| Message ID | 20241216091603.1247644-2-zhenglifeng1@huawei.com |
|---|---|
| State | New |
| Headers | show |
| Series | Support for autonomous selection in cppc_cpufreq | expand |
On 2024/12/17 21:48, Pierre Gondois wrote: > Hello Lifeng, > > On 12/16/24 10:16, Lifeng Zheng wrote: >> Rename cppc_get_perf() to cppc_get_reg_val() as a generic function to read >> cppc registers, with four changes: >> >> 1. Change the error kind to "no such device" when pcc_ss_id < 0, which >> means that this cpu cannot get a valid pcc_ss_id. >> >> 2. Add a check to verify if the register is a cpc supported one before >> using it. >> >> 3. Extract the operations if register is in pcc out as >> cppc_get_reg_val_in_pcc(). >> >> 4. Return the result of cpc_read() instead of 0. >> >> Add cppc_set_reg_val_in_pcc() and cppc_set_reg_val() as generic functions >> for setting cppc registers value. Unlike other set reg ABIs, >> cppc_set_reg_val() checks CPC_SUPPORTED right after getting the register, >> because the rest of the operations are meaningless if this register is not >> a cpc supported one. >> >> These functions can be used to reduce some existing code duplication. >> >> Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com> >> --- >> drivers/acpi/cppc_acpi.c | 111 +++++++++++++++++++++++++++++---------- >> 1 file changed, 84 insertions(+), 27 deletions(-) >> >> diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c >> index c1f3568d0c50..bb5333a503a2 100644 >> --- a/drivers/acpi/cppc_acpi.c >> +++ b/drivers/acpi/cppc_acpi.c >> @@ -1179,43 +1179,100 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val) >> return ret_val; >> } >> -static int cppc_get_perf(int cpunum, enum cppc_regs reg_idx, u64 *perf) >> +static int cppc_get_reg_val_in_pcc(int cpu, struct cpc_register_resource *reg, u64 *val) >> { >> - struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); >> + int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); >> + struct cppc_pcc_data *pcc_ss_data = NULL; >> + int ret; >> + >> + if (pcc_ss_id < 0) { >> + pr_debug("Invalid pcc_ss_id\n"); >> + return -ENODEV; >> + } >> + >> + pcc_ss_data = pcc_data[pcc_ss_id]; >> + >> + down_write(&pcc_ss_data->pcc_lock); >> + >> + if (send_pcc_cmd(pcc_ss_id, CMD_READ) >= 0) >> + ret = cpc_read(cpu, reg, val); >> + else >> + ret = -EIO; >> + >> + up_write(&pcc_ss_data->pcc_lock); >> + >> + return ret; >> +} >> + >> +static int cppc_get_reg_val(int cpu, enum cppc_regs reg_idx, u64 *val) >> +{ >> + struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu); >> struct cpc_register_resource *reg; >> if (!cpc_desc) { >> - pr_debug("No CPC descriptor for CPU:%d\n", cpunum); >> + pr_debug("No CPC descriptor for CPU:%d\n", cpu); >> return -ENODEV; >> } >> reg = &cpc_desc->cpc_regs[reg_idx]; >> - if (CPC_IN_PCC(reg)) { >> - int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum); >> - struct cppc_pcc_data *pcc_ss_data = NULL; >> - int ret = 0; >> - >> - if (pcc_ss_id < 0) >> - return -EIO; >> + if (!CPC_SUPPORTED(reg)) { >> + pr_debug("CPC register (reg_idx=%d) is not supported\n", reg_idx); >> + return -EOPNOTSUPP; >> + } > > I think this is only valid for optional fields. Meaning that: > - if the function is used one day for the mandatory 'Lowest Performance' > field, an integer value of 0 would be valid. > - if the function is used for a mandatory field containing a NULL Buffer, > it seems we would return -EFAULT currently, through cpc_read(). -EOPNOTSUPP > doesn't seem appropriate as the field would be mandatory. > > Maybe the function needs an additional 'bool optional' input parameter > to do these check conditionally. Indeed, I should have judged the type before doing this check. But adding a input parameter is not a really nice way to me. How about adding a bool list of length MAX_CPC_REG_ENT in cppc_acpi.h to indicate wheter it is optional? > >> - pcc_ss_data = pcc_data[pcc_ss_id]; >> + if (CPC_IN_PCC(reg)) >> + return cppc_get_reg_val_in_pcc(cpu, reg, val); >> - down_write(&pcc_ss_data->pcc_lock); >> + return cpc_read(cpu, reg, val); >> +} >> - if (send_pcc_cmd(pcc_ss_id, CMD_READ) >= 0) >> - cpc_read(cpunum, reg, perf); >> - else >> - ret = -EIO; >> +static int cppc_set_reg_val_in_pcc(int cpu, struct cpc_register_resource *reg, u64 val) >> +{ >> + int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); >> + struct cppc_pcc_data *pcc_ss_data = NULL; >> + int ret; >> - up_write(&pcc_ss_data->pcc_lock); >> + if (pcc_ss_id < 0) { >> + pr_debug("Invalid pcc_ss_id\n"); >> + return -ENODEV; >> + } >> + ret = cpc_write(cpu, reg, val); >> + if (ret) >> return ret; >> + >> + pcc_ss_data = pcc_data[pcc_ss_id]; >> + >> + down_write(&pcc_ss_data->pcc_lock); >> + /* after writing CPC, transfer the ownership of PCC to platform */ >> + ret = send_pcc_cmd(pcc_ss_id, CMD_WRITE); >> + up_write(&pcc_ss_data->pcc_lock); >> + >> + return ret; >> +} >> + >> +static int cppc_set_reg_val(int cpu, enum cppc_regs reg_idx, u64 val) >> +{ >> + struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu); >> + struct cpc_register_resource *reg; >> + >> + if (!cpc_desc) { >> + pr_debug("No CPC descriptor for CPU:%d\n", cpu); >> + return -ENODEV; >> } >> - cpc_read(cpunum, reg, perf); >> + reg = &cpc_desc->cpc_regs[reg_idx]; >> - return 0; >> + if (!CPC_SUPPORTED(reg)) { >> + pr_debug("CPC register (reg_idx=%d) is not supported\n", reg_idx); >> + return -EOPNOTSUPP; >> + } > > Similarly to cppc_get_reg_val(), if a field is: > - mandatory + integer: currently doesn't exist. Not sure we should > try to detect that, but might be safer. > - mandatory + buffer: should not return -EOPNOTSUPP I think > - optional + integer: e.g.: 'Autonomous Selection Enable Register', > we should return -EOPNOTSUPP. It seems that currently, if the integer > value is 1, I get a 'write error: Bad address' > - optional + buffer: > should effectively return -EOPNOTSUPP if the buffer is NULL. Actually, cpc_write() doesn't check field type and treats the field as a buffer. That's why you get 'Bad address' error when the integer value is 1. I think the existing code needs to be improved, otherwise there may be unexpected problems. Do you mean we should return -EOPNOTSUPP no matter what to be written if this field is a optional + integer one? And what about a mandatory + integer one. Should we directly write the int_value? Looking forward to your opinion. > >> + >> + if (CPC_IN_PCC(reg)) >> + return cppc_set_reg_val_in_pcc(cpu, reg, val); >> + >> + return cpc_write(cpu, reg, val); >> } >> /** >> @@ -1223,11 +1280,11 @@ static int cppc_get_perf(int cpunum, enum cppc_regs reg_idx, u64 *perf) >> * @cpunum: CPU from which to get desired performance. >> * @desired_perf: Return address. >> * >> - * Return: 0 for success, -EIO otherwise. >> + * Return: 0 for success, -ERRNO otherwise. >> */ >> int cppc_get_desired_perf(int cpunum, u64 *desired_perf) >> { >> - return cppc_get_perf(cpunum, DESIRED_PERF, desired_perf); >> + return cppc_get_reg_val(cpunum, DESIRED_PERF, desired_perf); >> } >> EXPORT_SYMBOL_GPL(cppc_get_desired_perf); >> @@ -1236,11 +1293,11 @@ EXPORT_SYMBOL_GPL(cppc_get_desired_perf); >> * @cpunum: CPU from which to get nominal performance. >> * @nominal_perf: Return address. >> * >> - * Return: 0 for success, -EIO otherwise. >> + * Return: 0 for success, -ERRNO otherwise. >> */ >> int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf) >> { >> - return cppc_get_perf(cpunum, NOMINAL_PERF, nominal_perf); >> + return cppc_get_reg_val(cpunum, NOMINAL_PERF, nominal_perf); >> } >> /** >> @@ -1248,11 +1305,11 @@ int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf) >> * @cpunum: CPU from which to get highest performance. >> * @highest_perf: Return address. >> * >> - * Return: 0 for success, -EIO otherwise. >> + * Return: 0 for success, -ERRNO otherwise. >> */ >> int cppc_get_highest_perf(int cpunum, u64 *highest_perf) >> { >> - return cppc_get_perf(cpunum, HIGHEST_PERF, highest_perf); >> + return cppc_get_reg_val(cpunum, HIGHEST_PERF, highest_perf); >> } >> EXPORT_SYMBOL_GPL(cppc_get_highest_perf); >> @@ -1261,11 +1318,11 @@ EXPORT_SYMBOL_GPL(cppc_get_highest_perf); >> * @cpunum: CPU from which to get epp preference value. >> * @epp_perf: Return address. >> * >> - * Return: 0 for success, -EIO otherwise. >> + * Return: 0 for success, -ERRNO otherwise. >> */ >> int cppc_get_epp_perf(int cpunum, u64 *epp_perf) >> { >> - return cppc_get_perf(cpunum, ENERGY_PERF, epp_perf); >> + return cppc_get_reg_val(cpunum, ENERGY_PERF, epp_perf); >> } >> EXPORT_SYMBOL_GPL(cppc_get_epp_perf); >> >
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index c1f3568d0c50..bb5333a503a2 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -1179,43 +1179,100 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val) return ret_val; } -static int cppc_get_perf(int cpunum, enum cppc_regs reg_idx, u64 *perf) +static int cppc_get_reg_val_in_pcc(int cpu, struct cpc_register_resource *reg, u64 *val) { - struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); + int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); + struct cppc_pcc_data *pcc_ss_data = NULL; + int ret; + + if (pcc_ss_id < 0) { + pr_debug("Invalid pcc_ss_id\n"); + return -ENODEV; + } + + pcc_ss_data = pcc_data[pcc_ss_id]; + + down_write(&pcc_ss_data->pcc_lock); + + if (send_pcc_cmd(pcc_ss_id, CMD_READ) >= 0) + ret = cpc_read(cpu, reg, val); + else + ret = -EIO; + + up_write(&pcc_ss_data->pcc_lock); + + return ret; +} + +static int cppc_get_reg_val(int cpu, enum cppc_regs reg_idx, u64 *val) +{ + struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu); struct cpc_register_resource *reg; if (!cpc_desc) { - pr_debug("No CPC descriptor for CPU:%d\n", cpunum); + pr_debug("No CPC descriptor for CPU:%d\n", cpu); return -ENODEV; } reg = &cpc_desc->cpc_regs[reg_idx]; - if (CPC_IN_PCC(reg)) { - int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum); - struct cppc_pcc_data *pcc_ss_data = NULL; - int ret = 0; - - if (pcc_ss_id < 0) - return -EIO; + if (!CPC_SUPPORTED(reg)) { + pr_debug("CPC register (reg_idx=%d) is not supported\n", reg_idx); + return -EOPNOTSUPP; + } - pcc_ss_data = pcc_data[pcc_ss_id]; + if (CPC_IN_PCC(reg)) + return cppc_get_reg_val_in_pcc(cpu, reg, val); - down_write(&pcc_ss_data->pcc_lock); + return cpc_read(cpu, reg, val); +} - if (send_pcc_cmd(pcc_ss_id, CMD_READ) >= 0) - cpc_read(cpunum, reg, perf); - else - ret = -EIO; +static int cppc_set_reg_val_in_pcc(int cpu, struct cpc_register_resource *reg, u64 val) +{ + int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); + struct cppc_pcc_data *pcc_ss_data = NULL; + int ret; - up_write(&pcc_ss_data->pcc_lock); + if (pcc_ss_id < 0) { + pr_debug("Invalid pcc_ss_id\n"); + return -ENODEV; + } + ret = cpc_write(cpu, reg, val); + if (ret) return ret; + + pcc_ss_data = pcc_data[pcc_ss_id]; + + down_write(&pcc_ss_data->pcc_lock); + /* after writing CPC, transfer the ownership of PCC to platform */ + ret = send_pcc_cmd(pcc_ss_id, CMD_WRITE); + up_write(&pcc_ss_data->pcc_lock); + + return ret; +} + +static int cppc_set_reg_val(int cpu, enum cppc_regs reg_idx, u64 val) +{ + struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu); + struct cpc_register_resource *reg; + + if (!cpc_desc) { + pr_debug("No CPC descriptor for CPU:%d\n", cpu); + return -ENODEV; } - cpc_read(cpunum, reg, perf); + reg = &cpc_desc->cpc_regs[reg_idx]; - return 0; + if (!CPC_SUPPORTED(reg)) { + pr_debug("CPC register (reg_idx=%d) is not supported\n", reg_idx); + return -EOPNOTSUPP; + } + + if (CPC_IN_PCC(reg)) + return cppc_set_reg_val_in_pcc(cpu, reg, val); + + return cpc_write(cpu, reg, val); } /** @@ -1223,11 +1280,11 @@ static int cppc_get_perf(int cpunum, enum cppc_regs reg_idx, u64 *perf) * @cpunum: CPU from which to get desired performance. * @desired_perf: Return address. * - * Return: 0 for success, -EIO otherwise. + * Return: 0 for success, -ERRNO otherwise. */ int cppc_get_desired_perf(int cpunum, u64 *desired_perf) { - return cppc_get_perf(cpunum, DESIRED_PERF, desired_perf); + return cppc_get_reg_val(cpunum, DESIRED_PERF, desired_perf); } EXPORT_SYMBOL_GPL(cppc_get_desired_perf); @@ -1236,11 +1293,11 @@ EXPORT_SYMBOL_GPL(cppc_get_desired_perf); * @cpunum: CPU from which to get nominal performance. * @nominal_perf: Return address. * - * Return: 0 for success, -EIO otherwise. + * Return: 0 for success, -ERRNO otherwise. */ int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf) { - return cppc_get_perf(cpunum, NOMINAL_PERF, nominal_perf); + return cppc_get_reg_val(cpunum, NOMINAL_PERF, nominal_perf); } /** @@ -1248,11 +1305,11 @@ int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf) * @cpunum: CPU from which to get highest performance. * @highest_perf: Return address. * - * Return: 0 for success, -EIO otherwise. + * Return: 0 for success, -ERRNO otherwise. */ int cppc_get_highest_perf(int cpunum, u64 *highest_perf) { - return cppc_get_perf(cpunum, HIGHEST_PERF, highest_perf); + return cppc_get_reg_val(cpunum, HIGHEST_PERF, highest_perf); } EXPORT_SYMBOL_GPL(cppc_get_highest_perf); @@ -1261,11 +1318,11 @@ EXPORT_SYMBOL_GPL(cppc_get_highest_perf); * @cpunum: CPU from which to get epp preference value. * @epp_perf: Return address. * - * Return: 0 for success, -EIO otherwise. + * Return: 0 for success, -ERRNO otherwise. */ int cppc_get_epp_perf(int cpunum, u64 *epp_perf) { - return cppc_get_perf(cpunum, ENERGY_PERF, epp_perf); + return cppc_get_reg_val(cpunum, ENERGY_PERF, epp_perf); } EXPORT_SYMBOL_GPL(cppc_get_epp_perf);
Rename cppc_get_perf() to cppc_get_reg_val() as a generic function to read cppc registers, with four changes: 1. Change the error kind to "no such device" when pcc_ss_id < 0, which means that this cpu cannot get a valid pcc_ss_id. 2. Add a check to verify if the register is a cpc supported one before using it. 3. Extract the operations if register is in pcc out as cppc_get_reg_val_in_pcc(). 4. Return the result of cpc_read() instead of 0. Add cppc_set_reg_val_in_pcc() and cppc_set_reg_val() as generic functions for setting cppc registers value. Unlike other set reg ABIs, cppc_set_reg_val() checks CPC_SUPPORTED right after getting the register, because the rest of the operations are meaningless if this register is not a cpc supported one. These functions can be used to reduce some existing code duplication. Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com> --- drivers/acpi/cppc_acpi.c | 111 +++++++++++++++++++++++++++++---------- 1 file changed, 84 insertions(+), 27 deletions(-)