text: /* SPDX-License-Identifier: GPL-2.0-or-later */
  /*
   * OpenRISC Linux
   *
   * Linux architectural port borrowing liberally from similar works of
   * others.  All original copyrights apply as per the original source
   * declaration.
   *
   * OpenRISC implementation:
   * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
   * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
   * et al.
   */
  
  #ifndef __ASM_OPENRISC_PGALLOC_H
  #define __ASM_OPENRISC_PGALLOC_H
  
  #include <asm/page.h>
  #include <linux/threads.h>
  #include <linux/mm.h>
  #include <linux/memblock.h>
  
  #define __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
  #include <asm-generic/pgalloc.h>
  
  extern int mem_init_done;
  
  #define pmd_populate_kernel(mm, pmd, pte) \
  	set_pmd(pmd, __pmd(_KERNPG_TABLE + __pa(pte)))
  
  static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
  				struct page *pte)
  {
  	set_pmd(pmd, __pmd(_KERNPG_TABLE +
  		     ((unsigned long)page_to_pfn(pte) <<
  		     (unsigned long) PAGE_SHIFT)));
  }
  
  /*
   * Allocate and free page tables.
   */
  static inline pgd_t *pgd_alloc(struct mm_struct *mm)
  {
  	pgd_t *ret = (pgd_t *)__get_free_page(GFP_KERNEL);
  
  	if (ret) {
  		memset(ret, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
  		memcpy(ret + USER_PTRS_PER_PGD,
  		       swapper_pg_dir + USER_PTRS_PER_PGD,
  		       (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
  
  	}
  	return ret;
  }
  
  #if 0
  /* FIXME: This seems to be the preferred style, but we are using
   * current_pgd (from mm->pgd) to load kernel pages so we need it
   * initialized.  This needs to be looked into.
   */
  extern inline pgd_t *pgd_alloc(struct mm_struct *mm)
  {
  	return (pgd_t *)get_zeroed_page(GFP_KERNEL);
  }
  #endif
  
  extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm);
  
  #define __pte_free_tlb(tlb, pte, addr)	\
  do {					\
  	pgtable_pte_page_dtor(pte);	\
  	tlb_remove_page((tlb), (pte));	\
  } while (0)
  
  #endif
  