Message-ID: <20250211103737.447704-2-sumitg@nvidia.com>
Date: Tue, 11 Feb 2025 16:07:33 +0530
From: Sumit Gupta <sumitg@...dia.com>
To: <rafael@...nel.org>, <viresh.kumar@...aro.org>, <lenb@...nel.org>,
	<robert.moore@...el.com>, <corbet@....net>, <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>, <sashal@...dia.com>, <vsethi@...dia.com>,
	<ksitaraman@...dia.com>, <sanjayc@...dia.com>, <bbasu@...dia.com>,
	<sumitg@...dia.com>
Subject: [Patch 1/5] ACPI: CPPC: add read perf ctrls api and rename few existing

Add new API cppc_get_perf_ctrls() to read the performance controls.
Rename the following existing API's for more clarity.
- cppc_set_perf() to cppc_set_perf_ctrls().
- cppc_get_perf_ctrs() to cppc_get_perf_fb_ctrs().
- cppc_get_perf_ctrs_sample() to cppc_get_perf_fb_ctrs_sample().

Also, remove redundant energy_perf field from 'struct cppc_perf_caps'.
It is also present in 'struct cppc_perf_ctrls' which is being used.

Signed-off-by: Sumit Gupta <sumitg@...dia.com>
---
 drivers/acpi/cppc_acpi.c       | 91 +++++++++++++++++++++++++++++-----
 drivers/cpufreq/cppc_cpufreq.c | 26 +++++-----
 include/acpi/cppc_acpi.h       | 14 ++++--
 3 files changed, 101 insertions(+), 30 deletions(-)

diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index f193e713825a..297e689f8214 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -59,7 +59,7 @@ struct cppc_pcc_data {
 	/*
 	 * Lock to provide controlled access to the PCC channel.
 	 *
-	 * For performance critical usecases(currently cppc_set_perf)
+	 * For performance critical usecases(currently cppc_set_perf_ctrls)
 	 *	We need to take read_lock and check if channel belongs to OSPM
 	 * before reading or writing to PCC subspace
 	 *	We need to take write_lock before transferring the channel
@@ -169,8 +169,8 @@ show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, guaranteed_perf);
 show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, lowest_freq);
 show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, nominal_freq);
 
-show_cppc_data(cppc_get_perf_ctrs, cppc_perf_fb_ctrs, reference_perf);
-show_cppc_data(cppc_get_perf_ctrs, cppc_perf_fb_ctrs, wraparound_time);
+show_cppc_data(cppc_get_perf_fb_ctrs, cppc_perf_fb_ctrs, reference_perf);
+show_cppc_data(cppc_get_perf_fb_ctrs, cppc_perf_fb_ctrs, wraparound_time);
 
 /* Check for valid access_width, otherwise, fallback to using bit_width */
 #define GET_BIT_WIDTH(reg) ((reg)->access_width ? (8 << ((reg)->access_width - 1)) : (reg)->bit_width)
@@ -189,7 +189,7 @@ static ssize_t show_feedback_ctrs(struct kobject *kobj,
 	struct cppc_perf_fb_ctrs fb_ctrs = {0};
 	int ret;
 
-	ret = cppc_get_perf_ctrs(cpc_ptr->cpu_id, &fb_ctrs);
+	ret = cppc_get_perf_fb_ctrs(cpc_ptr->cpu_id, &fb_ctrs);
 	if (ret)
 		return ret;
 
@@ -1360,7 +1360,7 @@ EXPORT_SYMBOL_GPL(cppc_get_perf_caps);
  *
  * CPPC has flexibility about how CPU performance counters are accessed.
  * One of the choices is PCC regions, which can have a high access latency. This
- * routine allows callers of cppc_get_perf_ctrs() to know this ahead of time.
+ * routine allows callers of cppc_get_perf_fb_ctrs() to know this ahead of time.
  *
  * Return: true if any of the counters are in PCC regions, false otherwise
  */
@@ -1398,13 +1398,13 @@ bool cppc_perf_ctrs_in_pcc(void)
 EXPORT_SYMBOL_GPL(cppc_perf_ctrs_in_pcc);
 
 /**
- * cppc_get_perf_ctrs - Read a CPU's performance feedback counters.
+ * cppc_get_perf_fb_ctrs - Read a CPU's performance feedback counters.
  * @cpunum: CPU from which to read counters.
  * @perf_fb_ctrs: ptr to cppc_perf_fb_ctrs. See cppc_acpi.h
  *
  * Return: 0 for success with perf_fb_ctrs populated else -ERRNO.
  */
-int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs)
+int cppc_get_perf_fb_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs)
 {
 	struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum);
 	struct cpc_register_resource *delivered_reg, *reference_reg,
@@ -1475,7 +1475,7 @@ int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs)
 		up_write(&pcc_ss_data->pcc_lock);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(cppc_get_perf_ctrs);
+EXPORT_SYMBOL_GPL(cppc_get_perf_fb_ctrs);
 
 /*
  * Set Energy Performance Preference Register value through
@@ -1674,15 +1674,82 @@ int cppc_set_enable(int cpu, bool enable)
 	return cpc_write(cpu, enable_reg, enable);
 }
 EXPORT_SYMBOL_GPL(cppc_set_enable);
+/**
+ * cppc_get_perf - Get a CPU's performance controls.
+ * @cpu: CPU for which to get performance controls.
+ * @perf_ctrls: ptr to cppc_perf_ctrls. See cppc_acpi.h
+ *
+ * Return: 0 for success with perf_ctrls, -ERRNO otherwise.
+ */
+int cppc_get_perf_ctrls(int cpu, struct cppc_perf_ctrls *perf_ctrls)
+{
+	struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu);
+	struct cpc_register_resource *desired_perf_reg, *min_perf_reg, *max_perf_reg,
+				     *energy_perf_reg;
+	u64 max, min, desired_perf, energy_perf;
+	int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu);
+	struct cppc_pcc_data *pcc_ss_data = NULL;
+	int ret = 0, regs_in_pcc = 0;
+
+	if (!cpc_desc) {
+		pr_debug("No CPC descriptor for CPU:%d\n", cpu);
+		return -ENODEV;
+	}
+
+	desired_perf_reg = &cpc_desc->cpc_regs[DESIRED_PERF];
+	min_perf_reg = &cpc_desc->cpc_regs[MIN_PERF];
+	max_perf_reg = &cpc_desc->cpc_regs[MAX_PERF];
+	energy_perf_reg = &cpc_desc->cpc_regs[ENERGY_PERF];
+
+	/* Are any of the regs PCC ?*/
+	if (CPC_IN_PCC(desired_perf_reg) || CPC_IN_PCC(min_perf_reg) ||
+	    CPC_IN_PCC(max_perf_reg) || CPC_IN_PCC(energy_perf_reg)) {
+		if (pcc_ss_id < 0) {
+			pr_debug("Invalid pcc_ss_id\n");
+			return -ENODEV;
+		}
+		pcc_ss_data = pcc_data[pcc_ss_id];
+		regs_in_pcc = 1;
+		down_write(&pcc_ss_data->pcc_lock);
+		/* Ring doorbell once to update PCC subspace */
+		if (send_pcc_cmd(pcc_ss_id, CMD_READ) < 0) {
+			ret = -EIO;
+			goto out_err;
+		}
+	}
+
+	/* Read optional elements if present */
+	if (CPC_SUPPORTED(max_perf_reg))
+		cpc_read(cpu, max_perf_reg, &max);
+	perf_ctrls->max_perf = max;
+
+	if (CPC_SUPPORTED(min_perf_reg))
+		cpc_read(cpu, min_perf_reg, &min);
+	perf_ctrls->min_perf = min;
+
+	if (CPC_SUPPORTED(desired_perf_reg))
+		cpc_read(cpu, desired_perf_reg, &desired_perf);
+	perf_ctrls->desired_perf = desired_perf;
+
+	if (CPC_SUPPORTED(energy_perf_reg))
+		cpc_read(cpu, energy_perf_reg, &energy_perf);
+	perf_ctrls->energy_perf = energy_perf;
+
+out_err:
+	if (regs_in_pcc)
+		up_write(&pcc_ss_data->pcc_lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cppc_get_perf_ctrls);
 
 /**
- * cppc_set_perf - Set a CPU's performance controls.
+ * cppc_set_perf_ctrls - Set a CPU's performance controls.
  * @cpu: CPU for which to set performance controls.
  * @perf_ctrls: ptr to cppc_perf_ctrls. See cppc_acpi.h
  *
  * Return: 0 for success, -ERRNO otherwise.
  */
-int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
+int cppc_set_perf_ctrls(int cpu, struct cppc_perf_ctrls *perf_ctrls)
 {
 	struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu);
 	struct cpc_register_resource *desired_reg, *min_perf_reg, *max_perf_reg;
@@ -1746,7 +1813,7 @@ int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
 	/*
 	 * This is Phase-II where we transfer the ownership of PCC to Platform
 	 *
-	 * Short Summary: Basically if we think of a group of cppc_set_perf
+	 * Short Summary: Basically if we think of a group of cppc_set_perf_ctrls
 	 * requests that happened in short overlapping interval. The last CPU to
 	 * come out of Phase-I will enter Phase-II and ring the doorbell.
 	 *
@@ -1805,7 +1872,7 @@ int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
 	}
 	return ret;
 }
-EXPORT_SYMBOL_GPL(cppc_set_perf);
+EXPORT_SYMBOL_GPL(cppc_set_perf_ctrls);
 
 /**
  * cppc_get_transition_latency - returns frequency transition latency in ns
diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
index b3d74f9adcf0..17c49653a3c4 100644
--- a/drivers/cpufreq/cppc_cpufreq.c
+++ b/drivers/cpufreq/cppc_cpufreq.c
@@ -90,7 +90,7 @@ static void cppc_scale_freq_workfn(struct kthread_work *work)
 	cppc_fi = container_of(work, struct cppc_freq_invariance, work);
 	cpu_data = cppc_fi->cpu_data;
 
-	if (cppc_get_perf_ctrs(cppc_fi->cpu, &fb_ctrs)) {
+	if (cppc_get_perf_fb_ctrs(cppc_fi->cpu, &fb_ctrs)) {
 		pr_warn("%s: failed to read perf counters\n", __func__);
 		return;
 	}
@@ -125,7 +125,7 @@ static void cppc_scale_freq_tick(void)
 	struct cppc_freq_invariance *cppc_fi = &per_cpu(cppc_freq_inv, smp_processor_id());
 
 	/*
-	 * cppc_get_perf_ctrs() can potentially sleep, call that from the right
+	 * cppc_get_perf_fb_ctrs() can potentially sleep, call that from the right
 	 * context.
 	 */
 	irq_work_queue(&cppc_fi->irq_work);
@@ -151,7 +151,7 @@ static void cppc_cpufreq_cpu_fie_init(struct cpufreq_policy *policy)
 		kthread_init_work(&cppc_fi->work, cppc_scale_freq_workfn);
 		init_irq_work(&cppc_fi->irq_work, cppc_irq_work);
 
-		ret = cppc_get_perf_ctrs(cpu, &cppc_fi->prev_perf_fb_ctrs);
+		ret = cppc_get_perf_fb_ctrs(cpu, &cppc_fi->prev_perf_fb_ctrs);
 		if (ret) {
 			pr_warn("%s: failed to read perf counters for cpu:%d: %d\n",
 				__func__, cpu, ret);
@@ -281,7 +281,7 @@ static int cppc_cpufreq_set_target(struct cpufreq_policy *policy,
 	freqs.new = target_freq;
 
 	cpufreq_freq_transition_begin(policy, &freqs);
-	ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls);
+	ret = cppc_set_perf_ctrls(cpu, &cpu_data->perf_ctrls);
 	cpufreq_freq_transition_end(policy, &freqs, ret != 0);
 
 	if (ret)
@@ -301,7 +301,7 @@ static unsigned int cppc_cpufreq_fast_switch(struct cpufreq_policy *policy,
 
 	desired_perf = cppc_khz_to_perf(&cpu_data->perf_caps, target_freq);
 	cpu_data->perf_ctrls.desired_perf = desired_perf;
-	ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls);
+	ret = cppc_set_perf_ctrls(cpu, &cpu_data->perf_ctrls);
 
 	if (ret) {
 		pr_debug("Failed to set target on CPU:%d. ret:%d\n",
@@ -657,7 +657,7 @@ static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
 	policy->cur = cppc_perf_to_khz(caps, caps->highest_perf);
 	cpu_data->perf_ctrls.desired_perf =  caps->highest_perf;
 
-	ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls);
+	ret = cppc_set_perf_ctrls(cpu, &cpu_data->perf_ctrls);
 	if (ret) {
 		pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
 			 caps->highest_perf, cpu, ret);
@@ -683,7 +683,7 @@ static void cppc_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 
 	cpu_data->perf_ctrls.desired_perf = caps->lowest_perf;
 
-	ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls);
+	ret = cppc_set_perf_ctrls(cpu, &cpu_data->perf_ctrls);
 	if (ret)
 		pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
 			 caps->lowest_perf, cpu, ret);
@@ -723,19 +723,19 @@ static int cppc_perf_from_fbctrs(struct cppc_cpudata *cpu_data,
 	return (reference_perf * delta_delivered) / delta_reference;
 }
 
-static int cppc_get_perf_ctrs_sample(int cpu,
-				     struct cppc_perf_fb_ctrs *fb_ctrs_t0,
-				     struct cppc_perf_fb_ctrs *fb_ctrs_t1)
+static int cppc_get_perf_fb_ctrs_sample(int cpu,
+					struct cppc_perf_fb_ctrs *fb_ctrs_t0,
+					struct cppc_perf_fb_ctrs *fb_ctrs_t1)
 {
 	int ret;
 
-	ret = cppc_get_perf_ctrs(cpu, fb_ctrs_t0);
+	ret = cppc_get_perf_fb_ctrs(cpu, fb_ctrs_t0);
 	if (ret)
 		return ret;
 
 	udelay(2); /* 2usec delay between sampling */
 
-	return cppc_get_perf_ctrs(cpu, fb_ctrs_t1);
+	return cppc_get_perf_fb_ctrs(cpu, fb_ctrs_t1);
 }
 
 static unsigned int cppc_cpufreq_get_rate(unsigned int cpu)
@@ -753,7 +753,7 @@ static unsigned int cppc_cpufreq_get_rate(unsigned int cpu)
 
 	cpufreq_cpu_put(policy);
 
-	ret = cppc_get_perf_ctrs_sample(cpu, &fb_ctrs_t0, &fb_ctrs_t1);
+	ret = cppc_get_perf_fb_ctrs_sample(cpu, &fb_ctrs_t0, &fb_ctrs_t1);
 	if (ret) {
 		if (ret == -EFAULT)
 			/* Any of the associated CPPC regs is 0. */
diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h
index 62d368bcd9ec..31f4fd288b65 100644
--- a/include/acpi/cppc_acpi.h
+++ b/include/acpi/cppc_acpi.h
@@ -110,7 +110,6 @@ struct cppc_perf_caps {
 	u32 lowest_nonlinear_perf;
 	u32 lowest_freq;
 	u32 nominal_freq;
-	u32 energy_perf;
 	bool auto_sel;
 };
 
@@ -142,8 +141,9 @@ struct cppc_cpudata {
 extern int cppc_get_desired_perf(int cpunum, u64 *desired_perf);
 extern int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf);
 extern int cppc_get_highest_perf(int cpunum, u64 *highest_perf);
-extern int cppc_get_perf_ctrs(int cpu, struct cppc_perf_fb_ctrs *perf_fb_ctrs);
-extern int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls);
+extern int cppc_get_perf_fb_ctrs(int cpu, struct cppc_perf_fb_ctrs *perf_fb_ctrs);
+extern int cppc_get_perf_ctrls(int cpu, struct cppc_perf_ctrls *perf_ctrls);
+extern int cppc_set_perf_ctrls(int cpu, struct cppc_perf_ctrls *perf_ctrls);
 extern int cppc_set_enable(int cpu, bool enable);
 extern int cppc_get_perf_caps(int cpu, struct cppc_perf_caps *caps);
 extern bool cppc_perf_ctrs_in_pcc(void);
@@ -177,11 +177,15 @@ static inline int cppc_get_highest_perf(int cpunum, u64 *highest_perf)
 {
 	return -EOPNOTSUPP;
 }
-static inline int cppc_get_perf_ctrs(int cpu, struct cppc_perf_fb_ctrs *perf_fb_ctrs)
+static inline int cppc_get_perf_fb_ctrs(int cpu, struct cppc_perf_fb_ctrs *perf_fb_ctrs)
+{
+	return -EOPNOTSUPP;
+}
+static inline int cppc_get_perf_ctrls(int cpu, struct cppc_perf_ctrls *perf_ctrls)
 {
 	return -EOPNOTSUPP;
 }
-static inline int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
+static inline int cppc_set_perf_ctrls(int cpu, struct cppc_perf_ctrls *perf_ctrls)
 {
 	return -EOPNOTSUPP;
 }
-- 
2.25.1

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