From 7bc1fcd399018245575974508c26e882da0bd915 Mon Sep 17 00:00:00 2001 From: Perry Yuan Date: Tue, 31 Jan 2023 17:00:06 +0800 Subject: ACPI: CPPC: Add AMD pstate energy performance preference cppc control 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. 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. Acked-by: Huang Rui Reviewed-by: Mario Limonciello Reviewed-by: Wyes Karny Tested-by: Wyes Karny Signed-off-by: Perry Yuan Signed-off-by: Rafael J. Wysocki --- drivers/acpi/cppc_acpi.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) (limited to 'drivers/acpi') diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index 0f17b1c32718..02d83c807271 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -1153,6 +1153,19 @@ 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 +1378,60 @@ out_err: } 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; + + 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 for CPU:%d\n", cpu); + 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. -- cgit v1.2.3