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 #include <asm/pgalloc.h>
  20
  21 static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size,
  22                                       pgprot_t prot, void *caller)
  23 {
  24         unsigned long last_addr;
  25         unsigned long offset = phys_addr & ~PAGE_MASK;
  26         int err;
  27         unsigned long addr;
  28         struct vm_struct *area;
  29
  30         /*
  31          * Page align the mapping address and size, taking account of any
  32          * offset.
  33          */
  34         phys_addr &= PAGE_MASK;
  35         size = PAGE_ALIGN(size + offset);
  36
  37         /*
  38          * Don't allow wraparound, zero size or outside PHYS_MASK.
  39          */
  40         last_addr = phys_addr + size - 1;
  41         if (!size || last_addr < phys_addr || (last_addr & ~PHYS_MASK))
  42                 return NULL;
  43
  44         /*
  45          * Don't allow RAM to be mapped.
  46          */
  47         if (WARN_ON(pfn_valid(__phys_to_pfn(phys_addr))))
  48                 return NULL;
  49
  50         area = get_vm_area_caller(size, VM_IOREMAP, caller);
  51         if (!area)
  52                 return NULL;
  53         addr = (unsigned long)area->addr;
  54         area->phys_addr = phys_addr;
  55
  56         err = ioremap_page_range(addr, addr + size, phys_addr, prot);
  57         if (err) {
  58                 vunmap((void *)addr);
  59                 return NULL;
  60         }
  61
  62         return (void __iomem *)(offset + addr);
  63 }
  64
  65 void __iomem *__ioremap(phys_addr_t phys_addr, size_t size, pgprot_t prot)
  66 {
  67         return __ioremap_caller(phys_addr, size, prot,
  68                                 __builtin_return_address(0));
  69 }
  70 EXPORT_SYMBOL(__ioremap);
  71
  72 void iounmap(volatile void __iomem *io_addr)
  73 {
  74         unsigned long addr = (unsigned long)io_addr & PAGE_MASK;
  75
  76         /*
  77          * We could get an address outside vmalloc range in case
  78          * of ioremap_cache() reusing a RAM mapping.
  79          */
  80         if (is_vmalloc_addr((void *)addr))
  81                 vunmap((void *)addr);
  82 }
  83 EXPORT_SYMBOL(iounmap);
  84
  85 void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size)
  86 {
  87         /* For normal memory we already have a cacheable mapping. */
  88         if (pfn_valid(__phys_to_pfn(phys_addr)))
  89                 return (void __iomem *)__phys_to_virt(phys_addr);
  90
  91         return __ioremap_caller(phys_addr, size, __pgprot(PROT_NORMAL),
  92                                 __builtin_return_address(0));
  93 }
  94 EXPORT_SYMBOL(ioremap_cache);
  95
  96 /*
  97  * Must be called after early_fixmap_init
  98  */
  99 void __init early_ioremap_init(void)
 100 {
 101         early_ioremap_setup();
 102 }