linux/mm/early_ioremap.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Provide common bits of early_ioremap() support for architectures needing
 * temporary mappings during boot before ioremap() is available.
 *
 * This is mostly a direct copy of the x86 early_ioremap implementation.
 *
 * (C) Copyright 1995 1996, 2014 Linus Torvalds
 *
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <asm/fixmap.h>
#include <asm/early_ioremap.h>
#include "internal.h"

#ifdef CONFIG_MMU
static int early_ioremap_debug __initdata;

static int __init early_ioremap_debug_setup(char *str)
{ … }
early_param(…);

static int after_paging_init __initdata;

pgprot_t __init __weak early_memremap_pgprot_adjust(resource_size_t phys_addr,
						    unsigned long size,
						    pgprot_t prot)
{ … }

void __init early_ioremap_reset(void)
{ … }

/*
 * Generally, ioremap() is available after paging_init() has been called.
 * Architectures wanting to allow early_ioremap after paging_init() can
 * define __late_set_fixmap and __late_clear_fixmap to do the right thing.
 */
#ifndef __late_set_fixmap
static inline void __init __late_set_fixmap(enum fixed_addresses idx,
					    phys_addr_t phys, pgprot_t prot)
{
	BUG();
}
#endif

#ifndef __late_clear_fixmap
static inline void __init __late_clear_fixmap(enum fixed_addresses idx)
{
	BUG();
}
#endif

static void __iomem *prev_map[FIX_BTMAPS_SLOTS] __initdata;
static unsigned long prev_size[FIX_BTMAPS_SLOTS] __initdata;
static unsigned long slot_virt[FIX_BTMAPS_SLOTS] __initdata;

void __init early_ioremap_setup(void)
{ … }

static int __init check_early_ioremap_leak(void)
{ … }
late_initcall(check_early_ioremap_leak);

static void __init __iomem *
__early_ioremap(resource_size_t phys_addr, unsigned long size, pgprot_t prot)
{ … }

void __init early_iounmap(void __iomem *addr, unsigned long size)
{ … }

/* Remap an IO device */
void __init __iomem *
early_ioremap(resource_size_t phys_addr, unsigned long size)
{ … }

/* Remap memory */
void __init *
early_memremap(resource_size_t phys_addr, unsigned long size)
{ … }
#ifdef FIXMAP_PAGE_RO
void __init *
early_memremap_ro(resource_size_t phys_addr, unsigned long size)
{ … }
#endif

#ifdef CONFIG_ARCH_USE_MEMREMAP_PROT
void __init *
early_memremap_prot(resource_size_t phys_addr, unsigned long size,
		    unsigned long prot_val)
{ … }
#endif

#define MAX_MAP_CHUNK …

void __init copy_from_early_mem(void *dest, phys_addr_t src, unsigned long size)
{ … }

#else /* CONFIG_MMU */

void __init __iomem *
early_ioremap(resource_size_t phys_addr, unsigned long size)
{
	return (__force void __iomem *)phys_addr;
}

/* Remap memory */
void __init *
early_memremap(resource_size_t phys_addr, unsigned long size)
{
	return (void *)phys_addr;
}
void __init *
early_memremap_ro(resource_size_t phys_addr, unsigned long size)
{
	return (void *)phys_addr;
}

void __init early_iounmap(void __iomem *addr, unsigned long size)
{
}

#endif /* CONFIG_MMU */


void __init early_memunmap(void *addr, unsigned long size)
{ … }