arch/riscv/include/asm/fixmap.h

Source file repositories/reference/linux-study-clean/arch/riscv/include/asm/fixmap.h

File Facts

System
Linux kernel
Corpus path
arch/riscv/include/asm/fixmap.h
Extension
.h
Size
1789 bytes
Lines
68
Domain
Architecture Layer
Bucket
arch/riscv
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

#ifndef _ASM_RISCV_FIXMAP_H
#define _ASM_RISCV_FIXMAP_H

#include <linux/kernel.h>
#include <linux/sizes.h>
#include <linux/pgtable.h>
#include <asm/page.h>

#ifdef CONFIG_MMU
/*
 * 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,
	/*
	 * The fdt fixmap mapping must be PMD aligned and will be mapped
	 * using PMD entries in fixmap_pmd in 64-bit and a PGD entry in 32-bit.
	 */
	FIX_FDT_END,
	FIX_FDT = FIX_FDT_END + FIX_FDT_SIZE / PAGE_SIZE - 1,

	/* Below fixmaps will be mapped using fixmap_pte */
	FIX_PTE,
	FIX_PMD,
	FIX_PUD,
	FIX_P4D,
	FIX_TEXT_POKE1,
	FIX_TEXT_POKE0,
	FIX_EARLYCON_MEM_BASE,

	__end_of_permanent_fixed_addresses,
	/*
	 * Temporary boot-time mappings, used by early_ioremap(),
	 * before ioremap() is functional.
	 */
#define NR_FIX_BTMAPS		(SZ_256K / PAGE_SIZE)
#define FIX_BTMAPS_SLOTS	7
#define TOTAL_FIX_BTMAPS	(NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)

	FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
	FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,

	__end_of_fixed_addresses
};

#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 /* CONFIG_MMU */
#endif /* _ASM_RISCV_FIXMAP_H */

Annotation

Implementation Notes