soc/amd/mendocino: Consume fsp misc_data hob

Provide support function to query fsp misc_data hob and return smu
reported power and thermal limit.

BUG=b:253301653
TEST=Use get_amd_smu_reported_tdp(&tdp) values match what FSP placed in
the hob.

Change-Id: I9f0d8cdd616726c5a714e99504b83b0126dd273b
Signed-off-by: Jason Glenesk <jason.glenesk@amd.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/73747
Reviewed-by: Martin Roth <martin.roth@amd.corp-partner.google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/amd/mendocino/Makefile.inc

@@ -30,6 +30,7 @@ ramstage-y	+= agesa_acpi.c
 ramstage-y	+= chip.c
 ramstage-y	+= cpu.c
 ramstage-y	+= fch.c
+ramstage-y	+= fsp_misc_data_hob.c
 ramstage-y	+= fsp_s_params.c
 ramstage-y	+= gpio.c
 ramstage-y	+= i2c.c

src/soc/amd/mendocino/fsp_misc_data_hob.c

@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <console/console.h>
+#include <FspGuids.h>
+#include <fsp/amd_misc_data.h>
+#include <fsp/amd_misc_data_hob.h>
+#include <fsp/util.h>
+#include <string.h>
+#include <types.h>
+
+static enum cb_err get_amd_misc_data_hob(const struct amd_misc_data **fsp_misc_data, int min_revision)
+{
+	static const struct amd_misc_data *fsp_misc_data_cache;
+	size_t hob_size = 0;
+	const struct amd_misc_data *hob;
+
+	if (fsp_misc_data_cache) {
+		*fsp_misc_data = fsp_misc_data_cache;
+		return CB_SUCCESS;
+	}
+
+	hob = fsp_find_extension_hob_by_guid(AMD_MISC_DATA_HOB_GUID.b, &hob_size);
+
+	if (hob == NULL || hob_size < sizeof(struct amd_misc_data)) {
+		printk(BIOS_ERR, "Couldn't find fsp misc data HOB.\n");
+		return CB_ERR;
+	}
+
+	if (hob->version < min_revision) {
+		printk(BIOS_ERR, "Unexpected fsp misc data HOB version.\n");
+		return CB_ERR;
+	}
+
+	fsp_misc_data_cache = hob;
+	*fsp_misc_data = fsp_misc_data_cache;
+	return CB_SUCCESS;
+}
+
+enum cb_err get_amd_smu_reported_tdp(uint32_t *tdp)
+{
+	const struct amd_misc_data *fsp_misc_data = NULL;
+
+	if (get_amd_misc_data_hob(&fsp_misc_data, AMD_MISC_DATA_VERSION) != CB_SUCCESS)
+		return CB_ERR;
+
+	*tdp = fsp_misc_data->smu_power_and_thm_limit;
+
+	return CB_SUCCESS;
+}

src/soc/amd/mendocino/include/fsp/amd_misc_data.h

@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef AMD_MISC_DATA_H
+#define AMD_MISC_DATA_H
+
+#include <types.h>
+
+enum cb_err get_amd_smu_reported_tdp(uint32_t *tdp);
+
+#endif /* AMD_MISC_DATA_H */

src/soc/amd/mendocino/include/fsp/amd_misc_data_hob.h

@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __AMD_MISC_DATA_HOB_H__
+#define __AMD_MISC_DATA_HOB_H__
+
+#define AMD_MISC_DATA_VERSION	2
+
+struct amd_misc_data {
+	uint8_t		version;
+	uint8_t		unused[3];
+	uint32_t	smu_power_and_thm_limit;
+} __packed;
+
+#endif /* __AMD_MISC_DATA_HOB_H__ */

src/vendorcode/amd/fsp/mendocino/FspGuids.h

@@ -21,4 +21,8 @@
 		GUID_INIT(0x3060C5EC, 0x7399, 0x432D, \
 		0xBC, 0x97, 0xBF, 0x95, 0xE4, 0x3D, 0x53, 0x0C )
 
+#define AMD_MISC_DATA_HOB_GUID \
+		GUID_INIT(0x27f7d972, 0x318f, 0x4665, \
+		0x8a, 0x99, 0xf4, 0x4c, 0x04, 0x4b, 0x49, 0x08)
+
 #endif /* __FSP_GUIDS__ */