tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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#if PAGE_DEFAULT_KEY
13static inline unsigned long sske_frame(unsigned long addr, unsigned char skey)
14{
15 asm volatile(".insn rrf,0xb22b0000,%[skey],%[addr],9,0"
16 : [addr] "+a" (addr) : [skey] "d" (skey));
17 return addr;
18}
19
20void __storage_key_init_range(unsigned long start, unsigned long end)
21{
22 unsigned long boundary, size;
23
24 while (start < end) {
25 if (MACHINE_HAS_EDAT1) {
26 /* set storage keys for a 1MB frame */
27 size = 1UL << 20;
28 boundary = (start + size) & ~(size - 1);
29 if (boundary <= end) {
30 do {
31 start = sske_frame(start, PAGE_DEFAULT_KEY);
32 } while (start < boundary);
33 continue;
34 }
35 }
36 page_set_storage_key(start, PAGE_DEFAULT_KEY, 0);
37 start += PAGE_SIZE;
38 }
39}
40#endif
41
42static pte_t *walk_page_table(unsigned long addr)
43{
44 pgd_t *pgdp;
45 pud_t *pudp;
46 pmd_t *pmdp;
47 pte_t *ptep;
48
49 pgdp = pgd_offset_k(addr);
50 if (pgd_none(*pgdp))
51 return NULL;
52 pudp = pud_offset(pgdp, addr);
53 if (pud_none(*pudp) || pud_large(*pudp))
54 return NULL;
55 pmdp = pmd_offset(pudp, addr);
56 if (pmd_none(*pmdp) || pmd_large(*pmdp))
57 return NULL;
58 ptep = pte_offset_kernel(pmdp, addr);
59 if (pte_none(*ptep))
60 return NULL;
61 return ptep;
62}
63
64static void change_page_attr(unsigned long addr, int numpages,
65 pte_t (*set) (pte_t))
66{
67 pte_t *ptep, pte;
68 int i;
69
70 for (i = 0; i < numpages; i++) {
71 ptep = walk_page_table(addr);
72 if (WARN_ON_ONCE(!ptep))
73 break;
74 pte = *ptep;
75 pte = set(pte);
76 __ptep_ipte(addr, ptep);
77 *ptep = pte;
78 addr += PAGE_SIZE;
79 }
80}
81
82int set_memory_ro(unsigned long addr, int numpages)
83{
84 change_page_attr(addr, numpages, pte_wrprotect);
85 return 0;
86}
87
88int set_memory_rw(unsigned long addr, int numpages)
89{
90 change_page_attr(addr, numpages, pte_mkwrite);
91 return 0;
92}
93
94/* not possible */
95int set_memory_nx(unsigned long addr, int numpages)
96{
97 return 0;
98}
99
100int set_memory_x(unsigned long addr, int numpages)
101{
102 return 0;
103}
104
105#ifdef CONFIG_DEBUG_PAGEALLOC
106void kernel_map_pages(struct page *page, int numpages, int enable)
107{
108 unsigned long address;
109 pgd_t *pgd;
110 pud_t *pud;
111 pmd_t *pmd;
112 pte_t *pte;
113 int i;
114
115 for (i = 0; i < numpages; i++) {
116 address = page_to_phys(page + i);
117 pgd = pgd_offset_k(address);
118 pud = pud_offset(pgd, address);
119 pmd = pmd_offset(pud, address);
120 pte = pte_offset_kernel(pmd, address);
121 if (!enable) {
122 __ptep_ipte(address, pte);
123 pte_val(*pte) = _PAGE_INVALID;
124 continue;
125 }
126 pte_val(*pte) = __pa(address);
127 }
128}
129
130#ifdef CONFIG_HIBERNATION
131bool kernel_page_present(struct page *page)
132{
133 unsigned long addr;
134 int cc;
135
136 addr = page_to_phys(page);
137 asm volatile(
138 " lra %1,0(%1)\n"
139 " ipm %0\n"
140 " srl %0,28"
141 : "=d" (cc), "+a" (addr) : : "cc");
142 return cc == 0;
143}
144#endif /* CONFIG_HIBERNATION */
145
146#endif /* CONFIG_DEBUG_PAGEALLOC */