1/*
  2 * Copyright 2010 Tilera Corporation. All Rights Reserved.
  3 *
  4 *   This program is free software; you can redistribute it and/or
  5 *   modify it under the terms of the GNU General Public License
  6 *   as published by the Free Software Foundation, version 2.
  7 *
  8 *   This program is distributed in the hope that it will be useful, but
  9 *   WITHOUT ANY WARRANTY; without even the implied warranty of
 10 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 11 *   NON INFRINGEMENT.  See the GNU General Public License for
 12 *   more details.
 13 */
 14
 15#ifndef _ASM_TILE_PGALLOC_H
 16#define _ASM_TILE_PGALLOC_H
 17
 18#include <linux/threads.h>
 19#include <linux/mm.h>
 20#include <linux/mmzone.h>
 21#include <asm/fixmap.h>
 22#include <asm/page.h>
 23#include <hv/hypervisor.h>
 24
 25/* Bits for the size of the second-level page table. */
 26#define L2_KERNEL_PGTABLE_SHIFT _HV_LOG2_L2_SIZE(HPAGE_SHIFT, PAGE_SHIFT)
 27
 28/* How big is a kernel L2 page table? */
 29#define L2_KERNEL_PGTABLE_SIZE (1UL << L2_KERNEL_PGTABLE_SHIFT)
 30
 31/* We currently allocate user L2 page tables by page (unlike kernel L2s). */
 32#if L2_KERNEL_PGTABLE_SHIFT < PAGE_SHIFT
 33#define L2_USER_PGTABLE_SHIFT PAGE_SHIFT
 34#else
 35#define L2_USER_PGTABLE_SHIFT L2_KERNEL_PGTABLE_SHIFT
 36#endif
 37
 38/* How many pages do we need, as an "order", for a user L2 page table? */
 39#define L2_USER_PGTABLE_ORDER (L2_USER_PGTABLE_SHIFT - PAGE_SHIFT)
 40
 41static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
 42{
 43#ifdef CONFIG_64BIT
 44	set_pte(pmdp, pmd);
 45#else
 46	set_pte(&pmdp->pud.pgd, pmd.pud.pgd);
 47#endif
 48}
 49
 50static inline void pmd_populate_kernel(struct mm_struct *mm,
 51				       pmd_t *pmd, pte_t *ptep)
 52{
 53	set_pmd(pmd, ptfn_pmd(HV_CPA_TO_PTFN(__pa(ptep)),
 54			      __pgprot(_PAGE_PRESENT)));
 55}
 56
 57static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
 58				pgtable_t page)
 59{
 60	set_pmd(pmd, ptfn_pmd(HV_CPA_TO_PTFN(PFN_PHYS(page_to_pfn(page))),
 61			      __pgprot(_PAGE_PRESENT)));
 62}
 63
 64/*
 65 * Allocate and free page tables.
 66 */
 67
 68extern pgd_t *pgd_alloc(struct mm_struct *mm);
 69extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
 70
 71extern pgtable_t pgtable_alloc_one(struct mm_struct *mm, unsigned long address,
 72				   int order);
 73extern void pgtable_free(struct mm_struct *mm, struct page *pte, int order);
 74
 75static inline pgtable_t pte_alloc_one(struct mm_struct *mm,
 76				      unsigned long address)
 77{
 78	return pgtable_alloc_one(mm, address, L2_USER_PGTABLE_ORDER);
 79}
 80
 81static inline void pte_free(struct mm_struct *mm, struct page *pte)
 82{
 83	pgtable_free(mm, pte, L2_USER_PGTABLE_ORDER);
 84}
 85
 86#define pmd_pgtable(pmd) pmd_page(pmd)
 87
 88static inline pte_t *
 89pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
 90{
 91	return pfn_to_kaddr(page_to_pfn(pte_alloc_one(mm, address)));
 92}
 93
 94static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
 95{
 96	BUG_ON((unsigned long)pte & (PAGE_SIZE-1));
 97	pte_free(mm, virt_to_page(pte));
 98}
 99
100extern void __pgtable_free_tlb(struct mmu_gather *tlb, struct page *pte,
101			       unsigned long address, int order);
102static inline void __pte_free_tlb(struct mmu_gather *tlb, struct page *pte,
103				  unsigned long address)
104{
105	__pgtable_free_tlb(tlb, pte, address, L2_USER_PGTABLE_ORDER);
106}
107
108#define check_pgt_cache()	do { } while (0)
109
110/*
111 * Get the small-page pte_t lowmem entry for a given pfn.
112 * This may or may not be in use, depending on whether the initial
113 * huge-page entry for the page has already been shattered.
114 */
115pte_t *get_prealloc_pte(unsigned long pfn);
116
117/* During init, we can shatter kernel huge pages if needed. */
118void shatter_pmd(pmd_t *pmd);
119
120/* After init, a more complex technique is required. */
121void shatter_huge_page(unsigned long addr);
122
123#ifdef __tilegx__
124
125#define pud_populate(mm, pud, pmd) \
126  pmd_populate_kernel((mm), (pmd_t *)(pud), (pte_t *)(pmd))
127
128/* Bits for the size of the L1 (intermediate) page table. */
129#define L1_KERNEL_PGTABLE_SHIFT _HV_LOG2_L1_SIZE(HPAGE_SHIFT)
130
131/* How big is a kernel L2 page table? */
132#define L1_KERNEL_PGTABLE_SIZE (1UL << L1_KERNEL_PGTABLE_SHIFT)
133
134/* We currently allocate L1 page tables by page. */
135#if L1_KERNEL_PGTABLE_SHIFT < PAGE_SHIFT
136#define L1_USER_PGTABLE_SHIFT PAGE_SHIFT
137#else
138#define L1_USER_PGTABLE_SHIFT L1_KERNEL_PGTABLE_SHIFT
139#endif
140
141/* How many pages do we need, as an "order", for an L1 page table? */
142#define L1_USER_PGTABLE_ORDER (L1_USER_PGTABLE_SHIFT - PAGE_SHIFT)
143
144static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
145{
146	struct page *p = pgtable_alloc_one(mm, address, L1_USER_PGTABLE_ORDER);
147	return (pmd_t *)page_to_virt(p);
148}
149
150static inline void pmd_free(struct mm_struct *mm, pmd_t *pmdp)
151{
152	pgtable_free(mm, virt_to_page(pmdp), L1_USER_PGTABLE_ORDER);
153}
154
155static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp,
156				  unsigned long address)
157{
158	__pgtable_free_tlb(tlb, virt_to_page(pmdp), address,
159			   L1_USER_PGTABLE_ORDER);
160}
161
162#endif /* __tilegx__ */
163
164#endif /* _ASM_TILE_PGALLOC_H */