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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pgtable.c (1739B)

      1/*
      2 * Copyright (C) 2009 Wind River Systems Inc
      3 *   Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
      4 *
      5 * This file is subject to the terms and conditions of the GNU General Public
      6 * License.  See the file "COPYING" in the main directory of this archive
      7 * for more details.
      8 */
      9
     10#include <linux/mm.h>
     11#include <linux/sched.h>
     12
     13#include <asm/cpuinfo.h>
     14
     15/* pteaddr:
     16 *   ptbase | vpn* | zero
     17 *   31-22  | 21-2 | 1-0
     18 *
     19 *   *vpn is preserved on double fault
     20 *
     21 * tlbacc:
     22 *   IG   |*flags| pfn
     23 *   31-25|24-20 | 19-0
     24 *
     25 *   *crwxg
     26 *
     27 * tlbmisc:
     28 *   resv  |way   |rd | we|pid |dbl|bad|perm|d
     29 *   31-24 |23-20 |19 | 20|17-4|3  |2  |1   |0
     30 *
     31 */
     32
     33/*
     34 * Initialize a new pgd / pmd table with invalid pointers.
     35 */
     36static void pgd_init(pgd_t *pgd)
     37{
     38	unsigned long *p = (unsigned long *) pgd;
     39	int i;
     40
     41	for (i = 0; i < USER_PTRS_PER_PGD; i += 8) {
     42		p[i + 0] = (unsigned long) invalid_pte_table;
     43		p[i + 1] = (unsigned long) invalid_pte_table;
     44		p[i + 2] = (unsigned long) invalid_pte_table;
     45		p[i + 3] = (unsigned long) invalid_pte_table;
     46		p[i + 4] = (unsigned long) invalid_pte_table;
     47		p[i + 5] = (unsigned long) invalid_pte_table;
     48		p[i + 6] = (unsigned long) invalid_pte_table;
     49		p[i + 7] = (unsigned long) invalid_pte_table;
     50	}
     51}
     52
     53pgd_t *pgd_alloc(struct mm_struct *mm)
     54{
     55	pgd_t *ret, *init;
     56
     57	ret = (pgd_t *) __get_free_pages(GFP_KERNEL, PGD_ORDER);
     58	if (ret) {
     59		init = pgd_offset(&init_mm, 0UL);
     60		pgd_init(ret);
     61		memcpy(ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
     62		       (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
     63	}
     64
     65	return ret;
     66}
     67
     68void __init pagetable_init(void)
     69{
     70	/* Initialize the entire pgd.  */
     71	pgd_init(swapper_pg_dir);
     72	pgd_init(swapper_pg_dir + USER_PTRS_PER_PGD);
     73}