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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pgalloc.h (2888B)

      1/* SPDX-License-Identifier: GPL-2.0-only */
      2/*
      3 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
      4 *
      5 * vineetg: June 2011
      6 *  -"/proc/meminfo | grep PageTables" kept on increasing
      7 *   Recently added pgtable dtor was not getting called.
      8 *
      9 * vineetg: May 2011
     10 *  -Variable pg-sz means that Page Tables could be variable sized themselves
     11 *    So calculate it based on addr traversal split [pgd-bits:pte-bits:xxx]
     12 *  -Page Table size capped to max 1 to save memory - hence verified.
     13 *  -Since these deal with constants, gcc compile-time optimizes them.
     14 *
     15 * vineetg: Nov 2010
     16 *  -Added pgtable ctor/dtor used for pgtable mem accounting
     17 *
     18 * vineetg: April 2010
     19 *  -Switched pgtable_t from being struct page * to unsigned long
     20 *      =Needed so that Page Table allocator (pte_alloc_one) is not forced to
     21 *       deal with struct page. That way in future we can make it allocate
     22 *       multiple PG Tbls in one Page Frame
     23 *      =sweet side effect is avoiding calls to ugly page_address( ) from the
     24 *       pg-tlb allocator sub-sys (pte_alloc_one, ptr_free, pmd_populate)
     25 *
     26 *  Amit Bhor, Sameer Dhavale: Codito Technologies 2004
     27 */
     28
     29#ifndef _ASM_ARC_PGALLOC_H
     30#define _ASM_ARC_PGALLOC_H
     31
     32#include <linux/mm.h>
     33#include <linux/log2.h>
     34#include <asm-generic/pgalloc.h>
     35
     36static inline void
     37pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, pte_t *pte)
     38{
     39	/*
     40	 * The cast to long below is OK in 32-bit PAE40 regime with long long pte
     41	 * Despite "wider" pte, the pte table needs to be in non-PAE low memory
     42	 * as all higher levels can only hold long pointers.
     43	 *
     44	 * The cast itself is needed given simplistic definition of set_pmd()
     45	 */
     46	set_pmd(pmd, __pmd((unsigned long)pte));
     47}
     48
     49static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd, pgtable_t pte_page)
     50{
     51	set_pmd(pmd, __pmd((unsigned long)page_address(pte_page)));
     52}
     53
     54static inline pgd_t *pgd_alloc(struct mm_struct *mm)
     55{
     56	pgd_t *ret = (pgd_t *) __get_free_page(GFP_KERNEL);
     57
     58	if (ret) {
     59		int num, num2;
     60		num = USER_PTRS_PER_PGD + USER_KERNEL_GUTTER / PGDIR_SIZE;
     61		memzero(ret, num * sizeof(pgd_t));
     62
     63		num2 = VMALLOC_SIZE / PGDIR_SIZE;
     64		memcpy(ret + num, swapper_pg_dir + num, num2 * sizeof(pgd_t));
     65
     66		memzero(ret + num + num2,
     67			       (PTRS_PER_PGD - num - num2) * sizeof(pgd_t));
     68
     69	}
     70	return ret;
     71}
     72
     73#if CONFIG_PGTABLE_LEVELS > 3
     74
     75static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4dp, pud_t *pudp)
     76{
     77	set_p4d(p4dp, __p4d((unsigned long)pudp));
     78}
     79
     80#define __pud_free_tlb(tlb, pmd, addr)  pud_free((tlb)->mm, pmd)
     81
     82#endif
     83
     84#if CONFIG_PGTABLE_LEVELS > 2
     85
     86static inline void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmdp)
     87{
     88	set_pud(pudp, __pud((unsigned long)pmdp));
     89}
     90
     91#define __pmd_free_tlb(tlb, pmd, addr)  pmd_free((tlb)->mm, pmd)
     92
     93#endif
     94
     95#define __pte_free_tlb(tlb, pte, addr)  pte_free((tlb)->mm, pte)
     96
     97#endif /* _ASM_ARC_PGALLOC_H */