1 files changed, 253 insertions, 0 deletions
diff --git a/arch/x86/lib/mrccache.c b/arch/x86/lib/mrccache.c
new file mode 100644
index 00000000000..53a1259d095
--- /dev/null
+++ b/arch/x86/lib/mrccache.c
@@ -0,0 +1,253 @@
+/*
+ * From coreboot src/southbridge/intel/bd82x6x/mrccache.c
+ *
+ * Copyright (C) 2014 Google Inc.
+ * Copyright (C) 2015 Bin Meng <bmeng.cn@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <fdtdec.h>
+#include <net.h>
+#include <spi.h>
+#include <spi_flash.h>
+#include <asm/mrccache.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static struct mrc_data_container *next_mrc_block(
+	struct mrc_data_container *cache)
+{
+	/* MRC data blocks are aligned within the region */
+	u32 mrc_size = sizeof(*cache) + cache->data_size;
+	u8 *region_ptr = (u8 *)cache;
+
+	if (mrc_size & (MRC_DATA_ALIGN - 1UL)) {
+		mrc_size &= ~(MRC_DATA_ALIGN - 1UL);
+		mrc_size += MRC_DATA_ALIGN;
+	}
+
+	region_ptr += mrc_size;
+
+	return (struct mrc_data_container *)region_ptr;
+}
+
+static int is_mrc_cache(struct mrc_data_container *cache)
+{
+	return cache && (cache->signature == MRC_DATA_SIGNATURE);
+}
+
+struct mrc_data_container *mrccache_find_current(struct mrc_region *entry)
+{
+	struct mrc_data_container *cache, *next;
+	ulong base_addr, end_addr;
+	uint id;
+
+	base_addr = entry->base + entry->offset;
+	end_addr = base_addr + entry->length;
+	cache = NULL;
+
+	/* Search for the last filled entry in the region */
+	for (id = 0, next = (struct mrc_data_container *)base_addr;
+	     is_mrc_cache(next);
+	     id++) {
+		cache = next;
+		next = next_mrc_block(next);
+		if ((ulong)next >= end_addr)
+			break;
+	}
+
+	if (id-- == 0) {
+		debug("%s: No valid MRC cache found.\n", __func__);
+		return NULL;
+	}
+
+	/* Verify checksum */
+	if (cache->checksum != compute_ip_checksum(cache->data,
+						   cache->data_size)) {
+		printf("%s: MRC cache checksum mismatch\n", __func__);
+		return NULL;
+	}
+
+	debug("%s: picked entry %u from cache block\n", __func__, id);
+
+	return cache;
+}
+
+/**
+ * find_next_mrc_cache() - get next cache entry
+ *
+ * @entry:	MRC cache flash area
+ * @cache:	Entry to start from
+ *
+ * @return next cache entry if found, NULL if we got to the end
+ */
+static struct mrc_data_container *find_next_mrc_cache(struct mrc_region *entry,
+		struct mrc_data_container *cache)
+{
+	ulong base_addr, end_addr;
+
+	base_addr = entry->base + entry->offset;
+	end_addr = base_addr + entry->length;
+
+	cache = next_mrc_block(cache);
+	if ((ulong)cache >= end_addr) {
+		/* Crossed the boundary */
+		cache = NULL;
+		debug("%s: no available entries found\n", __func__);
+	} else {
+		debug("%s: picked next entry from cache block at %p\n",
+		      __func__, cache);
+	}
+
+	return cache;
+}
+
+int mrccache_update(struct udevice *sf, struct mrc_region *entry,
+		    struct mrc_data_container *cur)
+{
+	struct mrc_data_container *cache;
+	ulong offset;
+	ulong base_addr;
+	int ret;
+
+	if (!is_mrc_cache(cur))
+		return -EINVAL;
+
+	/* Find the last used block */
+	base_addr = entry->base + entry->offset;
+	debug("Updating MRC cache data\n");
+	cache = mrccache_find_current(entry);
+	if (cache && (cache->data_size == cur->data_size) &&
+	    (!memcmp(cache, cur, cache->data_size + sizeof(*cur)))) {
+		debug("MRC data in flash is up to date. No update\n");
+		return -EEXIST;
+	}
+
+	/* Move to the next block, which will be the first unused block */
+	if (cache)
+		cache = find_next_mrc_cache(entry, cache);
+
+	/*
+	 * If we have got to the end, erase the entire mrc-cache area and start
+	 * again at block 0.
+	 */
+	if (!cache) {
+		debug("Erasing the MRC cache region of %x bytes at %x\n",
+		      entry->length, entry->offset);
+
+		ret = spi_flash_erase_dm(sf, entry->offset, entry->length);
+		if (ret) {
+			debug("Failed to erase flash region\n");
+			return ret;
+		}
+		cache = (struct mrc_data_container *)base_addr;
+	}
+
+	/* Write the data out */
+	offset = (ulong)cache - base_addr + entry->offset;
+	debug("Write MRC cache update to flash at %lx\n", offset);
+	ret = spi_flash_write_dm(sf, offset, cur->data_size + sizeof(*cur),
+				 cur);
+	if (ret) {
+		debug("Failed to write to SPI flash\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+int mrccache_reserve(void)
+{
+	struct mrc_data_container *cache;
+	u16 checksum;
+
+	if (!gd->arch.mrc_output_len)
+		return 0;
+
+	/* adjust stack pointer to store pure cache data plus the header */
+	gd->start_addr_sp -= (gd->arch.mrc_output_len + MRC_DATA_HEADER_SIZE);
+	cache = (struct mrc_data_container *)gd->start_addr_sp;
+
+	cache->signature = MRC_DATA_SIGNATURE;
+	cache->data_size = gd->arch.mrc_output_len;
+	checksum = compute_ip_checksum(gd->arch.mrc_output, cache->data_size);
+	debug("Saving %d bytes for MRC output data, checksum %04x\n",
+	      cache->data_size, checksum);
+	cache->checksum = checksum;
+	cache->reserved = 0;
+	memcpy(cache->data, gd->arch.mrc_output, cache->data_size);
+
+	/* gd->arch.mrc_output now points to the container */
+	gd->arch.mrc_output = (char *)cache;
+
+	gd->start_addr_sp &= ~0xf;
+
+	return 0;
+}
+
+int mrccache_get_region(struct udevice **devp, struct mrc_region *entry)
+{
+	const void *blob = gd->fdt_blob;
+	int node, mrc_node;
+	u32 reg[2];
+	int ret;
+
+	/* Find the flash chip within the SPI controller node */
+	node = fdtdec_next_compatible(blob, 0, COMPAT_GENERIC_SPI_FLASH);
+	if (node < 0)
+		return -ENOENT;
+
+	if (fdtdec_get_int_array(blob, node, "memory-map", reg, 2))
+		return -FDT_ERR_NOTFOUND;
+	entry->base = reg[0];
+
+	/* Find the place where we put the MRC cache */
+	mrc_node = fdt_subnode_offset(blob, node, "rw-mrc-cache");
+	if (mrc_node < 0)
+		return -EPERM;
+
+	if (fdtdec_get_int_array(blob, mrc_node, "reg", reg, 2))
+		return -FDT_ERR_NOTFOUND;
+	entry->offset = reg[0];
+	entry->length = reg[1];
+
+	if (devp) {
+		ret = uclass_get_device_by_of_offset(UCLASS_SPI_FLASH, node,
+						     devp);
+		debug("ret = %d\n", ret);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+int mrccache_save(void)
+{
+	struct mrc_data_container *data;
+	struct mrc_region entry;
+	struct udevice *sf;
+	int ret;
+
+	if (!gd->arch.mrc_output_len)
+		return 0;
+	debug("Saving %d bytes of MRC output data to SPI flash\n",
+	      gd->arch.mrc_output_len);
+
+	ret = mrccache_get_region(&sf, &entry);
+	if (ret)
+		goto err_entry;
+	data  = (struct mrc_data_container *)gd->arch.mrc_output;
+	ret = mrccache_update(sf, &entry, data);
+	if (!ret)
+		debug("Saved MRC data with checksum %04x\n", data->checksum);
+
+err_entry:
+	if (ret)
+		debug("%s: Failed: %d\n", __func__, ret);
+	return ret;
+}