x86: slimbootloader: Add memory configuration

Slim Bootloader provides memory map info thru its HOB list pointer.
Configure memory size and relocation memory from the HOB data, and
provide e820 entries as well.
- Get memory size from the memory map info HOB
- Set available top memory lower than 4GB for U-Boot relocation
- Provide e820 entries from the memory map info HOB

Signed-off-by: Aiden Park <aiden.park@intel.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>

arch/x86/cpu/slimbootloader/Makefile

@@ -2,4 +2,4 @@
 #
 # Copyright (C) 2019 Intel Corporation <www.intel.com>
 
-obj-y += car.o slimbootloader.o
+obj-y += car.o slimbootloader.o sdram.o

arch/x86/cpu/slimbootloader/sdram.c

@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019 Intel Corporation <www.intel.com>
+ */
+
+#include <common.h>
+#include <linux/sizes.h>
+#include <asm/e820.h>
+#include <asm/arch/slimbootloader.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/**
+ * This returns a data pointer of memory map info from the guid hob.
+ *
+ * @return: A data pointer of memory map info hob
+ */
+static struct sbl_memory_map_info *get_memory_map_info(void)
+{
+	struct sbl_memory_map_info *data;
+	const efi_guid_t guid = SBL_MEMORY_MAP_INFO_GUID;
+
+	if (!gd->arch.hob_list)
+		return NULL;
+
+	data = hob_get_guid_hob_data(gd->arch.hob_list, NULL, &guid);
+	if (!data)
+		panic("memory map info hob not found\n");
+	if (!data->count)
+		panic("invalid number of memory map entries\n");
+
+	return data;
+}
+
+#define for_each_if(condition) if (!(condition)) {} else
+
+#define for_each_memory_map_entry_reversed(iter, entries) \
+	for (iter = entries->count - 1; iter >= 0; iter--) \
+		for_each_if(entries->entry[iter].type == E820_RAM)
+
+/**
+ * This is to give usable memory region information for u-boot relocation.
+ * so search usable memory region lower than 4GB.
+ * The memory map entries from Slim Bootloader hob are already sorted.
+ *
+ * @total_size: The memory size that u-boot occupies
+ * @return    : The top available memory address lower than 4GB
+ */
+ulong board_get_usable_ram_top(ulong total_size)
+{
+	struct sbl_memory_map_info *data;
+	int i;
+	u64 addr_start;
+	u64 addr_end;
+	ulong ram_top;
+
+	data = get_memory_map_info();
+
+	/**
+	 * sorted memory map entries from Slim Bootloader based on physical
+	 * start memory address, from low to high. So do reversed search to
+	 * get highest usable, suitable size, 4KB aligned available memory
+	 * under 4GB.
+	 */
+	ram_top = 0;
+	for_each_memory_map_entry_reversed(i, data) {
+		addr_start = data->entry[i].addr;
+		addr_end = addr_start + data->entry[i].size;
+
+		if (addr_start > SZ_4G)
+			continue;
+
+		if (addr_end > SZ_4G)
+			addr_end = SZ_4G;
+
+		if (addr_end < total_size)
+			continue;
+
+		/* to relocate u-boot at 4K aligned memory */
+		addr_end = rounddown(addr_end - total_size, SZ_4K);
+		if (addr_end >= addr_start) {
+			ram_top = (ulong)addr_end + total_size;
+			break;
+		}
+	}
+
+	if (!ram_top)
+		panic("failed to find available memory for relocation!");
+
+	return ram_top;
+}
+
+/**
+ * The memory initialization has already been done in previous Slim Bootloader
+ * stage thru FSP-M. Instead, this sets the ram_size from the memory map info
+ * hob.
+ */
+int dram_init(void)
+{
+	struct sbl_memory_map_info *data;
+	int i;
+	u64 ram_size;
+
+	data = get_memory_map_info();
+
+	/**
+	 * sorted memory map entries from Slim Bootloader based on physical
+	 * start memory address, from low to high. So do reversed search to
+	 * simply get highest usable memory address as RAM size
+	 */
+	ram_size = 0;
+	for_each_memory_map_entry_reversed(i, data) {
+		/* simply use the highest usable memory address as RAM size */
+		ram_size = data->entry[i].addr + data->entry[i].size;
+		break;
+	}
+
+	if (!ram_size)
+		panic("failed to detect memory size");
+
+	gd->ram_size = ram_size;
+	return 0;
+}
+
+int dram_init_banksize(void)
+{
+	if (!CONFIG_NR_DRAM_BANKS)
+		return 0;
+
+	/* simply use a single bank to have whole size for now */
+	gd->bd->bi_dram[0].start = 0;
+	gd->bd->bi_dram[0].size = gd->ram_size;
+	return 0;
+}
+
+unsigned int install_e820_map(unsigned int max_entries,
+			      struct e820_entry *entries)
+{
+	struct sbl_memory_map_info *data;
+	unsigned int i;
+
+	data = get_memory_map_info();
+
+	for (i = 0; i < data->count; i++) {
+		entries[i].addr = data->entry[i].addr;
+		entries[i].size = data->entry[i].size;
+		entries[i].type = data->entry[i].type;
+	}
+
+	return i;
+}

arch/x86/include/asm/arch-slimbootloader/slimbootloader.h

@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2019 Intel Corporation <www.intel.com>
+ */
+
+#ifndef __SLIMBOOTLOADER_ARCH_H__
+#define __SLIMBOOTLOADER_ARCH_H__
+
+#include <common.h>
+#include <asm/hob.h>
+
+/**
+ * A GUID to get MemoryMap info hob which is provided by Slim Bootloader
+ */
+#define SBL_MEMORY_MAP_INFO_GUID \
+	EFI_GUID(0xa1ff7424, 0x7a1a, 0x478e, \
+		0xa9, 0xe4, 0x92, 0xf3, 0x57, 0xd1, 0x28, 0x32)
+
+/**
+ * A single entry of memory map information
+ *
+ * @addr: start address of a memory map entry
+ * @size: size of a memory map entry
+ * @type: usable:1, reserved:2, acpi:3, nvs:4, unusable:5
+ * @flag: only used in Slim Bootloader
+ * @rsvd: padding for alignment
+ */
+struct sbl_memory_map_entry {
+	u64	addr;
+	u64	size;
+	u8	type;
+	u8	flag;
+	u8	rsvd[6];
+};
+
+/**
+ * This includes all memory map entries which is sorted based on physical start
+ * address, from low to high, and carved out reserved, acpi nvs, acpi reclaim
+ * and usable memory.
+ *
+ * @rev  : revision of memory_map_info structure. currently 1.
+ * @rsvd : padding for alignment
+ * @count: the number of memory map entries
+ * @entry: array of all memory map entries
+ */
+struct sbl_memory_map_info {
+	u8	rev;
+	u8	rsvd[3];
+	u32	count;
+	struct sbl_memory_map_entry	entry[0];
+};
+
+#endif /* __SLIMBOOTLOADER_ARCH_H__ */