xref: /linux/arch/powerpc/include/asm/pte-walk.h (revision 8137a49e1567726eb10fcf55ad141ac19804ca6b)
1 #ifndef _ASM_POWERPC_PTE_WALK_H
2 #define _ASM_POWERPC_PTE_WALK_H
3 
4 #include <linux/sched.h>
5 
6 /* Don't use this directly */
7 extern pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
8 			       bool *is_thp, unsigned *hshift);
9 
10 static inline pte_t *find_linux_pte(pgd_t *pgdir, unsigned long ea,
11 				    bool *is_thp, unsigned *hshift)
12 {
13 	pte_t *pte;
14 
15 	VM_WARN(!arch_irqs_disabled(), "%s called with irq enabled\n", __func__);
16 	pte = __find_linux_pte(pgdir, ea, is_thp, hshift);
17 
18 #if defined(CONFIG_DEBUG_VM) &&						\
19 	!(defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE))
20 	/*
21 	 * We should not find huge page if these configs are not enabled.
22 	 */
23 	if (hshift)
24 		WARN_ON(*hshift);
25 #endif
26 	return pte;
27 }
28 
29 static inline pte_t *find_init_mm_pte(unsigned long ea, unsigned *hshift)
30 {
31 	pgd_t *pgdir = init_mm.pgd;
32 	return __find_linux_pte(pgdir, ea, NULL, hshift);
33 }
34 
35 /*
36  * Convert a kernel vmap virtual address (vmalloc or ioremap space) to a
37  * physical address, without taking locks. This can be used in real-mode.
38  */
39 static inline phys_addr_t ppc_find_vmap_phys(unsigned long addr)
40 {
41 	pte_t *ptep;
42 	phys_addr_t pa;
43 	int hugepage_shift;
44 
45 	/*
46 	 * init_mm does not free page tables, and does not do THP. It may
47 	 * have huge pages from huge vmalloc / ioremap etc.
48 	 */
49 	ptep = find_init_mm_pte(addr, &hugepage_shift);
50 	if (WARN_ON(!ptep))
51 		return 0;
52 
53 	pa = PFN_PHYS(pte_pfn(*ptep));
54 
55 	if (!hugepage_shift)
56 		hugepage_shift = PAGE_SHIFT;
57 
58 	pa |= addr & ((1ul << hugepage_shift) - 1);
59 
60 	return pa;
61 }
62 
63 /*
64  * This is what we should always use. Any other lockless page table lookup needs
65  * careful audit against THP split.
66  */
67 static inline pte_t *find_current_mm_pte(pgd_t *pgdir, unsigned long ea,
68 					 bool *is_thp, unsigned *hshift)
69 {
70 	pte_t *pte;
71 
72 	VM_WARN(!arch_irqs_disabled(), "%s called with irq enabled\n", __func__);
73 	VM_WARN(pgdir != current->mm->pgd,
74 		"%s lock less page table lookup called on wrong mm\n", __func__);
75 	pte = __find_linux_pte(pgdir, ea, is_thp, hshift);
76 
77 #if defined(CONFIG_DEBUG_VM) &&						\
78 	!(defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE))
79 	/*
80 	 * We should not find huge page if these configs are not enabled.
81 	 */
82 	if (hshift)
83 		WARN_ON(*hshift);
84 #endif
85 	return pte;
86 }
87 
88 #endif /* _ASM_POWERPC_PTE_WALK_H */
89