4b22eb47f23a1d116e2e457ae50a30d000e5c2b3
[sfrench/cifs-2.6.git] / arch / x86 / mm / pageattr-test.c
1 /*
2  * self test for change_page_attr.
3  *
4  * Clears the global bit on random pages in the direct mapping, then reverts
5  * and compares page tables forwards and afterwards.
6  */
7
8 #include <linux/mm.h>
9 #include <linux/random.h>
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/bootmem.h>
13 #include <asm/cacheflush.h>
14 #include <asm/pgtable.h>
15 #include <asm/kdebug.h>
16
17 enum {
18         NTEST = 400,
19 #ifdef CONFIG_X86_64
20         LOWEST_LEVEL = 4,
21         LPS = (1 << PMD_SHIFT),
22 #elif defined(CONFIG_X86_PAE)
23         LOWEST_LEVEL = 3,
24         LPS = (1 << PMD_SHIFT),
25 #else
26         LOWEST_LEVEL = 3, /* lookup_address lies here */
27         LPS = (1 << 22),
28 #endif
29         GPS = (1<<30)
30 };
31
32 #ifdef CONFIG_X86_64
33 #include <asm/proto.h>
34 #define max_mapped end_pfn_map
35 #else
36 #define max_mapped max_low_pfn
37 #endif
38
39 struct split_state {
40         long lpg, gpg, spg, exec;
41         long min_exec, max_exec;
42 };
43
44 static __init int print_split(struct split_state *s)
45 {
46         int printed = 0;
47         long i, expected, missed = 0;
48         int err = 0;
49
50         s->lpg = s->gpg = s->spg = s->exec = 0;
51         s->min_exec = ~0UL;
52         s->max_exec = 0;
53         for (i = 0; i < max_mapped; ) {
54                 int level;
55                 pte_t *pte;
56                 unsigned long adr = (unsigned long)__va(i << PAGE_SHIFT);
57
58                 pte = lookup_address(adr, &level);
59                 if (!pte) {
60                         if (!printed) {
61                                 dump_pagetable(adr);
62                                 printk("CPA %lx no pte level %d\n", adr, level);
63                                 printed = 1;
64                         }
65                         missed++;
66                         i++;
67                         continue;
68                 }
69
70                 if (level == 2 && sizeof(long) == 8) {
71                         s->gpg++;
72                         i += GPS/PAGE_SIZE;
73                 } else if (level != LOWEST_LEVEL) {
74                         if (!(pte_val(*pte) & _PAGE_PSE)) {
75                                 printk("%lx level %d but not PSE %Lx\n",
76                                         adr, level, (u64)pte_val(*pte));
77                                 err = 1;
78                         }
79                         s->lpg++;
80                         i += LPS/PAGE_SIZE;
81                 } else {
82                         s->spg++;
83                         i++;
84                 }
85                 if (!(pte_val(*pte) & _PAGE_NX)) {
86                         s->exec++;
87                         if (adr < s->min_exec)
88                                 s->min_exec = adr;
89                         if (adr > s->max_exec)
90                                 s->max_exec = adr;
91                 }
92         }
93         printk("CPA mapping 4k %lu large %lu gb %lu x %lu[%lx-%lx] miss %lu\n",
94                 s->spg, s->lpg, s->gpg, s->exec,
95                 s->min_exec != ~0UL ? s->min_exec : 0, s->max_exec, missed);
96         expected = (s->gpg*GPS + s->lpg*LPS)/PAGE_SIZE + s->spg + missed;
97         if (expected != i) {
98                 printk("CPA max_mapped %lu but expected %lu\n",
99                         max_mapped, expected);
100                 return 1;
101         }
102         return err;
103 }
104
105 static __init int state_same(struct split_state *a, struct split_state *b)
106 {
107         return a->lpg == b->lpg && a->gpg == b->gpg && a->spg == b->spg &&
108                         a->exec == b->exec;
109 }
110
111 static unsigned long addr[NTEST] __initdata;
112 static unsigned len[NTEST] __initdata;
113
114 /* Change the global bit on random pages in the direct mapping */
115 static __init int exercise_pageattr(void)
116 {
117         int i, k;
118         pte_t *pte, pte0;
119         int level;
120         int err;
121         struct split_state sa, sb, sc;
122         int failed = 0;
123         unsigned long *bm;
124
125         printk("CPA exercising pageattr\n");
126
127         bm = vmalloc((max_mapped + 7) / 8);
128         if (!bm) {
129                 printk("CPA Cannot vmalloc bitmap\n");
130                 return -ENOMEM;
131         }
132         memset(bm, 0, (max_mapped + 7) / 8);
133
134         failed += print_split(&sa);
135         srandom32(100);
136         for (i = 0; i < NTEST; i++) {
137                 unsigned long pfn = random32() % max_mapped;
138                 addr[i] = (unsigned long)__va(pfn << PAGE_SHIFT);
139                 len[i] = random32() % 100;
140                 len[i] = min_t(unsigned long, len[i], max_mapped - pfn - 1);
141                 if (len[i] == 0)
142                         len[i] = 1;
143
144                 pte = NULL;
145                 pte0 = pfn_pte(0, __pgprot(0)); /* shut gcc up */
146                 for (k = 0; k < len[i]; k++) {
147                         pte = lookup_address(addr[i] + k*PAGE_SIZE, &level);
148                         if (!pte || pgprot_val(pte_pgprot(*pte)) == 0) {
149                                 addr[i] = 0;
150                                 break;
151                         }
152                         if (k == 0)
153                                 pte0 = *pte;
154                         else if (pgprot_val(pte_pgprot(*pte)) !=
155                                         pgprot_val(pte_pgprot(pte0))) {
156                                 len[i] = k;
157                                 break;
158                         }
159                         if (test_bit(pfn + k, bm)) {
160                                 len[i] = k;
161                                 break;
162                         }
163                         __set_bit(pfn + k, bm);
164                 }
165                 if (!addr[i] || !pte || !k) {
166                         addr[i] = 0;
167                         continue;
168                 }
169
170                 err = change_page_attr(virt_to_page(addr[i]), len[i],
171                             pte_pgprot(pte_clrhuge(pte_clrglobal(pte0))));
172                 if (err < 0) {
173                         printk("CPA %d failed %d\n", i, err);
174                         failed++;
175                 }
176
177                 pte = lookup_address(addr[i], &level);
178                 if (!pte || pte_global(*pte) || pte_huge(*pte)) {
179                         printk("CPA %lx: bad pte %Lx\n", addr[i],
180                                 pte ? (u64)pte_val(*pte) : 0ULL);
181                         failed++;
182                 }
183                 if (level != LOWEST_LEVEL) {
184                         printk("CPA %lx: unexpected level %d\n", addr[i],
185                                         level);
186                         failed++;
187                 }
188
189         }
190         vfree(bm);
191         global_flush_tlb();
192
193         failed += print_split(&sb);
194
195         printk("CPA reverting everything\n");
196         for (i = 0; i < NTEST; i++) {
197                 if (!addr[i])
198                         continue;
199                 pte = lookup_address(addr[i], &level);
200                 if (!pte) {
201                         printk("CPA lookup of %lx failed\n", addr[i]);
202                         failed++;
203                         continue;
204                 }
205                 err = change_page_attr(virt_to_page(addr[i]), len[i],
206                                           pte_pgprot(pte_mkglobal(*pte)));
207                 if (err < 0) {
208                         printk("CPA reverting failed: %d\n", err);
209                         failed++;
210                 }
211                 pte = lookup_address(addr[i], &level);
212                 if (!pte || !pte_global(*pte)) {
213                         printk("CPA %lx: bad pte after revert %Lx\n", addr[i],
214                                pte ? (u64)pte_val(*pte) : 0ULL);
215                         failed++;
216                 }
217
218         }
219         global_flush_tlb();
220
221         failed += print_split(&sc);
222         if (!state_same(&sa, &sc))
223                 failed++;
224
225         if (failed)
226                 printk("CPA selftests NOT PASSED. Please report.\n");
227         else
228                 printk("CPA selftests PASSED\n");
229
230         return 0;
231 }
232
233 module_init(exercise_pageattr);