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 (2427B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * arch/parisc/mm/ioremap.c
      4 *
      5 * (C) Copyright 1995 1996 Linus Torvalds
      6 * (C) Copyright 2001-2019 Helge Deller <deller@gmx.de>
      7 * (C) Copyright 2005 Kyle McMartin <kyle@parisc-linux.org>
      8 */
      9
     10#include <linux/vmalloc.h>
     11#include <linux/errno.h>
     12#include <linux/module.h>
     13#include <linux/io.h>
     14#include <linux/mm.h>
     15
     16/*
     17 * Generic mapping function (not visible outside):
     18 */
     19
     20/*
     21 * Remap an arbitrary physical address space into the kernel virtual
     22 * address space.
     23 *
     24 * NOTE! We need to allow non-page-aligned mappings too: we will obviously
     25 * have to convert them into an offset in a page-aligned mapping, but the
     26 * caller shouldn't need to know that small detail.
     27 */
     28void __iomem *ioremap(unsigned long phys_addr, unsigned long size)
     29{
     30	void __iomem *addr;
     31	struct vm_struct *area;
     32	unsigned long offset, last_addr;
     33	pgprot_t pgprot;
     34
     35#ifdef CONFIG_EISA
     36	unsigned long end = phys_addr + size - 1;
     37	/* Support EISA addresses */
     38	if ((phys_addr >= 0x00080000 && end < 0x000fffff) ||
     39	    (phys_addr >= 0x00500000 && end < 0x03bfffff))
     40		phys_addr |= F_EXTEND(0xfc000000);
     41#endif
     42
     43	/* Don't allow wraparound or zero size */
     44	last_addr = phys_addr + size - 1;
     45	if (!size || last_addr < phys_addr)
     46		return NULL;
     47
     48	/*
     49	 * Don't allow anybody to remap normal RAM that we're using..
     50	 */
     51	if (phys_addr < virt_to_phys(high_memory)) {
     52		char *t_addr, *t_end;
     53		struct page *page;
     54
     55		t_addr = __va(phys_addr);
     56		t_end = t_addr + (size - 1);
     57	   
     58		for (page = virt_to_page(t_addr); 
     59		     page <= virt_to_page(t_end); page++) {
     60			if(!PageReserved(page))
     61				return NULL;
     62		}
     63	}
     64
     65	pgprot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY |
     66			  _PAGE_ACCESSED | _PAGE_NO_CACHE);
     67
     68	/*
     69	 * Mappings have to be page-aligned
     70	 */
     71	offset = phys_addr & ~PAGE_MASK;
     72	phys_addr &= PAGE_MASK;
     73	size = PAGE_ALIGN(last_addr + 1) - phys_addr;
     74
     75	/*
     76	 * Ok, go for it..
     77	 */
     78	area = get_vm_area(size, VM_IOREMAP);
     79	if (!area)
     80		return NULL;
     81
     82	addr = (void __iomem *) area->addr;
     83	if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size,
     84			       phys_addr, pgprot)) {
     85		vunmap(addr);
     86		return NULL;
     87	}
     88
     89	return (void __iomem *) (offset + (char __iomem *)addr);
     90}
     91EXPORT_SYMBOL(ioremap);
     92
     93void iounmap(const volatile void __iomem *io_addr)
     94{
     95	unsigned long addr = (unsigned long)io_addr & PAGE_MASK;
     96
     97	if (is_vmalloc_addr((void *)addr))
     98		vunmap((void *)addr);
     99}
    100EXPORT_SYMBOL(iounmap);