--- /dev/null
+/*
+ * 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_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);
+
+ 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;
+ 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) {
+ 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(&freqs, CPUFREQ_POSTCHANGE);
+ pr_debug("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);
+
+ 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, 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)
+ 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");
+ 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;
+ policy->cur = pcc_get_freq(cpu);
+
+ if (!policy->cur) {
+ pr_debug("init: Unable to get current CPU frequency\n");
+ result = -EINVAL;
+ goto out;
+ }
+
+ 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",
+ .owner = THIS_MODULE,
+};
+
+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);
projects / firefly-linux-kernel-4.4.55.git / blobdiff