From 0f1d683fb35d6c6f49ef696c95757f3970682a0e Mon Sep 17 00:00:00 2001 From: Naga Chumbalkar Date: Thu, 17 Dec 2009 20:18:27 +0000 Subject: [CPUFREQ] Processor Clocking Control interface driver Processor Clocking Control (PCC) is an interface between the BIOS and OSPM. Based on the server workload, OSPM can request what frequency it expects from a logical CPU, and the BIOS will achieve that frequency transparently. This patch introduces driver support for PCC. OSPM uses the PCC driver to communicate with the BIOS via the PCC interface. There is a Documentation file that provides a link to the PCC Specification, and also provides a summary of the PCC interface. Currently, certain HP ProLiant platforms implement the PCC interface. However, any platform whose BIOS implements the PCC Specification, can utilize this driver. V2 --> V1 changes (based on Dominik's suggestions): - Removed the dependency on CPU_FREQ_TABLE - "cpufreq_stats" will no longer PANIC. Actually, it will not load anymore because it is not applicable. - Removed the sanity check for target frequency in the ->target routine. NOTE: A patch to sanitize the target frequency requested by "ondemand" is needed to ensure that the target freq < policy->min. Can this driver be queued up for the 2.6.33 tree? Signed-off-by: Naga Chumbalkar Signed-off-by: Matthew Garrett Signed-off-by: Thomas Renninger Signed-off-by: Dave Jones --- arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c | 621 ++++++++++++++++++++++++++++++ 1 file changed, 621 insertions(+) create mode 100644 arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c (limited to 'arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c') diff --git a/arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c new file mode 100644 index 000000000000..29368854533c --- /dev/null +++ b/arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c @@ -0,0 +1,621 @@ +/* + * pcc-cpufreq.c - Processor Clocking Control firmware cpufreq interface + * + * Copyright (C) 2009 Red Hat, Matthew Garrett + * Copyright (C) 2009 Hewlett-Packard Development Company, L.P. + * Nagananda Chumbalkar + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * 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 +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +#include + +#define PCC_VERSION "1.00.00" +#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] = {0x63, 0x9B, 0x2C, 0x9F, 0x70, 0x91, 0x49, 0x1f, + 0xBB, 0x4F, 0xA5, 0x98, 0x2F, 0xA1, 0xB5, 0x46}; + +struct pcc_cpu { + u32 input_offset; + u32 output_offset; +}; + +static struct pcc_cpu *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 -EINVAL; +} + +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; + 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; + + 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%llx\n", + (u64)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 pcch_null; + } + + result = pcc_get_offset(cpu); + if (result) { + dprintk("init: PCCP evaluation failed\n"); + goto free; + } + + 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); + + dprintk("init: policy->max is %d, policy->min is %d\n", + policy->max, policy->min); + + return 0; +free: + pcc_clear_mapping(); + free_percpu(pcc_cpu_info); +pcch_null: + 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); -- cgit v1.2.1 From fb4635932a4e19c2f55383f968a0e9b64da37354 Mon Sep 17 00:00:00 2001 From: Dave Jones Date: Thu, 7 Jan 2010 15:26:22 -0500 Subject: [CPUFREQ] Fix cast warning in pcc driver. arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c:458: warning: cast from pointer to integer of different size Signed-off-by: Dave Jones --- arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c') diff --git a/arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c index 29368854533c..ff36d2979a90 100644 --- a/arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c +++ b/arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c @@ -455,8 +455,7 @@ static int __init pcc_cpufreq_probe(void) } pcch_hdr = pcch_virt_addr; - dprintk("probe: PCCH header (virtual) addr: 0x%llx\n", - (u64)pcch_hdr); + 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," -- cgit v1.2.1