linux_dsm_epyc7002/arch/riscv/include/asm/soc.h
Damien Le Moal 335b139057
riscv: Add SOC early init support
Add a mechanism for early SoC initialization for platforms that need
additional hardware initialization not possible through the regular
device tree and drivers mechanism. With this, a SoC specific
initialization function can be called very early, before DTB parsing
is done by parse_dtb() in Linux RISC-V kernel setup code.

This can be very useful for early hardware initialization for No-MMU
kernels booted directly in M-mode because it is quite likely that no
other booting stage exist prior to the No-MMU kernel.

Example use of a SoC early initialization is as follows:

static void vendor_abc_early_init(const void *fdt)
{
	/*
	 * some early init code here that can use simple matches
	 * against the flat device tree file.
	 */
}
SOC_EARLY_INIT_DECLARE("vendor,abc", abc_early_init);

This early initialization function is executed only if the flat device
tree for the board has a 'compatible = "vendor,abc"' entry;

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-04-03 10:46:43 -07:00

24 lines
591 B
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Copyright (C) 2020 Western Digital Corporation or its affiliates.
*/
#ifndef _ASM_RISCV_SOC_H
#define _ASM_RISCV_SOC_H
#include <linux/of.h>
#include <linux/linkage.h>
#include <linux/types.h>
#define SOC_EARLY_INIT_DECLARE(name, compat, fn) \
static const struct of_device_id __soc_early_init__##name \
__used __section(__soc_early_init_table) \
= { .compatible = compat, .data = fn }
void soc_early_init(void);
extern unsigned long __soc_early_init_table_start;
extern unsigned long __soc_early_init_table_end;
#endif