text: /* SPDX-License-Identifier: GPL-2.0-only */
  /*
   * Based on arch/arm/include/asm/pgalloc.h
   *
   * Copyright (C) 2000-2001 Russell King
   * Copyright (C) 2012 ARM Ltd.
   */
  #ifndef __ASM_PGALLOC_H
  #define __ASM_PGALLOC_H
  
  #include <asm/pgtable-hwdef.h>
  #include <asm/processor.h>
  #include <asm/cacheflush.h>
  #include <asm/tlbflush.h>
  
  #define check_pgt_cache()		do { } while (0)
  
  #define PGALLOC_GFP	(GFP_KERNEL | __GFP_ZERO)
  #define PGD_SIZE	(PTRS_PER_PGD * sizeof(pgd_t))
  
  #if CONFIG_PGTABLE_LEVELS > 2
  
  static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
  {
  	struct page *page;
  
  	page = alloc_page(PGALLOC_GFP);
  	if (!page)
  		return NULL;
  	if (!pgtable_pmd_page_ctor(page)) {
  		__free_page(page);
  		return NULL;
  	}
  	return page_address(page);
  }
  
  static inline void pmd_free(struct mm_struct *mm, pmd_t *pmdp)
  {
  	BUG_ON((unsigned long)pmdp & (PAGE_SIZE-1));
  	pgtable_pmd_page_dtor(virt_to_page(pmdp));
  	free_page((unsigned long)pmdp);
  }
  
  static inline void __pud_populate(pud_t *pudp, phys_addr_t pmdp, pudval_t prot)
  {
  	set_pud(pudp, __pud(__phys_to_pud_val(pmdp) | prot));
  }
  
  static inline void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmdp)
  {
  	__pud_populate(pudp, __pa(pmdp), PMD_TYPE_TABLE);
  }
  #else
  static inline void __pud_populate(pud_t *pudp, phys_addr_t pmdp, pudval_t prot)
  {
  	BUILD_BUG();
  }
  #endif	/* CONFIG_PGTABLE_LEVELS > 2 */
  
  #if CONFIG_PGTABLE_LEVELS > 3
  
  static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
  {
  	return (pud_t *)__get_free_page(PGALLOC_GFP);
  }
  
  static inline void pud_free(struct mm_struct *mm, pud_t *pudp)
  {
  	BUG_ON((unsigned long)pudp & (PAGE_SIZE-1));
  	free_page((unsigned long)pudp);
  }
  
  static inline void __pgd_populate(pgd_t *pgdp, phys_addr_t pudp, pgdval_t prot)
  {
  	set_pgd(pgdp, __pgd(__phys_to_pgd_val(pudp) | prot));
  }
  
  static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgdp, pud_t *pudp)
  {
  	__pgd_populate(pgdp, __pa(pudp), PUD_TYPE_TABLE);
  }
  #else
  static inline void __pgd_populate(pgd_t *pgdp, phys_addr_t pudp, pgdval_t prot)
  {
  	BUILD_BUG();
  }
  #endif	/* CONFIG_PGTABLE_LEVELS > 3 */
  
  extern pgd_t *pgd_alloc(struct mm_struct *mm);
  extern void pgd_free(struct mm_struct *mm, pgd_t *pgdp);
  
  static inline pte_t *
  pte_alloc_one_kernel(struct mm_struct *mm)
  {
  	return (pte_t *)__get_free_page(PGALLOC_GFP);
  }
  
  static inline pgtable_t
  pte_alloc_one(struct mm_struct *mm)
  {
  	struct page *pte;
  
  	pte = alloc_pages(PGALLOC_GFP, 0);
  	if (!pte)
  		return NULL;
  	if (!pgtable_page_ctor(pte)) {
  		__free_page(pte);
  		return NULL;
  	}
  	return pte;
  }
  
  /*
   * Free a PTE table.
   */
  static inline void pte_free_kernel(struct mm_struct *mm, pte_t *ptep)
  {
  	if (ptep)
  		free_page((unsigned long)ptep);
  }
  
  static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
  {
  	pgtable_page_dtor(pte);
  	__free_page(pte);
  }
  
  static inline void __pmd_populate(pmd_t *pmdp, phys_addr_t ptep,
  				  pmdval_t prot)
  {
  	set_pmd(pmdp, __pmd(__phys_to_pmd_val(ptep) | prot));
  }
  
  /*
   * Populate the pmdp entry with a pointer to the pte.  This pmd is part
   * of the mm address space.
   */
  static inline void
  pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep)
  {
  	/*
  	 * The pmd must be loaded with the physical address of the PTE table
  	 */
  	__pmd_populate(pmdp, __pa(ptep), PMD_TYPE_TABLE);
  }
  
  static inline void
  pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep)
  {
  	__pmd_populate(pmdp, page_to_phys(ptep), PMD_TYPE_TABLE);
  }
  #define pmd_pgtable(pmd) pmd_page(pmd)
  
  #endif
  