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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uncached.c (1214B)

      1// SPDX-License-Identifier: GPL-2.0
      2#include <linux/init.h>
      3#include <linux/module.h>
      4#include <linux/sizes.h>
      5#include <asm/page.h>
      6#include <asm/addrspace.h>
      7
      8/*
      9 * This is the offset of the uncached section from its cached alias.
     10 *
     11 * Legacy platforms handle trivial transitions between cached and
     12 * uncached segments by making use of the 1:1 mapping relationship in
     13 * 512MB lowmem, others via a special uncached mapping.
     14 *
     15 * Default value only valid in 29 bit mode, in 32bit mode this will be
     16 * updated by the early PMB initialization code.
     17 */
     18unsigned long cached_to_uncached = SZ_512M;
     19unsigned long uncached_size = SZ_512M;
     20unsigned long uncached_start, uncached_end;
     21EXPORT_SYMBOL(uncached_start);
     22EXPORT_SYMBOL(uncached_end);
     23
     24int virt_addr_uncached(unsigned long kaddr)
     25{
     26	return (kaddr >= uncached_start) && (kaddr < uncached_end);
     27}
     28EXPORT_SYMBOL(virt_addr_uncached);
     29
     30void __init uncached_init(void)
     31{
     32#if defined(CONFIG_29BIT) || !defined(CONFIG_MMU)
     33	uncached_start = P2SEG;
     34#else
     35	uncached_start = memory_end;
     36#endif
     37	uncached_end = uncached_start + uncached_size;
     38}
     39
     40void __init uncached_resize(unsigned long size)
     41{
     42	uncached_size = size;
     43	uncached_end = uncached_start + uncached_size;
     44}