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
  20 static 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
  64 void __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 }
  69 EXPORT_SYMBOL(__ioremap);
  70
  71 void 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 }
  82 EXPORT_SYMBOL(iounmap);
  83
  84 void __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 }
  93 EXPORT_SYMBOL(ioremap_cache);
  94
  95 /*
  96  * Must be called after early_fixmap_init
  97  */
  98 void __init early_ioremap_init(void)
  99 {
 100         early_ioremap_setup();
 101 }