linux-kernel - [PATCH v2 2/7] ACPI: CPPC: extend APIs to support auto

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Message-ID: <20250823200121.1320197-3-sumitg@nvidia.com>
Date: Sun, 24 Aug 2025 01:31:15 +0530
From: Sumit Gupta <sumitg@...dia.com>
To: <rafael@...nel.org>, <viresh.kumar@...aro.org>, <lenb@...nel.org>,
	<robert.moore@...el.com>, <corbet@....net>, <pierre.gondois@....com>,
	<zhenglifeng1@...wei.com>, <ray.huang@....com>, <gautham.shenoy@....com>,
	<mario.limonciello@....com>, <perry.yuan@....com>,
	<linux-pm@...r.kernel.org>, <linux-acpi@...r.kernel.org>,
	<linux-doc@...r.kernel.org>, <acpica-devel@...ts.linux.dev>,
	<linux-kernel@...r.kernel.org>
CC: <linux-tegra@...r.kernel.org>, <treding@...dia.com>,
	<jonathanh@...dia.com>, <vsethi@...dia.com>, <ksitaraman@...dia.com>,
	<sanjayc@...dia.com>, <bbasu@...dia.com>, <sumitg@...dia.com>
Subject: [PATCH v2 2/7] ACPI: CPPC: extend APIs to support auto_sel and epp

Add read of auto_sel in cppc_get_perf_caps().
Add write of auto_sel and epp in cppc_set_epp_and_autosel().

Signed-off-by: Sumit Gupta <sumitg@...dia.com>
---
 drivers/acpi/cppc_acpi.c | 32 +++++++++++++++++++++++++++-----
 1 file changed, 27 insertions(+), 5 deletions(-)

diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 24baaa298af3..fbcfbe4bcbf0 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -1344,8 +1344,8 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
 	struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum);
 	struct cpc_register_resource *highest_reg, *lowest_reg,
 		*lowest_non_linear_reg, *nominal_reg, *guaranteed_reg,
-		*low_freq_reg = NULL, *nom_freq_reg = NULL;
-	u64 high, low, guaranteed, nom, min_nonlinear, low_f = 0, nom_f = 0;
+		*low_freq_reg = NULL, *nom_freq_reg = NULL, *auto_sel_reg = NULL;
+	u64 high, low, guaranteed, nom, min_nonlinear, low_f = 0, nom_f = 0, auto_sel = 0;
 	int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum);
 	struct cppc_pcc_data *pcc_ss_data = NULL;
 	int ret = 0, regs_in_pcc = 0;
@@ -1362,11 +1362,12 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
 	low_freq_reg = &cpc_desc->cpc_regs[LOWEST_FREQ];
 	nom_freq_reg = &cpc_desc->cpc_regs[NOMINAL_FREQ];
 	guaranteed_reg = &cpc_desc->cpc_regs[GUARANTEED_PERF];
+	auto_sel_reg = &cpc_desc->cpc_regs[AUTO_SEL_ENABLE];
 
 	/* Are any of the regs PCC ?*/
 	if (CPC_IN_PCC(highest_reg) || CPC_IN_PCC(lowest_reg) ||
 		CPC_IN_PCC(lowest_non_linear_reg) || CPC_IN_PCC(nominal_reg) ||
-		CPC_IN_PCC(low_freq_reg) || CPC_IN_PCC(nom_freq_reg)) {
+		CPC_IN_PCC(low_freq_reg) || CPC_IN_PCC(nom_freq_reg) || CPC_IN_PCC(auto_sel_reg)) {
 		if (pcc_ss_id < 0) {
 			pr_debug("Invalid pcc_ss_id\n");
 			return -ENODEV;
@@ -1414,6 +1415,9 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
 	perf_caps->lowest_freq = low_f;
 	perf_caps->nominal_freq = nom_f;
 
+	if (CPC_SUPPORTED(auto_sel_reg))
+		cpc_read(cpunum, auto_sel_reg, &auto_sel);
+	perf_caps->auto_sel = (bool)auto_sel;
 
 out_err:
 	if (regs_in_pcc)
@@ -1555,6 +1559,8 @@ int cppc_set_epp_and_autosel(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool e
 	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;
+	bool autosel_support_in_ffh_or_sysmem;
+	bool epp_support_in_ffh_or_sysmem;
 	int ret;
 
 	if (!cpc_desc) {
@@ -1565,6 +1571,11 @@ int cppc_set_epp_and_autosel(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool e
 	auto_sel_reg = &cpc_desc->cpc_regs[AUTO_SEL_ENABLE];
 	epp_set_reg = &cpc_desc->cpc_regs[ENERGY_PERF];
 
+	epp_support_in_ffh_or_sysmem = CPC_SUPPORTED(epp_set_reg) &&
+				(CPC_IN_FFH(epp_set_reg) || CPC_IN_SYSTEM_MEMORY(epp_set_reg));
+	autosel_support_in_ffh_or_sysmem = CPC_SUPPORTED(auto_sel_reg) &&
+				(CPC_IN_FFH(auto_sel_reg) || CPC_IN_SYSTEM_MEMORY(auto_sel_reg));
+
 	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);
@@ -1590,8 +1601,19 @@ int cppc_set_epp_and_autosel(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool e
 		ret = send_pcc_cmd(pcc_ss_id, CMD_WRITE);
 		up_write(&pcc_ss_data->pcc_lock);
 	} else if (osc_cpc_flexible_adr_space_confirmed &&
-		   CPC_SUPPORTED(epp_set_reg) && CPC_IN_FFH(epp_set_reg)) {
-		ret = cpc_write(cpu, epp_set_reg, perf_ctrls->energy_perf);
+		   epp_support_in_ffh_or_sysmem && autosel_support_in_ffh_or_sysmem) {
+			ret = cpc_write(cpu, auto_sel_reg, enable);
+			if (ret) {
+				pr_debug("Failed to write auto_sel=%d for CPU:%d\n", enable, cpu);
+				return ret;
+			}
+
+			ret = cpc_write(cpu, epp_set_reg, perf_ctrls->energy_perf);
+			if (ret) {
+				pr_debug("Failed to write energy_perf=%u for CPU:%d\n",
+					 perf_ctrls->energy_perf, cpu);
+				return ret;
+			}
 	} else {
 		ret = -ENOTSUPP;
 		pr_debug("_CPC in PCC and _CPC in FFH are not supported\n");
-- 
2.34.1