Messages in this thread | | | From | "Yuan, Perry" <> | Subject | RE: [PATCH v3 1/8] ACPI: CPPC: Add AMD pstate energy performance preference cppc control | Date | Sun, 13 Nov 2022 16:28:24 +0000 |
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[AMD Official Use Only - General]
Hi Mario,
> -----Original Message----- > From: Limonciello, Mario <Mario.Limonciello@amd.com> > Sent: Tuesday, November 8, 2022 2:45 AM > To: Yuan, Perry <Perry.Yuan@amd.com>; rafael.j.wysocki@intel.com; Huang, > Ray <Ray.Huang@amd.com>; viresh.kumar@linaro.org > Cc: Sharma, Deepak <Deepak.Sharma@amd.com>; Fontenot, Nathan > <Nathan.Fontenot@amd.com>; Deucher, Alexander > <Alexander.Deucher@amd.com>; Huang, Shimmer > <Shimmer.Huang@amd.com>; Du, Xiaojian <Xiaojian.Du@amd.com>; Meng, > Li (Jassmine) <Li.Meng@amd.com>; linux-pm@vger.kernel.org; linux- > kernel@vger.kernel.org > Subject: Re: [PATCH v3 1/8] ACPI: CPPC: Add AMD pstate energy performance > preference cppc control > > On 11/7/2022 11:56, Perry Yuan wrote: > > Add the EPP(Energy Performance Preference) support for the AMD SoCs > > without the dedicated CPPC MSR, those SoCs need to add this cppc acpi > > functions to update EPP values and desired perf value. > > As far as I can tell this is generic code. Although the reason you're submitting > it is for enabling AMD SoCs, the commit message should be worded as such. >
Thanks for your suggestions, fixed in V4.
> > > > In order to get EPP worked, cppc_get_epp_caps() will query EPP > > preference value and cppc_set_epp_perf() will set EPP new value. > > Before the EPP works, pstate driver will use cppc_set_auto_epp() to > > enable EPP function from firmware firstly. > > This could more succinctly say: > > "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." >
Changed in v4 as you suggested.
> > > > Signed-off-by: Perry Yuan <Perry.Yuan@amd.com> > > --- > > drivers/acpi/cppc_acpi.c | 126 > +++++++++++++++++++++++++++++++++++++++ > > include/acpi/cppc_acpi.h | 17 ++++++ > > 2 files changed, 143 insertions(+) > > > > diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index > > 093675b1a1ff..d9c38dee1f48 100644 > > --- a/drivers/acpi/cppc_acpi.c > > +++ b/drivers/acpi/cppc_acpi.c > > @@ -1365,6 +1365,132 @@ int cppc_get_perf_ctrs(int cpunum, struct > cppc_perf_fb_ctrs *perf_fb_ctrs) > > } > > EXPORT_SYMBOL_GPL(cppc_get_perf_ctrs); > > > > +/** > > + * cppc_get_epp_caps - Get the energy preference register value. > > + * @cpunum: CPU from which to get epp preference level. > > + * @perf_caps: Return address. > > + * > > + * Return: 0 for success, -EIO otherwise. > > + */ > > +int cppc_get_epp_caps(int cpunum, struct cppc_perf_caps *perf_caps) { > > + struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); > > + struct cpc_register_resource *energy_perf_reg; > > + u64 energy_perf; > > + > > + if (!cpc_desc) { > > + pr_warn("No CPC descriptor for CPU:%d\n", cpunum); > > + return -ENODEV; > > + } > > + > > + energy_perf_reg = &cpc_desc->cpc_regs[ENERGY_PERF]; > > + > > + if (!CPC_SUPPORTED(energy_perf_reg)) > > + pr_warn("energy perf reg update is unsupported!\n"); > > No need to add a explanation point at the end. > > As this is a per-CPU message I wonder if this would be better as > pr_warn_once()? Othewrise some systems with large numbers of cores > might potentially show this message quite a few times.
I made some new changes and combined the two Epp call functions. Remove some unnecessary log printing. Please help to take a look at the V4 if you have any concerns.
Perry .
> > > + > > + if (CPC_IN_PCC(energy_perf_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 -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) { > > + cpc_read(cpunum, energy_perf_reg, &energy_perf); > > + perf_caps->energy_perf = energy_perf; > > + } else { > > + ret = -EIO; > > + } > > + > > + up_write(&pcc_ss_data->pcc_lock); > > + > > + return ret; > > + } > > + > > + return 0; > > +} > > +EXPORT_SYMBOL_GPL(cppc_get_epp_caps); > > + > > +int cppc_set_auto_epp(int cpu, bool enable) { > > + int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); > > + 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; > > + > > + if (!cpc_desc) { > > + pr_warn("No CPC descriptor for CPU:%d\n", cpu); > > Is this actually warn worthy? I would think it's fine a debug like we have for > the other _CPC missing messages. >
Fixed in V4.
> > + return -EINVAL; > > + } > > + > > + auto_sel_reg = &cpc_desc->cpc_regs[AUTO_SEL_ENABLE]; > > + > > + if (CPC_IN_PCC(auto_sel_reg)) { > > + if (pcc_ss_id < 0) > > + return -ENODEV; > > + > > + ret = cpc_write(cpu, auto_sel_reg, enable); > > + 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; > > + } > > + > > + return cpc_write(cpu, auto_sel_reg, enable); } > > +EXPORT_SYMBOL_GPL(cppc_set_auto_epp); > > + > > +/* > > + * Set Energy Performance Preference Register value through > > + * Performance Controls Interface > > + */ > > +int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls) { > > + int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); > > + struct cpc_register_resource *epp_set_reg; > > + struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu); > > + struct cppc_pcc_data *pcc_ss_data = NULL; > > + int ret = -EINVAL; > > + > > + if (!cpc_desc) { > > + pr_warn("No CPC descriptor for CPU:%d\n", cpu); > > Is this actually warn worthy? I would think it's fine a debug like we have for > the other _CPC missing messages.
Fixed in V4.
> > > + return -EINVAL; > > + } > > + > > + epp_set_reg = &cpc_desc->cpc_regs[ENERGY_PERF]; > > + > > + if (CPC_IN_PCC(epp_set_reg)) { > > + if (pcc_ss_id < 0) > > + return -ENODEV; > > + > > + 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); > > cppc_set_auto_epp and cppc_set_epp_perf have nearly the same code in the > if block. I wonder if it's worth having a static helper function for this purpose > that takes "reg" and "value" as arguments?
Good idea, Ray also suggested to merge them. I combined the two calls into single in V4. Please take a look.
Perry.
> > > + } > > + > > + 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..10d91aeedaca 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 +151,9 @@ 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_set_auto_epp(int cpu, bool enable); extern int > > +cppc_get_epp_caps(int cpunum, struct cppc_perf_caps *perf_caps); > > +extern int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls > > +*perf_ctrls); > > #else /* !CONFIG_ACPI_CPPC_LIB */ > > static inline int cppc_get_desired_perf(int cpunum, u64 *desired_perf) > > { > > @@ -202,6 +207,18 @@ static inline int cpc_write_ffh(int cpunum, struct > cpc_reg *reg, u64 val) > > { > > return -ENOTSUPP; > > } > > +static inline int cppc_set_auto_epp(int cpu, bool enable) { > > + return -ENOTSUPP; > > +} > > +static inline int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls > > +*perf_ctrls) { > > + return -ENOTSUPP; > > +} > > +static inline int cppc_get_epp_caps(int cpunum, struct cppc_perf_caps > > +*perf_caps) { > > + return -ENOTSUPP; > > +} > > #endif /* !CONFIG_ACPI_CPPC_LIB */ > > > > #endif /* _CPPC_ACPI_H*/
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