soc/intel/mtl: Fill in SPD data on both channels of DDR5 memory

Apply CB:75284 to Meteor Lake.

CB:52731 introduced support for reading SPD from the EEPROM via SMBus.
Replace the now unneeded workaround for DDR5 with filling in the correct
channels for DDR5.

Change-Id: I600d8fd480cb84d5dcb679e4f0bdeeaaebfab386
Signed-off-by: Jeremy Soller <jeremy@system76.com>
Signed-off-by: Tim Crawford <tcrawford@system76.com>

src/include/spd_bin.h

@@ -36,6 +36,18 @@
 #define DDR4_SPD_PART_OFF	329
 #define DDR4_SPD_PART_LEN	20
 #define DDR4_SPD_SN_OFF		325
+#define MAX_SPD_PAGE_SIZE_SPD5	128
+#define MAX_SPD_SIZE		(SPD_PAGE_LEN * 4)
+#define SPD_HUB_MEMREG(addr)	((u8)(0x80 | (addr)))
+#define SPD5_MR11		0x0B
+#define SPD5_MR0		0x00
+#define SPD5_MEMREG_REG(addr)	((u8)((~0x80) & (addr)))
+#define SPD5_MR0_SPD5_HUB_DEV	0x51
+
+struct spd_offset_table {
+	u16 start;		/* Offset 0 */
+	u16 end;		/* Offset 2 */
+};
 
 struct spd_block {
 	u8 addr_map[CONFIG_DIMM_MAX]; /* 7 bit I2C addresses */

src/lib/spd_cache.c

@@ -209,7 +209,9 @@ enum cb_err spd_fill_from_cache(uint8_t *spd_cache, struct spd_block *blk)
 
 	dram_type = *(spd_cache + SC_SPD_OFFSET(i) + SPD_DRAM_TYPE);
 
-	if (dram_type == SPD_DRAM_DDR4)
+	if (dram_type == SPD_DRAM_DDR5)
+		blk->len = CONFIG_DIMM_SPD_SIZE;
+	else if (dram_type == SPD_DRAM_DDR4)
 		blk->len = SPD_PAGE_LEN_DDR4;
 	else
 		blk->len = SPD_PAGE_LEN;

src/soc/intel/common/block/smbus/smbuslib.c

@@ -13,8 +13,11 @@ static void update_spd_len(struct spd_block *blk)
 		if (blk->spd_array[i] != NULL)
 			j |= blk->spd_array[i][SPD_DRAM_TYPE];
 
+	/* If spd used is DDR5, then its length is 1024 byte. */
+	if (j == SPD_DRAM_DDR5)
+		blk->len = CONFIG_DIMM_SPD_SIZE;
 	/* If spd used is DDR4, then its length is 512 byte. */
-	if (j == SPD_DRAM_DDR4)
+	else if (j == SPD_DRAM_DDR4)
 		blk->len = SPD_PAGE_LEN_DDR4;
 	else
 		blk->len = SPD_PAGE_LEN;
@@ -37,6 +40,61 @@ static void smbus_read_spd(u8 *spd, u8 addr)
 	}
 }
 
+static void switch_page(u8 spd_addr, u8 new_page)
+{
+	u32 offset;
+	/*
+	 *  By default,an SPD5 hub accepts 1 byte addressing pointing
+	 *  to the first 128 bytes of memory. MR11[2:0] selects the page
+	 *  pointer to address the entire 1024 bytes of non-volatile memory.
+	 */
+	offset = SPD5_MEMREG_REG(SPD5_MR11);
+	smbus_write_byte(spd_addr, offset, new_page);
+}
+
+/*
+ * Read the SPD data over the SMBus, at the specified SPD address,
+ * starting at the specified starting offset and read the given amount of data.
+ */
+static void smbus_read_spd5(u8 *spd, u8 spd_addr, u16 size)
+{
+	u8 page = ~0;
+	u32 max_page_size = MAX_SPD_PAGE_SIZE_SPD5;
+
+	if (size > MAX_SPD_SIZE) {
+		printk(BIOS_ERR, "Maximum SPD size reached\n");
+		return;
+	}
+	for (int i = 0; i < size; i++) {
+		u8 next_page = (u8) (i / max_page_size);
+		if (next_page != page) {
+			switch_page(spd_addr, next_page);
+			page = next_page;
+		}
+		unsigned int byte_addr = SPD_HUB_MEMREG(i % max_page_size);
+		spd[i] = smbus_read_byte(spd_addr, byte_addr);
+	}
+}
+
+/* Read SPD5 MR0 and check if SPD Byte 0 matches the SPD5 HUB MR0 identifier.*/
+static int is_spd5_hub(u8 spd_addr)
+{
+	u8 spd_hub_byte;
+
+	spd_hub_byte = smbus_read_byte(spd_addr, SPD5_MEMREG_REG(SPD5_MR0));
+	return spd_hub_byte == SPD5_MR0_SPD5_HUB_DEV;
+}
+
+/*
+ * Reset the SPD page back to page 0 on an SPD5 Hub device at the
+ * input SPD SMbus address.
+ */
+static void reset_page_spd5(u8 spd_addr)
+{
+	/* Set SPD5 MR11[2:0] = 0 (Page 0) */
+	smbus_write_byte(spd_addr, SPD5_MEMREG_REG(SPD5_MR11), 0);
+}
+
 /* return -1 if SMBus errors otherwise return 0 */
 static int get_spd(u8 *spd, u8 addr)
 {
@@ -52,22 +110,31 @@ static int get_spd(u8 *spd, u8 addr)
 		return -1;
 	}
 
-	if (i2c_eeprom_read(addr, 0, SPD_PAGE_LEN, spd) < 0) {
+	if (is_spd5_hub(addr)) {
-		printk(BIOS_INFO, "do_i2c_eeprom_read failed, using fallback\n");
+		smbus_read_spd5(spd, addr, CONFIG_DIMM_SPD_SIZE);
-		smbus_read_spd(spd, addr);
-	}
 
-	/* Check if module is DDR4, DDR4 spd is 512 byte. */
+		/* Reset the page for the next loop iteration */
-	if (spd[SPD_DRAM_TYPE] == SPD_DRAM_DDR4 && CONFIG_DIMM_SPD_SIZE > SPD_PAGE_LEN) {
+		reset_page_spd5(addr);
-		/* Switch to page 1 */
+	} else {
-		smbus_write_byte(SPD_PAGE_1, 0, 0);
 
-		if (i2c_eeprom_read(addr, 0, SPD_PAGE_LEN, spd + SPD_PAGE_LEN) < 0) {
+		if (i2c_eeprom_read(addr, 0, SPD_PAGE_LEN, spd) < 0) {
 			printk(BIOS_INFO, "do_i2c_eeprom_read failed, using fallback\n");
-			smbus_read_spd(spd + SPD_PAGE_LEN, addr);
+			smbus_read_spd(spd, addr);
+		}
+
+		/* Check if module is DDR4, DDR4 spd is 512 byte. */
+		if (spd[SPD_DRAM_TYPE] == SPD_DRAM_DDR4 &&
+					CONFIG_DIMM_SPD_SIZE > SPD_PAGE_LEN) {
+			/* Switch to page 1 */
+			smbus_write_byte(SPD_PAGE_1, 0, 0);
+
+			if (i2c_eeprom_read(addr, 0, SPD_PAGE_LEN, spd + SPD_PAGE_LEN) < 0) {
+				printk(BIOS_INFO, "do_i2c_eeprom_read failed, using fallback\n");
+				smbus_read_spd(spd + SPD_PAGE_LEN, addr);
+			}
+			/* Restore to page 0 */
+			smbus_write_byte(SPD_PAGE_0, 0, 0);
 		}
-		/* Restore to page 0 */
-		smbus_write_byte(SPD_PAGE_0, 0, 0);
 	}
 	return 0;
 }

src/soc/intel/meteorlake/meminit.c

@@ -8,7 +8,7 @@
 #define LPX_PHYSICAL_CH_WIDTH		16
 #define LPX_CHANNELS			CHANNEL_COUNT(LPX_PHYSICAL_CH_WIDTH)
 
-#define DDR5_PHYSICAL_CH_WIDTH		32
+#define DDR5_PHYSICAL_CH_WIDTH		64 /* 32*2 */
 #define DDR5_CHANNELS			CHANNEL_COUNT(DDR5_PHYSICAL_CH_WIDTH)
 
 static void set_rcomp_config(FSP_M_CONFIG *mem_cfg, const struct mb_cfg *mb_cfg)
@@ -38,18 +38,16 @@ static const struct soc_mem_cfg soc_mem_cfg[] = {
 		.num_phys_channels = DDR5_CHANNELS,
 		.phys_to_mrc_map = {
 			[0] = 0,
-			[1] = 1,
+			[1] = 4,
-			[2] = 4,
-			[3] = 5,
 		},
 		.md_phy_masks = {
 			/*
-			 * Physical channels 0 and 1 are populated in case of
+			 * Only channel 0 is populated in case of half-populated
-			 * half-populated configurations.
+			 * configuration.
 			 */
-			.half_channel = BIT(0) | BIT(1),
+			.half_channel = BIT(0),
-			/* In mixed topologies, channels 2 and 3 are always memory-down. */
+			/* In mixed topologies, either channel 0 or 1 can be memory-down. */
-			.mixed_topo = BIT(2) | BIT(3),
+			.mixed_topo = BIT(0) | BIT(1),
 		},
 	},
 	[MEM_TYPE_LP5X] = {
@@ -75,7 +73,8 @@ static const struct soc_mem_cfg soc_mem_cfg[] = {
 	},
 };
 
-static void mem_init_spd_upds(FSP_M_CONFIG *mem_cfg, const struct mem_channel_data *data)
+static void mem_init_spd_upds(FSP_M_CONFIG *mem_cfg, const struct mem_channel_data *data,
+				bool expand_channels)
 {
 	efi_uintn_t *spd_upds[MRC_CHANNELS][CONFIG_DIMMS_PER_CHANNEL] = {
 		[0] = { &mem_cfg->MemorySpdPtr000, &mem_cfg->MemorySpdPtr001, },
@@ -108,7 +107,16 @@ static void mem_init_spd_upds(FSP_M_CONFIG *mem_cfg, const struct mem_channel_da
 		for (dimm = 0; dimm < CONFIG_DIMMS_PER_CHANNEL; dimm++) {
 			efi_uintn_t *spd_ptr = spd_upds[ch][dimm];
 
-			*spd_ptr = data->spd[ch][dimm];
+			// In DDR5 systems, we need to copy the SPD data such that:
+			// Channel 0 data is used by channel 0 and 1
+			// Channel 2 data is used by channel 2 and 3
+			// Channel 4 data is used by channel 4 and 5
+			// Channel 6 data is used by channel 6 and 7
+			if (expand_channels)
+				*spd_ptr = data->spd[ch & 6][dimm];
+			else
+				*spd_ptr = data->spd[ch][dimm];
+
 			if (*spd_ptr)
 				enable_channel = 1;
 		}
@@ -174,27 +182,12 @@ static void mem_init_dqs_upds(FSP_M_CONFIG *mem_cfg, const struct mem_channel_da
 	mem_init_dq_dqs_upds(dqs_upds, mb_cfg->dqs_map, upd_size, data, auto_detect);
 }
 
-#define DDR5_CH_DIMM_OFFSET(ch, dimm)        ((ch) * CONFIG_DIMMS_PER_CHANNEL + (dimm))
-
-static void ddr5_fill_dimm_module_info(FSP_M_CONFIG *mem_cfg, const struct mb_cfg *mb_cfg,
-					const struct mem_spd *spd_info)
-{
-	for (size_t ch = 0; ch < soc_mem_cfg[MEM_TYPE_DDR5].num_phys_channels; ch++) {
-		for (size_t dimm = 0; dimm < CONFIG_DIMMS_PER_CHANNEL; dimm++) {
-			size_t mrc_ch = soc_mem_cfg[MEM_TYPE_DDR5].phys_to_mrc_map[ch];
-			mem_cfg->SpdAddressTable[DDR5_CH_DIMM_OFFSET(mrc_ch, dimm)] =
-				spd_info->smbus[ch].addr_dimm[dimm] << 1;
-		}
-	}
-	mem_init_dq_upds(mem_cfg, NULL, mb_cfg, true);
-	mem_init_dqs_upds(mem_cfg, NULL, mb_cfg, true);
-}
-
 void memcfg_init(FSPM_UPD *memupd, const struct mb_cfg *mb_cfg,
 		 const struct mem_spd *spd_info, bool half_populated)
 {
 	struct mem_channel_data data;
 	bool dq_dqs_auto_detect = false;
+	bool expand_channels = false;
 	FSP_M_CONFIG *mem_cfg = &memupd->FspmConfig;
 
 	mem_cfg->ECT = mb_cfg->ect;
@@ -205,14 +198,7 @@ void memcfg_init(FSPM_UPD *memupd, const struct mb_cfg *mb_cfg,
 	case MEM_TYPE_DDR5:
 		meminit_ddr(mem_cfg, &mb_cfg->ddr_config);
 		dq_dqs_auto_detect = true;
-		/*
+		expand_channels = true;
-		* TODO: Drop this workaround once SMBus driver in coreboot is updated to
-		* support DDR5 EEPROM reading.
-		*/
-		if (spd_info->topo == MEM_TOPO_DIMM_MODULE) {
-			ddr5_fill_dimm_module_info(mem_cfg, mb_cfg, spd_info);
-			return;
-		}
 		break;
 	case MEM_TYPE_LP5X:
 		meminit_lp5x(mem_cfg, &mb_cfg->lp5x_config);
@@ -221,9 +207,9 @@ void memcfg_init(FSPM_UPD *memupd, const struct mb_cfg *mb_cfg,
 		die("Unsupported memory type(%d)\n", mb_cfg->type);
 	}
 
-	mem_populate_channel_data(memupd, &soc_mem_cfg[mb_cfg->type], spd_info,
+	mem_populate_channel_data(memupd, &soc_mem_cfg[mb_cfg->type], spd_info, half_populated,
-					 half_populated, &data);
+			&data);
-	mem_init_spd_upds(mem_cfg, &data);
+	mem_init_spd_upds(mem_cfg, &data, expand_channels);
 	mem_init_dq_upds(mem_cfg, &data, mb_cfg, dq_dqs_auto_detect);
 	mem_init_dqs_upds(mem_cfg, &data, mb_cfg, dq_dqs_auto_detect);
 }