arch/powerpc/mm/ioremap_64.c

   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 void __iomem *__ioremap_caller(phys_addr_t addr, unsigned long size,
   8                                pgprot_t prot, void *caller)
   9 {
  10         phys_addr_t paligned, offset;
  11         void __iomem *ret;
  12         int err;
  13
  14         /* We don't support the 4K PFN hack with ioremap */
  15         if (pgprot_val(prot) & H_PAGE_4K_PFN)
  16                 return NULL;
  17
  18         /*
  19          * Choose an address to map it to. Once the vmalloc system is running,
  20          * we use it. Before that, we map using addresses going up from
  21          * ioremap_bot.  vmalloc will use the addresses from IOREMAP_BASE
  22          * through ioremap_bot.
  23          */
  24         paligned = addr & PAGE_MASK;
  25         offset = addr & ~PAGE_MASK;
  26         size = PAGE_ALIGN(addr + size) - paligned;
  27
  28         if (size == 0 || paligned == 0)
  29                 return NULL;
  30
  31         if (slab_is_available())
  32                 return do_ioremap(paligned, offset, size, prot, caller);
  33
  34         pr_warn("ioremap() called early from %pS. Use early_ioremap() instead\n", caller);
  35
  36         err = early_ioremap_range(ioremap_bot, paligned, size, prot);
  37         if (err)
  38                 return NULL;
  39
  40         ret = (void __iomem *)ioremap_bot + offset;
  41         ioremap_bot += size;
  42
  43         return ret;
  44 }
  45
  46 /*
  47  * Unmap an IO region and remove it from vmalloc'd list.
  48  * Access to IO memory should be serialized by driver.
  49  */
  50 void iounmap(volatile void __iomem *token)
  51 {
  52         void *addr;
  53
  54         if (!slab_is_available())
  55                 return;
  56
  57         addr = (void *)((unsigned long __force)PCI_FIX_ADDR(token) & PAGE_MASK);
  58
  59         if ((unsigned long)addr < ioremap_bot) {
  60                 pr_warn("Attempt to iounmap early bolted mapping at 0x%p\n", addr);
  61                 return;
  62         }
  63         vunmap(addr);
  64 }
  65 EXPORT_SYMBOL(iounmap);