cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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ioremap.c (2597B)

      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
     20static 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_is_map_memory(__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
     64void __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}
     69EXPORT_SYMBOL(__ioremap);
     70
     71void 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}
     82EXPORT_SYMBOL(iounmap);
     83
     84void __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_is_map_memory(__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}
     93EXPORT_SYMBOL(ioremap_cache);
     94
     95/*
     96 * Must be called after early_fixmap_init
     97 */
     98void __init early_ioremap_init(void)
     99{
    100	early_ioremap_setup();
    101}
    102
    103bool arch_memremap_can_ram_remap(resource_size_t offset, size_t size,
    104				 unsigned long flags)
    105{
    106	unsigned long pfn = PHYS_PFN(offset);
    107
    108	return pfn_is_map_memory(pfn);
    109}