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
16 #ifndef _ASM_TILE_PGTABLE_32_H
17 #define _ASM_TILE_PGTABLE_32_H
18
19 /*
20 * The level-1 index is defined by the huge page size. A PGD is composed
21 * of PTRS_PER_PGD pgd_t's and is the top level of the page table.
22 */
23 #define PGDIR_SHIFT HPAGE_SHIFT
24 #define PGDIR_SIZE HPAGE_SIZE
25 #define PGDIR_MASK (~(PGDIR_SIZE-1))
26 #define PTRS_PER_PGD _HV_L1_ENTRIES(HPAGE_SHIFT)
27 #define PGD_INDEX(va) _HV_L1_INDEX(va, HPAGE_SHIFT)
28 #define SIZEOF_PGD _HV_L1_SIZE(HPAGE_SHIFT)
29
30 /*
31 * The level-2 index is defined by the difference between the huge
32 * page size and the normal page size. A PTE is composed of
33 * PTRS_PER_PTE pte_t's and is the bottom level of the page table.
34 * Note that the hypervisor docs use PTE for what we call pte_t, so
35 * this nomenclature is somewhat confusing.
36 */
37 #define PTRS_PER_PTE _HV_L2_ENTRIES(HPAGE_SHIFT, PAGE_SHIFT)
38 #define PTE_INDEX(va) _HV_L2_INDEX(va, HPAGE_SHIFT, PAGE_SHIFT)
39 #define SIZEOF_PTE _HV_L2_SIZE(HPAGE_SHIFT, PAGE_SHIFT)
40
41 #ifndef __ASSEMBLY__
42
43 /*
44 * Right now we initialize only a single pte table. It can be extended
45 * easily, subsequent pte tables have to be allocated in one physical
46 * chunk of RAM.
47 *
48 * HOWEVER, if we are using an allocation scheme with slop after the
49 * end of the page table (e.g. where our L2 page tables are 2KB but
50 * our pages are 64KB and we are allocating via the page allocator)
51 * we can't extend it easily.
52 */
53 #define LAST_PKMAP PTRS_PER_PTE
54
55 #define PKMAP_BASE ((FIXADDR_BOOT_START - PAGE_SIZE*LAST_PKMAP) & PGDIR_MASK)
56
57 #ifdef CONFIG_HIGHMEM
58 # define _VMALLOC_END (PKMAP_BASE & ~(HPAGE_SIZE-1))
59 #else
60 # define _VMALLOC_END (FIXADDR_START & ~(HPAGE_SIZE-1))
61 #endif
62
63 /*
64 * Align the vmalloc area to an L2 page table, and leave a guard page
65 * at the beginning and end. The vmalloc code also puts in an internal
66 * guard page between each allocation.
67 */
68 #define VMALLOC_END (_VMALLOC_END - PAGE_SIZE)
69 extern unsigned long VMALLOC_RESERVE /* = CONFIG_VMALLOC_RESERVE */;
70 #define _VMALLOC_START (_VMALLOC_END - VMALLOC_RESERVE)
71 #define VMALLOC_START (_VMALLOC_START + PAGE_SIZE)
72
73 /* This is the maximum possible amount of lowmem. */
74 #define MAXMEM (_VMALLOC_START - PAGE_OFFSET)
75
76 /* We have no pmd or pud since we are strictly a two-level page table */
77 #include <asm-generic/pgtable-nopmd.h>
78
pud_huge_page(pud_t pud)79 static inline int pud_huge_page(pud_t pud) { return 0; }
80
81 /* We don't define any pgds for these addresses. */
pgd_addr_invalid(unsigned long addr)82 static inline int pgd_addr_invalid(unsigned long addr)
83 {
84 return addr >= MEM_HV_START;
85 }
86
87 /*
88 * Provide versions of these routines that can be used safely when
89 * the hypervisor may be asynchronously modifying dirty/accessed bits.
90 * ptep_get_and_clear() matches the generic one but we provide it to
91 * be parallel with the 64-bit code.
92 */
93 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
94 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
95
96 extern int ptep_test_and_clear_young(struct vm_area_struct *,
97 unsigned long addr, pte_t *);
98 extern void ptep_set_wrprotect(struct mm_struct *,
99 unsigned long addr, pte_t *);
100
101 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
ptep_get_and_clear(struct mm_struct * mm,unsigned long addr,pte_t * ptep)102 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
103 unsigned long addr, pte_t *ptep)
104 {
105 pte_t pte = *ptep;
106 pte_clear(_mm, addr, ptep);
107 return pte;
108 }
109
110 /*
111 * pmds are wrappers around pgds, which are the same as ptes.
112 * It's often convenient to "cast" back and forth and use the pte methods,
113 * which are the methods supplied by the hypervisor.
114 */
115 #define pmd_pte(pmd) ((pmd).pud.pgd)
116 #define pmdp_ptep(pmdp) (&(pmdp)->pud.pgd)
117 #define pte_pmd(pte) ((pmd_t){ { (pte) } })
118
119 #endif /* __ASSEMBLY__ */
120
121 #endif /* _ASM_TILE_PGTABLE_32_H */
122