x86: Add common SDRAM-init code

The code to call the memory reference code is common to several Intel CPUs.
Add common code for performing this init. Intel calls this 'Pre-EFI-Init'
(PEI), where EFI stands for Extensible Firmware Interface.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

3 files changed, 327 insertions, 0 deletions

diff --git a/arch/x86/cpu/intel_common/Makefile b/arch/x86/cpu/intel_common/Makefile
index 74b097a..804c539 100644
--- a/arch/x86/cpu/intel_common/Makefile
+++ b/arch/x86/cpu/intel_common/Makefile
@@ -13,3 +13,4 @@ obj-y += microcode.o
 endif
 obj-y += pch.o
 obj-$(CONFIG_HAVE_MRC) += report_platform.o
+obj-$(CONFIG_HAVE_MRC) += mrc.o
diff --git a/arch/x86/cpu/intel_common/mrc.c b/arch/x86/cpu/intel_common/mrc.c
new file mode 100644
index 0000000..01b6e86
--- /dev/null
+++ b/arch/x86/cpu/intel_common/mrc.c
@@ -0,0 +1,271 @@
+/*
+ * Copyright (c) 2016 Google, Inc
+ *
+ * SPDX-License-Identifier:	GPL-2.0
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <syscon.h>
+#include <asm/cpu.h>
+#include <asm/gpio.h>
+#include <asm/intel_regs.h>
+#include <asm/mrc_common.h>
+#include <asm/pch_common.h>
+#include <asm/post.h>
+#include <asm/arch/me.h>
+#include <asm/report_platform.h>
+
+static const char *const ecc_decoder[] = {
+	"inactive",
+	"active on IO",
+	"disabled on IO",
+	"active"
+};
+
+ulong mrc_common_board_get_usable_ram_top(ulong total_size)
+{
+	struct memory_info *info = &gd->arch.meminfo;
+	uintptr_t dest_addr = 0;
+	struct memory_area *largest = NULL;
+	int i;
+
+	/* Find largest area of memory below 4GB */
+
+	for (i = 0; i < info->num_areas; i++) {
+		struct memory_area *area = &info->area[i];
+
+		if (area->start >= 1ULL << 32)
+			continue;
+		if (!largest || area->size > largest->size)
+			largest = area;
+	}
+
+	/* If no suitable area was found, return an error. */
+	assert(largest);
+	if (!largest || largest->size < (2 << 20))
+		panic("No available memory found for relocation");
+
+	dest_addr = largest->start + largest->size;
+
+	return (ulong)dest_addr;
+}
+
+void mrc_common_dram_init_banksize(void)
+{
+	struct memory_info *info = &gd->arch.meminfo;
+	int num_banks;
+	int i;
+
+	for (i = 0, num_banks = 0; i < info->num_areas; i++) {
+		struct memory_area *area = &info->area[i];
+
+		if (area->start >= 1ULL << 32)
+			continue;
+		gd->bd->bi_dram[num_banks].start = area->start;
+		gd->bd->bi_dram[num_banks].size = area->size;
+		num_banks++;
+	}
+}
+
+int mrc_add_memory_area(struct memory_info *info, uint64_t start,
+			  uint64_t end)
+{
+	struct memory_area *ptr;
+
+	if (info->num_areas == CONFIG_NR_DRAM_BANKS)
+		return -ENOSPC;
+
+	ptr = &info->area[info->num_areas];
+	ptr->start = start;
+	ptr->size = end - start;
+	info->total_memory += ptr->size;
+	if (ptr->start < (1ULL << 32))
+		info->total_32bit_memory += ptr->size;
+	debug("%d: memory %llx size %llx, total now %llx / %llx\n",
+	      info->num_areas, ptr->start, ptr->size,
+	      info->total_32bit_memory, info->total_memory);
+	info->num_areas++;
+
+	return 0;
+}
+
+/*
+ * Dump in the log memory controller configuration as read from the memory
+ * controller registers.
+ */
+void report_memory_config(void)
+{
+	u32 addr_decoder_common, addr_decode_ch[2];
+	int i;
+
+	addr_decoder_common = readl(MCHBAR_REG(0x5000));
+	addr_decode_ch[0] = readl(MCHBAR_REG(0x5004));
+	addr_decode_ch[1] = readl(MCHBAR_REG(0x5008));
+
+	debug("memcfg DDR3 clock %d MHz\n",
+	      (readl(MCHBAR_REG(0x5e04)) * 13333 * 2 + 50) / 100);
+	debug("memcfg channel assignment: A: %d, B % d, C % d\n",
+	      addr_decoder_common & 3,
+	      (addr_decoder_common >> 2) & 3,
+	      (addr_decoder_common >> 4) & 3);
+
+	for (i = 0; i < ARRAY_SIZE(addr_decode_ch); i++) {
+		u32 ch_conf = addr_decode_ch[i];
+		debug("memcfg channel[%d] config (%8.8x):\n", i, ch_conf);
+		debug("   ECC %s\n", ecc_decoder[(ch_conf >> 24) & 3]);
+		debug("   enhanced interleave mode %s\n",
+		      ((ch_conf >> 22) & 1) ? "on" : "off");
+		debug("   rank interleave %s\n",
+		      ((ch_conf >> 21) & 1) ? "on" : "off");
+		debug("   DIMMA %d MB width x%d %s rank%s\n",
+		      ((ch_conf >> 0) & 0xff) * 256,
+		      ((ch_conf >> 19) & 1) ? 16 : 8,
+		      ((ch_conf >> 17) & 1) ? "dual" : "single",
+		      ((ch_conf >> 16) & 1) ? "" : ", selected");
+		debug("   DIMMB %d MB width x%d %s rank%s\n",
+		      ((ch_conf >> 8) & 0xff) * 256,
+		      ((ch_conf >> 20) & 1) ? 16 : 8,
+		      ((ch_conf >> 18) & 1) ? "dual" : "single",
+		      ((ch_conf >> 16) & 1) ? ", selected" : "");
+	}
+}
+
+int mrc_locate_spd(struct udevice *dev, int size, const void **spd_datap)
+{
+	const void *blob = gd->fdt_blob;
+	int spd_index;
+	struct gpio_desc desc[4];
+	int spd_node;
+	int node;
+	int ret;
+
+	ret = gpio_request_list_by_name(dev, "board-id-gpios", desc,
+					ARRAY_SIZE(desc), GPIOD_IS_IN);
+	if (ret < 0) {
+		debug("%s: gpio ret=%d\n", __func__, ret);
+		return ret;
+	}
+	spd_index = dm_gpio_get_values_as_int(desc, ret);
+	debug("spd index %d\n", spd_index);
+
+	node = fdt_first_subnode(blob, dev->of_offset);
+	if (node < 0)
+		return -EINVAL;
+	for (spd_node = fdt_first_subnode(blob, node);
+	     spd_node > 0;
+	     spd_node = fdt_next_subnode(blob, spd_node)) {
+		int len;
+
+		if (fdtdec_get_int(blob, spd_node, "reg", -1) != spd_index)
+			continue;
+		*spd_datap = fdt_getprop(blob, spd_node, "data", &len);
+		if (len < size) {
+			printf("Missing SPD data\n");
+			return -EINVAL;
+		}
+
+		debug("Using SDRAM SPD data for '%s'\n",
+		      fdt_get_name(blob, spd_node, NULL));
+		return 0;
+	}
+
+	printf("No SPD data found for index %d\n", spd_index);
+	return -ENOENT;
+}
+
+asmlinkage void sdram_console_tx_byte(unsigned char byte)
+{
+#ifdef DEBUG
+	putc(byte);
+#endif
+}
+
+/**
+ * Find the PEI executable in the ROM and execute it.
+ *
+ * @me_dev: Management Engine device
+ * @pei_data: configuration data for UEFI PEI reference code
+ */
+static int sdram_initialise(struct udevice *dev, struct udevice *me_dev,
+			    void *pei_data, bool use_asm_linkage)
+{
+	unsigned version;
+	const char *data;
+
+	report_platform_info(dev);
+	debug("Starting UEFI PEI System Agent\n");
+
+	debug("PEI data at %p:\n", pei_data);
+
+	data = (char *)CONFIG_X86_MRC_ADDR;
+	if (data) {
+		int rv;
+		ulong start;
+
+		debug("Calling MRC at %p\n", data);
+		post_code(POST_PRE_MRC);
+		start = get_timer(0);
+		if (use_asm_linkage) {
+			asmlinkage int (*func)(void *);
+
+			func = (asmlinkage int (*)(void *))data;
+			rv = func(pei_data);
+		} else {
+			int (*func)(void *);
+
+			func = (int (*)(void *))data;
+			rv = func(pei_data);
+		}
+		post_code(POST_MRC);
+		if (rv) {
+			switch (rv) {
+			case -1:
+				printf("PEI version mismatch.\n");
+				break;
+			case -2:
+				printf("Invalid memory frequency.\n");
+				break;
+			default:
+				printf("MRC returned %x.\n", rv);
+			}
+			printf("Nonzero MRC return value.\n");
+			return -EFAULT;
+		}
+		debug("MRC execution time %lu ms\n", get_timer(start));
+	} else {
+		printf("UEFI PEI System Agent not found.\n");
+		return -ENOSYS;
+	}
+
+	version = readl(MCHBAR_REG(MCHBAR_PEI_VERSION));
+	debug("System Agent Version %d.%d.%d Build %d\n",
+	      version >> 24 , (version >> 16) & 0xff,
+	      (version >> 8) & 0xff, version & 0xff);
+
+#if CONFIG_USBDEBUG
+	/* mrc.bin reconfigures USB, so reinit it to have debug */
+	early_usbdebug_init();
+#endif
+
+	return 0;
+}
+
+int mrc_common_init(struct udevice *dev, void *pei_data, bool use_asm_linkage)
+{
+	struct udevice *me_dev;
+	int ret;
+
+	ret = syscon_get_by_driver_data(X86_SYSCON_ME, &me_dev);
+	if (ret)
+		return ret;
+
+	ret = sdram_initialise(dev, me_dev, pei_data, use_asm_linkage);
+	if (ret)
+		return ret;
+	quick_ram_check();
+	post_code(POST_DRAM);
+	report_memory_config();
+
+	return 0;
+}
diff --git a/arch/x86/include/asm/mrc_common.h b/arch/x86/include/asm/mrc_common.h
new file mode 100644
index 0000000..cad24f2
--- /dev/null
+++ b/arch/x86/include/asm/mrc_common.h
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2016 Google, Inc
+ *
+ * SPDX-License-Identifier:	GPL-2.0
+ */
+
+#ifndef __ASM_MRC_COMMON_H
+#define __ASM_MRC_COMMON_H
+
+#include <linux/linkage.h>
+
+/**
+ * mrc_common_init() - Set up SDRAM
+ *
+ * This calls the memory reference code (MRC) to set up SDRAM
+ *
+ * @dev:	Northbridge device
+ * @pei_data:	Platform-specific data required by the MRC
+ * @use_asm_linkage: true if the call to MRC requires asmlinkage, false if it
+ * uses normal U-Boot calling
+ * @return 0 if OK, -ve on error
+ */
+int mrc_common_init(struct udevice *dev, void *pei_data, bool use_asm_linkage);
+
+asmlinkage void sdram_console_tx_byte(unsigned char byte);
+
+int mrc_locate_spd(struct udevice *dev, int size, const void **spd_datap);
+
+void report_memory_config(void);
+
+/**
+ * mrc_add_memory_area() - Add a new usable memory area to our list
+ *
+ * Note: @start and @end must not span the first 4GB boundary
+ *
+ * @info:	Place to store memory info
+ * @start:	Start of this memory area
+ * @end:	End of this memory area + 1
+ */
+int mrc_add_memory_area(struct memory_info *info, uint64_t start,
+			  uint64_t end);
+
+/*
+ * This function looks for the highest region of memory lower than 4GB which
+ * has enough space for U-Boot where U-Boot is aligned on a page boundary.
+ * It overrides the default implementation found elsewhere which simply
+ * picks the end of ram, wherever that may be. The location of the stack,
+ * the relocation address, and how far U-Boot is moved by relocation are
+ * set in the global data structure.
+ */
+ulong mrc_common_board_get_usable_ram_top(ulong total_size);
+
+void mrc_common_dram_init_banksize(void);
+
+#endif