The ACPI processor driver is currently tied too closely to the ACPI P-states (PSS) and other related constructs for controlling CPU performance.

The newer ACPI specification (v5.1 onwards) introduces alternative methods to PSS. These new mechanisms are described within each ACPI Processor object and so they need to be scanned whenever a new Processor object is detected. This patch introduces a new Kconfig symbol to allow for finer configurability among the two options for controlling performance states. There is no change in functionality and the option is auto-selected by the architectures which support it.

The following patchwork introduces CPPC: A newer method of controlling CPU performance. The OS is not expected to support CPPC and PSS at runtime. So the kconfig option lets us make these two mutually exclusive at compile time.

Signed-off-by: Ashwin Chaugule ashwin.chaugule@linaro.org --- drivers/acpi/Kconfig | 15 ++++--- drivers/acpi/Makefile | 5 ++- drivers/acpi/processor_driver.c | 86 +++++++++++++++++++++++++++-------------- include/acpi/processor.h | 28 +++++++++++++- 4 files changed, 96 insertions(+), 38 deletions(-)

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index 114cf48..d6e2a86 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -189,17 +189,20 @@ config ACPI_DOCK This driver supports ACPI-controlled docking stations and removable drive bays such as the IBM Ultrabay and the Dell Module Bay.

+config ACPI_CPU_FREQ_PSS + bool + select THERMAL + config ACPI_PROCESSOR tristate "Processor" - select THERMAL - select CPU_IDLE depends on X86 || IA64 + select CPU_IDLE + select ACPI_CPU_FREQ_PSS default y help - This driver installs ACPI as the idle handler for Linux and uses - ACPI C2 and C3 processor states to save power on systems that - support it. It is required by several flavors of cpufreq - performance-state drivers. + This driver adds support for the ACPI Processor package. It is required + by several flavors of cpufreq performance-state, thermal, throttling and + idle drivers.

To compile this driver as a module, choose M here: the module will be called processor. diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index 8321430..7e97aef 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -80,8 +80,9 @@ obj-$(CONFIG_ACPI_CUSTOM_METHOD)+= custom_method.o obj-$(CONFIG_ACPI_BGRT) += bgrt.o

# processor has its own "processor." module_param namespace -processor-y := processor_driver.o processor_throttling.o -processor-y += processor_idle.o processor_thermal.o +processor-y := processor_driver.o processor_idle.o +processor-$(CONFIG_ACPI_CPU_FREQ_PSS) += processor_throttling.o \ + processor_thermal.o processor-$(CONFIG_CPU_FREQ) += processor_perflib.o

obj-$(CONFIG_ACPI_PROCESSOR_AGGREGATOR) += acpi_pad.o diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c index d9f7158..16d44ad 100644 --- a/drivers/acpi/processor_driver.c +++ b/drivers/acpi/processor_driver.c @@ -163,34 +163,24 @@ static struct notifier_block __refdata acpi_cpu_notifier = { .notifier_call = acpi_cpu_soft_notify, };

-static int __acpi_processor_start(struct acpi_device *device) +#ifdef CONFIG_ACPI_CPU_FREQ_PSS +static int acpi_pss_perf_init(struct acpi_processor *pr, + struct acpi_device *device) { - struct acpi_processor *pr = acpi_driver_data(device); - acpi_status status; int result = 0;

- if (!pr) - return -ENODEV; - - if (pr->flags.need_hotplug_init) - return 0; - -#ifdef CONFIG_CPU_FREQ acpi_processor_ppc_has_changed(pr, 0); -#endif + acpi_processor_get_throttling_info(pr);

if (pr->flags.throttling) pr->flags.limit = 1;

- if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver) - acpi_processor_power_init(pr); - pr->cdev = thermal_cooling_device_register("Processor", device, &processor_cooling_ops); if (IS_ERR(pr->cdev)) { result = PTR_ERR(pr->cdev); - goto err_power_exit; + return result; }

dev_dbg(&device->dev, "registered as cooling_device%d\n", @@ -204,6 +194,7 @@ static int __acpi_processor_start(struct acpi_device *device) "Failed to create sysfs link 'thermal_cooling'\n"); goto err_thermal_unregister; } + result = sysfs_create_link(&pr->cdev->device.kobj, &device->dev.kobj, "device"); @@ -213,17 +204,61 @@ static int __acpi_processor_start(struct acpi_device *device) goto err_remove_sysfs_thermal; }

- status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, - acpi_processor_notify, device); - if (ACPI_SUCCESS(status)) - return 0; - sysfs_remove_link(&pr->cdev->device.kobj, "device"); err_remove_sysfs_thermal: sysfs_remove_link(&device->dev.kobj, "thermal_cooling"); err_thermal_unregister: thermal_cooling_device_unregister(pr->cdev); - err_power_exit: + + return result; +} + +static void acpi_pss_perf_exit(struct acpi_processor *pr, + struct acpi_device *device) +{ + if (pr->cdev) { + sysfs_remove_link(&device->dev.kobj, "thermal_cooling"); + sysfs_remove_link(&pr->cdev->device.kobj, "device"); + thermal_cooling_device_unregister(pr->cdev); + pr->cdev = NULL; + } +} +#else +static inline int acpi_pss_perf_init(struct acpi_processor *pr, + struct acpi_device *device) +{ + return 0; +} + +static inline void acpi_pss_perf_exit(struct acpi_processor *pr, + struct acpi_device *device) {} +#endif /* CONFIG_ACPI_CPU_FREQ_PSS */ + +static int __acpi_processor_start(struct acpi_device *device) +{ + struct acpi_processor *pr = acpi_driver_data(device); + acpi_status status; + int result = 0; + + if (!pr) + return -ENODEV; + + if (pr->flags.need_hotplug_init) + return 0; + + if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver) + acpi_processor_power_init(pr); + + result = acpi_pss_perf_init(pr, device); + if (result) + goto err_power_exit; + + status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, + acpi_processor_notify, device); + if (ACPI_SUCCESS(status)) + return 0; + +err_power_exit: acpi_processor_power_exit(pr); return result; } @@ -252,15 +287,10 @@ static int acpi_processor_stop(struct device *dev) pr = acpi_driver_data(device); if (!pr) return 0; - acpi_processor_power_exit(pr);

- if (pr->cdev) { - sysfs_remove_link(&device->dev.kobj, "thermal_cooling"); - sysfs_remove_link(&pr->cdev->device.kobj, "device"); - thermal_cooling_device_unregister(pr->cdev); - pr->cdev = NULL; - } + acpi_pss_perf_exit(pr, device); + return 0; }

diff --git a/include/acpi/processor.h b/include/acpi/processor.h index 4188a4d..b6c9178 100644 --- a/include/acpi/processor.h +++ b/include/acpi/processor.h @@ -318,6 +318,7 @@ int acpi_get_cpuid(acpi_handle, int type, u32 acpi_id); void acpi_processor_set_pdc(acpi_handle handle);

/* in processor_throttling.c */ +#ifdef CONFIG_ACPI_CPU_FREQ_PSS int acpi_processor_tstate_has_changed(struct acpi_processor *pr); int acpi_processor_get_throttling_info(struct acpi_processor *pr); extern int acpi_processor_set_throttling(struct acpi_processor *pr, @@ -330,6 +331,29 @@ extern void acpi_processor_reevaluate_tstate(struct acpi_processor *pr, unsigned long action); extern const struct file_operations acpi_processor_throttling_fops; extern void acpi_processor_throttling_init(void); +#else +static inline int acpi_processor_tstate_has_changed(struct acpi_processor *pr) +{ + return 0; +} + +static inline int acpi_processor_get_throttling_info(struct acpi_processor *pr) +{ + return -ENODEV; +} + +static inline int acpi_processor_set_throttling(struct acpi_processor *pr, + int state, bool force) +{ + return -ENODEV; +} + +static inline void acpi_processor_reevaluate_tstate(struct acpi_processor *pr, + unsigned long action) {} + +static inline void acpi_processor_throttling_init(void) {} +#endif /* CONFIG_ACPI_CPU_FREQ_PSS */ + /* in processor_idle.c */ int acpi_processor_power_init(struct acpi_processor *pr); int acpi_processor_power_exit(struct acpi_processor *pr); @@ -348,7 +372,7 @@ static inline void acpi_processor_syscore_exit(void) {} /* in processor_thermal.c */ int acpi_processor_get_limit_info(struct acpi_processor *pr); extern const struct thermal_cooling_device_ops processor_cooling_ops; -#ifdef CONFIG_CPU_FREQ +#if defined(CONFIG_ACPI_CPU_FREQ_PSS) & defined(CONFIG_CPU_FREQ) void acpi_thermal_cpufreq_init(void); void acpi_thermal_cpufreq_exit(void); #else @@ -360,6 +384,6 @@ static inline void acpi_thermal_cpufreq_exit(void) { return; } -#endif +#endif /* CONFIG_ACPI_CPU_FREQ_PSS */

#endif

CPPC stands for Collaborative Processor Performance Controls and is defined in the ACPI v5.0+ spec. It describes CPU performance controls on an abstract and continuous scale allowing the platform (e.g. remote power processor) to flexibly optimize CPU performance with its knowledge of power budgets and other architecture specific knowledge.

This patch adds a shim which exports commonly used functions to get and set CPPC specific controls for each CPU. This enables CPUFreq drivers to gather per CPU performance data and use with exisiting governors or even allows for customized governors which are implemented inside CPUFreq drivers.

Signed-off-by: Ashwin Chaugule ashwin.chaugule@linaro.org Reviewed-by: Al Stone al.stone@linaro.org --- drivers/acpi/Kconfig | 14 + drivers/acpi/Makefile | 1 + drivers/acpi/cppc_acpi.c | 812 +++++++++++++++++++++++++++++++++++++++++++++++ include/acpi/cppc_acpi.h | 137 ++++++++ 4 files changed, 964 insertions(+) create mode 100644 drivers/acpi/cppc_acpi.c create mode 100644 include/acpi/cppc_acpi.h

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index 54e9729..c6ec903 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -197,6 +197,20 @@ config ACPI_PROCESSOR_IDLE bool select CPU_IDLE

+config ACPI_CPPC_LIB + bool + depends on ACPI_PROCESSOR + depends on !ACPI_CPU_FREQ_PSS + select MAILBOX + select PCC + help + This file implements common functionality to parse + CPPC tables as described in the ACPI 5.1+ spec. The + routines implemented are meant to be used by other + drivers to control CPU performance using CPPC semantics. + If your platform does not support CPPC in firmware, + leave this option disabled. + config ACPI_PROCESSOR tristate "Processor" depends on X86 || IA64 diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index 3ea59ae..4c393a69 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -78,6 +78,7 @@ obj-$(CONFIG_ACPI_HED) += hed.o obj-$(CONFIG_ACPI_EC_DEBUGFS) += ec_sys.o obj-$(CONFIG_ACPI_CUSTOM_METHOD)+= custom_method.o obj-$(CONFIG_ACPI_BGRT) += bgrt.o +obj-$(CONFIG_ACPI_CPPC_LIB) += cppc_acpi.o

# processor has its own "processor." module_param namespace processor-y := processor_driver.o diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c new file mode 100644 index 0000000..9c89767 --- /dev/null +++ b/drivers/acpi/cppc_acpi.c @@ -0,0 +1,812 @@ +/* + * CPPC (Collaborative Processor Performance Control) methods used + * by CPUfreq drivers. + * + * (C) Copyright 2014, 2015 Linaro Ltd. + * Author: Ashwin Chaugule ashwin.chaugule@linaro.org + * + * 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. + * + * CPPC describes a few methods for controlling CPU performance using + * information from a per CPU table called CPC. This table is described in + * the ACPI v5.0+ specification. The table consists of a list of + * registers which may be memory mapped or hardware registers and also may + * include some static integer values. + * + * CPU performance is on an abstract continuous scale as against a discretized + * P-state scale which is tied to CPU frequency only. In brief, the basic + * operation involves: + * + * - OS makes a CPU performance request. (Can provide min and max bounds) + * + * - Platform (such as BMC) is free to optimize request within requested bounds + * depending on power/thermal budgets etc. + * + * - Platform conveys its decision back to OS + * + * The communication between OS and platform occurs through another medium + * called (PCC) Platform Communication Channel. This is a generic mailbox like + * mechanism which includes doorbell semantics to indicate register updates. + * See drivers/mailbox/pcc.c for details on PCC. + * + * Finer details about the PCC and CPPC spec are available in the latest + * ACPI 5.1 specification. + */ + +#define pr_fmt(fmt) "ACPI CPPC: " fmt + +#include <linux/cpufreq.h> +#include <linux/delay.h> + +#include <acpi/cppc_acpi.h> +/* + * Lock to provide mutually exclusive access to the PCC + * channel. e.g. When the remote updates the shared region + * with new data, the reader needs to be protected from + * other CPUs activity on the same channel. + */ +static DEFINE_SPINLOCK(pcc_lock); + +static DEFINE_PER_CPU(struct cpc_desc *, cpc_desc_ptr); + +/* This layer handles all the PCC specifics for CPPC. */ +static struct mbox_chan *pcc_channel; +static void __iomem *pcc_comm_addr; +static u64 comm_base_addr; +static int pcc_subspace_idx = -1; +static u16 pcc_cmd_delay; +static int pcc_channel_acquired; + +#define NUM_RETRIES 500 + +static int send_pcc_cmd(u16 cmd) +{ + int err, result = 0; + int retries = NUM_RETRIES; + struct acpi_pcct_hw_reduced *pcct_ss = pcc_channel->con_priv; + struct acpi_pcct_shared_memory *generic_comm_base = + (struct acpi_pcct_shared_memory *) pcc_comm_addr; + u32 cmd_latency = pcct_ss->latency; + + /* Write to the shared comm region. */ + writew(cmd, &generic_comm_base->command); + + /* Flip CMD COMPLETE bit */ + writew(0, &generic_comm_base->status); + + err = mbox_send_message(pcc_channel, &cmd); + if (err < 0) { + pr_err("Err sending PCC mbox message. cmd:%d, ret:%d\n", + cmd, err); + return err; + } + + /* Wait for a nominal time to let platform processes command. */ + udelay(cmd_latency); + + /* Retry in case the remote processor was too slow to catch up. */ + while (retries--) { + result = readw_relaxed(&generic_comm_base->status) + & PCC_CMD_COMPLETE ? 0 : -EIO; + if (!result) { + /* Success. */ + retries = NUM_RETRIES; + break; + } + } + + mbox_client_txdone(pcc_channel, result); + return result; +} + +static void cppc_chan_tx_done(struct mbox_client *cl, void *mssg, int ret) +{ + if (ret) + pr_debug("TX did not complete: CMD sent:%x, ret:%d\n", + *(u16 *)mssg, ret); + else + pr_debug("TX completed. CMD sent:%x, ret:%d\n", + *(u16 *)mssg, ret); +} + +struct mbox_client cppc_mbox_cl = { + .tx_done = cppc_chan_tx_done, + .knows_txdone = true, +}; + +static int acpi_get_psd(struct cpc_desc *cpc_ptr, acpi_handle handle) +{ + int result = 0; + acpi_status status = AE_OK; + struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL}; + struct acpi_buffer format = {sizeof("NNNNN"), "NNNNN"}; + struct acpi_buffer state = {0, NULL}; + union acpi_object *psd = NULL; + struct acpi_psd_package *pdomain; + + status = acpi_evaluate_object(handle, "_PSD", NULL, &buffer); + if (ACPI_FAILURE(status)) + return -ENODEV; + + psd = buffer.pointer; + if (!psd || (psd->type != ACPI_TYPE_PACKAGE)) { + pr_err("Invalid _PSD data\n"); + result = -ENODATA; + goto end; + } + + if (psd->package.count != 1) { + pr_err("Invalid _PSD data\n"); + result = -ENODATA; + goto end; + } + + pdomain = &(cpc_ptr->domain_info); + + state.length = sizeof(struct acpi_psd_package); + state.pointer = pdomain; + + status = acpi_extract_package(&(psd->package.elements[0]), + &format, &state); + if (ACPI_FAILURE(status)) { + pr_err("Invalid _PSD data\n"); + result = -ENODATA; + goto end; + } + + if (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES) { + pr_err("Unknown _PSD:num_entries\n"); + result = -ENODATA; + goto end; + } + + if (pdomain->revision != ACPI_PSD_REV0_REVISION) { + pr_err("Unknown _PSD:revision\n"); + result = -ENODATA; + goto end; + } + + if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL && + pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY && + pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) { + pr_err("Invalid _PSD:coord_type\n"); + result = -ENODATA; + goto end; + } +end: + kfree(buffer.pointer); + return result; +} + +int acpi_get_psd_map(struct cpudata **all_cpu_data) +{ + int count_target; + int retval = 0; + unsigned int i, j; + cpumask_var_t covered_cpus; + struct cpudata *pr, *match_pr; + struct acpi_psd_package *pdomain; + struct acpi_psd_package *match_pdomain; + struct cpc_desc *cpc_ptr, *match_cpc_ptr; + + if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL)) + return -ENOMEM; + + /* + * Now that we have _PSD data from all CPUs, lets setup P-state + * domain info. + */ + for_each_possible_cpu(i) { + pr = all_cpu_data[i]; + if (!pr) + continue; + + if (cpumask_test_cpu(i, covered_cpus)) + continue; + + cpc_ptr = per_cpu(cpc_desc_ptr, i); + if (!cpc_ptr) + continue; + + pdomain = &(cpc_ptr->domain_info); + cpumask_set_cpu(i, pr->shared_cpu_map); + cpumask_set_cpu(i, covered_cpus); + if (pdomain->num_processors <= 1) + continue; + + /* Validate the Domain info */ + count_target = pdomain->num_processors; + if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL) + pr->shared_type = CPUFREQ_SHARED_TYPE_ALL; + else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL) + pr->shared_type = CPUFREQ_SHARED_TYPE_HW; + else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY) + pr->shared_type = CPUFREQ_SHARED_TYPE_ANY; + + for_each_possible_cpu(j) { + if (i == j) + continue; + + match_cpc_ptr = per_cpu(cpc_desc_ptr, j); + if (!match_cpc_ptr) + continue; + + match_pdomain = &(match_cpc_ptr->domain_info); + if (match_pdomain->domain != pdomain->domain) + continue; + + /* Here i and j are in the same domain */ + + if (match_pdomain->num_processors != count_target) { + retval = -EINVAL; + goto err_ret; + } + + if (pdomain->coord_type != match_pdomain->coord_type) { + retval = -EINVAL; + goto err_ret; + } + + cpumask_set_cpu(j, covered_cpus); + cpumask_set_cpu(j, pr->shared_cpu_map); + } + + for_each_possible_cpu(j) { + if (i == j) + continue; + + match_pr = all_cpu_data[j]; + if (!match_pr) + continue; + + match_cpc_ptr = per_cpu(cpc_desc_ptr, j); + if (!match_cpc_ptr) + continue; + + match_pdomain = &(match_cpc_ptr->domain_info); + if (match_pdomain->domain != pdomain->domain) + continue; + + match_pr->shared_type = pr->shared_type; + cpumask_copy(match_pr->shared_cpu_map, + pr->shared_cpu_map); + } + } + +err_ret: + for_each_possible_cpu(i) { + pr = all_cpu_data[i]; + if (!pr) + continue; + + /* Assume no coordination on any error parsing domain info */ + if (retval) { + cpumask_clear(pr->shared_cpu_map); + cpumask_set_cpu(i, pr->shared_cpu_map); + pr->shared_type = CPUFREQ_SHARED_TYPE_ALL; + } + } + + free_cpumask_var(covered_cpus); + return retval; +} +EXPORT_SYMBOL_GPL(acpi_get_psd_map); + +static int register_pcc_channel(unsigned pcc_subspace_idx) +{ + struct acpi_pcct_subspace *cppc_ss; + unsigned int len; + + if (pcc_subspace_idx >= 0) { + pcc_channel = pcc_mbox_request_channel(&cppc_mbox_cl, + pcc_subspace_idx); + + if (IS_ERR(pcc_channel)) { + pr_err("No PCC communication channel found\n"); + return -ENODEV; + } + + /* + * The PCC mailbox controller driver should + * have parsed the PCCT (global table of all + * PCC channels) and stored pointers to the + * subspace communication region in con_priv. + */ + cppc_ss = pcc_channel->con_priv; + + if (!cppc_ss) { + pr_err("No PCC subspace found for CPPC\n"); + return -ENODEV; + } + + /* + * This is the shared communication region + * for the OS and Platform to communicate over. + */ + comm_base_addr = cppc_ss->base_address; + len = cppc_ss->length; + pcc_cmd_delay = cppc_ss->min_turnaround_time; + + pcc_comm_addr = ioremap(comm_base_addr, len); + if (!pcc_comm_addr) { + pr_err("Failed to ioremap PCC comm region mem\n"); + return -ENOMEM; + } + + /* Set flag so that we dont come here for each CPU. */ + pcc_channel_acquired = 1; + + } else + /* + * For the case where registers are not defined as PCC regs. + * Assuming all regs are FFH / SystemIO. + */ + pr_debug("No PCC subspace detected in any CPC entries.\n"); + + return 0; +} + +/** + * acpi_cppc_processor_probe - The _CPC table is a per CPU table + * which a bunch of entries which may be registers or integers. + * An example table looks like the following. + * + * Name(_CPC, Package() + * { + * 17, + * NumEntries + * 1, + * // Revision + * ResourceTemplate(){Register(PCC, 32, 0, 0x120, 2)}, + * // Highest Performance + * ResourceTemplate(){Register(PCC, 32, 0, 0x124, 2)}, + * // Nominal Performance + * ResourceTemplate(){Register(PCC, 32, 0, 0x128, 2)}, + * // Lowest Nonlinear Performance + * ResourceTemplate(){Register(PCC, 32, 0, 0x12C, 2)}, + * // Lowest Performance + * ResourceTemplate(){Register(PCC, 32, 0, 0x130, 2)}, + * // Guaranteed Performance Register + * ResourceTemplate(){Register(PCC, 32, 0, 0x110, 2)}, + * // Desired Performance Register + * ResourceTemplate(){Register(SystemMemory, 0, 0, 0, 0)}, + * .. + * .. + * .. + * + * } + * Each Register() encodes how to access that specific register. + * e.g. a sample PCC entry has the following encoding: + * + * Register ( + * PCC, + * AddressSpaceKeyword + * 8, + * //RegisterBitWidth + * 8, + * //RegisterBitOffset + * 0x30, + * //RegisterAddress + * 9 + * //AccessSize (subspace ID) + * 0 + * ) + * } + * + * This function walks through all the per CPU _CPC entries and extracts + * the Register details. + * + * Return: 0 for success or negative value for err. + */ +int acpi_cppc_processor_probe(struct acpi_processor *pr) +{ + struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL}; + union acpi_object *out_obj, *cpc_obj; + struct cpc_desc *cpc_ptr; + struct cpc_reg *gas_t; + acpi_handle handle = pr->handle; + unsigned int num_ent, i, cpc_rev, ret = 0; + acpi_status status; + + /* Parse the ACPI _CPC table for this cpu. */ + if (!acpi_has_method(handle, "_CPC")) { + pr_debug("_CPC table not found\n"); + ret = -ENODEV; + goto out_buf_free; + } + + status = acpi_evaluate_object(handle, "_CPC", NULL, &output); + if (ACPI_FAILURE(status)) { + ret = -ENODEV; + goto out_buf_free; + } + + out_obj = (union acpi_object *) output.pointer; + if (out_obj->type != ACPI_TYPE_PACKAGE) { + ret = -ENODEV; + goto out_buf_free; + } + + cpc_ptr = kzalloc(sizeof(struct cpc_desc), GFP_KERNEL); + if (!cpc_ptr) + return -ENOMEM; + + /* First entry is NumEntries. */ + cpc_obj = &out_obj->package.elements[0]; + if (cpc_obj->type == ACPI_TYPE_INTEGER) { + num_ent = cpc_obj->integer.value; + } else { + pr_debug("Unexpected entry type(%d) for NumEntries\n", + cpc_obj->type); + goto out_free; + } + + /* Only support CPPCv2. Bail otherwise. */ + if (num_ent != CPPC_NUM_ENT) { + pr_err("Firmware exports %d entries. Expected: %d\n", + num_ent, CPPC_NUM_ENT); + ret = -EINVAL; + goto out_free; + } + + /* Second entry should be revision. */ + cpc_obj = &out_obj->package.elements[1]; + if (cpc_obj->type == ACPI_TYPE_INTEGER) { + cpc_rev = cpc_obj->integer.value; + } else { + pr_debug("Unexpected entry type(%d) for Revision\n", + cpc_obj->type); + goto out_free; + } + + if (cpc_rev != CPPC_REV) { + pr_err("Firmware exports revision:%d. Expected:%d\n", + cpc_rev, CPPC_REV); + goto out_free; + } + + /* Iterate through remaining entries in _CPC */ + for (i = 2; i < num_ent; i++) { + cpc_obj = &out_obj->package.elements[i]; + + if (cpc_obj->type == ACPI_TYPE_INTEGER) { + cpc_ptr->cpc_regs[i-2].type = + ACPI_TYPE_INTEGER; + cpc_ptr->cpc_regs[i-2].cpc_entry.int_value = + cpc_obj->integer.value; + } else if (cpc_obj->type == ACPI_TYPE_BUFFER) { + gas_t = (struct cpc_reg *) + cpc_obj->buffer.pointer; + + /* + * The PCC Subspace index is encoded inside + * the CPC table entries. The same PCC index + * will be used for all the PCC entries, + * so extract it only once. + */ + if (gas_t->space_id == + ACPI_ADR_SPACE_PLATFORM_COMM) { + if (pcc_subspace_idx < 0) + pcc_subspace_idx = + gas_t->access_width; + else if (pcc_subspace_idx != + gas_t->access_width) { + /* + * Mismatched PCC id detected. + * Firmware bug. + */ + goto out_free; + } + } + + cpc_ptr->cpc_regs[i-2].type = + ACPI_TYPE_BUFFER; + cpc_ptr->cpc_regs[i-2].cpc_entry.reg = + (struct cpc_reg) { + .space_id = gas_t->space_id, + .length = gas_t->length, + .bit_width = gas_t->bit_width, + .bit_offset = gas_t->bit_offset, + .address = gas_t->address, + .access_width = + gas_t->access_width, + }; + } else { + pr_debug("Error in entry:%d in CPC table.\n", i); + ret = -EINVAL; + goto out_free; + } + } + + /* Plug it into this CPUs CPC descriptor. */ + per_cpu(cpc_desc_ptr, pr->id) = cpc_ptr; + + /* Parse PSD data for this CPU */ + ret = acpi_get_psd(cpc_ptr, handle); + if (ret) + goto out_free; + + /* Register PCC channel once for all CPUs. */ + if (!pcc_channel_acquired) { + ret = register_pcc_channel(pcc_subspace_idx); + if (ret) + goto out_free; + } + + /* Everything looks okay */ + pr_info("Successfully parsed CPC struct for CPU: %d\n", pr->id); + + kfree(output.pointer); + return 0; + +out_free: + cpc_ptr = per_cpu(cpc_desc_ptr, pr->id); + kfree(cpc_ptr); + +out_buf_free: + kfree(output.pointer); + return -ENODEV; +} +EXPORT_SYMBOL_GPL(acpi_cppc_processor_probe); + +static u64 cpc_trans(struct cpc_register_resource *reg, int cmd, u64 write_val, + bool is_pcc) +{ + u64 addr; + u64 read_val = 0; + + /* PCC communication addr space begins at byte offset 0x8. */ + addr = is_pcc ? (u64)pcc_comm_addr + 0x8 + reg->cpc_entry.reg.address : + reg->cpc_entry.reg.address; + + if (reg->type == ACPI_TYPE_BUFFER) { + switch (reg->cpc_entry.reg.bit_width) { + case 8: + if (cmd == CMD_READ) + read_val = readb((void *) (addr)); + else if (cmd == CMD_WRITE) + writeb(write_val, (void *)(addr)); + else + pr_debug("Unsupported cmd type: %d\n", cmd); + break; + case 16: + if (cmd == CMD_READ) + read_val = readw((void *) (addr)); + else if (cmd == CMD_WRITE) + writew(write_val, (void *)(addr)); + else + pr_debug("Unsupported cmd type: %d\n", cmd); + break; + case 32: + if (cmd == CMD_READ) + read_val = readl((void *) (addr)); + else if (cmd == CMD_WRITE) + writel(write_val, (void *)(addr)); + else + pr_debug("Unsupported cmd type: %d\n", cmd); + break; + case 64: + if (cmd == CMD_READ) + read_val = readq((void *) (addr)); + else if (cmd == CMD_WRITE) + writeq(write_val, (void *)(addr)); + else + pr_debug("Unsupported cmd type: %d\n", cmd); + break; + default: + pr_debug("Unsupported bit width for CPC cmd:%d\n", + cmd); + break; + } + } else if (reg->type == ACPI_TYPE_INTEGER) { + if (cmd == CMD_READ) + read_val = reg->cpc_entry.int_value; + else if (cmd == CMD_WRITE) + reg->cpc_entry.int_value = write_val; + else + pr_debug("Unsupported cmd type: %d\n", cmd); + } else + pr_debug("Unsupported CPC entry type:%d\n", reg->type); + + return read_val; +} + +/** + * cppc_get_perf_caps - Get a CPUs performance capabilities. + * @cpunum: CPU from which to get capabilities info. + * @perf_caps: ptr to cppc_perf_caps. See cppc_acpi.h + * + * Return - 0 for success with perf_caps populated else + * -ERRNO. + */ +int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps) +{ + struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); + struct cpc_register_resource *highest_reg, *lowest_reg, *ref_perf, + *nom_perf; + u64 min, max, ref, nom; + bool is_pcc = false; + int ret; + + if (!cpc_desc) { + pr_debug("No CPC descriptor for CPU:%d\n", cpunum); + return -ENODEV; + } + + highest_reg = &cpc_desc->cpc_regs[HIGHEST_PERF]; + lowest_reg = &cpc_desc->cpc_regs[LOWEST_PERF]; + ref_perf = &cpc_desc->cpc_regs[REFERENCE_PERF]; + nom_perf = &cpc_desc->cpc_regs[NOMINAL_PERF]; + + spin_lock(&pcc_lock); + + /* Are any of the regs PCC ?*/ + if ((highest_reg->cpc_entry.reg.space_id == + ACPI_ADR_SPACE_PLATFORM_COMM) || + (lowest_reg->cpc_entry.reg.space_id == + ACPI_ADR_SPACE_PLATFORM_COMM) || + (ref_perf->cpc_entry.reg.space_id == + ACPI_ADR_SPACE_PLATFORM_COMM) || + (nom_perf->cpc_entry.reg.space_id == + ACPI_ADR_SPACE_PLATFORM_COMM)) + is_pcc = true; + + if (is_pcc) { + /* + * Min time OS should wait before sending + * next command. + */ + udelay(pcc_cmd_delay); + /* Ring doorbell */ + ret = send_pcc_cmd(CMD_READ); + if (ret) { + spin_unlock(&pcc_lock); + return -EIO; + } + } + + max = cpc_trans(highest_reg, CMD_READ, 0, is_pcc); + perf_caps->highest_perf = max; + + min = cpc_trans(lowest_reg, CMD_READ, 0, is_pcc); + perf_caps->lowest_perf = min; + + ref = cpc_trans(ref_perf, CMD_READ, 0, is_pcc); + perf_caps->reference_perf = ref; + + nom = cpc_trans(nom_perf, CMD_READ, 0, is_pcc); + perf_caps->nominal_perf = nom; + + if (!ref) + perf_caps->reference_perf = perf_caps->nominal_perf; + + spin_unlock(&pcc_lock); + + if (!perf_caps->highest_perf || + !perf_caps->lowest_perf || + !perf_caps->reference_perf || + !perf_caps->nominal_perf) { + return -EINVAL; + } + + return 0; +} +EXPORT_SYMBOL_GPL(cppc_get_perf_caps); + +/** + * cppc_get_perf_ctrs - Read a CPUs performance feedback counters. + * @cpunum: CPU from which to read counters. + * @perf_fb_ctrs: ptr to cppc_perf_fb_ctrs. See cppc_acpi.h + * + * Return - 0 for success with perf_fb_ctrs populated else + * -ERRNO. + */ +int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs) +{ + struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); + struct cpc_register_resource *delivered_reg, *reference_reg; + u64 delivered, reference; + bool is_pcc = false; + int ret; + + if (!cpc_desc) { + pr_debug("No CPC descriptor for CPU:%d\n", cpunum); + return -ENODEV; + } + + delivered_reg = &cpc_desc->cpc_regs[DELIVERED_CTR]; + reference_reg = &cpc_desc->cpc_regs[REFERENCE_CTR]; + + spin_lock(&pcc_lock); + + /* Are any of the regs PCC ?*/ + if ((delivered_reg->cpc_entry.reg.space_id == + ACPI_ADR_SPACE_PLATFORM_COMM) || + (reference_reg->cpc_entry.reg.space_id == + ACPI_ADR_SPACE_PLATFORM_COMM)) + is_pcc = true; + + if (is_pcc) { + /* + * Min time OS should wait before sending + * next command. + */ + udelay(pcc_cmd_delay); + /* Ring doorbell */ + ret = send_pcc_cmd(CMD_READ); + if (ret) { + spin_unlock(&pcc_lock); + return -EIO; + } + } + + delivered = cpc_trans(delivered_reg, CMD_READ, 0, is_pcc); + reference = cpc_trans(reference_reg, CMD_READ, 0, is_pcc); + + spin_unlock(&pcc_lock); + + if (!delivered || !reference) + return -EINVAL; + + perf_fb_ctrs->delivered = delivered; + perf_fb_ctrs->reference = reference; + + perf_fb_ctrs->delivered -= perf_fb_ctrs->prev_delivered; + perf_fb_ctrs->reference -= perf_fb_ctrs->prev_reference; + + perf_fb_ctrs->prev_delivered = delivered; + perf_fb_ctrs->prev_reference = reference; + + return 0; +} +EXPORT_SYMBOL_GPL(cppc_get_perf_ctrs); + +/** + * cppc_set_perf - Set a CPUs performance controls. + * @cpu: CPU for which to set performance controls. + * @perf_ctrls: ptr to cppc_perf_ctrls. See cppc_acpi.h + * + * Return: 0 for success, -ERRNO otherwise. + */ +int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls) +{ + struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu); + struct cpc_register_resource *desired_reg; + int ret = 0; + bool is_pcc = false; + + if (!cpc_desc) { + pr_debug("No CPC descriptor for CPU:%d\n", cpu); + return -ENODEV; + } + + desired_reg = &cpc_desc->cpc_regs[DESIRED_PERF]; + + spin_lock(&pcc_lock); + + /* Is this a PCC reg ?*/ + if (desired_reg->cpc_entry.reg.space_id == + ACPI_ADR_SPACE_PLATFORM_COMM) + is_pcc = true; + + cpc_trans(desired_reg, CMD_WRITE, + perf_ctrls->desired_perf, is_pcc); + + if (is_pcc) { + /* + * Min time OS should wait before sending + * next command. + */ + udelay(pcc_cmd_delay); + /* Ring doorbell */ + ret = send_pcc_cmd(CMD_READ); + } + + spin_unlock(&pcc_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(cppc_set_perf); diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h new file mode 100644 index 0000000..b97d2b6 --- /dev/null +++ b/include/acpi/cppc_acpi.h @@ -0,0 +1,137 @@ +/* + * CPPC (Collaborative Processor Performance Control) methods used + * by CPUfreq drivers. + * + * (C) Copyright 2014, 2015 Linaro Ltd. + * Author: Ashwin Chaugule ashwin.chaugule@linaro.org + * + * 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. + */ + +#ifndef _CPPC_ACPI_H +#define _CPPC_ACPI_H + +#include <linux/acpi.h> +#include <linux/mailbox_controller.h> +#include <linux/mailbox_client.h> +#include <linux/types.h> + +#include <acpi/processor.h> + +/* Only support CPPCv2 for now. */ +#define CPPC_NUM_ENT 21 +#define CPPC_REV 2 + +#define PCC_CMD_COMPLETE 1 +#define MAX_CPC_REG_ENT 19 + +/* CPPC specific PCC commands. */ +#define CMD_READ 0 +#define CMD_WRITE 1 + +/* Each register has the folowing format. */ +struct cpc_reg { + u8 descriptor; + u16 length; + u8 space_id; + u8 bit_width; + u8 bit_offset; + u8 access_width; + u64 __iomem address; +} __packed; + +/* + * Each entry in the CPC table is either + * of type ACPI_TYPE_BUFFER or + * ACPI_TYPE_INTEGER. + */ +struct cpc_register_resource { + acpi_object_type type; + union { + struct cpc_reg reg; + u64 int_value; + } cpc_entry; +}; + +/* Container to hold the CPC details for each CPU */ +struct cpc_desc { + int num_entries; + int version; + struct cpc_register_resource cpc_regs[MAX_CPC_REG_ENT]; + struct acpi_psd_package domain_info; +}; + +/* These are indexes into the per-cpu cpc_regs[]. Order is important. */ +enum cppc_regs { + HIGHEST_PERF, + NOMINAL_PERF, + LOW_NON_LINEAR_PERF, + LOWEST_PERF, + GUARANTEED_PERF, + DESIRED_PERF, + MIN_PERF, + MAX_PERF, + PERF_REDUC_TOLERANCE, + TIME_WINDOW, + CTR_WRAP_TIME, + REFERENCE_CTR, + DELIVERED_CTR, + PERF_LIMITED, + ENABLE, + AUTO_SEL_ENABLE, + AUTO_ACT_WINDOW, + ENERGY_PERF, + REFERENCE_PERF, +}; + +/* + * Categorization of registers as described + * in the ACPI v.5.1 spec. + * XXX: Only filling up ones which are used by governors + * today. + */ +struct cppc_perf_caps { + u32 highest_perf; + u32 nominal_perf; + u32 reference_perf; + u32 lowest_perf; +}; + +struct cppc_perf_ctrls { + u32 max_perf; + u32 min_perf; + u32 desired_perf; +}; + +struct cppc_perf_fb_ctrs { + u64 reference; + u64 prev_reference; + u64 delivered; + u64 prev_delivered; +}; + +/* Per CPU container for runtime CPPC management. */ +struct cpudata { + int cpu; + struct cppc_perf_caps perf_caps; + struct cppc_perf_ctrls perf_ctrls; + struct cppc_perf_fb_ctrs perf_fb_ctrs; + struct cpufreq_policy *cur_policy; + unsigned int shared_type; + cpumask_var_t shared_cpu_map; +}; + +extern int cppc_get_perf_ctrs(int cpu, struct cppc_perf_fb_ctrs *perf_fb_ctrs); +extern int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls); +extern int cppc_get_perf_caps(int cpu, struct cppc_perf_caps *caps); +extern int acpi_get_psd_map(struct cpudata **); + +/* Methods to interact with the PCC mailbox controller. */ +extern struct mbox_chan * + pcc_mbox_request_channel(struct mbox_client *, unsigned int); +extern int mbox_send_message(struct mbox_chan *chan, void *mssg); + +#endif /* _CPPC_ACPI_H*/

Add weak functions for architectures which do not support hot-adding and removing CPUs which aren't detected at bootup. (e.g. via MADT).

This helps preserve the Kconfig dependency from:

commit cbfc1bae55bb ("[ACPI] ACPI_HOTPLUG_CPU Kconfig dependency update")

prevent:

HOTPLUG_CPU=y ACPI_PROCESSOR=y ACPI_HOTPLUG_CPU=n

Signed-off-by: Ashwin Chaugule ashwin.chaugule@linaro.org --- drivers/acpi/acpi_processor.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)

diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 92a5f73..e1e0285 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -164,6 +164,24 @@ static int acpi_processor_errata(void) -------------------------------------------------------------------------- */

#ifdef CONFIG_ACPI_HOTPLUG_CPU +int __weak acpi_map_cpu(acpi_handle handle, + phys_cpuid_t physid, int *pcpu) +{ + return -ENODEV; +} + +int __weak acpi_unmap_cpu(int cpu) +{ + return -ENODEV; +} + +int __weak arch_register_cpu(int cpu) +{ + return -ENODEV; +} + +void __weak arch_unregister_cpu(int cpu) {} + static int acpi_processor_hotadd_init(struct acpi_processor *pr) { unsigned long long sta;

PCC is made selectable only by clients which use it. e.g. CPPC Default it to disabled so that it is not included accidentally on platforms which dont use it.

Signed-off-by: Ashwin Chaugule ashwin.chaugule@linaro.org Reviewed-by: Al Stone al.stone@linaro.org --- drivers/mailbox/Kconfig | 1 + 1 file changed, 1 insertion(+)

diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig index e269f08..bbec500 100644 --- a/drivers/mailbox/Kconfig +++ b/drivers/mailbox/Kconfig @@ -46,6 +46,7 @@ config OMAP_MBOX_KFIFO_SIZE config PCC bool "Platform Communication Channel Driver" depends on ACPI + default n help ACPI 5.0+ spec defines a generic mode of communication between the OS and a platform such as the BMC. This medium