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_32.c (2305B)

      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#include <mm/mmu_decl.h>
      8
      9void __iomem *ioremap_wt(phys_addr_t addr, unsigned long size)
     10{
     11	pgprot_t prot = pgprot_cached_wthru(PAGE_KERNEL);
     12
     13	return __ioremap_caller(addr, size, prot, __builtin_return_address(0));
     14}
     15EXPORT_SYMBOL(ioremap_wt);
     16
     17void __iomem *
     18__ioremap_caller(phys_addr_t addr, unsigned long size, pgprot_t prot, void *caller)
     19{
     20	unsigned long v;
     21	phys_addr_t p, offset;
     22	int err;
     23
     24	/*
     25	 * Choose an address to map it to.
     26	 * Once the vmalloc system is running, we use it.
     27	 * Before then, we use space going down from IOREMAP_TOP
     28	 * (ioremap_bot records where we're up to).
     29	 */
     30	p = addr & PAGE_MASK;
     31	offset = addr & ~PAGE_MASK;
     32	size = PAGE_ALIGN(addr + size) - p;
     33
     34	/*
     35	 * If the address lies within the first 16 MB, assume it's in ISA
     36	 * memory space
     37	 */
     38	if (p < 16 * 1024 * 1024)
     39		p += _ISA_MEM_BASE;
     40
     41#ifndef CONFIG_CRASH_DUMP
     42	/*
     43	 * Don't allow anybody to remap normal RAM that we're using.
     44	 * mem_init() sets high_memory so only do the check after that.
     45	 */
     46	if (slab_is_available() && p <= virt_to_phys(high_memory - 1) &&
     47	    page_is_ram(__phys_to_pfn(p))) {
     48		pr_warn("%s(): phys addr 0x%llx is RAM lr %ps\n", __func__,
     49			(unsigned long long)p, __builtin_return_address(0));
     50		return NULL;
     51	}
     52#endif
     53
     54	if (size == 0)
     55		return NULL;
     56
     57	/*
     58	 * Is it already mapped?  Perhaps overlapped by a previous
     59	 * mapping.
     60	 */
     61	v = p_block_mapped(p);
     62	if (v)
     63		return (void __iomem *)v + offset;
     64
     65	if (slab_is_available())
     66		return do_ioremap(p, offset, size, prot, caller);
     67
     68	/*
     69	 * Should check if it is a candidate for a BAT mapping
     70	 */
     71	pr_warn("ioremap() called early from %pS. Use early_ioremap() instead\n", caller);
     72
     73	err = early_ioremap_range(ioremap_bot - size - PAGE_SIZE, p, size, prot);
     74	if (err)
     75		return NULL;
     76	ioremap_bot -= size + PAGE_SIZE;
     77
     78	return (void __iomem *)ioremap_bot + offset;
     79}
     80
     81void iounmap(volatile void __iomem *addr)
     82{
     83	/*
     84	 * If mapped by BATs then there is nothing to do.
     85	 * Calling vfree() generates a benign warning.
     86	 */
     87	if (v_block_mapped((unsigned long)addr))
     88		return;
     89
     90	if (addr > high_memory && (unsigned long)addr < ioremap_bot)
     91		vunmap((void *)(PAGE_MASK & (unsigned long)addr));
     92}
     93EXPORT_SYMBOL(iounmap);