text: /* SPDX-License-Identifier: GPL-2.0-only */
  /*
   * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
   *
   * vineetg: June 2011
   *  -"/proc/meminfo | grep PageTables" kept on increasing
   *   Recently added pgtable dtor was not getting called.
   *
   * vineetg: May 2011
   *  -Variable pg-sz means that Page Tables could be variable sized themselves
   *    So calculate it based on addr traversal split [pgd-bits:pte-bits:xxx]
   *  -Page Table size capped to max 1 to save memory - hence verified.
   *  -Since these deal with constants, gcc compile-time optimizes them.
   *
   * vineetg: Nov 2010
   *  -Added pgtable ctor/dtor used for pgtable mem accounting
   *
   * vineetg: April 2010
   *  -Switched pgtable_t from being struct page * to unsigned long
   *      =Needed so that Page Table allocator (pte_alloc_one) is not forced to
   *       to deal with struct page. Thay way in future we can make it allocate
   *       multiple PG Tbls in one Page Frame
   *      =sweet side effect is avoiding calls to ugly page_address( ) from the
   *       pg-tlb allocator sub-sys (pte_alloc_one, ptr_free, pmd_populate
   *
   *  Amit Bhor, Sameer Dhavale: Codito Technologies 2004
   */
  
  #ifndef _ASM_ARC_PGALLOC_H
  #define _ASM_ARC_PGALLOC_H
  
  #include <linux/mm.h>
  #include <linux/log2.h>
  
  static inline void
  pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, pte_t *pte)
  {
  	pmd_set(pmd, pte);
  }
  
  static inline void
  pmd_populate(struct mm_struct *mm, pmd_t *pmd, pgtable_t ptep)
  {
  	pmd_set(pmd, (pte_t *) ptep);
  }
  
  static inline int __get_order_pgd(void)
  {
  	return get_order(PTRS_PER_PGD * sizeof(pgd_t));
  }
  
  static inline pgd_t *pgd_alloc(struct mm_struct *mm)
  {
  	int num, num2;
  	pgd_t *ret = (pgd_t *) __get_free_pages(GFP_KERNEL, __get_order_pgd());
  
  	if (ret) {
  		num = USER_PTRS_PER_PGD + USER_KERNEL_GUTTER / PGDIR_SIZE;
  		memzero(ret, num * sizeof(pgd_t));
  
  		num2 = VMALLOC_SIZE / PGDIR_SIZE;
  		memcpy(ret + num, swapper_pg_dir + num, num2 * sizeof(pgd_t));
  
  		memzero(ret + num + num2,
  			       (PTRS_PER_PGD - num - num2) * sizeof(pgd_t));
  
  	}
  	return ret;
  }
  
  static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
  {
  	free_pages((unsigned long)pgd, __get_order_pgd());
  }
  
  
  /*
   * With software-only page-tables, addr-split for traversal is tweakable and
   * that directly governs how big tables would be at each level.
   * Further, the MMU page size is configurable.
   * Thus we need to programatically assert the size constraint
   * All of this is const math, allowing gcc to do constant folding/propagation.
   */
  
  static inline int __get_order_pte(void)
  {
  	return get_order(PTRS_PER_PTE * sizeof(pte_t));
  }
  
  static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
  {
  	pte_t *pte;
  
  	pte = (pte_t *) __get_free_pages(GFP_KERNEL | __GFP_ZERO,
  					 __get_order_pte());
  
  	return pte;
  }
  
  static inline pgtable_t
  pte_alloc_one(struct mm_struct *mm)
  {
  	pgtable_t pte_pg;
  	struct page *page;
  
  	pte_pg = (pgtable_t)__get_free_pages(GFP_KERNEL, __get_order_pte());
  	if (!pte_pg)
  		return 0;
  	memzero((void *)pte_pg, PTRS_PER_PTE * sizeof(pte_t));
  	page = virt_to_page(pte_pg);
  	if (!pgtable_pte_page_ctor(page)) {
  		__free_page(page);
  		return 0;
  	}
  
  	return pte_pg;
  }
  
  static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
  {
  	free_pages((unsigned long)pte, __get_order_pte()); /* takes phy addr */
  }
  
  static inline void pte_free(struct mm_struct *mm, pgtable_t ptep)
  {
  	pgtable_pte_page_dtor(virt_to_page(ptep));
  	free_pages((unsigned long)ptep, __get_order_pte());
  }
  
  #define __pte_free_tlb(tlb, pte, addr)  pte_free((tlb)->mm, pte)
  
  #define pmd_pgtable(pmd)	((pgtable_t) pmd_page_vaddr(pmd))
  
  #endif /* _ASM_ARC_PGALLOC_H */
  