linux_dsm_epyc7002/arch/riscv/include/asm/fixmap.h
Anup Patel f2c17aabc9 RISC-V: Implement compile-time fixed mappings
This patch implements compile-time virtual to physical mappings. These
compile-time fixed mappings can be used by earlycon, ACPI, and early
ioremap for creating fixed mappings when FIX_EARLYCON_MEM=y.

To start with, we have enabled compile-time fixed mappings for earlycon.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
2019-02-21 11:26:42 +05:30

45 lines
1.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2019 Western Digital Corporation or its affiliates.
*/
#ifndef _ASM_RISCV_FIXMAP_H
#define _ASM_RISCV_FIXMAP_H
#include <linux/kernel.h>
#include <linux/sizes.h>
#include <asm/page.h>
#include <asm/pgtable.h>
/*
* Here we define all the compile-time 'special' virtual addresses.
* The point is to have a constant address at compile time, but to
* set the physical address only in the boot process.
*
* These 'compile-time allocated' memory buffers are page-sized. Use
* set_fixmap(idx,phys) to associate physical memory with fixmap indices.
*/
enum fixed_addresses {
FIX_HOLE,
FIX_EARLYCON_MEM_BASE,
__end_of_fixed_addresses
};
#define FIXADDR_SIZE (__end_of_fixed_addresses * PAGE_SIZE)
#define FIXADDR_TOP (PAGE_OFFSET)
#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
#define FIXMAP_PAGE_IO PAGE_KERNEL
#define __early_set_fixmap __set_fixmap
#define __late_set_fixmap __set_fixmap
#define __late_clear_fixmap(idx) __set_fixmap((idx), 0, FIXMAP_PAGE_CLEAR)
extern void __set_fixmap(enum fixed_addresses idx,
phys_addr_t phys, pgprot_t prot);
#include <asm-generic/fixmap.h>
#endif /* _ASM_RISCV_FIXMAP_H */