Messages in this thread | | | Date | Mon, 19 Dec 2022 15:09:32 -0600 | Subject | Re: [PATCH v8 01/13] ACPI: CPPC: Add AMD pstate energy performance preference cppc control | From | "Limonciello, Mario" <> |
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For this patch there's a few small nits you should fix for v9. With those fixed:
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
On 12/19/2022 00:40, Perry Yuan wrote: > From: Perry Yuan <Perry.Yuan@amd.com> > > Add support for setting and querying EPP preferences to the generic > CPPC driver. This enables downstream drivers such as amd-pstate to discover > and use these values
Missing a period here at end of the sentence.
> > Downstream drivers that want to use the new symbols cppc_get_epp_caps > and cppc_set_epp_perf for querying and setting EPP preferences will need > to call cppc_set_epp_perf to enable the EPP function firstly. > > Signed-off-by: Perry Yuan <Perry.Yuan@amd.com> > --- > drivers/acpi/cppc_acpi.c | 76 +++++++++++++++++++++++++++++++++++++--- > include/acpi/cppc_acpi.h | 12 +++++++ > 2 files changed, 83 insertions(+), 5 deletions(-) > > diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c > index 093675b1a1ff..81081eb899ea 100644 > --- a/drivers/acpi/cppc_acpi.c > +++ b/drivers/acpi/cppc_acpi.c > @@ -1093,6 +1093,9 @@ static int cppc_get_perf(int cpunum, enum cppc_regs reg_idx, u64 *perf) > { > struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); > struct cpc_register_resource *reg; > + int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum); > + struct cppc_pcc_data *pcc_ss_data = NULL; > + int ret = -EINVAL; > > if (!cpc_desc) { > pr_debug("No CPC descriptor for CPU:%d\n", cpunum); > @@ -1102,10 +1105,6 @@ static int cppc_get_perf(int cpunum, enum cppc_regs reg_idx, u64 *perf) > 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; > > @@ -1125,7 +1124,7 @@ static int cppc_get_perf(int cpunum, enum cppc_regs reg_idx, u64 *perf) > > cpc_read(cpunum, reg, perf); > > - return 0; > + return ret; > } > > /** > @@ -1153,6 +1152,19 @@ int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf) > return cppc_get_perf(cpunum, NOMINAL_PERF, nominal_perf); > } > > +/** > + * cppc_get_epp_perf - Get the epp register value. > + * @cpunum: CPU from which to get epp preference value. > + * @epp_perf: Return address. > + * > + * Return: 0 for success, -EIO otherwise. > + */ > +int cppc_get_epp_perf(int cpunum, u64 *epp_perf) > +{ > + return cppc_get_perf(cpunum, ENERGY_PERF, epp_perf); > +} > +EXPORT_SYMBOL_GPL(cppc_get_epp_perf); > + > /** > * cppc_get_perf_caps - Get a CPU's performance capabilities. > * @cpunum: CPU from which to get capabilities info. > @@ -1365,6 +1377,60 @@ int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs) > } > EXPORT_SYMBOL_GPL(cppc_get_perf_ctrs); > > +/* > + * Set Energy Performance Preference Register value through > + * Performance Controls Interface > + */ > +int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool enable) > +{ > + int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); > + struct cpc_register_resource *epp_set_reg; > + struct cpc_register_resource *auto_sel_reg; > + struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu); > + struct cppc_pcc_data *pcc_ss_data = NULL; > + int ret = -EINVAL;
AFAICT, you don't actually ever return -EINVAL in this function. I think you should just avoid initializing this variable.
> + > + if (!cpc_desc) { > + pr_debug("No CPC descriptor for CPU:%d\n", cpu); > + return -ENODEV; > + } > + > + auto_sel_reg = &cpc_desc->cpc_regs[AUTO_SEL_ENABLE]; > + epp_set_reg = &cpc_desc->cpc_regs[ENERGY_PERF]; > + > + if (CPC_IN_PCC(epp_set_reg) || CPC_IN_PCC(auto_sel_reg)) { > + if (pcc_ss_id < 0) { > + pr_debug("Invalid pcc_ss_id\n");
Would it perhaps be useful to note the cpu # for this message?
> + return -ENODEV; > + } > + > + if (CPC_SUPPORTED(auto_sel_reg)) { > + ret = cpc_write(cpu, auto_sel_reg, enable); > + if (ret) > + return ret; > + } > + > + if (CPC_SUPPORTED(epp_set_reg)) { > + ret = cpc_write(cpu, epp_set_reg, perf_ctrls->energy_perf); > + 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); > + } else { > + ret = -ENOTSUPP; > + pr_debug("_CPC in PCC is not supported\n"); > + } > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(cppc_set_epp_perf); > + > /** > * cppc_set_enable - Set to enable CPPC on the processor by writing the > * Continuous Performance Control package EnableRegister field. > diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h > index c5614444031f..6b487a5bd638 100644 > --- a/include/acpi/cppc_acpi.h > +++ b/include/acpi/cppc_acpi.h > @@ -108,12 +108,14 @@ struct cppc_perf_caps { > u32 lowest_nonlinear_perf; > u32 lowest_freq; > u32 nominal_freq; > + u32 energy_perf; > }; > > struct cppc_perf_ctrls { > u32 max_perf; > u32 min_perf; > u32 desired_perf; > + u32 energy_perf; > }; > > struct cppc_perf_fb_ctrs { > @@ -149,6 +151,8 @@ extern bool cpc_ffh_supported(void); > extern bool cpc_supported_by_cpu(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); > +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); > #else /* !CONFIG_ACPI_CPPC_LIB */ > static inline int cppc_get_desired_perf(int cpunum, u64 *desired_perf) > { > @@ -202,6 +206,14 @@ static inline int cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val) > { > return -ENOTSUPP; > } > +static inline int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool enable) > +{ > + return -ENOTSUPP; > +} > +static inline int cppc_get_epp_perf(int cpunum, u64 *epp_perf) > +{ > + return -ENOTSUPP; > +} > #endif /* !CONFIG_ACPI_CPPC_LIB */ > > #endif /* _CPPC_ACPI_H*/
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