params[0].buffer.length = 16;
	316	in_params[0].buffer.pointer = OSC_UUID;
	317	in_params[1].type = ACPI_TYPE_INTEGER;
	318	in_params[1].integer.value = 1;
	319	in_params[2].type = ACPI_TYPE_INTEGER;
	320	in_params[2].integer.value = 2;
	321	in_params[3].type = ACPI_TYPE_BUFFER;
	322	in_params[3].buffer.length = 8;
	323	in_params[3].buffer.pointer = (u8 *)&capabilities;
	324
	325	capabilities[0] = OSC_QUERY_ENABLE;
	326	capabilities[1] = 0x1;
	327
	328	status = acpi_evaluate_object(*handle, "_OSC", &input, &output);
	329	if (ACPI_FAILURE(status))
	330	return -ENODEV;
	331
	332	if (!output.length)
	333	return -ENODEV;
	334
	335	out_obj = output.pointer;
	336	if (out_obj->type != ACPI_TYPE_BUFFER) {
	337	ret = -ENODEV;
	338	goto out_free;
	339	}
	340
	341	errors = ((u32 )out_obj->buffer.pointer) & ~(1 << 0);
	342	if (errors) {
	343	ret = -ENODEV;
	344	goto out_free;
	345	}
	346
	347	supported = ((u32 )(out_obj->buffer.pointer + 4));
	348	if (!(supported & 0x1)) {
	349	ret = -ENODEV;
	350	goto out_free;
	351	}
	352
	353	kfree(output.pointer);
	354	capabilities[0] = 0x0;
	355	capabilities[1] = 0x1;
	356
	357	status = acpi_evaluate_object(*handle, "_OSC", &input, &output);
	358	if (ACPI_FAILURE(status))
	359	return -ENODEV;
	360
	361	if (!output.length)
	362	return -ENODEV;
	363
	364	out_obj = output.pointer;
36829306 PE	365	if (out_obj->type != ACPI_TYPE_BUFFER) {
	366	ret = -ENODEV;
	367	goto out_free;
	368	}
0f1d683f NC	369
0f1d683f NC	370	errors = ((u32 )out_obj->buffer.pointer) & ~(1 << 0);
36829306 PE	371	if (errors) {
	372	ret = -ENODEV;
	373	goto out_free;
	374	}
0f1d683f NC	375
0f1d683f NC	376	supported = ((u32 )(out_obj->buffer.pointer + 4));
36829306 PE	377	if (!(supported & 0x1)) {
	378	ret = -ENODEV;
	379	goto out_free;
	380	}
0f1d683f NC	381
	382	out_free:
	383	kfree(output.pointer);
	384	return ret;
	385	}
	386
	387	static int __init pcc_cpufreq_probe(void)
	388	{
	389	acpi_status status;
	390	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
	391	struct pcc_memory_resource *mem_resource;
	392	struct pcc_register_resource *reg_resource;
	393	union acpi_object out_obj, member;
7ca9b574	394	acpi_handle handle, osc_handle;
0f1d683f NC	395	int ret = 0;
	396
	397	status = acpi_get_handle(NULL, "\\_SB", &handle);
	398	if (ACPI_FAILURE(status))
	399	return -ENODEV;
	400
7ca9b574	401	if (!acpi_has_method(handle, "PCCH"))
47f8bcf3 MG	402	return -ENODEV;
47f8bcf3 MG	403
0f1d683f NC	404	status = acpi_get_handle(handle, "_OSC", &osc_handle);
	405	if (ACPI_SUCCESS(status)) {
	406	ret = pcc_cpufreq_do_osc(&osc_handle);
	407	if (ret)
2d06d8c4	408	pr_debug("probe: _OSC evaluation did not succeed\n");
0f1d683f NC	409	/* Firmware's use of _OSC is optional */
	410	ret = 0;
	411	}
	412
	413	status = acpi_evaluate_object(handle, "PCCH", NULL, &output);
	414	if (ACPI_FAILURE(status))
	415	return -ENODEV;
	416
	417	out_obj = output.pointer;
	418	if (out_obj->type != ACPI_TYPE_PACKAGE) {
	419	ret = -ENODEV;
	420	goto out_free;
	421	}
	422
	423	member = &out_obj->package.elements[0];
	424	if (member->type != ACPI_TYPE_BUFFER) {
	425	ret = -ENODEV;
	426	goto out_free;
	427	}
	428
	429	mem_resource = (struct pcc_memory_resource *)member->buffer.pointer;
	430
2d06d8c4	431	pr_debug("probe: mem_resource descriptor: 0x%x,"
0f1d683f NC	432	" length: %d, space_id: %d, resource_usage: %d,"
	433	" type_specific: %d, granularity: 0x%llx,"
	434	" minimum: 0x%llx, maximum: 0x%llx,"
	435	" translation_offset: 0x%llx, address_length: 0x%llx\n",
	436	mem_resource->descriptor, mem_resource->length,
	437	mem_resource->space_id, mem_resource->resource_usage,
	438	mem_resource->type_specific, mem_resource->granularity,
	439	mem_resource->minimum, mem_resource->maximum,
	440	mem_resource->translation_offset,
	441	mem_resource->address_length);
	442
	443	if (mem_resource->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) {
	444	ret = -ENODEV;
	445	goto out_free;
	446	}
	447
	448	pcch_virt_addr = ioremap_nocache(mem_resource->minimum,
	449	mem_resource->address_length);
	450	if (pcch_virt_addr == NULL) {
2d06d8c4	451	pr_debug("probe: could not map shared mem region\n");
d06a8a4f	452	ret = -ENOMEM;
0f1d683f NC	453	goto out_free;
	454	}
	455	pcch_hdr = pcch_virt_addr;
	456
2d06d8c4 DB	457	pr_debug("probe: PCCH header (virtual) addr: 0x%p\n", pcch_hdr);
2d06d8c4 DB	458	pr_debug("probe: PCCH header is at physical address: 0x%llx,"
0f1d683f NC	459	" signature: 0x%x, length: %d bytes, major: %d, minor: %d,"
	460	" supported features: 0x%x, command field: 0x%x,"
	461	" status field: 0x%x, nominal latency: %d us\n",
	462	mem_resource->minimum, ioread32(&pcch_hdr->signature),
	463	ioread16(&pcch_hdr->length), ioread8(&pcch_hdr->major),
	464	ioread8(&pcch_hdr->minor), ioread32(&pcch_hdr->features),
	465	ioread16(&pcch_hdr->command), ioread16(&pcch_hdr->status),
	466	ioread32(&pcch_hdr->latency));
	467
2d06d8c4	468	pr_debug("probe: min time between commands: %d us,"
0f1d683f NC	469	" max time between commands: %d us,"
	470	" nominal CPU frequency: %d MHz,"
	471	" minimum CPU frequency: %d MHz,"
	472	" minimum CPU frequency without throttling: %d MHz\n",
	473	ioread32(&pcch_hdr->minimum_time),
	474	ioread32(&pcch_hdr->maximum_time),
	475	ioread32(&pcch_hdr->nominal),
	476	ioread32(&pcch_hdr->throttled_frequency),
	477	ioread32(&pcch_hdr->minimum_frequency));
	478
	479	member = &out_obj->package.elements[1];
	480	if (member->type != ACPI_TYPE_BUFFER) {
	481	ret = -ENODEV;
	482	goto pcch_free;
	483	}
	484
	485	reg_resource = (struct pcc_register_resource *)member->buffer.pointer;
	486
	487	doorbell.space_id = reg_resource->space_id;
	488	doorbell.bit_width = reg_resource->bit_width;
	489	doorbell.bit_offset = reg_resource->bit_offset;
3c67a829	490	doorbell.access_width = 4;
0f1d683f NC	491	doorbell.address = reg_resource->address;
0f1d683f NC	492
2d06d8c4	493	pr_debug("probe: doorbell: space_id is %d, bit_width is %d, "
0f1d683f NC	494	"bit_offset is %d, access_width is %d, address is 0x%llx\n",
	495	doorbell.space_id, doorbell.bit_width, doorbell.bit_offset,
	496	doorbell.access_width, reg_resource->address);
	497
	498	member = &out_obj->package.elements[2];
	499	if (member->type != ACPI_TYPE_INTEGER) {
	500	ret = -ENODEV;
	501	goto pcch_free;
	502	}
	503
	504	doorbell_preserve = member->integer.value;
	505
	506	member = &out_obj->package.elements[3];
	507	if (member->type != ACPI_TYPE_INTEGER) {
	508	ret = -ENODEV;
	509	goto pcch_free;
	510	}
	511
	512	doorbell_write = member->integer.value;
	513
2d06d8c4	514	pr_debug("probe: doorbell_preserve: 0x%llx,"
0f1d683f NC	515	" doorbell_write: 0x%llx\n",
	516	doorbell_preserve, doorbell_write);
	517
	518	pcc_cpu_info = alloc_percpu(struct pcc_cpu);
	519	if (!pcc_cpu_info) {
	520	ret = -ENOMEM;
	521	goto pcch_free;
	522	}
	523
	524	printk(KERN_DEBUG "pcc-cpufreq: (v%s) driver loaded with frequency"
	525	" limits: %d MHz, %d MHz\n", PCC_VERSION,
	526	ioread32(&pcch_hdr->minimum_frequency),
	527	ioread32(&pcch_hdr->nominal));
	528	kfree(output.pointer);
	529	return ret;
	530	pcch_free:
	531	pcc_clear_mapping();
	532	out_free:
	533	kfree(output.pointer);
	534	return ret;
	535	}
	536
	537	static int pcc_cpufreq_cpu_init(struct cpufreq_policy *policy)
	538	{
	539	unsigned int cpu = policy->cpu;
	540	unsigned int result = 0;
	541
	542	if (!pcch_virt_addr) {
	543	result = -1;
179ee434	544	goto out;
0f1d683f NC	545	}
	546
	547	result = pcc_get_offset(cpu);
	548	if (result) {
2d06d8c4	549	pr_debug("init: PCCP evaluation failed\n");
179ee434	550	goto out;
0f1d683f NC	551	}
	552
	553	policy->max = policy->cpuinfo.max_freq =
	554	ioread32(&pcch_hdr->nominal) * 1000;
	555	policy->min = policy->cpuinfo.min_freq =
	556	ioread32(&pcch_hdr->minimum_frequency) * 1000;
179ee434	557
2d06d8c4	558	pr_debug("init: policy->max is %d, policy->min is %d\n",
0f1d683f	559	policy->max, policy->min);
179ee434	560	out:
0f1d683f NC	561	return result;
	562	}
	563
	564	static int pcc_cpufreq_cpu_exit(struct cpufreq_policy *policy)
	565	{
	566	return 0;
	567	}
	568
	569	static struct cpufreq_driver pcc_cpufreq_driver = {
	570	.flags = CPUFREQ_CONST_LOOPS,
	571	.get = pcc_get_freq,
	572	.verify = pcc_cpufreq_verify,
	573	.target = pcc_cpufreq_target,
	574	.init = pcc_cpufreq_cpu_init,
	575	.exit = pcc_cpufreq_cpu_exit,
	576	.name = "pcc-cpufreq",
0f1d683f NC	577	};
	578
	579	static int __init pcc_cpufreq_init(void)
	580	{
	581	int ret;
	582
	583	if (acpi_disabled)
	584	return 0;
	585
	586	ret = pcc_cpufreq_probe();
	587	if (ret) {
2d06d8c4	588	pr_debug("pcc_cpufreq_init: PCCH evaluation failed\n");
0f1d683f NC	589	return ret;
	590	}
	591
	592	ret = cpufreq_register_driver(&pcc_cpufreq_driver);
	593
	594	return ret;
	595	}
	596
	597	static void __exit pcc_cpufreq_exit(void)
	598	{
	599	cpufreq_unregister_driver(&pcc_cpufreq_driver);
	600
	601	pcc_clear_mapping();
	602
	603	free_percpu(pcc_cpu_info);
	604	}
	605
7e7e8fe6 LS	606	static const struct acpi_device_id processor_device_ids[] = {
	607	{ACPI_PROCESSOR_OBJECT_HID, },
	608	{ACPI_PROCESSOR_DEVICE_HID, },
	609	{},
	610	};
	611	MODULE_DEVICE_TABLE(acpi, processor_device_ids);
	612
0f1d683f NC	613	MODULE_AUTHOR("Matthew Garrett, Naga Chumbalkar");
	614	MODULE_VERSION(PCC_VERSION);
	615	MODULE_DESCRIPTION("Processor Clocking Control interface driver");
	616	MODULE_LICENSE("GPL");
	617
	618	late_initcall(pcc_cpufreq_init);
	619	module_exit(pcc_cpufreq_exit);