1 #ifndef _ASM_POWERPC_PGTABLE_64K_H
2 #define _ASM_POWERPC_PGTABLE_64K_H
3
4 #include <asm-generic/pgtable-nopud.h>
5
6
7 #define PTE_INDEX_SIZE 12
8 #define PMD_INDEX_SIZE 12
9 #define PUD_INDEX_SIZE 0
10 #define PGD_INDEX_SIZE 4
11
12 #ifndef __ASSEMBLY__
13 #define PTE_TABLE_SIZE (sizeof(real_pte_t) << PTE_INDEX_SIZE)
14 #define PMD_TABLE_SIZE (sizeof(pmd_t) << PMD_INDEX_SIZE)
15 #define PGD_TABLE_SIZE (sizeof(pgd_t) << PGD_INDEX_SIZE)
16
17 #define PTRS_PER_PTE (1 << PTE_INDEX_SIZE)
18 #define PTRS_PER_PMD (1 << PMD_INDEX_SIZE)
19 #define PTRS_PER_PGD (1 << PGD_INDEX_SIZE)
20
21 #ifdef CONFIG_PPC_SUBPAGE_PROT
22 /*
23 * For the sub-page protection option, we extend the PGD with one of
24 * these. Basically we have a 3-level tree, with the top level being
25 * the protptrs array. To optimize speed and memory consumption when
26 * only addresses < 4GB are being protected, pointers to the first
27 * four pages of sub-page protection words are stored in the low_prot
28 * array.
29 * Each page of sub-page protection words protects 1GB (4 bytes
30 * protects 64k). For the 3-level tree, each page of pointers then
31 * protects 8TB.
32 */
33 struct subpage_prot_table {
34 unsigned long maxaddr; /* only addresses < this are protected */
35 unsigned int **protptrs[2];
36 unsigned int *low_prot[4];
37 };
38
39 #undef PGD_TABLE_SIZE
40 #define PGD_TABLE_SIZE ((sizeof(pgd_t) << PGD_INDEX_SIZE) + \
41 sizeof(struct subpage_prot_table))
42
43 #define SBP_L1_BITS (PAGE_SHIFT - 2)
44 #define SBP_L2_BITS (PAGE_SHIFT - 3)
45 #define SBP_L1_COUNT (1 << SBP_L1_BITS)
46 #define SBP_L2_COUNT (1 << SBP_L2_BITS)
47 #define SBP_L2_SHIFT (PAGE_SHIFT + SBP_L1_BITS)
48 #define SBP_L3_SHIFT (SBP_L2_SHIFT + SBP_L2_BITS)
49
50 extern void subpage_prot_free(pgd_t *pgd);
51
pgd_subpage_prot(pgd_t * pgd)52 static inline struct subpage_prot_table *pgd_subpage_prot(pgd_t *pgd)
53 {
54 return (struct subpage_prot_table *)(pgd + PTRS_PER_PGD);
55 }
56 #endif /* CONFIG_PPC_SUBPAGE_PROT */
57 #endif /* __ASSEMBLY__ */
58
59 /* With 4k base page size, hugepage PTEs go at the PMD level */
60 #define MIN_HUGEPTE_SHIFT PAGE_SHIFT
61
62 /* PMD_SHIFT determines what a second-level page table entry can map */
63 #define PMD_SHIFT (PAGE_SHIFT + PTE_INDEX_SIZE)
64 #define PMD_SIZE (1UL << PMD_SHIFT)
65 #define PMD_MASK (~(PMD_SIZE-1))
66
67 /* PGDIR_SHIFT determines what a third-level page table entry can map */
68 #define PGDIR_SHIFT (PMD_SHIFT + PMD_INDEX_SIZE)
69 #define PGDIR_SIZE (1UL << PGDIR_SHIFT)
70 #define PGDIR_MASK (~(PGDIR_SIZE-1))
71
72 /* Additional PTE bits (don't change without checking asm in hash_low.S) */
73 #define __HAVE_ARCH_PTE_SPECIAL
74 #define _PAGE_SPECIAL 0x00000400 /* software: special page */
75 #define _PAGE_HPTE_SUB 0x0ffff000 /* combo only: sub pages HPTE bits */
76 #define _PAGE_HPTE_SUB0 0x08000000 /* combo only: first sub page */
77 #define _PAGE_COMBO 0x10000000 /* this is a combo 4k page */
78 #define _PAGE_4K_PFN 0x20000000 /* PFN is for a single 4k page */
79
80 /* For 64K page, we don't have a separate _PAGE_HASHPTE bit. Instead,
81 * we set that to be the whole sub-bits mask. The C code will only
82 * test this, so a multi-bit mask will work. For combo pages, this
83 * is equivalent as effectively, the old _PAGE_HASHPTE was an OR of
84 * all the sub bits. For real 64k pages, we now have the assembly set
85 * _PAGE_HPTE_SUB0 in addition to setting the HIDX bits which overlap
86 * that mask. This is fine as long as the HIDX bits are never set on
87 * a PTE that isn't hashed, which is the case today.
88 *
89 * A little nit is for the huge page C code, which does the hashing
90 * in C, we need to provide which bit to use.
91 */
92 #define _PAGE_HASHPTE _PAGE_HPTE_SUB
93
94 /* Note the full page bits must be in the same location as for normal
95 * 4k pages as the same asssembly will be used to insert 64K pages
96 * wether the kernel has CONFIG_PPC_64K_PAGES or not
97 */
98 #define _PAGE_F_SECOND 0x00008000 /* full page: hidx bits */
99 #define _PAGE_F_GIX 0x00007000 /* full page: hidx bits */
100
101 /* PTE flags to conserve for HPTE identification */
102 #define _PAGE_HPTEFLAGS (_PAGE_BUSY | _PAGE_HASHPTE | _PAGE_COMBO)
103
104 /* Shift to put page number into pte.
105 *
106 * That gives us a max RPN of 34 bits, which means a max of 50 bits
107 * of addressable physical space, or 46 bits for the special 4k PFNs.
108 */
109 #define PTE_RPN_SHIFT (30)
110 #define PTE_RPN_MAX (1UL << (64 - PTE_RPN_SHIFT))
111 #define PTE_RPN_MASK (~((1UL<<PTE_RPN_SHIFT)-1))
112
113 /* _PAGE_CHG_MASK masks of bits that are to be preserved accross
114 * pgprot changes
115 */
116 #define _PAGE_CHG_MASK (PTE_RPN_MASK | _PAGE_HPTEFLAGS | _PAGE_DIRTY | \
117 _PAGE_ACCESSED | _PAGE_SPECIAL)
118
119 /* Bits to mask out from a PMD to get to the PTE page */
120 #define PMD_MASKED_BITS 0x1ff
121 /* Bits to mask out from a PGD/PUD to get to the PMD page */
122 #define PUD_MASKED_BITS 0x1ff
123
124 /* Manipulate "rpte" values */
125 #define __real_pte(e,p) ((real_pte_t) { \
126 (e), pte_val(*((p) + PTRS_PER_PTE)) })
127 #define __rpte_to_hidx(r,index) ((pte_val((r).pte) & _PAGE_COMBO) ? \
128 (((r).hidx >> ((index)<<2)) & 0xf) : ((pte_val((r).pte) >> 12) & 0xf))
129 #define __rpte_to_pte(r) ((r).pte)
130 #define __rpte_sub_valid(rpte, index) \
131 (pte_val(rpte.pte) & (_PAGE_HPTE_SUB0 >> (index)))
132
133
134 /* Trick: we set __end to va + 64k, which happens works for
135 * a 16M page as well as we want only one iteration
136 */
137 #define pte_iterate_hashed_subpages(rpte, psize, va, index, shift) \
138 do { \
139 unsigned long __end = va + PAGE_SIZE; \
140 unsigned __split = (psize == MMU_PAGE_4K || \
141 psize == MMU_PAGE_64K_AP); \
142 shift = mmu_psize_defs[psize].shift; \
143 for (index = 0; va < __end; index++, va += (1L << shift)) { \
144 if (!__split || __rpte_sub_valid(rpte, index)) do { \
145
146 #define pte_iterate_hashed_end() } while(0); } } while(0)
147
148 #define pte_pagesize_index(mm, addr, pte) \
149 (((pte) & _PAGE_COMBO)? MMU_PAGE_4K: MMU_PAGE_64K)
150
151 #define remap_4k_pfn(vma, addr, pfn, prot) \
152 remap_pfn_range((vma), (addr), (pfn), PAGE_SIZE, \
153 __pgprot(pgprot_val((prot)) | _PAGE_4K_PFN))
154
155 #endif /* _ASM_POWERPC_PGTABLE_64K_H */
156