linux/include/acpi/cppc_acpi.h

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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* CPPC (Collaborative Processor Performance Control) methods used
* by CPUfreq drivers.
*
* (C) Copyright 2014, 2015 Linaro Ltd.
* Author: Ashwin Chaugule <ashwin.chaugule@linaro.org>
*/
#ifndef _CPPC_ACPI_H
#define _CPPC_ACPI_H
#include <linux/acpi.h>
#include <linux/cpufreq.h>
#include <linux/types.h>
#include <acpi/pcc.h>
#include <acpi/processor.h>
/* Support CPPCv2 and CPPCv3 */
#define CPPC_V2_REV 2
#define CPPC_V3_REV 3
#define CPPC_V2_NUM_ENT 21
#define CPPC_V3_NUM_ENT 23
#define PCC_CMD_COMPLETE_MASK (1 << 0)
#define PCC_ERROR_MASK (1 << 2)
#define MAX_CPC_REG_ENT 21
/* 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 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;
u64 __iomem *sys_mem_vaddr;
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;
int cpu_id;
int write_cmd_status;
int write_cmd_id;
struct cpc_register_resource cpc_regs[MAX_CPC_REG_ENT];
struct acpi_psd_package domain_info;
struct kobject kobj;
};
/* 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,
LOWEST_FREQ,
NOMINAL_FREQ,
};
/*
* 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 guaranteed_perf;
u32 highest_perf;
u32 nominal_perf;
u32 lowest_perf;
u32 lowest_nonlinear_perf;
u32 lowest_freq;
u32 nominal_freq;
};
struct cppc_perf_ctrls {
u32 max_perf;
u32 min_perf;
u32 desired_perf;
};
struct cppc_perf_fb_ctrs {
u64 reference;
u64 delivered;
u64 reference_perf;
u64 wraparound_time;
};
/* Per CPU container for runtime CPPC management. */
struct cppc_cpudata {
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00
struct list_head node;
struct cppc_perf_caps perf_caps;
struct cppc_perf_ctrls perf_ctrls;
struct cppc_perf_fb_ctrs perf_fb_ctrs;
unsigned int shared_type;
cpumask_var_t shared_cpu_map;
};
#ifdef CONFIG_ACPI_CPPC_LIB
extern int cppc_get_desired_perf(int cpunum, u64 *desired_perf);
extern int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf);
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_set_enable(int cpu, bool enable);
extern int cppc_get_perf_caps(int cpu, struct cppc_perf_caps *caps);
cppc_cpufreq: replace per-cpu data array with a list The cppc_cpudata per-cpu storage was inefficient (1) additional to causing functional issues (2) when CPUs are hotplugged out, due to per-cpu data being improperly initialised. (1) The amount of information needed for CPPC performance control in its cpufreq driver depends on the domain (PSD) coordination type: ANY: One set of CPPC control and capability data (e.g desired performance, highest/lowest performance, etc) applies to all CPUs in the domain. ALL: Same as ANY. To be noted that this type is not currently supported. When supported, information about which CPUs belong to a domain is needed in order for frequency change requests to be sent to each of them. HW: It's necessary to store CPPC control and capability information for all the CPUs. HW will then coordinate the performance state based on their limitations and requests. NONE: Same as HW. No HW coordination is expected. Despite this, the previous initialisation code would indiscriminately allocate memory for all CPUs (all_cpu_data) and unnecessarily duplicate performance capabilities and the domain sharing mask and type for each possible CPU. (2) With the current per-cpu structure, when having ANY coordination, the cppc_cpudata cpu information is not initialised (will remain 0) for all CPUs in a policy, other than policy->cpu. When policy->cpu is hotplugged out, the driver will incorrectly use the uninitialised (0) value of the other CPUs when making frequency changes. Additionally, the previous values stored in the perf_ctrls.desired_perf will be lost when policy->cpu changes. Therefore replace the array of per cpu data with a list. The memory for each structure is allocated at policy init, where a single structure can be allocated per policy, not per cpu. In order to accommodate the struct list_head node in the cppc_cpudata structure, the now unused cpu and cur_policy variables are removed. For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1, (4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows: Before patch: - ANY coordination: total slack req alloc/free caller 0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810 0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808 128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070 768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4 After patch: - ANY coordination: total slack req alloc/free caller 256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410 0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274 Additional notes: - A pointer to the policy's cppc_cpudata is stored in policy->driver_data - Driver registration is skipped if _CPC entries are not present. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-14 12:38:23 +00:00
extern bool acpi_cpc_valid(void);
extern int acpi_get_psd_map(unsigned int cpu, struct cppc_cpudata *cpu_data);
extern unsigned int cppc_get_transition_latency(int cpu);
extern bool cpc_ffh_supported(void);
extern int cpc_read_ffh(int cpunum, struct cpc_reg *reg, u64 *val);
extern int cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val);
#else /* !CONFIG_ACPI_CPPC_LIB */
static inline int cppc_get_desired_perf(int cpunum, u64 *desired_perf)
{
return -ENOTSUPP;
}
static inline int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf)
{
return -ENOTSUPP;
}
static inline int cppc_get_perf_ctrs(int cpu, struct cppc_perf_fb_ctrs *perf_fb_ctrs)
{
return -ENOTSUPP;
}
static inline int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
{
return -ENOTSUPP;
}
static inline int cppc_set_enable(int cpu, bool enable)
{
return -ENOTSUPP;
}
static inline int cppc_get_perf_caps(int cpu, struct cppc_perf_caps *caps)
{
return -ENOTSUPP;
}
static inline bool acpi_cpc_valid(void)
{
return false;
}
static inline unsigned int cppc_get_transition_latency(int cpu)
{
return CPUFREQ_ETERNAL;
}
static inline bool cpc_ffh_supported(void)
{
return false;
}
static inline int cpc_read_ffh(int cpunum, struct cpc_reg *reg, u64 *val)
{
return -ENOTSUPP;
}
static inline int cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val)
{
return -ENOTSUPP;
}
#endif /* !CONFIG_ACPI_CPPC_LIB */
#endif /* _CPPC_ACPI_H*/