soc/amd/picasso: move APOB NV cache to common code

Also rename mrc_cache to apob_cache.

BUG=b:181766974

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I4877b05443452c7409006c1656e9d574e93150a0
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51267
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Raul Rangel <rrangel@chromium.org>

3 files changed, 182 insertions, 0 deletions

diff --git a/src/soc/amd/common/block/apob/Kconfig b/src/soc/amd/common/block/apob/Kconfig
new file mode 100644
index 0000000000..b0cca51f3c
--- /dev/null
+++ b/src/soc/amd/common/block/apob/Kconfig
@@ -0,0 +1,5 @@
+config SOC_AMD_COMMON_BLOCK_APOB
+	bool
+	help
+	  Select this option to add firmware support for the non-volatile APOB
+	  cache to the build.
diff --git a/src/soc/amd/common/block/apob/Makefile.inc b/src/soc/amd/common/block/apob/Makefile.inc
new file mode 100644
index 0000000000..16baf81813
--- /dev/null
+++ b/src/soc/amd/common/block/apob/Makefile.inc
@@ -0,0 +1,3 @@
+ifeq ($(CONFIG_SOC_AMD_COMMON_BLOCK_APOB),y)
+romstage-y += apob_cache.c
+endif # CONFIG_SOC_AMD_COMMON_BLOCK_APOB
diff --git a/src/soc/amd/common/block/apob/apob_cache.c b/src/soc/amd/common/block/apob/apob_cache.c
new file mode 100644
index 0000000000..6b31143f84
--- /dev/null
+++ b/src/soc/amd/common/block/apob/apob_cache.c
@@ -0,0 +1,174 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include <acpi/acpi.h>
+#include <amdblocks/apob_cache.h>
+#include <assert.h>
+#include <boot_device.h>
+#include <commonlib/region.h>
+#include <console/console.h>
+#include <fmap.h>
+#include <spi_flash.h>
+#include <stdint.h>
+#include <string.h>
+
+#define DEFAULT_MRC_CACHE "RW_MRC_CACHE"
+/* PSP requires this value to be 64KiB */
+#define DEFAULT_MRC_CACHE_SIZE 0x10000
+
+#if !CONFIG_PSP_APOB_DRAM_ADDRESS
+#error Incorrect APOB configuration setting(s)
+#endif
+
+#define APOB_SIGNATURE 0x424F5041	/* 'APOB' */
+
+/* APOB_BASE_HEADER from AGESA */
+struct apob_base_header {
+	uint32_t   signature;			/* APOB signature */
+	uint32_t   version;			/* Version */
+	uint32_t   size;			/* APOB Size */
+	uint32_t   offset_of_first_entry;	/* APOB Header Size */
+};
+
+static bool apob_header_valid(const struct apob_base_header *apob_header_ptr, const char *where)
+{
+	if (apob_header_ptr->signature != APOB_SIGNATURE) {
+		printk(BIOS_WARNING, "Invalid %s APOB signature %x\n",
+			where, apob_header_ptr->signature);
+		return false;
+	}
+
+	if (apob_header_ptr->size == 0 || apob_header_ptr->size > DEFAULT_MRC_CACHE_SIZE) {
+		printk(BIOS_WARNING, "%s APOB data is too large %x > %x\n",
+			where, apob_header_ptr->size, DEFAULT_MRC_CACHE_SIZE);
+		return false;
+	}
+
+	return true;
+}
+
+static void *get_apob_dram_address(void)
+{
+	/*
+	 * TODO: Find the APOB destination by parsing the PSP's tables
+	 * (once vboot is implemented).
+	 */
+	void *apob_src_ram = (void *)(uintptr_t)CONFIG_PSP_APOB_DRAM_ADDRESS;
+
+	if (apob_header_valid(apob_src_ram, "RAM") == false)
+		return NULL;
+
+	return apob_src_ram;
+}
+
+static int get_nv_region(struct region *r)
+{
+	if  (fmap_locate_area(DEFAULT_MRC_CACHE, r) < 0) {
+		printk(BIOS_ERR, "Error: No APOB NV region is found in flash\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+static void *get_apob_from_nv_region(struct region *region)
+{
+	struct region_device read_rdev;
+	struct apob_base_header apob_header;
+
+	if (boot_device_ro_subregion(region, &read_rdev) < 0) {
+		printk(BIOS_ERR, "Failed boot_device_ro_subregion\n");
+		return NULL;
+	}
+
+	if (rdev_readat(&read_rdev, &apob_header, 0, sizeof(apob_header)) < 0) {
+		printk(BIOS_ERR, "Couldn't read APOB header!\n");
+		return NULL;
+	}
+
+	if (apob_header_valid(&apob_header, "ROM") == false) {
+		printk(BIOS_ERR, "No APOB NV data!\n");
+		return NULL;
+	}
+
+	assert(CONFIG(BOOT_DEVICE_MEMORY_MAPPED));
+	return rdev_mmap_full(&read_rdev);
+}
+
+/* Save APOB buffer to flash */
+void soc_update_apob_cache(void)
+{
+	struct apob_base_header *apob_rom;
+	struct region_device write_rdev;
+	struct region region;
+	bool update_needed = false;
+	const struct apob_base_header *apob_src_ram;
+
+	/* Nothing to update in case of S3 resume. */
+	if (acpi_is_wakeup_s3())
+		return;
+
+	apob_src_ram = get_apob_dram_address();
+	if (apob_src_ram == NULL)
+		return;
+
+	if (get_nv_region(&region) != 0)
+		return;
+
+	apob_rom = get_apob_from_nv_region(&region);
+	if (apob_rom == NULL) {
+		update_needed = true;
+	} else if (memcmp(apob_src_ram, apob_rom, apob_src_ram->size)) {
+		printk(BIOS_INFO, "APOB RAM copy differs from flash\n");
+		update_needed = true;
+	} else
+		printk(BIOS_DEBUG, "APOB valid copy is already in flash\n");
+
+	if (!update_needed)
+		return;
+
+	printk(BIOS_SPEW, "Copy APOB from RAM 0x%p/0x%x to flash 0x%zx/0x%zx\n",
+		apob_src_ram, apob_src_ram->size,
+		region_offset(&region), region_sz(&region));
+
+	if (boot_device_rw_subregion(&region, &write_rdev) < 0) {
+		printk(BIOS_ERR, "Failed boot_device_rw_subregion\n");
+		return;
+	}
+
+	/* write data to flash region */
+	if (rdev_eraseat(&write_rdev, 0, DEFAULT_MRC_CACHE_SIZE) < 0) {
+		printk(BIOS_ERR, "Error: APOB flash region erase failed\n");
+		return;
+	}
+
+	if (rdev_writeat(&write_rdev, apob_src_ram, 0, apob_src_ram->size) < 0) {
+		printk(BIOS_ERR, "Error: APOB flash region update failed\n");
+		return;
+	}
+
+	printk(BIOS_INFO, "Updated APOB in flash\n");
+}
+
+static void *get_apob_nv_address(void)
+{
+	struct region region;
+
+	if (get_nv_region(&region) != 0)
+		return NULL;
+
+	return get_apob_from_nv_region(&region);
+}
+
+void *soc_fill_apob_cache(void)
+{
+	/* If this is non-S3 boot, then use the APOB data placed by PSP in DRAM. */
+	if (!acpi_is_wakeup_s3())
+		return get_apob_dram_address();
+
+	/*
+	 * In case of S3 resume, PSP does not copy APOB data to DRAM. Thus, coreboot needs to
+	 * provide the APOB NV data from RW_MRC_CACHE on SPI flash so that FSP can use it
+	 * without having to traverse the BIOS directory table.
+	 */
+	return get_apob_nv_address();
+}