LXR linux/arch/arm64/mm/ioremap.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Based on arch/arm/mm/ioremap.c
   4 *
   5 * (C) Copyright 1995 1996 Linus Torvalds
   6 * Hacked for ARM by Phil Blundell <philb@gnu.org>
   7 * Hacked to allow all architectures to build, and various cleanups
   8 * by Russell King
   9 * Copyright (C) 2012 ARM Ltd.
  10 */
  11
  12#include <linux/export.h>
  13#include <linux/mm.h>
  14#include <linux/vmalloc.h>
  15#include <linux/io.h>
  16
  17#include <asm/fixmap.h>
  18#include <asm/tlbflush.h>
  19
  20static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size,
  21                                      pgprot_t prot, void *caller)
  22{
  23        unsigned long last_addr;
  24        unsigned long offset = phys_addr & ~PAGE_MASK;
  25        int err;
  26        unsigned long addr;
  27        struct vm_struct *area;
  28
  29        /*
  30         * Page align the mapping address and size, taking account of any
  31         * offset.
  32         */
  33        phys_addr &= PAGE_MASK;
  34        size = PAGE_ALIGN(size + offset);
  35
  36        /*
  37         * Don't allow wraparound, zero size or outside PHYS_MASK.
  38         */
  39        last_addr = phys_addr + size - 1;
  40        if (!size || last_addr < phys_addr || (last_addr & ~PHYS_MASK))
  41                return NULL;
  42
  43        /*
  44         * Don't allow RAM to be mapped.
  45         */
  46        if (WARN_ON(pfn_valid(__phys_to_pfn(phys_addr))))
  47                return NULL;
  48
  49        area = get_vm_area_caller(size, VM_IOREMAP, caller);
  50        if (!area)
  51                return NULL;
  52        addr = (unsigned long)area->addr;
  53        area->phys_addr = phys_addr;
  54
  55        err = ioremap_page_range(addr, addr + size, phys_addr, prot);
  56        if (err) {
  57                vunmap((void *)addr);
  58                return NULL;
  59        }
  60
  61        return (void __iomem *)(offset + addr);
  62}
  63
  64void __iomem *__ioremap(phys_addr_t phys_addr, size_t size, pgprot_t prot)
  65{
  66        return __ioremap_caller(phys_addr, size, prot,
  67                                __builtin_return_address(0));
  68}
  69EXPORT_SYMBOL(__ioremap);
  70
  71void iounmap(volatile void __iomem *io_addr)
  72{
  73        unsigned long addr = (unsigned long)io_addr & PAGE_MASK;
  74
  75        /*
  76         * We could get an address outside vmalloc range in case
  77         * of ioremap_cache() reusing a RAM mapping.
  78         */
  79        if (is_vmalloc_addr((void *)addr))
  80                vunmap((void *)addr);
  81}
  82EXPORT_SYMBOL(iounmap);
  83
  84void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size)
  85{
  86        /* For normal memory we already have a cacheable mapping. */
  87        if (pfn_valid(__phys_to_pfn(phys_addr)))
  88                return (void __iomem *)__phys_to_virt(phys_addr);
  89
  90        return __ioremap_caller(phys_addr, size, __pgprot(PROT_NORMAL),
  91                                __builtin_return_address(0));
  92}
  93EXPORT_SYMBOL(ioremap_cache);
  94
  95/*
  96 * Must be called after early_fixmap_init
  97 */
  98void __init early_ioremap_init(void)
  99{
 100        early_ioremap_setup();
 101}
 102