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/mm.h>
  12#include <linux/vmalloc.h>
  13#include <asm/io.h>
  14#include <asm/meminit.h>
  15
  16static inline void __iomem *
  17__ioremap_uc(unsigned long phys_addr)
  18{
  19        return (void __iomem *) (__IA64_UNCACHED_OFFSET | phys_addr);
  20}
  21
  22void __iomem *
  23early_ioremap (unsigned long phys_addr, unsigned long size)
  24{
  25        u64 attr;
  26        attr = kern_mem_attribute(phys_addr, size);
  27        if (attr & EFI_MEMORY_WB)
  28                return (void __iomem *) phys_to_virt(phys_addr);
  29        return __ioremap_uc(phys_addr);
  30}
  31
  32void __iomem *
  33ioremap (unsigned long phys_addr, unsigned long size)
  34{
  35        void __iomem *addr;
  36        struct vm_struct *area;
  37        unsigned long offset;
  38        pgprot_t prot;
  39        u64 attr;
  40        unsigned long gran_base, gran_size;
  41        unsigned long page_base;
  42
  43        /*
  44         * For things in kern_memmap, we must use the same attribute
  45         * as the rest of the kernel.  For more details, see
  46         * Documentation/ia64/aliasing.rst.
  47         */
  48        attr = kern_mem_attribute(phys_addr, size);
  49        if (attr & EFI_MEMORY_WB)
  50                return (void __iomem *) phys_to_virt(phys_addr);
  51        else if (attr & EFI_MEMORY_UC)
  52                return __ioremap_uc(phys_addr);
  53
  54        /*
  55         * Some chipsets don't support UC access to memory.  If
  56         * WB is supported for the whole granule, we prefer that.
  57         */
  58        gran_base = GRANULEROUNDDOWN(phys_addr);
  59        gran_size = GRANULEROUNDUP(phys_addr + size) - gran_base;
  60        if (efi_mem_attribute(gran_base, gran_size) & EFI_MEMORY_WB)
  61                return (void __iomem *) phys_to_virt(phys_addr);
  62
  63        /*
  64         * WB is not supported for the whole granule, so we can't use
  65         * the region 7 identity mapping.  If we can safely cover the
  66         * area with kernel page table mappings, we can use those
  67         * instead.
  68         */
  69        page_base = phys_addr & PAGE_MASK;
  70        size = PAGE_ALIGN(phys_addr + size) - page_base;
  71        if (efi_mem_attribute(page_base, size) & EFI_MEMORY_WB) {
  72                prot = PAGE_KERNEL;
  73
  74                /*
  75                 * Mappings have to be page-aligned
  76                 */
  77                offset = phys_addr & ~PAGE_MASK;
  78                phys_addr &= PAGE_MASK;
  79
  80                /*
  81                 * Ok, go for it..
  82                 */
  83                area = get_vm_area(size, VM_IOREMAP);
  84                if (!area)
  85                        return NULL;
  86
  87                area->phys_addr = phys_addr;
  88                addr = (void __iomem *) area->addr;
  89                if (ioremap_page_range((unsigned long) addr,
  90                                (unsigned long) addr + size, phys_addr, prot)) {
  91                        vunmap((void __force *) addr);
  92                        return NULL;
  93                }
  94
  95                return (void __iomem *) (offset + (char __iomem *)addr);
  96        }
  97
  98        return __ioremap_uc(phys_addr);
  99}
 100EXPORT_SYMBOL(ioremap);
 101
 102void __iomem *
 103ioremap_uc(unsigned long phys_addr, unsigned long size)
 104{
 105        if (kern_mem_attribute(phys_addr, size) & EFI_MEMORY_WB)
 106                return NULL;
 107
 108        return __ioremap_uc(phys_addr);
 109}
 110EXPORT_SYMBOL(ioremap_uc);
 111
 112void
 113early_iounmap (volatile void __iomem *addr, unsigned long size)
 114{
 115}
 116
 117void
 118iounmap (volatile void __iomem *addr)
 119{
 120        if (REGION_NUMBER(addr) == RGN_GATE)
 121                vunmap((void *) ((unsigned long) addr & PAGE_MASK));
 122}
 123EXPORT_SYMBOL(iounmap);
 124