xref: /linux/arch/s390/mm/pageattr.c (revision b889fcf63cb62e7fdb7816565e28f44dbe4a76a5)
1 /*
2  * Copyright IBM Corp. 2011
3  * Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
4  */
5 #include <linux/hugetlb.h>
6 #include <linux/module.h>
7 #include <linux/mm.h>
8 #include <asm/cacheflush.h>
9 #include <asm/pgtable.h>
10 #include <asm/page.h>
11 
12 void storage_key_init_range(unsigned long start, unsigned long end)
13 {
14 	unsigned long boundary, function, size;
15 
16 	while (start < end) {
17 		if (MACHINE_HAS_EDAT2) {
18 			/* set storage keys for a 2GB frame */
19 			function = 0x22000 | PAGE_DEFAULT_KEY;
20 			size = 1UL << 31;
21 			boundary = (start + size) & ~(size - 1);
22 			if (boundary <= end) {
23 				do {
24 					start = pfmf(function, start);
25 				} while (start < boundary);
26 				continue;
27 			}
28 		}
29 		if (MACHINE_HAS_EDAT1) {
30 			/* set storage keys for a 1MB frame */
31 			function = 0x21000 | PAGE_DEFAULT_KEY;
32 			size = 1UL << 20;
33 			boundary = (start + size) & ~(size - 1);
34 			if (boundary <= end) {
35 				do {
36 					start = pfmf(function, start);
37 				} while (start < boundary);
38 				continue;
39 			}
40 		}
41 		page_set_storage_key(start, PAGE_DEFAULT_KEY, 0);
42 		start += PAGE_SIZE;
43 	}
44 }
45 
46 static pte_t *walk_page_table(unsigned long addr)
47 {
48 	pgd_t *pgdp;
49 	pud_t *pudp;
50 	pmd_t *pmdp;
51 	pte_t *ptep;
52 
53 	pgdp = pgd_offset_k(addr);
54 	if (pgd_none(*pgdp))
55 		return NULL;
56 	pudp = pud_offset(pgdp, addr);
57 	if (pud_none(*pudp) || pud_large(*pudp))
58 		return NULL;
59 	pmdp = pmd_offset(pudp, addr);
60 	if (pmd_none(*pmdp) || pmd_large(*pmdp))
61 		return NULL;
62 	ptep = pte_offset_kernel(pmdp, addr);
63 	if (pte_none(*ptep))
64 		return NULL;
65 	return ptep;
66 }
67 
68 static void change_page_attr(unsigned long addr, int numpages,
69 			     pte_t (*set) (pte_t))
70 {
71 	pte_t *ptep, pte;
72 	int i;
73 
74 	for (i = 0; i < numpages; i++) {
75 		ptep = walk_page_table(addr);
76 		if (WARN_ON_ONCE(!ptep))
77 			break;
78 		pte = *ptep;
79 		pte = set(pte);
80 		__ptep_ipte(addr, ptep);
81 		*ptep = pte;
82 		addr += PAGE_SIZE;
83 	}
84 }
85 
86 int set_memory_ro(unsigned long addr, int numpages)
87 {
88 	change_page_attr(addr, numpages, pte_wrprotect);
89 	return 0;
90 }
91 
92 int set_memory_rw(unsigned long addr, int numpages)
93 {
94 	change_page_attr(addr, numpages, pte_mkwrite);
95 	return 0;
96 }
97 
98 /* not possible */
99 int set_memory_nx(unsigned long addr, int numpages)
100 {
101 	return 0;
102 }
103 
104 int set_memory_x(unsigned long addr, int numpages)
105 {
106 	return 0;
107 }
108 
109 #ifdef CONFIG_DEBUG_PAGEALLOC
110 void kernel_map_pages(struct page *page, int numpages, int enable)
111 {
112 	unsigned long address;
113 	pgd_t *pgd;
114 	pud_t *pud;
115 	pmd_t *pmd;
116 	pte_t *pte;
117 	int i;
118 
119 	for (i = 0; i < numpages; i++) {
120 		address = page_to_phys(page + i);
121 		pgd = pgd_offset_k(address);
122 		pud = pud_offset(pgd, address);
123 		pmd = pmd_offset(pud, address);
124 		pte = pte_offset_kernel(pmd, address);
125 		if (!enable) {
126 			__ptep_ipte(address, pte);
127 			pte_val(*pte) = _PAGE_TYPE_EMPTY;
128 			continue;
129 		}
130 		*pte = mk_pte_phys(address, __pgprot(_PAGE_TYPE_RW));
131 	}
132 }
133 
134 #ifdef CONFIG_HIBERNATION
135 bool kernel_page_present(struct page *page)
136 {
137 	unsigned long addr;
138 	int cc;
139 
140 	addr = page_to_phys(page);
141 	asm volatile(
142 		"	lra	%1,0(%1)\n"
143 		"	ipm	%0\n"
144 		"	srl	%0,28"
145 		: "=d" (cc), "+a" (addr) : : "cc");
146 	return cc == 0;
147 }
148 #endif /* CONFIG_HIBERNATION */
149 
150 #endif /* CONFIG_DEBUG_PAGEALLOC */
151