soc/intel/xeon_sp/acpi.c: Add ACPI C-State table

Add the soc ACPI _CST table.
The table may be customized to support the different state
combinations and set by the mainboard config.

Tested on deltalake with acpi_idle driver.
Note, intel_idle may not use ACPI _CST table.

Change-Id: I359daa9556edbe263ab0a7f1849c96c8fe1a0da0
Signed-off-by: Marc Jones <marcjones@sysproconsulting.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49494
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Jay Talbott <JayTalbott@sysproconsulting.com>

1 files changed, 78 insertions, 2 deletions

diff --git a/src/soc/intel/xeon_sp/acpi.c b/src/soc/intel/xeon_sp/acpi.c
index b271264b07..5e5267de8a 100644
--- a/src/soc/intel/xeon_sp/acpi.c
+++ b/src/soc/intel/xeon_sp/acpi.c
@@ -6,10 +6,86 @@
 #include <soc/util.h>
 #include <string.h>
 
+#include "chip.h"
+
+/*
+ * List of supported C-states in this processor.
+ */
+enum {
+	C_STATE_C1,	/* 0 */
+	C_STATE_C3,	/* 1 */
+	C_STATE_C6,	/* 2 */
+	C_STATE_C7,	/* 3 */
+	NUM_C_STATES
+};
+
+static const acpi_cstate_t cstate_map[NUM_C_STATES] = {
+	[C_STATE_C1] = {
+		/* C1 */
+		.latency = 1,
+		.power = 0x3e8,
+		.resource = MWAIT_RES(0, 0),
+	},
+	[C_STATE_C3] = {
+		/* C3 */
+		.latency = 15,
+		.power = 0x1f4,
+		.resource = MWAIT_RES(1, 0),
+	},
+	[C_STATE_C6] = {
+		/* C6 */
+		.latency = 41,
+		.power = 0x15e,
+		.resource = MWAIT_RES(2, 0),
+	},
+	[C_STATE_C7] = {
+		/* C7 */
+		.latency = 41,
+		.power = 0x0c8,
+		.resource = MWAIT_RES(3, 0),
+	}
+};
+
+/* Max states supported */
+static int cstate_set_all[] = {
+	C_STATE_C1,
+	C_STATE_C3,
+	C_STATE_C6,
+	C_STATE_C7
+};
+
+static int cstate_set_c1_c6[] = {
+	C_STATE_C1,
+	C_STATE_C6,
+};
+
 acpi_cstate_t *soc_get_cstate_map(size_t *entries)
 {
-	*entries = 0;
-	return NULL;
+	static acpi_cstate_t map[ARRAY_SIZE(cstate_set_all)];
+	int *cstate_set;
+	int i;
+
+	const config_t *config = config_of_soc();
+
+	const enum acpi_cstate_mode states = config->cstate_states;
+
+	switch (states) {
+	case CSTATES_C1C6:
+		*entries = ARRAY_SIZE(cstate_set_c1_c6);
+		cstate_set = cstate_set_c1_c6;
+		break;
+	case CSTATES_ALL:
+	default:
+		*entries = ARRAY_SIZE(cstate_set_all);
+		cstate_set = cstate_set_all;
+		break;
+	}
+
+	for (i = 0; i < *entries; i++) {
+		map[i] = cstate_map[cstate_set[i]];
+		map[i].ctype = i + 1;
+	}
+	return map;
 }
 
 static void print_madt_ioapic(int socket, int stack,