Add sysfs interfaces for CPPC autonomous selection in the cppc_cpufreq driver. Signed-off-by: Lifeng Zheng <zhenglifeng1@xxxxxxxxxx> --- .../ABI/testing/sysfs-devices-system-cpu | 54 +++++++ drivers/cpufreq/cppc_cpufreq.c | 138 ++++++++++++++++++ 2 files changed, 192 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 206079d3bd5b..3d87c3bb3fe2 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -268,6 +268,60 @@ Description: Discover CPUs in the same CPU frequency coordination domain This file is only present if the acpi-cpufreq or the cppc-cpufreq drivers are in use. +What: /sys/devices/system/cpu/cpuX/cpufreq/auto_select +Date: October 2024 +Contact: linux-pm@xxxxxxxxxxxxxxx +Description: Autonomous selection enable + + Read/write interface to control autonomous selection enable + Read returns autonomous selection status: + 0: autonomous selection is disabled + 1: autonomous selection is enabled + + Write 'y' or '1' or 'on' to enable autonomous selection. + Write 'n' or '0' or 'off' to disable autonomous selection. + + This file only presents if the cppc-cpufreq driver is in use. + +What: /sys/devices/system/cpu/cpuX/cpufreq/auto_act_window +Date: October 2024 +Contact: linux-pm@xxxxxxxxxxxxxxx +Description: Autonomous activity window + + This file indicates a moving utilization sensitivity window to + the platform's autonomous selection policy. + + Read/write an integer represents autonomous activity window (in + microseconds) from/to this file. The max value to write is + 1270000000 but the max significand is 127. This means that if 128 + is written to this file, 127 will be stored. If the value is + greater than 130, only the first two digits will be saved as + significand. + + Writing a zero value to this file enable the platform to + determine an appropriate Activity Window depending on the workload. + + Writing to this file only has meaning when Autonomous Selection is + enabled. + + This file only presents if the cppc-cpufreq driver is in use. + +What: /sys/devices/system/cpu/cpuX/cpufreq/energy_perf +Date: October 2024 +Contact: linux-pm@xxxxxxxxxxxxxxx +Description: Energy performance preference + + Read/write an 8-bit integer from/to this file. This file + represents a range of values from 0 (performance preference) to + 0xFF (energy efficiency preference) that influences the rate of + performance increase/decrease and the result of the hardware's + energy efficiency and performance optimization policies. + + Writing to this file only has meaning when Autonomous Selection is + enabled. + + This file only presents if the cppc-cpufreq driver is in use. + What: /sys/devices/system/cpu/cpu*/cache/index3/cache_disable_{0,1} Date: August 2008 diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c index 2b8708475ac7..351ecdd49ad4 100644 --- a/drivers/cpufreq/cppc_cpufreq.c +++ b/drivers/cpufreq/cppc_cpufreq.c @@ -792,10 +792,148 @@ static ssize_t show_freqdomain_cpus(struct cpufreq_policy *policy, char *buf) return cpufreq_show_cpus(cpu_data->shared_cpu_map, buf); } + +static ssize_t show_auto_select(struct cpufreq_policy *policy, char *buf) +{ + u64 val; + int ret; + + ret = cppc_get_auto_sel(policy->cpu, &val); + + /* show "<unsupported>" when this register is not supported by cpc */ + if (ret == -EOPNOTSUPP) + return sysfs_emit(buf, "%s\n", "<unsupported>"); + + if (ret) + return ret; + + return sysfs_emit(buf, "%llu\n", val); +} + +static ssize_t store_auto_select(struct cpufreq_policy *policy, + const char *buf, size_t count) +{ + bool val; + int ret; + + ret = kstrtobool(buf, &val); + if (ret) + return ret; + + ret = cppc_set_auto_sel(policy->cpu, val); + if (ret) + return ret; + + return count; +} + +#define AUTO_ACT_WINDOW_SIG_BIT_SIZE (7) +#define AUTO_ACT_WINDOW_EXP_BIT_SIZE (3) +#define AUTO_ACT_WINDOW_MAX_SIG ((1 << AUTO_ACT_WINDOW_SIG_BIT_SIZE) - 1) +#define AUTO_ACT_WINDOW_MAX_EXP ((1 << AUTO_ACT_WINDOW_EXP_BIT_SIZE) - 1) +/* AUTO_ACT_WINDOW_MAX_SIG is 127, so 128 and 129 will decay to 127 when writing */ +#define AUTO_ACT_WINDOW_SIG_CARRY_THRESH 129 + +static ssize_t show_auto_act_window(struct cpufreq_policy *policy, char *buf) +{ + unsigned int exp; + u64 val, sig; + int ret; + + ret = cppc_get_auto_act_window(policy->cpu, &val); + + /* show "<unsupported>" when this register is not supported by cpc */ + if (ret == -EOPNOTSUPP) + return sysfs_emit(buf, "%s\n", "<unsupported>"); + + if (ret) + return ret; + + sig = val & AUTO_ACT_WINDOW_MAX_SIG; + exp = (val >> AUTO_ACT_WINDOW_SIG_BIT_SIZE) & AUTO_ACT_WINDOW_MAX_EXP; + + return sysfs_emit(buf, "%llu\n", sig * int_pow(10, exp)); +} + +static ssize_t store_auto_act_window(struct cpufreq_policy *policy, + const char *buf, size_t count) +{ + unsigned long usec; + int digits = 0; + int ret; + + ret = kstrtoul(buf, 0, &usec); + if (ret) + return ret; + + if (usec > AUTO_ACT_WINDOW_MAX_SIG * int_pow(10, AUTO_ACT_WINDOW_MAX_EXP)) + return -EINVAL; + + while (usec > AUTO_ACT_WINDOW_SIG_CARRY_THRESH) { + usec /= 10; + digits += 1; + } + + if (usec > AUTO_ACT_WINDOW_MAX_SIG) + usec = AUTO_ACT_WINDOW_MAX_SIG; + + ret = cppc_set_auto_act_window(policy->cpu, + (digits << AUTO_ACT_WINDOW_SIG_BIT_SIZE) + usec); + if (ret) + return ret; + + return count; +} + +static ssize_t show_energy_perf(struct cpufreq_policy *policy, char *buf) +{ + u64 val; + int ret; + + ret = cppc_get_epp_perf(policy->cpu, &val); + + /* show "<unsupported>" when this register is not supported by cpc */ + if (ret == -EOPNOTSUPP) + return sysfs_emit(buf, "%s\n", "<unsupported>"); + + if (ret) + return ret; + + return sysfs_emit(buf, "%llu\n", val); +} + +#define ENERGY_PERF_MAX (0xFF) + +static ssize_t store_energy_perf(struct cpufreq_policy *policy, + const char *buf, size_t count) +{ + unsigned long val; + int ret; + + ret = kstrtoul(buf, 0, &val); + if (ret) + return ret; + + if (val > ENERGY_PERF_MAX) + return -EINVAL; + + ret = cppc_set_epp(policy->cpu, val); + if (ret) + return ret; + + return count; +} + cpufreq_freq_attr_ro(freqdomain_cpus); +cpufreq_freq_attr_rw(auto_select); +cpufreq_freq_attr_rw(auto_act_window); +cpufreq_freq_attr_rw(energy_perf); static struct freq_attr *cppc_cpufreq_attr[] = { &freqdomain_cpus, + &auto_select, + &auto_act_window, + &energy_perf, NULL, }; -- 2.33.0