dram: Add basic DDR4 SPD parsing

Add ability to decode basic fields of DDR4 SPDs and produce SMBIOS table
17. XMP, schemas, extended field parising is totally not yet implemented.
Also, put CRC function used in DDR2, DDR3 and DDR4 ina  common file.

Signed-off-by: Andrey Petrov <anpetrov@fb.com>
Change-Id: If3befbc55cf37e1018baa432cb2f03743b929211
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34680
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-by: David Hendricks <david.hendricks@gmail.com>

5 files changed, 296 insertions, 22 deletions

diff --git a/src/device/dram/Makefile.inc b/src/device/dram/Makefile.inc
index c982ef49e8..f397a534f2 100644
--- a/src/device/dram/Makefile.inc
+++ b/src/device/dram/Makefile.inc
@@ -1 +1 @@
-romstage-y += ddr3.c ddr2.c
+romstage-y += ddr4.c ddr3.c ddr2.c ddr_common.c
diff --git a/src/device/dram/ddr2.c b/src/device/dram/ddr2.c
index 60588b880b..d66b576623 100644
--- a/src/device/dram/ddr2.c
+++ b/src/device/dram/ddr2.c
@@ -93,7 +93,7 @@ u16 spd_ddr2_calc_unique_crc(const u8 *spd, int len)
 	for (i = 93; i <= 98; i++)
 		id_bytes[j++] = spd[i];
 
-	return ddr3_crc16(id_bytes, 15);
+	return ddr_crc16(id_bytes, 15);
 }
 
 /**
diff --git a/src/device/dram/ddr3.c b/src/device/dram/ddr3.c
index 834dc83db6..4a900fab47 100644
--- a/src/device/dram/ddr3.c
+++ b/src/device/dram/ddr3.c
@@ -23,6 +23,7 @@
 #include <console/console.h>
 #include <device/device.h>
 #include <device/dram/ddr3.h>
+#include <device/dram/common.h>
 #include <string.h>
 #include <memory_info.h>
 #include <cbmem.h>
@@ -50,24 +51,6 @@ int spd_dimm_is_registered_ddr3(enum spd_dimm_type type)
 	return 0;
 }
 
-u16 ddr3_crc16(const u8 *ptr, int n_crc)
-{
-	int i;
-	u16 crc = 0;
-
-	while (--n_crc >= 0) {
-		crc = crc ^ ((int)*ptr++ << 8);
-		for (i = 0; i < 8; ++i)
-			if (crc & 0x8000) {
-				crc = (crc << 1) ^ 0x1021;
-			} else {
-				crc = crc << 1;
-			}
-	}
-
-	return crc;
-}
-
 /**
  * \brief Calculate the CRC of a DDR3 SPD
  *
@@ -91,7 +74,7 @@ u16 spd_ddr3_calc_crc(u8 *spd, int len)
 		/* Not enough bytes available to get the CRC */
 		return 0;
 
-	return ddr3_crc16(spd, n_crc);
+	return ddr_crc16(spd, n_crc);
 }
 
 /**
@@ -108,7 +91,7 @@ u16 spd_ddr3_calc_unique_crc(u8 *spd, int len)
 		/* Not enough bytes available to get the CRC */
 		return 0;
 
-	return ddr3_crc16(&spd[117], 11);
+	return ddr_crc16(&spd[117], 11);
 }
 
 /**
diff --git a/src/device/dram/ddr4.c b/src/device/dram/ddr4.c
new file mode 100644
index 0000000000..5927b41281
--- /dev/null
+++ b/src/device/dram/ddr4.c
@@ -0,0 +1,248 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2019 Facebook, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <console/console.h>
+#include <cbmem.h>
+#include <device/device.h>
+#include <device/dram/ddr4.h>
+#include <string.h>
+#include <memory_info.h>
+#include <smbios.h>
+#include <types.h>
+
+typedef enum {
+	BLOCK_0, /* Base Configuration and DRAM Parameters */
+	BLOCK_1,
+	BLOCK_1_L, /* Standard Module Parameters */
+	BLOCK_1_H, /* Hybrid Module Parameters */
+	BLOCK_2,
+	BLOCK_2_L, /* Hybrid Module Extended Function Parameters */
+	BLOCK_2_H, /* Manufacturing Information */
+	BLOCK_3    /* End user programmable */
+} spd_block_type;
+
+typedef struct {
+	spd_block_type type;
+	uint16_t start;     /* starting offset from beginning of the spd */
+	uint16_t len;       /* size of the block */
+	uint16_t crc_start; /* offset from start of crc bytes, 0 if none */
+} spd_block;
+
+/* 'SPD contents architecture' as per datasheet */
+const spd_block spd_blocks[] = {
+	{.type = BLOCK_0, 0, 128, 126},   {.type = BLOCK_1, 128, 128, 126},
+	{.type = BLOCK_1_L, 128, 64, 0},  {.type = BLOCK_1_H, 192, 64, 0},
+	{.type = BLOCK_2_L, 256, 64, 62}, {.type = BLOCK_2_H, 320, 64, 0},
+	{.type = BLOCK_3, 384, 128, 0} };
+
+static bool verify_block(const spd_block *block, spd_raw_data spd)
+{
+	uint16_t crc, spd_crc;
+
+	spd_crc = (spd[block->start + block->crc_start + 1] << 8)
+		  | spd[block->start + block->crc_start];
+	crc = ddr_crc16(&spd[block->start], block->len - 2);
+
+	return spd_crc == crc;
+}
+
+/* Check if given block is 'reserved' for a given module type */
+static bool block_exists(spd_block_type type, u8 dimm_type)
+{
+	bool is_hybrid;
+
+	switch (type) {
+	case BLOCK_0: /* fall-through */
+	case BLOCK_1: /* fall-through */
+	case BLOCK_1_L: /* fall-through */
+	case BLOCK_1_H: /* fall-through */
+	case BLOCK_2_H: /* fall-through */
+	case BLOCK_3: /* fall-through */
+		return true;
+	case BLOCK_2_L:
+		is_hybrid = (dimm_type >> 4) & ((1 << 3) - 1);
+		if (is_hybrid)
+			return true;
+		return false;
+	default: /* fall-through */
+		return false;
+	}
+}
+
+
+/**
+ * \brief Decode the raw SPD data
+ *
+ * Decodes a raw SPD data from a DDR4 DIMM, and organizes it into a
+ * @ref dimm_attr structure. The SPD data must first be read in a contiguous
+ * array, and passed to this function.
+ *
+ * @param dimm pointer to @ref dimm_attr structure where the decoded data is to
+ *	       be stored
+ * @param spd array of raw data previously read from the SPD.
+ *
+ * @return @ref spd_status enumerator
+ *		SPD_STATUS_OK -- decoding was successful
+ *		SPD_STATUS_INVALID -- invalid SPD or not a DDR4 SPD
+ *		SPD_STATUS_CRC_ERROR -- checksum mismatch
+ */
+int spd_decode_ddr4(dimm_attr *dimm, spd_raw_data spd)
+{
+	u8 reg8;
+	u8 bus_width, sdram_width;
+	u16 cap_per_die_mbit;
+	u16 spd_bytes_total, spd_bytes_used;
+	const uint16_t spd_bytes_used_table[] = {0, 128, 256, 384, 512};
+
+	/* Make sure that the SPD dump is indeed from a DDR4 module */
+	if (spd[2] != SPD_MEMORY_TYPE_DDR4_SDRAM) {
+		printk(BIOS_ERR, "Not a DDR4 SPD!\n");
+		dimm->dram_type = SPD_MEMORY_TYPE_UNDEFINED;
+		return SPD_STATUS_INVALID;
+	}
+
+	spd_bytes_total = (spd[0] >> 4) & ((1 << 3) - 1);
+	spd_bytes_used = spd[0] & ((1 << 4) - 1);
+
+	if (!spd_bytes_total || !spd_bytes_used) {
+		printk(BIOS_ERR, "SPD failed basic sanity checks\n");
+		return SPD_STATUS_INVALID;
+	}
+
+	spd_bytes_total = 256 << (spd_bytes_total - 1);
+	spd_bytes_used = spd_bytes_used_table[spd_bytes_used];
+
+	/* Verify CRC of blocks that have them, do not step over 'used' length */
+	for (int i = 0; i < ARRAY_SIZE(spd_blocks); i++) {
+		/* this block is not checksumed */
+		if (spd_blocks[i].crc_start == 0)
+			continue;
+		/* we shouldn't have this block */
+		if (spd_blocks[i].start + spd_blocks[i].len > spd_bytes_used)
+			continue;
+		/* check if block exists in the current schema */
+		if (!block_exists(spd_blocks[i].type, spd[3]))
+			continue;
+		if (!verify_block(&spd_blocks[i], spd)) {
+			printk(BIOS_ERR, "CRC failed for block %d\n", i);
+			return SPD_STATUS_CRC_ERROR;
+		}
+	}
+
+	dimm->dram_type = SPD_MEMORY_TYPE_DDR4_SDRAM;
+	dimm->dimm_type = spd[3] & ((1 << 4) - 1);
+
+	reg8 = spd[13] & ((1 << 4) - 1);
+	dimm->bus_width = reg8;
+	bus_width = 8 << (reg8 & ((1 << 3) - 1));
+
+	reg8 = spd[12] & ((1 << 3) - 1);
+	dimm->sdram_width = reg8;
+	sdram_width = 4 << reg8;
+
+	reg8 = spd[4] & ((1 << 4) - 1);
+	dimm->cap_per_die_mbit = reg8;
+	cap_per_die_mbit = (1 << reg8) * 256;
+
+	reg8 = (spd[12] >> 3) & ((1 << 3) - 1);
+	dimm->ranks = reg8 + 1;
+
+	if (!bus_width || !sdram_width) {
+		printk(BIOS_ERR, "SPD information is invalid");
+		dimm->size_mb = 0;
+		return SPD_STATUS_INVALID;
+	}
+
+	/* seems to be only one, in mV */
+	dimm->vdd_voltage = 1200;
+
+	/* calculate size */
+	dimm->size_mb = cap_per_die_mbit / 8 * bus_width / sdram_width * dimm->ranks;
+
+	/* make sure we have the manufacturing information block */
+	if (spd_bytes_used > 320) {
+		dimm->manufacturer_id = (spd[351] << 8) | spd[350];
+		memcpy(dimm->part_number, &spd[329], SPD_DDR4_PART_LEN);
+		dimm->part_number[SPD_DDR4_PART_LEN] = 0;
+		memcpy(dimm->serial_number, &spd[325], sizeof(dimm->serial_number));
+	}
+	return SPD_STATUS_OK;
+}
+
+enum cb_err spd_add_smbios17_ddr4(const u8 channel, const u8 slot, const u16 selected_freq,
+				  const dimm_attr *info)
+{
+	struct memory_info *mem_info;
+	struct dimm_info *dimm;
+
+	/*
+	 * Allocate CBMEM area for DIMM information used to populate SMBIOS
+	 * table 17
+	 */
+	mem_info = cbmem_find(CBMEM_ID_MEMINFO);
+	if (!mem_info) {
+		mem_info = cbmem_add(CBMEM_ID_MEMINFO, sizeof(*mem_info));
+
+		printk(BIOS_DEBUG, "CBMEM entry for DIMM info: 0x%p\n", mem_info);
+		if (!mem_info)
+			return CB_ERR;
+
+		memset(mem_info, 0, sizeof(*mem_info));
+	}
+
+	if (mem_info->dimm_cnt >= ARRAY_SIZE(mem_info->dimm)) {
+		printk(BIOS_WARNING, "BUG: Too many DIMM infos for %s.\n", __func__);
+		return CB_ERR;
+	}
+
+	dimm = &mem_info->dimm[mem_info->dimm_cnt];
+	if (info->size_mb) {
+		dimm->ddr_type = MEMORY_TYPE_DDR4;
+		dimm->ddr_frequency = selected_freq;
+		dimm->dimm_size = info->size_mb;
+		dimm->channel_num = channel;
+		dimm->rank_per_dimm = info->ranks;
+		dimm->dimm_num = slot;
+		memcpy(dimm->module_part_number, info->part_number, SPD_DDR4_PART_LEN);
+		dimm->mod_id = info->manufacturer_id;
+
+		switch (info->dimm_type) {
+		case SPD_DIMM_TYPE_SO_DIMM:
+			dimm->mod_type = SPD_SODIMM;
+			break;
+		case SPD_DIMM_TYPE_72B_SO_RDIMM:
+			dimm->mod_type = SPD_72B_SO_RDIMM;
+			break;
+		case SPD_DIMM_TYPE_UDIMM:
+			dimm->mod_type = SPD_UDIMM;
+			break;
+		case SPD_DIMM_TYPE_RDIMM:
+			dimm->mod_type = SPD_RDIMM;
+			break;
+		default:
+			dimm->mod_type = SPD_UNDEFINED;
+			break;
+		}
+
+		dimm->bus_width = info->bus_width;
+		memcpy(dimm->serial, info->serial_number,
+		       MIN(sizeof(dimm->serial), sizeof(info->serial_number)));
+
+		dimm->vdd_voltage = info->vdd_voltage;
+		mem_info->dimm_cnt++;
+	}
+
+	return CB_SUCCESS;
+}
diff --git a/src/device/dram/ddr_common.c b/src/device/dram/ddr_common.c
new file mode 100644
index 0000000000..eb36bf52a0
--- /dev/null
+++ b/src/device/dram/ddr_common.c
@@ -0,0 +1,43 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2019 Facebook, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <console/console.h>
+#include <device/dram/common.h>
+#include <types.h>
+
+/**
+ * \brief Calculate the CRC of a DDR SPD data
+ *
+ * @param spd pointer to raw SPD data
+ * @param len length of data in SPD
+ *
+ * @return the CRC of the SPD data
+ */
+u16 ddr_crc16(const u8 *ptr, int n_crc)
+{
+	int i;
+	u16 crc = 0;
+
+	while (--n_crc >= 0) {
+		crc = crc ^ ((int)*ptr++ << 8);
+		for (i = 0; i < 8; ++i)
+			if (crc & 0x8000)
+				crc = (crc << 1) ^ 0x1021;
+			else
+				crc = crc << 1;
+	}
+
+	return crc;
+}