1 #ifndef _ASM_POWERPC_BOOK3S_64_HASH_64K_H
2 #define _ASM_POWERPC_BOOK3S_64_HASH_64K_H
3 
4 #include <asm-generic/pgtable-nopud.h>
5 
6 #define PTE_INDEX_SIZE  8
7 #define PMD_INDEX_SIZE  10
8 #define PUD_INDEX_SIZE	0
9 #define PGD_INDEX_SIZE  12
10 
11 #define PTRS_PER_PTE	(1 << PTE_INDEX_SIZE)
12 #define PTRS_PER_PMD	(1 << PMD_INDEX_SIZE)
13 #define PTRS_PER_PGD	(1 << PGD_INDEX_SIZE)
14 
15 /* With 4k base page size, hugepage PTEs go at the PMD level */
16 #define MIN_HUGEPTE_SHIFT	PAGE_SHIFT
17 
18 /* PMD_SHIFT determines what a second-level page table entry can map */
19 #define PMD_SHIFT	(PAGE_SHIFT + PTE_INDEX_SIZE)
20 #define PMD_SIZE	(1UL << PMD_SHIFT)
21 #define PMD_MASK	(~(PMD_SIZE-1))
22 
23 /* PGDIR_SHIFT determines what a third-level page table entry can map */
24 #define PGDIR_SHIFT	(PMD_SHIFT + PMD_INDEX_SIZE)
25 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
26 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
27 
28 /* Bits to mask out from a PMD to get to the PTE page */
29 /* PMDs point to PTE table fragments which are 4K aligned.  */
30 #define PMD_MASKED_BITS		0xfff
31 /* Bits to mask out from a PGD/PUD to get to the PMD page */
32 #define PUD_MASKED_BITS		0x1ff
33 
34 #define _PAGE_COMBO	0x00020000 /* this is a combo 4k page */
35 #define _PAGE_4K_PFN	0x00040000 /* PFN is for a single 4k page */
36 /*
37  * Used to track subpage group valid if _PAGE_COMBO is set
38  * This overloads _PAGE_F_GIX and _PAGE_F_SECOND
39  */
40 #define _PAGE_COMBO_VALID	(_PAGE_F_GIX | _PAGE_F_SECOND)
41 
42 /* PTE flags to conserve for HPTE identification */
43 #define _PAGE_HPTEFLAGS (_PAGE_BUSY | _PAGE_HASHPTE | _PAGE_COMBO)
44 
45 /* Shift to put page number into pte.
46  *
47  * That gives us a max RPN of 34 bits, which means a max of 50 bits
48  * of addressable physical space, or 46 bits for the special 4k PFNs.
49  */
50 #define PTE_RPN_SHIFT	(30)
51 
52 #ifndef __ASSEMBLY__
53 
54 /*
55  * With 64K pages on hash table, we have a special PTE format that
56  * uses a second "half" of the page table to encode sub-page information
57  * in order to deal with 64K made of 4K HW pages. Thus we override the
58  * generic accessors and iterators here
59  */
60 #define __real_pte __real_pte
61 static inline real_pte_t __real_pte(pte_t pte, pte_t *ptep)
62 {
63 	real_pte_t rpte;
64 
65 	rpte.pte = pte;
66 	rpte.hidx = 0;
67 	if (pte_val(pte) & _PAGE_COMBO) {
68 		/*
69 		 * Make sure we order the hidx load against the _PAGE_COMBO
70 		 * check. The store side ordering is done in __hash_page_4K
71 		 */
72 		smp_rmb();
73 		rpte.hidx = pte_val(*((ptep) + PTRS_PER_PTE));
74 	}
75 	return rpte;
76 }
77 
78 static inline unsigned long __rpte_to_hidx(real_pte_t rpte, unsigned long index)
79 {
80 	if ((pte_val(rpte.pte) & _PAGE_COMBO))
81 		return (rpte.hidx >> (index<<2)) & 0xf;
82 	return (pte_val(rpte.pte) >> 12) & 0xf;
83 }
84 
85 #define __rpte_to_pte(r)	((r).pte)
86 extern bool __rpte_sub_valid(real_pte_t rpte, unsigned long index);
87 /*
88  * Trick: we set __end to va + 64k, which happens works for
89  * a 16M page as well as we want only one iteration
90  */
91 #define pte_iterate_hashed_subpages(rpte, psize, vpn, index, shift)	\
92 	do {								\
93 		unsigned long __end = vpn + (1UL << (PAGE_SHIFT - VPN_SHIFT));	\
94 		unsigned __split = (psize == MMU_PAGE_4K ||		\
95 				    psize == MMU_PAGE_64K_AP);		\
96 		shift = mmu_psize_defs[psize].shift;			\
97 		for (index = 0; vpn < __end; index++,			\
98 			     vpn += (1L << (shift - VPN_SHIFT))) {	\
99 			if (!__split || __rpte_sub_valid(rpte, index))	\
100 				do {
101 
102 #define pte_iterate_hashed_end() } while(0); } } while(0)
103 
104 #define pte_pagesize_index(mm, addr, pte)	\
105 	(((pte) & _PAGE_COMBO)? MMU_PAGE_4K: MMU_PAGE_64K)
106 
107 #define remap_4k_pfn(vma, addr, pfn, prot)				\
108 	(WARN_ON(((pfn) >= (1UL << (64 - PTE_RPN_SHIFT)))) ? -EINVAL :	\
109 		remap_pfn_range((vma), (addr), (pfn), PAGE_SIZE,	\
110 			__pgprot(pgprot_val((prot)) | _PAGE_4K_PFN)))
111 
112 #define PTE_TABLE_SIZE	(sizeof(real_pte_t) << PTE_INDEX_SIZE)
113 #define PMD_TABLE_SIZE	(sizeof(pmd_t) << PMD_INDEX_SIZE)
114 #define PGD_TABLE_SIZE	(sizeof(pgd_t) << PGD_INDEX_SIZE)
115 
116 #define pgd_pte(pgd)	(pud_pte(((pud_t){ pgd })))
117 #define pte_pgd(pte)	((pgd_t)pte_pud(pte))
118 
119 #endif	/* __ASSEMBLY__ */
120 
121 #endif /* _ASM_POWERPC_BOOK3S_64_HASH_64K_H */
122