From c984f5d5d45bd5f80d6a9d8541e809300c963aca Mon Sep 17 00:00:00 2001 From: Wyes Karny Date: Tue, 7 Mar 2023 11:27:36 +0000 Subject: ACPI: CPPC: Add auto select register read/write support For some AMD shared memory based systems, the autonomous selection bit needed to be set explicitly. Add autonomous selection register related APIs to acpi driver, which amd_pstate driver uses later. Acked-by: Huang Rui Reviewed-by: Mario Limonciello Tested-by: Oleksandr Natalenko Signed-off-by: Wyes Karny [ rjw: Fixed up kerneldoc comments, white space adjustment, subject edits ] Signed-off-by: Rafael J. Wysocki --- drivers/acpi/cppc_acpi.c | 96 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 96 insertions(+) (limited to 'drivers/acpi') diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index 523bad4e3a0c..7ff269a78c20 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -1433,6 +1433,102 @@ int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool enable) } EXPORT_SYMBOL_GPL(cppc_set_epp_perf); +/** + * cppc_get_auto_sel_caps - Read autonomous selection register. + * @cpunum : CPU from which to read register. + * @perf_caps : struct where autonomous selection register value is updated. + */ +int cppc_get_auto_sel_caps(int cpunum, struct cppc_perf_caps *perf_caps) +{ + struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); + struct cpc_register_resource *auto_sel_reg; + u64 auto_sel; + + if (!cpc_desc) { + pr_debug("No CPC descriptor for CPU:%d\n", cpunum); + return -ENODEV; + } + + auto_sel_reg = &cpc_desc->cpc_regs[AUTO_SEL_ENABLE]; + + if (!CPC_SUPPORTED(auto_sel_reg)) + pr_warn_once("Autonomous mode is not unsupported!\n"); + + if (CPC_IN_PCC(auto_sel_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, auto_sel_reg, &auto_sel); + perf_caps->auto_sel = (bool)auto_sel; + } else { + ret = -EIO; + } + + up_write(&pcc_ss_data->pcc_lock); + + return ret; + } + + return 0; +} +EXPORT_SYMBOL_GPL(cppc_get_auto_sel_caps); + +/** + * cppc_set_auto_sel - Write autonomous selection register. + * @cpu : CPU to which to write register. + * @enable : the desired value of autonomous selection resiter to be updated. + */ +int cppc_set_auto_sel(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_debug("No CPC descriptor for CPU:%d\n", cpu); + return -ENODEV; + } + + auto_sel_reg = &cpc_desc->cpc_regs[AUTO_SEL_ENABLE]; + + if (CPC_IN_PCC(auto_sel_reg)) { + if (pcc_ss_id < 0) { + pr_debug("Invalid pcc_ss_id\n"); + return -ENODEV; + } + + if (CPC_SUPPORTED(auto_sel_reg)) { + 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); + } else { + ret = -ENOTSUPP; + pr_debug("_CPC in PCC is not supported\n"); + } + + return ret; +} +EXPORT_SYMBOL_GPL(cppc_set_auto_sel); + /** * cppc_set_enable - Set to enable CPPC on the processor by writing the * Continuous Performance Control package EnableRegister field. -- cgit v1.2.3