| Message ID | 20250409065703.1461867-9-zhenglifeng1@huawei.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add functions for getting and setting registers related to autonomous selection in cppc_acpi | expand |
On 2025/4/10 2:59, Mario Limonciello wrote: > On 4/9/2025 1:57 AM, Lifeng Zheng wrote: >> cppc_set_epp - write energy performance preference register value, based on >> ACPI 6.5, s8.4.6.1.7 >> >> cppc_get_auto_act_window - read autonomous activity window register value, >> based on ACPI 6.5, s8.4.6.1.6 >> >> cppc_set_auto_act_window - write autonomous activity window register value, >> based on ACPI 6.5, s8.4.6.1.6 >> >> Reviewed-by: Pierre Gondois <pierre.gondois@arm.com> >> Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com> >> --- >> drivers/acpi/cppc_acpi.c | 80 ++++++++++++++++++++++++++++++++++++++++ >> include/acpi/cppc_acpi.h | 24 ++++++++++++ >> 2 files changed, 104 insertions(+) >> >> diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c >> index ef2394c074e3..3d5eace44af5 100644 >> --- a/drivers/acpi/cppc_acpi.c >> +++ b/drivers/acpi/cppc_acpi.c >> @@ -1608,6 +1608,86 @@ int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool enable) >> } >> EXPORT_SYMBOL_GPL(cppc_set_epp_perf); >> +/** >> + * cppc_set_epp() - Write the EPP register. >> + * @cpu: CPU on which to write register. >> + * @epp_val: Value to write to the EPP register. >> + */ >> +int cppc_set_epp(int cpu, u64 epp_val) > > Any reason this is a u64 argument when the biggest value you can support is 0xFF? Presumably you could drop the the bounds check below if you limited the variable size. cppc_get_epp_perf() uses u64, so I think it is better to keep the same. > >> +{ >> + if (epp_val > CPPC_ENERGY_PERF_MAX) >> + return -EINVAL; >> + >> + return cppc_set_reg_val(cpu, ENERGY_PERF, epp_val); >> +} >> +EXPORT_SYMBOL_GPL(cppc_set_epp); >> + >> +/** >> + * cppc_get_auto_act_window() - Read autonomous activity window register. >> + * @cpu: CPU from which to read register. >> + * @auto_act_window: Return address. >> + * >> + * According to ACPI 6.5, s8.4.6.1.6, the value read from the autonomous >> + * activity window register consists of two parts: a 7 bits value indicate >> + * significand and a 3 bits value indicate exponent. >> + */ >> +int cppc_get_auto_act_window(int cpu, u64 *auto_act_window) >> +{ >> + unsigned int exp; >> + u64 val, sig; >> + int ret; >> + >> + ret = cppc_get_reg_val(cpu, AUTO_ACT_WINDOW, &val); >> + if (ret) >> + return ret; >> + >> + sig = val & CPPC_AUTO_ACT_WINDOW_MAX_SIG; >> + exp = (val >> CPPC_AUTO_ACT_WINDOW_SIG_BIT_SIZE) & CPPC_AUTO_ACT_WINDOW_MAX_EXP; >> + *auto_act_window = sig * int_pow(10, exp); >> + >> + return 0; >> +} >> +EXPORT_SYMBOL_GPL(cppc_get_auto_act_window); > > Since this is exported code, do you perhaps want a check that auto_act_window is not NULL to avoid a possible accidental NULL pointer dereference? Yes. Make sense. Thanks! > >> + >> +/** >> + * cppc_set_auto_act_window() - Write autonomous activity window register. >> + * @cpu: CPU on which to write register. >> + * @auto_act_window: usec value to write to the autonomous activity window register. >> + * >> + * According to ACPI 6.5, s8.4.6.1.6, the value to write to the autonomous >> + * activity window register consists of two parts: a 7 bits value indicate >> + * significand and a 3 bits value indicate exponent. >> + */ >> +int cppc_set_auto_act_window(int cpu, u64 auto_act_window) >> +{ >> + /* The max value to stroe is 1270000000 */ > > store Thanks! > >> + u64 max_val = CPPC_AUTO_ACT_WINDOW_MAX_SIG * int_pow(10, CPPC_AUTO_ACT_WINDOW_MAX_EXP); >> + int exp = 0; >> + u64 val; >> + >> + if (auto_act_window > max_val) >> + return -EINVAL; >> + >> + /* >> + * The max significand is 127, when auto_act_window is larger than >> + * 129, discard the precision of the last digit and increase the >> + * exponent by 1. >> + */ >> + while (auto_act_window > CPPC_AUTO_ACT_WINDOW_SIG_CARRY_THRESH) { >> + auto_act_window /= 10; >> + exp += 1; >> + } >> + >> + /* For 128 and 129, cut it to 127. */ >> + if (auto_act_window > CPPC_AUTO_ACT_WINDOW_MAX_SIG) >> + auto_act_window = CPPC_AUTO_ACT_WINDOW_MAX_SIG; >> + >> + val = (exp << CPPC_AUTO_ACT_WINDOW_SIG_BIT_SIZE) + auto_act_window; >> + >> + return cppc_set_reg_val(cpu, AUTO_ACT_WINDOW, val); >> +} >> +EXPORT_SYMBOL_GPL(cppc_set_auto_act_window); >> + >> /** >> * cppc_get_auto_sel() - Read autonomous selection register. >> * @cpu: CPU from which to read register. >> diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h >> index 31767c65be20..325e9543e08f 100644 >> --- a/include/acpi/cppc_acpi.h >> +++ b/include/acpi/cppc_acpi.h >> @@ -32,6 +32,15 @@ >> #define CMD_READ 0 >> #define CMD_WRITE 1 >> +#define CPPC_AUTO_ACT_WINDOW_SIG_BIT_SIZE (7) >> +#define CPPC_AUTO_ACT_WINDOW_EXP_BIT_SIZE (3) >> +#define CPPC_AUTO_ACT_WINDOW_MAX_SIG ((1 << CPPC_AUTO_ACT_WINDOW_SIG_BIT_SIZE) - 1) >> +#define CPPC_AUTO_ACT_WINDOW_MAX_EXP ((1 << CPPC_AUTO_ACT_WINDOW_EXP_BIT_SIZE) - 1) >> +/* CPPC_AUTO_ACT_WINDOW_MAX_SIG is 127, so 128 and 129 will decay to 127 when writing */ >> +#define CPPC_AUTO_ACT_WINDOW_SIG_CARRY_THRESH 129 >> + >> +#define CPPC_ENERGY_PERF_MAX (0xFF) >> + >> /* Each register has the folowing format. */ >> struct cpc_reg { >> u8 descriptor; >> @@ -159,6 +168,9 @@ 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); >> extern int cppc_get_epp_perf(int cpunum, u64 *epp_perf); >> extern int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool enable); >> +extern int cppc_set_epp(int cpu, u64 epp_val); >> +extern int cppc_get_auto_act_window(int cpu, u64 *auto_act_window); >> +extern int cppc_set_auto_act_window(int cpu, u64 auto_act_window); >> extern int cppc_get_auto_sel(int cpu, bool *enable); >> extern int cppc_set_auto_sel(int cpu, bool enable); >> extern int amd_get_highest_perf(unsigned int cpu, u32 *highest_perf); >> @@ -229,6 +241,18 @@ static inline int cppc_get_epp_perf(int cpunum, u64 *epp_perf) >> { >> return -EOPNOTSUPP; >> } >> +static inline int cppc_set_epp(int cpu, u64 epp_val) >> +{ >> + return -EOPNOTSUPP; >> +} >> +static inline int cppc_get_auto_act_window(int cpu, u64 *auto_act_window) >> +{ >> + return -EOPNOTSUPP; >> +} >> +static inline int cppc_set_auto_act_window(int cpu, u64 auto_act_window) >> +{ >> + return -EOPNOTSUPP; >> +} >> static inline int cppc_get_auto_sel(int cpu, bool *enable) >> { >> return -EOPNOTSUPP; >
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index ef2394c074e3..3d5eace44af5 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -1608,6 +1608,86 @@ int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool enable) } EXPORT_SYMBOL_GPL(cppc_set_epp_perf); +/** + * cppc_set_epp() - Write the EPP register. + * @cpu: CPU on which to write register. + * @epp_val: Value to write to the EPP register. + */ +int cppc_set_epp(int cpu, u64 epp_val) +{ + if (epp_val > CPPC_ENERGY_PERF_MAX) + return -EINVAL; + + return cppc_set_reg_val(cpu, ENERGY_PERF, epp_val); +} +EXPORT_SYMBOL_GPL(cppc_set_epp); + +/** + * cppc_get_auto_act_window() - Read autonomous activity window register. + * @cpu: CPU from which to read register. + * @auto_act_window: Return address. + * + * According to ACPI 6.5, s8.4.6.1.6, the value read from the autonomous + * activity window register consists of two parts: a 7 bits value indicate + * significand and a 3 bits value indicate exponent. + */ +int cppc_get_auto_act_window(int cpu, u64 *auto_act_window) +{ + unsigned int exp; + u64 val, sig; + int ret; + + ret = cppc_get_reg_val(cpu, AUTO_ACT_WINDOW, &val); + if (ret) + return ret; + + sig = val & CPPC_AUTO_ACT_WINDOW_MAX_SIG; + exp = (val >> CPPC_AUTO_ACT_WINDOW_SIG_BIT_SIZE) & CPPC_AUTO_ACT_WINDOW_MAX_EXP; + *auto_act_window = sig * int_pow(10, exp); + + return 0; +} +EXPORT_SYMBOL_GPL(cppc_get_auto_act_window); + +/** + * cppc_set_auto_act_window() - Write autonomous activity window register. + * @cpu: CPU on which to write register. + * @auto_act_window: usec value to write to the autonomous activity window register. + * + * According to ACPI 6.5, s8.4.6.1.6, the value to write to the autonomous + * activity window register consists of two parts: a 7 bits value indicate + * significand and a 3 bits value indicate exponent. + */ +int cppc_set_auto_act_window(int cpu, u64 auto_act_window) +{ + /* The max value to stroe is 1270000000 */ + u64 max_val = CPPC_AUTO_ACT_WINDOW_MAX_SIG * int_pow(10, CPPC_AUTO_ACT_WINDOW_MAX_EXP); + int exp = 0; + u64 val; + + if (auto_act_window > max_val) + return -EINVAL; + + /* + * The max significand is 127, when auto_act_window is larger than + * 129, discard the precision of the last digit and increase the + * exponent by 1. + */ + while (auto_act_window > CPPC_AUTO_ACT_WINDOW_SIG_CARRY_THRESH) { + auto_act_window /= 10; + exp += 1; + } + + /* For 128 and 129, cut it to 127. */ + if (auto_act_window > CPPC_AUTO_ACT_WINDOW_MAX_SIG) + auto_act_window = CPPC_AUTO_ACT_WINDOW_MAX_SIG; + + val = (exp << CPPC_AUTO_ACT_WINDOW_SIG_BIT_SIZE) + auto_act_window; + + return cppc_set_reg_val(cpu, AUTO_ACT_WINDOW, val); +} +EXPORT_SYMBOL_GPL(cppc_set_auto_act_window); + /** * cppc_get_auto_sel() - Read autonomous selection register. * @cpu: CPU from which to read register. diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h index 31767c65be20..325e9543e08f 100644 --- a/include/acpi/cppc_acpi.h +++ b/include/acpi/cppc_acpi.h @@ -32,6 +32,15 @@ #define CMD_READ 0 #define CMD_WRITE 1 +#define CPPC_AUTO_ACT_WINDOW_SIG_BIT_SIZE (7) +#define CPPC_AUTO_ACT_WINDOW_EXP_BIT_SIZE (3) +#define CPPC_AUTO_ACT_WINDOW_MAX_SIG ((1 << CPPC_AUTO_ACT_WINDOW_SIG_BIT_SIZE) - 1) +#define CPPC_AUTO_ACT_WINDOW_MAX_EXP ((1 << CPPC_AUTO_ACT_WINDOW_EXP_BIT_SIZE) - 1) +/* CPPC_AUTO_ACT_WINDOW_MAX_SIG is 127, so 128 and 129 will decay to 127 when writing */ +#define CPPC_AUTO_ACT_WINDOW_SIG_CARRY_THRESH 129 + +#define CPPC_ENERGY_PERF_MAX (0xFF) + /* Each register has the folowing format. */ struct cpc_reg { u8 descriptor; @@ -159,6 +168,9 @@ 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); extern int cppc_get_epp_perf(int cpunum, u64 *epp_perf); extern int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool enable); +extern int cppc_set_epp(int cpu, u64 epp_val); +extern int cppc_get_auto_act_window(int cpu, u64 *auto_act_window); +extern int cppc_set_auto_act_window(int cpu, u64 auto_act_window); extern int cppc_get_auto_sel(int cpu, bool *enable); extern int cppc_set_auto_sel(int cpu, bool enable); extern int amd_get_highest_perf(unsigned int cpu, u32 *highest_perf); @@ -229,6 +241,18 @@ static inline int cppc_get_epp_perf(int cpunum, u64 *epp_perf) { return -EOPNOTSUPP; } +static inline int cppc_set_epp(int cpu, u64 epp_val) +{ + return -EOPNOTSUPP; +} +static inline int cppc_get_auto_act_window(int cpu, u64 *auto_act_window) +{ + return -EOPNOTSUPP; +} +static inline int cppc_set_auto_act_window(int cpu, u64 auto_act_window) +{ + return -EOPNOTSUPP; +} static inline int cppc_get_auto_sel(int cpu, bool *enable) { return -EOPNOTSUPP;