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1da177e4 LT |
1 | /* |
2 | * linux/arch/m68k/mm/memory.c | |
3 | * | |
4 | * Copyright (C) 1995 Hamish Macdonald | |
5 | */ | |
6 | ||
2e811488 | 7 | #include <linux/module.h> |
1da177e4 LT |
8 | #include <linux/mm.h> |
9 | #include <linux/kernel.h> | |
10 | #include <linux/string.h> | |
11 | #include <linux/types.h> | |
12 | #include <linux/slab.h> | |
13 | #include <linux/init.h> | |
14 | #include <linux/pagemap.h> | |
15 | ||
16 | #include <asm/setup.h> | |
17 | #include <asm/segment.h> | |
18 | #include <asm/page.h> | |
19 | #include <asm/pgalloc.h> | |
20 | #include <asm/system.h> | |
21 | #include <asm/traps.h> | |
22 | #include <asm/machdep.h> | |
23 | ||
24 | ||
25 | /* ++andreas: {get,free}_pointer_table rewritten to use unused fields from | |
26 | struct page instead of separately kmalloced struct. Stolen from | |
27 | arch/sparc/mm/srmmu.c ... */ | |
28 | ||
29 | typedef struct list_head ptable_desc; | |
30 | static LIST_HEAD(ptable_list); | |
31 | ||
32 | #define PD_PTABLE(page) ((ptable_desc *)&(virt_to_page(page)->lru)) | |
33 | #define PD_PAGE(ptable) (list_entry(ptable, struct page, lru)) | |
34 | #define PD_MARKBITS(dp) (*(unsigned char *)&PD_PAGE(dp)->index) | |
35 | ||
36 | #define PTABLE_SIZE (PTRS_PER_PMD * sizeof(pmd_t)) | |
37 | ||
38 | void __init init_pointer_table(unsigned long ptable) | |
39 | { | |
40 | ptable_desc *dp; | |
41 | unsigned long page = ptable & PAGE_MASK; | |
42 | unsigned char mask = 1 << ((ptable - page)/PTABLE_SIZE); | |
43 | ||
44 | dp = PD_PTABLE(page); | |
45 | if (!(PD_MARKBITS(dp) & mask)) { | |
46 | PD_MARKBITS(dp) = 0xff; | |
47 | list_add(dp, &ptable_list); | |
48 | } | |
49 | ||
50 | PD_MARKBITS(dp) &= ~mask; | |
51 | #ifdef DEBUG | |
52 | printk("init_pointer_table: %lx, %x\n", ptable, PD_MARKBITS(dp)); | |
53 | #endif | |
54 | ||
55 | /* unreserve the page so it's possible to free that page */ | |
56 | PD_PAGE(dp)->flags &= ~(1 << PG_reserved); | |
7835e98b | 57 | init_page_count(PD_PAGE(dp)); |
1da177e4 LT |
58 | |
59 | return; | |
60 | } | |
61 | ||
62 | pmd_t *get_pointer_table (void) | |
63 | { | |
64 | ptable_desc *dp = ptable_list.next; | |
65 | unsigned char mask = PD_MARKBITS (dp); | |
66 | unsigned char tmp; | |
67 | unsigned int off; | |
68 | ||
69 | /* | |
70 | * For a pointer table for a user process address space, a | |
71 | * table is taken from a page allocated for the purpose. Each | |
72 | * page can hold 8 pointer tables. The page is remapped in | |
73 | * virtual address space to be noncacheable. | |
74 | */ | |
75 | if (mask == 0) { | |
76 | void *page; | |
77 | ptable_desc *new; | |
78 | ||
79 | if (!(page = (void *)get_zeroed_page(GFP_KERNEL))) | |
80 | return NULL; | |
81 | ||
82 | flush_tlb_kernel_page(page); | |
83 | nocache_page(page); | |
84 | ||
85 | new = PD_PTABLE(page); | |
86 | PD_MARKBITS(new) = 0xfe; | |
87 | list_add_tail(new, dp); | |
88 | ||
89 | return (pmd_t *)page; | |
90 | } | |
91 | ||
92 | for (tmp = 1, off = 0; (mask & tmp) == 0; tmp <<= 1, off += PTABLE_SIZE) | |
93 | ; | |
94 | PD_MARKBITS(dp) = mask & ~tmp; | |
95 | if (!PD_MARKBITS(dp)) { | |
96 | /* move to end of list */ | |
a7addcea | 97 | list_move_tail(dp, &ptable_list); |
1da177e4 LT |
98 | } |
99 | return (pmd_t *) (page_address(PD_PAGE(dp)) + off); | |
100 | } | |
101 | ||
102 | int free_pointer_table (pmd_t *ptable) | |
103 | { | |
104 | ptable_desc *dp; | |
105 | unsigned long page = (unsigned long)ptable & PAGE_MASK; | |
106 | unsigned char mask = 1 << (((unsigned long)ptable - page)/PTABLE_SIZE); | |
107 | ||
108 | dp = PD_PTABLE(page); | |
109 | if (PD_MARKBITS (dp) & mask) | |
110 | panic ("table already free!"); | |
111 | ||
112 | PD_MARKBITS (dp) |= mask; | |
113 | ||
114 | if (PD_MARKBITS(dp) == 0xff) { | |
115 | /* all tables in page are free, free page */ | |
116 | list_del(dp); | |
117 | cache_page((void *)page); | |
118 | free_page (page); | |
119 | return 1; | |
120 | } else if (ptable_list.next != dp) { | |
121 | /* | |
122 | * move this descriptor to the front of the list, since | |
123 | * it has one or more free tables. | |
124 | */ | |
a7addcea | 125 | list_move(dp, &ptable_list); |
1da177e4 LT |
126 | } |
127 | return 0; | |
128 | } | |
129 | ||
1da177e4 LT |
130 | /* invalidate page in both caches */ |
131 | static inline void clear040(unsigned long paddr) | |
132 | { | |
133 | asm volatile ( | |
134 | "nop\n\t" | |
135 | ".chip 68040\n\t" | |
136 | "cinvp %%bc,(%0)\n\t" | |
137 | ".chip 68k" | |
138 | : : "a" (paddr)); | |
139 | } | |
140 | ||
141 | /* invalidate page in i-cache */ | |
142 | static inline void cleari040(unsigned long paddr) | |
143 | { | |
144 | asm volatile ( | |
145 | "nop\n\t" | |
146 | ".chip 68040\n\t" | |
147 | "cinvp %%ic,(%0)\n\t" | |
148 | ".chip 68k" | |
149 | : : "a" (paddr)); | |
150 | } | |
151 | ||
152 | /* push page in both caches */ | |
153 | /* RZ: cpush %bc DOES invalidate %ic, regardless of DPI */ | |
154 | static inline void push040(unsigned long paddr) | |
155 | { | |
156 | asm volatile ( | |
157 | "nop\n\t" | |
158 | ".chip 68040\n\t" | |
159 | "cpushp %%bc,(%0)\n\t" | |
160 | ".chip 68k" | |
161 | : : "a" (paddr)); | |
162 | } | |
163 | ||
164 | /* push and invalidate page in both caches, must disable ints | |
165 | * to avoid invalidating valid data */ | |
166 | static inline void pushcl040(unsigned long paddr) | |
167 | { | |
168 | unsigned long flags; | |
169 | ||
170 | local_irq_save(flags); | |
171 | push040(paddr); | |
172 | if (CPU_IS_060) | |
173 | clear040(paddr); | |
174 | local_irq_restore(flags); | |
175 | } | |
176 | ||
177 | /* | |
178 | * 040: Hit every page containing an address in the range paddr..paddr+len-1. | |
179 | * (Low order bits of the ea of a CINVP/CPUSHP are "don't care"s). | |
180 | * Hit every page until there is a page or less to go. Hit the next page, | |
181 | * and the one after that if the range hits it. | |
182 | */ | |
183 | /* ++roman: A little bit more care is required here: The CINVP instruction | |
184 | * invalidates cache entries WITHOUT WRITING DIRTY DATA BACK! So the beginning | |
185 | * and the end of the region must be treated differently if they are not | |
186 | * exactly at the beginning or end of a page boundary. Else, maybe too much | |
187 | * data becomes invalidated and thus lost forever. CPUSHP does what we need: | |
188 | * it invalidates the page after pushing dirty data to memory. (Thanks to Jes | |
189 | * for discovering the problem!) | |
190 | */ | |
191 | /* ... but on the '060, CPUSH doesn't invalidate (for us, since we have set | |
192 | * the DPI bit in the CACR; would it cause problems with temporarily changing | |
193 | * this?). So we have to push first and then additionally to invalidate. | |
194 | */ | |
195 | ||
196 | ||
197 | /* | |
198 | * cache_clear() semantics: Clear any cache entries for the area in question, | |
199 | * without writing back dirty entries first. This is useful if the data will | |
200 | * be overwritten anyway, e.g. by DMA to memory. The range is defined by a | |
201 | * _physical_ address. | |
202 | */ | |
203 | ||
204 | void cache_clear (unsigned long paddr, int len) | |
205 | { | |
206 | if (CPU_IS_040_OR_060) { | |
207 | int tmp; | |
208 | ||
209 | /* | |
210 | * We need special treatment for the first page, in case it | |
211 | * is not page-aligned. Page align the addresses to work | |
212 | * around bug I17 in the 68060. | |
213 | */ | |
214 | if ((tmp = -paddr & (PAGE_SIZE - 1))) { | |
215 | pushcl040(paddr & PAGE_MASK); | |
216 | if ((len -= tmp) <= 0) | |
217 | return; | |
218 | paddr += tmp; | |
219 | } | |
220 | tmp = PAGE_SIZE; | |
221 | paddr &= PAGE_MASK; | |
222 | while ((len -= tmp) >= 0) { | |
223 | clear040(paddr); | |
224 | paddr += tmp; | |
225 | } | |
226 | if ((len += tmp)) | |
227 | /* a page boundary gets crossed at the end */ | |
228 | pushcl040(paddr); | |
229 | } | |
230 | else /* 68030 or 68020 */ | |
231 | asm volatile ("movec %/cacr,%/d0\n\t" | |
232 | "oriw %0,%/d0\n\t" | |
233 | "movec %/d0,%/cacr" | |
234 | : : "i" (FLUSH_I_AND_D) | |
235 | : "d0"); | |
236 | #ifdef CONFIG_M68K_L2_CACHE | |
237 | if(mach_l2_flush) | |
238 | mach_l2_flush(0); | |
239 | #endif | |
240 | } | |
bf8af91b | 241 | EXPORT_SYMBOL(cache_clear); |
1da177e4 LT |
242 | |
243 | ||
244 | /* | |
245 | * cache_push() semantics: Write back any dirty cache data in the given area, | |
246 | * and invalidate the range in the instruction cache. It needs not (but may) | |
247 | * invalidate those entries also in the data cache. The range is defined by a | |
248 | * _physical_ address. | |
249 | */ | |
250 | ||
251 | void cache_push (unsigned long paddr, int len) | |
252 | { | |
253 | if (CPU_IS_040_OR_060) { | |
254 | int tmp = PAGE_SIZE; | |
255 | ||
256 | /* | |
257 | * on 68040 or 68060, push cache lines for pages in the range; | |
258 | * on the '040 this also invalidates the pushed lines, but not on | |
259 | * the '060! | |
260 | */ | |
261 | len += paddr & (PAGE_SIZE - 1); | |
262 | ||
263 | /* | |
264 | * Work around bug I17 in the 68060 affecting some instruction | |
265 | * lines not being invalidated properly. | |
266 | */ | |
267 | paddr &= PAGE_MASK; | |
268 | ||
269 | do { | |
270 | push040(paddr); | |
271 | paddr += tmp; | |
272 | } while ((len -= tmp) > 0); | |
273 | } | |
274 | /* | |
275 | * 68030/68020 have no writeback cache. On the other hand, | |
276 | * cache_push is actually a superset of cache_clear (the lines | |
277 | * get written back and invalidated), so we should make sure | |
278 | * to perform the corresponding actions. After all, this is getting | |
279 | * called in places where we've just loaded code, or whatever, so | |
280 | * flushing the icache is appropriate; flushing the dcache shouldn't | |
281 | * be required. | |
282 | */ | |
283 | else /* 68030 or 68020 */ | |
284 | asm volatile ("movec %/cacr,%/d0\n\t" | |
285 | "oriw %0,%/d0\n\t" | |
286 | "movec %/d0,%/cacr" | |
287 | : : "i" (FLUSH_I) | |
288 | : "d0"); | |
289 | #ifdef CONFIG_M68K_L2_CACHE | |
290 | if(mach_l2_flush) | |
291 | mach_l2_flush(1); | |
292 | #endif | |
293 | } | |
bf8af91b | 294 | EXPORT_SYMBOL(cache_push); |
1da177e4 | 295 |