root/arch/powerpc/mm/ioremap_64.c

DEFINITIONS

1. __ioremap_at
2. __iounmap_at
3. __ioremap_caller
4. iounmap

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 
   3 #include <linux/io.h>
   4 #include <linux/slab.h>
   5 #include <linux/vmalloc.h>
   6 
   7 /**
   8  * Low level function to establish the page tables for an IO mapping
   9  */
  10 void __iomem *__ioremap_at(phys_addr_t pa, void *ea, unsigned long size, pgprot_t prot)
  11 {
  12         int ret;
  13         unsigned long va = (unsigned long)ea;
  14 
  15         /* We don't support the 4K PFN hack with ioremap */
  16         if (pgprot_val(prot) & H_PAGE_4K_PFN)
  17                 return NULL;
  18 
  19         if ((ea + size) >= (void *)IOREMAP_END) {
  20                 pr_warn("Outside the supported range\n");
  21                 return NULL;
  22         }
  23 
  24         WARN_ON(pa & ~PAGE_MASK);
  25         WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
  26         WARN_ON(size & ~PAGE_MASK);
  27 
  28         if (slab_is_available()) {
  29                 ret = ioremap_page_range(va, va + size, pa, prot);
  30                 if (ret)
  31                         unmap_kernel_range(va, size);
  32         } else {
  33                 ret = early_ioremap_range(va, pa, size, prot);
  34         }
  35 
  36         if (ret)
  37                 return NULL;
  38 
  39         return (void __iomem *)ea;
  40 }
  41 EXPORT_SYMBOL(__ioremap_at);
  42 
  43 /**
  44  * Low level function to tear down the page tables for an IO mapping. This is
  45  * used for mappings that are manipulated manually, like partial unmapping of
  46  * PCI IOs or ISA space.
  47  */
  48 void __iounmap_at(void *ea, unsigned long size)
  49 {
  50         WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
  51         WARN_ON(size & ~PAGE_MASK);
  52 
  53         unmap_kernel_range((unsigned long)ea, size);
  54 }
  55 EXPORT_SYMBOL(__iounmap_at);
  56 
  57 void __iomem *__ioremap_caller(phys_addr_t addr, unsigned long size,
  58                                pgprot_t prot, void *caller)
  59 {
  60         phys_addr_t paligned, offset;
  61         void __iomem *ret;
  62         int err;
  63 
  64         /* We don't support the 4K PFN hack with ioremap */
  65         if (pgprot_val(prot) & H_PAGE_4K_PFN)
  66                 return NULL;
  67 
  68         /*
  69          * Choose an address to map it to. Once the vmalloc system is running,
  70          * we use it. Before that, we map using addresses going up from
  71          * ioremap_bot.  vmalloc will use the addresses from IOREMAP_BASE
  72          * through ioremap_bot.
  73          */
  74         paligned = addr & PAGE_MASK;
  75         offset = addr & ~PAGE_MASK;
  76         size = PAGE_ALIGN(addr + size) - paligned;
  77 
  78         if (size == 0 || paligned == 0)
  79                 return NULL;
  80 
  81         if (slab_is_available())
  82                 return do_ioremap(paligned, offset, size, prot, caller);
  83 
  84         err = early_ioremap_range(ioremap_bot, paligned, size, prot);
  85         if (err)
  86                 return NULL;
  87 
  88         ret = (void __iomem *)ioremap_bot + offset;
  89         ioremap_bot += size;
  90 
  91         return ret;
  92 }
  93 
  94 /*
  95  * Unmap an IO region and remove it from vmalloc'd list.
  96  * Access to IO memory should be serialized by driver.
  97  */
  98 void iounmap(volatile void __iomem *token)
  99 {
 100         void *addr;
 101 
 102         if (!slab_is_available())
 103                 return;
 104 
 105         addr = (void *)((unsigned long __force)PCI_FIX_ADDR(token) & PAGE_MASK);
 106 
 107         if ((unsigned long)addr < ioremap_bot) {
 108                 pr_warn("Attempt to iounmap early bolted mapping at 0x%p\n", addr);
 109                 return;
 110         }
 111         vunmap(addr);
 112 }
 113 EXPORT_SYMBOL(iounmap);