diff mbox series

[SRU,focal:linux-gcp,05/17] ACPI: processor: Introduce acpi_processor_evaluate_cst()

Message ID 20240911042726.959018-6-marcelo.cerri@canonical.com
State New
Headers show
Series lp:#2080324 - linux-gcp: Improve idle support | expand

Commit Message

Marcelo Henrique Cerri Sept. 11, 2024, 4:27 a.m. UTC 
From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>

BugLink: https://bugs.launchpad.net/bugs/2080324

In order to separate the ACPI _CST evaluation from checks
specific to the ACPI processor driver, move the majority of
the acpi_processor_get_power_info_cst() function body to a new
function, acpi_processor_evaluate_cst(), that will extract
the C-states information from _CST output, and redefine
acpi_processor_get_power_info_cst() as a wrapper around it.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
(cherry picked from commit 987c785319b99e32602f7f86cfae3cf9b81e402b)
Signed-off-by: Marcelo Henrique Cerri <marcelo.cerri@canonical.com>
---
 drivers/acpi/processor_idle.c | 52 +++++++++++++++++++++--------------
 1 file changed, 32 insertions(+), 20 deletions(-)
diff mbox series

Patch

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 34cc23abd038..aca7c306f2cb 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -298,21 +298,17 @@  static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 	return 0;
 }
 
-static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
+static int acpi_processor_evaluate_cst(acpi_handle handle, u32 cpu,
+				       struct acpi_processor_power *info)
 {
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object *cst;
 	acpi_status status;
 	u64 count;
-	int current_count;
+	int current_count = 0;
 	int i, ret = 0;
-	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
-	union acpi_object *cst;
-
-	if (nocst)
-		return -ENODEV;
 
-	current_count = 0;
-
-	status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
+	status = acpi_evaluate_object(handle, "_CST", NULL, &buffer);
 	if (ACPI_FAILURE(status)) {
 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
 		return -ENODEV;
@@ -336,9 +332,6 @@  static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 		goto end;
 	}
 
-	/* Tell driver that at least _CST is supported. */
-	pr->flags.has_cst = 1;
-
 	for (i = 1; i <= count; i++) {
 		union acpi_object *element;
 		union acpi_object *obj;
@@ -384,7 +377,7 @@  static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 		cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 		if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 			if (acpi_processor_ffh_cstate_probe
-					(pr->id, &cx, reg) == 0) {
+					(cpu, &cx, reg) == 0) {
 				cx.entry_method = ACPI_CSTATE_FFH;
 			} else if (cx.type == ACPI_STATE_C1) {
 				/*
@@ -433,7 +426,7 @@  static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 			continue;
 
 		current_count++;
-		memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
+		memcpy(&info->states[current_count], &cx, sizeof(cx));
 
 		/*
 		 * We support total ACPI_PROCESSOR_MAX_POWER - 1
@@ -447,12 +440,9 @@  static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 		}
 	}
 
-	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
-			  current_count));
+	acpi_handle_info(handle, "Found %d idle states\n", current_count);
 
-	/* Validate number of power states discovered */
-	if (current_count < 2)
-		ret = -EFAULT;
+	info->count = current_count;
 
       end:
 	kfree(buffer.pointer);
@@ -460,6 +450,28 @@  static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 	return ret;
 }
 
+static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
+{
+	int ret;
+
+	if (nocst)
+		return -ENODEV;
+
+	ret = acpi_processor_evaluate_cst(pr->handle, pr->id, &pr->power);
+	if (ret)
+		return ret;
+
+	/*
+	 * It is expected that there will be at least 2 states, C1 and
+	 * something else (C2 or C3), so fail if that is not the case.
+	 */
+	if (pr->power.count < 2)
+		return -EFAULT;
+
+	pr->flags.has_cst = 1;
+	return 0;
+}
+
 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 					   struct acpi_processor_cx *cx)
 {