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>

1 files changed, 55 insertions, 0 deletions

diff --git a/arch/x86/include/asm/mrc_common.h b/arch/x86/include/asm/mrc_common.h
new file mode 100644
index 0000000000..cad24f22ad
--- /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