arch/openrisc/include/asm/pgalloc.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * OpenRISC Linux
   4  *
   5  * Linux architectural port borrowing liberally from similar works of
   6  * others.  All original copyrights apply as per the original source
   7  * declaration.
   8  *
   9  * OpenRISC implementation:
  10  * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
  11  * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
  12  * et al.
  13  */
  14
  15 #ifndef __ASM_OPENRISC_PGALLOC_H
  16 #define __ASM_OPENRISC_PGALLOC_H
  17
  18 #include <asm/page.h>
  19 #include <linux/threads.h>
  20 #include <linux/mm.h>
  21 #include <linux/memblock.h>
  22
  23 #define __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
  24 #include <asm-generic/pgalloc.h>
  25
  26 extern int mem_init_done;
  27
  28 #define pmd_populate_kernel(mm, pmd, pte) \
  29         set_pmd(pmd, __pmd(_KERNPG_TABLE + __pa(pte)))
  30
  31 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
  32                                 struct page *pte)
  33 {
  34         set_pmd(pmd, __pmd(_KERNPG_TABLE +
  35                      ((unsigned long)page_to_pfn(pte) <<
  36                      (unsigned long) PAGE_SHIFT)));
  37 }
  38
  39 /*
  40  * Allocate and free page tables.
  41  */
  42 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
  43 {
  44         pgd_t *ret = (pgd_t *)__get_free_page(GFP_KERNEL);
  45
  46         if (ret) {
  47                 memset(ret, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
  48                 memcpy(ret + USER_PTRS_PER_PGD,
  49                        swapper_pg_dir + USER_PTRS_PER_PGD,
  50                        (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
  51
  52         }
  53         return ret;
  54 }
  55
  56 #if 0
  57 /* FIXME: This seems to be the preferred style, but we are using
  58  * current_pgd (from mm->pgd) to load kernel pages so we need it
  59  * initialized.  This needs to be looked into.
  60  */
  61 extern inline pgd_t *pgd_alloc(struct mm_struct *mm)
  62 {
  63         return (pgd_t *)get_zeroed_page(GFP_KERNEL);
  64 }
  65 #endif
  66
  67 extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm);
  68
  69 #define __pte_free_tlb(tlb, pte, addr)                          \
  70 do {                                                            \
  71         pagetable_pte_dtor(page_ptdesc(pte));                   \
  72         tlb_remove_page_ptdesc((tlb), (page_ptdesc(pte)));      \
  73 } while (0)
  74
  75 #endif