1/*
  2 *  arch/arm/include/asm/pgalloc.h
  3 *
  4 *  Copyright (C) 2000-2001 Russell King
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License version 2 as
  8 * published by the Free Software Foundation.
  9 */
 10#ifndef _ASMARM_PGALLOC_H
 11#define _ASMARM_PGALLOC_H
 12
 13#include <linux/pagemap.h>
 14
 15#include <asm/domain.h>
 16#include <asm/pgtable-hwdef.h>
 17#include <asm/processor.h>
 18#include <asm/cacheflush.h>
 19#include <asm/tlbflush.h>
 20
 21#define check_pgt_cache()		do { } while (0)
 22
 23#ifdef CONFIG_MMU
 24
 25#define _PAGE_USER_TABLE	(PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_USER))
 26#define _PAGE_KERNEL_TABLE	(PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_KERNEL))
 27
 28#ifdef CONFIG_ARM_LPAE
 29
 30static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
 31{
 32	return (pmd_t *)get_zeroed_page(GFP_KERNEL | __GFP_REPEAT);
 33}
 34
 35static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
 36{
 37	BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
 38	free_page((unsigned long)pmd);
 39}
 40
 41static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
 42{
 43	set_pud(pud, __pud(__pa(pmd) | PMD_TYPE_TABLE));
 44}
 45
 46#else	/* !CONFIG_ARM_LPAE */
 47
 48/*
 49 * Since we have only two-level page tables, these are trivial
 50 */
 51#define pmd_alloc_one(mm,addr)		({ BUG(); ((pmd_t *)2); })
 52#define pmd_free(mm, pmd)		do { } while (0)
 53#define pud_populate(mm,pmd,pte)	BUG()
 54
 55#endif	/* CONFIG_ARM_LPAE */
 56
 57extern pgd_t *pgd_alloc(struct mm_struct *mm);
 58extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
 59
 60#define PGALLOC_GFP	(GFP_KERNEL | __GFP_NOTRACK | __GFP_REPEAT | __GFP_ZERO)
 61
 62static inline void clean_pte_table(pte_t *pte)
 63{
 64	clean_dcache_area(pte + PTE_HWTABLE_PTRS, PTE_HWTABLE_SIZE);
 65}
 66
 67/*
 68 * Allocate one PTE table.
 69 *
 70 * This actually allocates two hardware PTE tables, but we wrap this up
 71 * into one table thus:
 72 *
 73 *  +------------+
 74 *  | Linux pt 0 |
 75 *  +------------+
 76 *  | Linux pt 1 |
 77 *  +------------+
 78 *  |  h/w pt 0  |
 79 *  +------------+
 80 *  |  h/w pt 1  |
 81 *  +------------+
 82 */
 83static inline pte_t *
 84pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr)
 85{
 86	pte_t *pte;
 87
 88	pte = (pte_t *)__get_free_page(PGALLOC_GFP);
 89	if (pte)
 90		clean_pte_table(pte);
 91
 92	return pte;
 93}
 94
 95static inline pgtable_t
 96pte_alloc_one(struct mm_struct *mm, unsigned long addr)
 97{
 98	struct page *pte;
 99
100#ifdef CONFIG_HIGHPTE
101	pte = alloc_pages(PGALLOC_GFP | __GFP_HIGHMEM, 0);
102#else
103	pte = alloc_pages(PGALLOC_GFP, 0);
104#endif
105	if (pte) {
106		if (!PageHighMem(pte))
107			clean_pte_table(page_address(pte));
108		pgtable_page_ctor(pte);
109	}
110
111	return pte;
112}
113
114/*
115 * Free one PTE table.
116 */
117static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
118{
119	if (pte)
120		free_page((unsigned long)pte);
121}
122
123static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
124{
125	pgtable_page_dtor(pte);
126	__free_page(pte);
127}
128
129static inline void __pmd_populate(pmd_t *pmdp, phys_addr_t pte,
130				  pmdval_t prot)
131{
132	pmdval_t pmdval = (pte + PTE_HWTABLE_OFF) | prot;
133	pmdp[0] = __pmd(pmdval);
134#ifndef CONFIG_ARM_LPAE
135	pmdp[1] = __pmd(pmdval + 256 * sizeof(pte_t));
136#endif
137	flush_pmd_entry(pmdp);
138}
139
140/*
141 * Populate the pmdp entry with a pointer to the pte.  This pmd is part
142 * of the mm address space.
143 *
144 * Ensure that we always set both PMD entries.
145 */
146static inline void
147pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep)
148{
149	/*
150	 * The pmd must be loaded with the physical address of the PTE table
151	 */
152	__pmd_populate(pmdp, __pa(ptep), _PAGE_KERNEL_TABLE);
153}
154
155static inline void
156pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep)
157{
158	__pmd_populate(pmdp, page_to_phys(ptep), _PAGE_USER_TABLE);
159}
160#define pmd_pgtable(pmd) pmd_page(pmd)
161
162#endif /* CONFIG_MMU */
163
164#endif