summaryrefslogtreecommitdiff
path: root/arch/s390/mm/pageattr.c
blob: 426c9d462d1ce3fe58e021802ffedd3fc413cd35 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
/*
 * Copyright IBM Corp. 2011
 * Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
 */
#include <linux/hugetlb.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <asm/cacheflush.h>
#include <asm/facility.h>
#include <asm/pgtable.h>
#include <asm/page.h>

#if PAGE_DEFAULT_KEY
static inline unsigned long sske_frame(unsigned long addr, unsigned char skey)
{
	asm volatile(".insn rrf,0xb22b0000,%[skey],%[addr],9,0"
		     : [addr] "+a" (addr) : [skey] "d" (skey));
	return addr;
}

void __storage_key_init_range(unsigned long start, unsigned long end)
{
	unsigned long boundary, size;

	while (start < end) {
		if (MACHINE_HAS_EDAT1) {
			/* set storage keys for a 1MB frame */
			size = 1UL << 20;
			boundary = (start + size) & ~(size - 1);
			if (boundary <= end) {
				do {
					start = sske_frame(start, PAGE_DEFAULT_KEY);
				} while (start < boundary);
				continue;
			}
		}
		page_set_storage_key(start, PAGE_DEFAULT_KEY, 0);
		start += PAGE_SIZE;
	}
}
#endif

static pte_t *walk_page_table(unsigned long addr)
{
	pgd_t *pgdp;
	pud_t *pudp;
	pmd_t *pmdp;
	pte_t *ptep;

	pgdp = pgd_offset_k(addr);
	if (pgd_none(*pgdp))
		return NULL;
	pudp = pud_offset(pgdp, addr);
	if (pud_none(*pudp) || pud_large(*pudp))
		return NULL;
	pmdp = pmd_offset(pudp, addr);
	if (pmd_none(*pmdp) || pmd_large(*pmdp))
		return NULL;
	ptep = pte_offset_kernel(pmdp, addr);
	if (pte_none(*ptep))
		return NULL;
	return ptep;
}

static void change_page_attr(unsigned long addr, int numpages,
			     pte_t (*set) (pte_t))
{
	pte_t *ptep, pte;
	int i;

	for (i = 0; i < numpages; i++) {
		ptep = walk_page_table(addr);
		if (WARN_ON_ONCE(!ptep))
			break;
		pte = *ptep;
		pte = set(pte);
		__ptep_ipte(addr, ptep);
		*ptep = pte;
		addr += PAGE_SIZE;
	}
}

int set_memory_ro(unsigned long addr, int numpages)
{
	change_page_attr(addr, numpages, pte_wrprotect);
	return 0;
}

int set_memory_rw(unsigned long addr, int numpages)
{
	change_page_attr(addr, numpages, pte_mkwrite);
	return 0;
}

/* not possible */
int set_memory_nx(unsigned long addr, int numpages)
{
	return 0;
}

int set_memory_x(unsigned long addr, int numpages)
{
	return 0;
}

#ifdef CONFIG_DEBUG_PAGEALLOC

static void ipte_range(pte_t *pte, unsigned long address, int nr)
{
	int i;

	if (test_facility(13) && IS_ENABLED(CONFIG_64BIT)) {
		__ptep_ipte_range(address, nr - 1, pte);
		return;
	}
	for (i = 0; i < nr; i++) {
		__ptep_ipte(address, pte);
		address += PAGE_SIZE;
		pte++;
	}
}

void __kernel_map_pages(struct page *page, int numpages, int enable)
{
	unsigned long address;
	int nr, i, j;
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;
	pte_t *pte;

	for (i = 0; i < numpages;) {
		address = page_to_phys(page + i);
		pgd = pgd_offset_k(address);
		pud = pud_offset(pgd, address);
		pmd = pmd_offset(pud, address);
		pte = pte_offset_kernel(pmd, address);
		nr = (unsigned long)pte >> ilog2(sizeof(long));
		nr = PTRS_PER_PTE - (nr & (PTRS_PER_PTE - 1));
		nr = min(numpages - i, nr);
		if (enable) {
			for (j = 0; j < nr; j++) {
				pte_val(*pte) = __pa(address);
				address += PAGE_SIZE;
				pte++;
			}
		} else {
			ipte_range(pte, address, nr);
		}
		i += nr;
	}
}

#ifdef CONFIG_HIBERNATION
bool kernel_page_present(struct page *page)
{
	unsigned long addr;
	int cc;

	addr = page_to_phys(page);
	asm volatile(
		"	lra	%1,0(%1)\n"
		"	ipm	%0\n"
		"	srl	%0,28"
		: "=d" (cc), "+a" (addr) : : "cc");
	return cc == 0;
}
#endif /* CONFIG_HIBERNATION */

#endif /* CONFIG_DEBUG_PAGEALLOC */