LXR linux/arch/ia64/mm/ioremap.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * (c) Copyright 2006, 2007 Hewlett-Packard Development Company, L.P.
   4 *      Bjorn Helgaas <bjorn.helgaas@hp.com>
   5 */
   6
   7#include <linux/compiler.h>
   8#include <linux/module.h>
   9#include <linux/efi.h>
  10#include <linux/io.h>
  11#include <linux/vmalloc.h>
  12#include <asm/io.h>
  13#include <asm/meminit.h>
  14
  15static inline void __iomem *
  16__ioremap_uc(unsigned long phys_addr)
  17{
  18        return (void __iomem *) (__IA64_UNCACHED_OFFSET | phys_addr);
  19}
  20
  21void __iomem *
  22early_ioremap (unsigned long phys_addr, unsigned long size)
  23{
  24        u64 attr;
  25        attr = kern_mem_attribute(phys_addr, size);
  26        if (attr & EFI_MEMORY_WB)
  27                return (void __iomem *) phys_to_virt(phys_addr);
  28        return __ioremap_uc(phys_addr);
  29}
  30
  31void __iomem *
  32ioremap (unsigned long phys_addr, unsigned long size)
  33{
  34        void __iomem *addr;
  35        struct vm_struct *area;
  36        unsigned long offset;
  37        pgprot_t prot;
  38        u64 attr;
  39        unsigned long gran_base, gran_size;
  40        unsigned long page_base;
  41
  42        /*
  43         * For things in kern_memmap, we must use the same attribute
  44         * as the rest of the kernel.  For more details, see
  45         * Documentation/ia64/aliasing.rst.
  46         */
  47        attr = kern_mem_attribute(phys_addr, size);
  48        if (attr & EFI_MEMORY_WB)
  49                return (void __iomem *) phys_to_virt(phys_addr);
  50        else if (attr & EFI_MEMORY_UC)
  51                return __ioremap_uc(phys_addr);
  52
  53        /*
  54         * Some chipsets don't support UC access to memory.  If
  55         * WB is supported for the whole granule, we prefer that.
  56         */
  57        gran_base = GRANULEROUNDDOWN(phys_addr);
  58        gran_size = GRANULEROUNDUP(phys_addr + size) - gran_base;
  59        if (efi_mem_attribute(gran_base, gran_size) & EFI_MEMORY_WB)
  60                return (void __iomem *) phys_to_virt(phys_addr);
  61
  62        /*
  63         * WB is not supported for the whole granule, so we can't use
  64         * the region 7 identity mapping.  If we can safely cover the
  65         * area with kernel page table mappings, we can use those
  66         * instead.
  67         */
  68        page_base = phys_addr & PAGE_MASK;
  69        size = PAGE_ALIGN(phys_addr + size) - page_base;
  70        if (efi_mem_attribute(page_base, size) & EFI_MEMORY_WB) {
  71                prot = PAGE_KERNEL;
  72
  73                /*
  74                 * Mappings have to be page-aligned
  75                 */
  76                offset = phys_addr & ~PAGE_MASK;
  77                phys_addr &= PAGE_MASK;
  78
  79                /*
  80                 * Ok, go for it..
  81                 */
  82                area = get_vm_area(size, VM_IOREMAP);
  83                if (!area)
  84                        return NULL;
  85
  86                area->phys_addr = phys_addr;
  87                addr = (void __iomem *) area->addr;
  88                if (ioremap_page_range((unsigned long) addr,
  89                                (unsigned long) addr + size, phys_addr, prot)) {
  90                        vunmap((void __force *) addr);
  91                        return NULL;
  92                }
  93
  94                return (void __iomem *) (offset + (char __iomem *)addr);
  95        }
  96
  97        return __ioremap_uc(phys_addr);
  98}
  99EXPORT_SYMBOL(ioremap);
 100
 101void __iomem *
 102ioremap_nocache (unsigned long phys_addr, unsigned long size)
 103{
 104        if (kern_mem_attribute(phys_addr, size) & EFI_MEMORY_WB)
 105                return NULL;
 106
 107        return __ioremap_uc(phys_addr);
 108}
 109EXPORT_SYMBOL(ioremap_nocache);
 110
 111void
 112early_iounmap (volatile void __iomem *addr, unsigned long size)
 113{
 114}
 115
 116void
 117iounmap (volatile void __iomem *addr)
 118{
 119        if (REGION_NUMBER(addr) == RGN_GATE)
 120                vunmap((void *) ((unsigned long) addr & PAGE_MASK));
 121}
 122EXPORT_SYMBOL(iounmap);
 123