[mirror_ubuntu-bionic-kernel.git] / arch / x86 / kernel / cpu / 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

#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER,	\
					     "pcc-cpufreq", msg)

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_limits(policy, policy->cpuinfo.min_freq,
				     policy->cpuinfo.max_freq);
	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);

	dprintk("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) {
		dprintk("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);

	dprintk("get: SUCCESS: (virtual) output_offset for cpu %d is "
		"0x%x, 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) {
		dprintk("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);

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

	freqs.new = target_freq;
	freqs.cpu = cpu;
	cpufreq_notify_transition(&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) {
		dprintk("target: FAILED for cpu %d, with status: 0x%x\n",
			cpu, status);
		goto cmd_incomplete;
	}
	iowrite16(0, &pcch_hdr->status);

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

	return 0;

cmd_incomplete:
	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);

	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);

	dprintk("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, pcch_handle;
	int ret = 0;

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

	status = acpi_get_handle(handle, "PCCH", &pcch_handle);
	if (ACPI_FAILURE(status))
		return -ENODEV;

	status = acpi_get_handle(handle, "_OSC", &osc_handle);
	if (ACPI_SUCCESS(status)) {
		ret = pcc_cpufreq_do_osc(&osc_handle);
		if (ret)
			dprintk("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;

	dprintk("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) {
		dprintk("probe: could not map shared mem region\n");
		goto out_free;
	}
	pcch_hdr = pcch_virt_addr;

	dprintk("probe: PCCH header (virtual) addr: 0x%p\n", pcch_hdr);
	dprintk("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));

	dprintk("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;

	dprintk("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;

	dprintk("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) {
		dprintk("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;
	policy->cur = pcc_get_freq(cpu);

	if (!policy->cur) {
		dprintk("init: Unable to get current CPU frequency\n");
		result = -EINVAL;
		goto out;
	}

	dprintk("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",
	.owner = THIS_MODULE,
};

static int __init pcc_cpufreq_init(void)
{
	int ret;

	if (acpi_disabled)
		return 0;

	ret = pcc_cpufreq_probe();
	if (ret) {
		dprintk("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
	51	#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, \
	52	"pcc-cpufreq", msg)
	53
	54	struct pcc_register_resource {
	55	u8 descriptor;
	56	u16 length;
	57	u8 space_id;
	58	u8 bit_width;
	59	u8 bit_offset;
	60	u8 access_size;
	61	u64 address;
	62	} __attribute__ ((packed));
	63
	64	struct pcc_memory_resource {
	65	u8 descriptor;
	66	u16 length;
	67	u8 space_id;
	68	u8 resource_usage;
	69	u8 type_specific;
	70	u64 granularity;
	71	u64 minimum;
	72	u64 maximum;
	73	u64 translation_offset;
	74	u64 address_length;
	75	} __attribute__ ((packed));
	76
	77	static struct cpufreq_driver pcc_cpufreq_driver;
	78
	79	struct pcc_header {
	80	u32 signature;
	81	u16 length;
	82	u8 major;
	83	u8 minor;
	84	u32 features;
	85	u16 command;
	86	u16 status;
	87	u32 latency;
	88	u32 minimum_time;
	89	u32 maximum_time;
	90	u32 nominal;
	91	u32 throttled_frequency;
	92	u32 minimum_frequency;
	93	};
	94
	95	static void __iomem *pcch_virt_addr;
	96	static struct pcc_header __iomem *pcch_hdr;
	97
	98	static DEFINE_SPINLOCK(pcc_lock);
	99
	100	static struct acpi_generic_address doorbell;
	101
	102	static u64 doorbell_preserve;
	103	static u64 doorbell_write;
	104
904cc1e6	105	static u8 OSC_UUID[16] = {0x9F, 0x2C, 0x9B, 0x63, 0x91, 0x70, 0x1f, 0x49,
0f1d683f NC	106	0xBB, 0x4F, 0xA5, 0x98, 0x2F, 0xA1, 0xB5, 0x46};
	107
	108	struct pcc_cpu {
	109	u32 input_offset;
	110	u32 output_offset;
	111	};
	112
a3da3234	113	static struct pcc_cpu __percpu *pcc_cpu_info;
0f1d683f NC	114
	115	static int pcc_cpufreq_verify(struct cpufreq_policy *policy)
	116	{
	117	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
	118	policy->cpuinfo.max_freq);
	119	return 0;
	120	}
	121
	122	static inline void pcc_cmd(void)
	123	{
	124	u64 doorbell_value;
	125	int i;
	126
	127	acpi_read(&doorbell_value, &doorbell);
	128	acpi_write((doorbell_value & doorbell_preserve) \| doorbell_write,
	129	&doorbell);
	130
	131	for (i = 0; i < POLL_LOOPS; i++) {
	132	if (ioread16(&pcch_hdr->status) & CMD_COMPLETE)
	133	break;
	134	}
	135	}
	136
	137	static inline void pcc_clear_mapping(void)
	138	{
	139	if (pcch_virt_addr)
	140	iounmap(pcch_virt_addr);
	141	pcch_virt_addr = NULL;
	142	}
	143
	144	static unsigned int pcc_get_freq(unsigned int cpu)
	145	{
	146	struct pcc_cpu *pcc_cpu_data;
	147	unsigned int curr_freq;
	148	unsigned int freq_limit;
	149	u16 status;
	150	u32 input_buffer;
	151	u32 output_buffer;
	152
	153	spin_lock(&pcc_lock);
	154
	155	dprintk("get: get_freq for CPU %d\n", cpu);
	156	pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
	157
	158	input_buffer = 0x1;
	159	iowrite32(input_buffer,
	160	(pcch_virt_addr + pcc_cpu_data->input_offset));
	161	iowrite16(CMD_GET_FREQ, &pcch_hdr->command);
	162
	163	pcc_cmd();
	164
	165	output_buffer =
	166	ioread32(pcch_virt_addr + pcc_cpu_data->output_offset);
	167
	168	/* Clear the input buffer - we are done with the current command */
	169	memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
	170
	171	status = ioread16(&pcch_hdr->status);
	172	if (status != CMD_COMPLETE) {
	173	dprintk("get: FAILED: for CPU %d, status is %d\n",
	174	cpu, status);
	175	goto cmd_incomplete;
	176	}
	177	iowrite16(0, &pcch_hdr->status);
178	curr_freq = (((ioread32(&pcch_hdr->nominal) * (output_buffer & 0xff))
179	/ 100) * 1000);
180
181	dprintk("get: SUCCESS: (virtual) output_offset for cpu %d is "
182	"0x%x, contains a value of: 0x%x. Speed is: %d MHz\n",
183	cpu, (pcch_virt_addr + pcc_cpu_data->output_offset),
184	output_buffer, curr_freq);
185
186	freq_limit = (output_buffer >> 8) & 0xff;
187	if (freq_limit != 0xff) {
188	dprintk("get: frequency for cpu %d is being temporarily"
189	" capped at %d\n", cpu, curr_freq);
190	}
191
192	spin_unlock(&pcc_lock);
193	return curr_freq;
194
195	cmd_incomplete:
196	iowrite16(0, &pcch_hdr->status);
197	spin_unlock(&pcc_lock);
1f858ef2	198	return 0;
0f1d683f NC	199	}
	200
	201	static int pcc_cpufreq_target(struct cpufreq_policy *policy,
	202	unsigned int target_freq,
	203	unsigned int relation)
	204	{
	205	struct pcc_cpu *pcc_cpu_data;
	206	struct cpufreq_freqs freqs;
	207	u16 status;
	208	u32 input_buffer;
	209	int cpu;
	210
	211	spin_lock(&pcc_lock);
	212	cpu = policy->cpu;
	213	pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
	214
	215	dprintk("target: CPU %d should go to target freq: %d "
	216	"(virtual) input_offset is 0x%x\n",
	217	cpu, target_freq,
	218	(pcch_virt_addr + pcc_cpu_data->input_offset));
	219
	220	freqs.new = target_freq;
	221	freqs.cpu = cpu;
	222	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
	223
	224	input_buffer = 0x1 \| (((target_freq * 100)
	225	/ (ioread32(&pcch_hdr->nominal) * 1000)) << 8);
	226	iowrite32(input_buffer,
	227	(pcch_virt_addr + pcc_cpu_data->input_offset));
	228	iowrite16(CMD_SET_FREQ, &pcch_hdr->command);
	229
	230	pcc_cmd();
	231
	232	/* Clear the input buffer - we are done with the current command */
	233	memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
	234
	235	status = ioread16(&pcch_hdr->status);
	236	if (status != CMD_COMPLETE) {
	237	dprintk("target: FAILED for cpu %d, with status: 0x%x\n",
	238	cpu, status);
	239	goto cmd_incomplete;
	240	}
	241	iowrite16(0, &pcch_hdr->status);
	242
	243	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
	244	dprintk("target: was SUCCESSFUL for cpu %d\n", cpu);
	245	spin_unlock(&pcc_lock);
	246
	247	return 0;
	248
	249	cmd_incomplete:
	250	iowrite16(0, &pcch_hdr->status);
	251	spin_unlock(&pcc_lock);
	252	return -EINVAL;
	253	}
	254
	255	static int pcc_get_offset(int cpu)
	256	{
	257	acpi_status status;
	258	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
	259	union acpi_object pccp, offset;
	260	struct pcc_cpu *pcc_cpu_data;
	261	struct acpi_processor *pr;
	262	int ret = 0;
263
264	pr = per_cpu(processors, cpu);
265	pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
266
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
296	dprintk("pcc_get_offset: for CPU %d: pcc_cpu_data "
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;
47f8bcf3	398	acpi_handle handle, osc_handle, pcch_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
47f8bcf3 MG	405	status = acpi_get_handle(handle, "PCCH", &pcch_handle);
	406	if (ACPI_FAILURE(status))
	407	return -ENODEV;
	408
0f1d683f NC	409	status = acpi_get_handle(handle, "_OSC", &osc_handle);
	410	if (ACPI_SUCCESS(status)) {
	411	ret = pcc_cpufreq_do_osc(&osc_handle);
	412	if (ret)
	413	dprintk("probe: _OSC evaluation did not succeed\n");
	414	/* Firmware's use of _OSC is optional */
	415	ret = 0;
	416	}
	417
	418	status = acpi_evaluate_object(handle, "PCCH", NULL, &output);
	419	if (ACPI_FAILURE(status))
	420	return -ENODEV;
	421
	422	out_obj = output.pointer;
	423	if (out_obj->type != ACPI_TYPE_PACKAGE) {
	424	ret = -ENODEV;
	425	goto out_free;
	426	}
	427
	428	member = &out_obj->package.elements[0];
	429	if (member->type != ACPI_TYPE_BUFFER) {
	430	ret = -ENODEV;
	431	goto out_free;
	432	}
	433
	434	mem_resource = (struct pcc_memory_resource *)member->buffer.pointer;
	435
	436	dprintk("probe: mem_resource descriptor: 0x%x,"
	437	" length: %d, space_id: %d, resource_usage: %d,"
	438	" type_specific: %d, granularity: 0x%llx,"
	439	" minimum: 0x%llx, maximum: 0x%llx,"
	440	" translation_offset: 0x%llx, address_length: 0x%llx\n",
	441	mem_resource->descriptor, mem_resource->length,
	442	mem_resource->space_id, mem_resource->resource_usage,
	443	mem_resource->type_specific, mem_resource->granularity,
	444	mem_resource->minimum, mem_resource->maximum,
	445	mem_resource->translation_offset,
	446	mem_resource->address_length);
	447
	448	if (mem_resource->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) {
	449	ret = -ENODEV;
	450	goto out_free;
	451	}
	452
	453	pcch_virt_addr = ioremap_nocache(mem_resource->minimum,
	454	mem_resource->address_length);
	455	if (pcch_virt_addr == NULL) {
	456	dprintk("probe: could not map shared mem region\n");
	457	goto out_free;
	458	}
	459	pcch_hdr = pcch_virt_addr;
	460
fb463593	461	dprintk("probe: PCCH header (virtual) addr: 0x%p\n", pcch_hdr);
0f1d683f NC	462	dprintk("probe: PCCH header is at physical address: 0x%llx,"
	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
	472	dprintk("probe: min time between commands: %d us,"
	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
	497	dprintk("probe: doorbell: space_id is %d, bit_width is %d, "
	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
	518	dprintk("probe: doorbell_preserve: 0x%llx,"
	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) {
	553	dprintk("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;
	561	policy->cur = pcc_get_freq(cpu);
	562
179ee434 MG	563	if (!policy->cur) {
	564	dprintk("init: Unable to get current CPU frequency\n");
	565	result = -EINVAL;
	566	goto out;
	567	}
	568
0f1d683f NC	569	dprintk("init: policy->max is %d, policy->min is %d\n",
0f1d683f NC	570	policy->max, policy->min);
179ee434	571	out:
0f1d683f NC	572	return result;
	573	}
	574
	575	static int pcc_cpufreq_cpu_exit(struct cpufreq_policy *policy)
	576	{
	577	return 0;
	578	}
	579
	580	static struct cpufreq_driver pcc_cpufreq_driver = {
	581	.flags = CPUFREQ_CONST_LOOPS,
	582	.get = pcc_get_freq,
	583	.verify = pcc_cpufreq_verify,
	584	.target = pcc_cpufreq_target,
	585	.init = pcc_cpufreq_cpu_init,
	586	.exit = pcc_cpufreq_cpu_exit,
	587	.name = "pcc-cpufreq",
	588	.owner = THIS_MODULE,
	589	};
	590
	591	static int __init pcc_cpufreq_init(void)
	592	{
	593	int ret;
	594
	595	if (acpi_disabled)
	596	return 0;
	597
	598	ret = pcc_cpufreq_probe();
	599	if (ret) {
	600	dprintk("pcc_cpufreq_init: PCCH evaluation failed\n");
	601	return ret;
	602	}
	603
	604	ret = cpufreq_register_driver(&pcc_cpufreq_driver);
	605
	606	return ret;
	607	}
	608
	609	static void __exit pcc_cpufreq_exit(void)
	610	{
	611	cpufreq_unregister_driver(&pcc_cpufreq_driver);
	612
	613	pcc_clear_mapping();
	614
	615	free_percpu(pcc_cpu_info);
	616	}
	617
	618	MODULE_AUTHOR("Matthew Garrett, Naga Chumbalkar");
	619	MODULE_VERSION(PCC_VERSION);
	620	MODULE_DESCRIPTION("Processor Clocking Control interface driver");
	621	MODULE_LICENSE("GPL");
	622
	623	late_initcall(pcc_cpufreq_init);
	624	module_exit(pcc_cpufreq_exit);