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14cf11af PM |
1 | /* |
2 | * This file contains the routines for handling the MMU on those | |
3 | * PowerPC implementations where the MMU substantially follows the | |
4 | * architecture specification. This includes the 6xx, 7xx, 7xxx, | |
5 | * 8260, and POWER3 implementations but excludes the 8xx and 4xx. | |
6 | * -- paulus | |
7 | * | |
8 | * Derived from arch/ppc/mm/init.c: | |
9 | * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) | |
10 | * | |
11 | * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) | |
12 | * and Cort Dougan (PReP) (cort@cs.nmt.edu) | |
13 | * Copyright (C) 1996 Paul Mackerras | |
14 | * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk). | |
15 | * | |
16 | * Derived from "arch/i386/mm/init.c" | |
17 | * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds | |
18 | * | |
19 | * This program is free software; you can redistribute it and/or | |
20 | * modify it under the terms of the GNU General Public License | |
21 | * as published by the Free Software Foundation; either version | |
22 | * 2 of the License, or (at your option) any later version. | |
23 | * | |
24 | */ | |
25 | ||
14cf11af PM |
26 | #include <linux/kernel.h> |
27 | #include <linux/mm.h> | |
28 | #include <linux/init.h> | |
29 | #include <linux/highmem.h> | |
30 | ||
31 | #include <asm/prom.h> | |
32 | #include <asm/mmu.h> | |
33 | #include <asm/machdep.h> | |
7c8c6b97 | 34 | #include <asm/lmb.h> |
14cf11af PM |
35 | |
36 | #include "mmu_decl.h" | |
14cf11af PM |
37 | |
38 | PTE *Hash, *Hash_end; | |
39 | unsigned long Hash_size, Hash_mask; | |
40 | unsigned long _SDR1; | |
41 | ||
42 | union ubat { /* BAT register values to be loaded */ | |
43 | BAT bat; | |
14cf11af | 44 | u32 word[2]; |
ee0339f2 | 45 | } BATS[8][2]; /* 8 pairs of IBAT, DBAT */ |
14cf11af PM |
46 | |
47 | struct batrange { /* stores address ranges mapped by BATs */ | |
48 | unsigned long start; | |
49 | unsigned long limit; | |
50 | unsigned long phys; | |
ee0339f2 | 51 | } bat_addrs[8]; |
14cf11af PM |
52 | |
53 | /* | |
54 | * Return PA for this VA if it is mapped by a BAT, or 0 | |
55 | */ | |
56 | unsigned long v_mapped_by_bats(unsigned long va) | |
57 | { | |
58 | int b; | |
59 | for (b = 0; b < 4; ++b) | |
60 | if (va >= bat_addrs[b].start && va < bat_addrs[b].limit) | |
61 | return bat_addrs[b].phys + (va - bat_addrs[b].start); | |
62 | return 0; | |
63 | } | |
64 | ||
65 | /* | |
66 | * Return VA for a given PA or 0 if not mapped | |
67 | */ | |
68 | unsigned long p_mapped_by_bats(unsigned long pa) | |
69 | { | |
70 | int b; | |
71 | for (b = 0; b < 4; ++b) | |
72 | if (pa >= bat_addrs[b].phys | |
73 | && pa < (bat_addrs[b].limit-bat_addrs[b].start) | |
74 | +bat_addrs[b].phys) | |
75 | return bat_addrs[b].start+(pa-bat_addrs[b].phys); | |
76 | return 0; | |
77 | } | |
78 | ||
79 | unsigned long __init mmu_mapin_ram(void) | |
80 | { | |
81 | #ifdef CONFIG_POWER4 | |
82 | return 0; | |
83 | #else | |
84 | unsigned long tot, bl, done; | |
85 | unsigned long max_size = (256<<20); | |
86 | unsigned long align; | |
87 | ||
88 | if (__map_without_bats) | |
89 | return 0; | |
90 | ||
91 | /* Set up BAT2 and if necessary BAT3 to cover RAM. */ | |
92 | ||
93 | /* Make sure we don't map a block larger than the | |
94 | smallest alignment of the physical address. */ | |
95 | /* alignment of PPC_MEMSTART */ | |
96 | align = ~(PPC_MEMSTART-1) & PPC_MEMSTART; | |
97 | /* set BAT block size to MIN(max_size, align) */ | |
98 | if (align && align < max_size) | |
99 | max_size = align; | |
100 | ||
101 | tot = total_lowmem; | |
102 | for (bl = 128<<10; bl < max_size; bl <<= 1) { | |
103 | if (bl * 2 > tot) | |
104 | break; | |
105 | } | |
106 | ||
107 | setbat(2, KERNELBASE, PPC_MEMSTART, bl, _PAGE_RAM); | |
108 | done = (unsigned long)bat_addrs[2].limit - KERNELBASE + 1; | |
109 | if ((done < tot) && !bat_addrs[3].limit) { | |
110 | /* use BAT3 to cover a bit more */ | |
111 | tot -= done; | |
112 | for (bl = 128<<10; bl < max_size; bl <<= 1) | |
113 | if (bl * 2 > tot) | |
114 | break; | |
115 | setbat(3, KERNELBASE+done, PPC_MEMSTART+done, bl, _PAGE_RAM); | |
116 | done = (unsigned long)bat_addrs[3].limit - KERNELBASE + 1; | |
117 | } | |
118 | ||
119 | return done; | |
120 | #endif | |
121 | } | |
122 | ||
123 | /* | |
124 | * Set up one of the I/D BAT (block address translation) register pairs. | |
125 | * The parameters are not checked; in particular size must be a power | |
126 | * of 2 between 128k and 256M. | |
127 | */ | |
128 | void __init setbat(int index, unsigned long virt, unsigned long phys, | |
129 | unsigned int size, int flags) | |
130 | { | |
131 | unsigned int bl; | |
132 | int wimgxpp; | |
133 | union ubat *bat = BATS[index]; | |
134 | ||
135 | if (((flags & _PAGE_NO_CACHE) == 0) && | |
136 | cpu_has_feature(CPU_FTR_NEED_COHERENT)) | |
137 | flags |= _PAGE_COHERENT; | |
138 | ||
139 | bl = (size >> 17) - 1; | |
140 | if (PVR_VER(mfspr(SPRN_PVR)) != 1) { | |
141 | /* 603, 604, etc. */ | |
142 | /* Do DBAT first */ | |
143 | wimgxpp = flags & (_PAGE_WRITETHRU | _PAGE_NO_CACHE | |
144 | | _PAGE_COHERENT | _PAGE_GUARDED); | |
145 | wimgxpp |= (flags & _PAGE_RW)? BPP_RW: BPP_RX; | |
146 | bat[1].word[0] = virt | (bl << 2) | 2; /* Vs=1, Vp=0 */ | |
147 | bat[1].word[1] = phys | wimgxpp; | |
148 | #ifndef CONFIG_KGDB /* want user access for breakpoints */ | |
149 | if (flags & _PAGE_USER) | |
150 | #endif | |
151 | bat[1].bat.batu.vp = 1; | |
152 | if (flags & _PAGE_GUARDED) { | |
153 | /* G bit must be zero in IBATs */ | |
154 | bat[0].word[0] = bat[0].word[1] = 0; | |
155 | } else { | |
156 | /* make IBAT same as DBAT */ | |
157 | bat[0] = bat[1]; | |
158 | } | |
159 | } else { | |
160 | /* 601 cpu */ | |
161 | if (bl > BL_8M) | |
162 | bl = BL_8M; | |
163 | wimgxpp = flags & (_PAGE_WRITETHRU | _PAGE_NO_CACHE | |
164 | | _PAGE_COHERENT); | |
165 | wimgxpp |= (flags & _PAGE_RW)? | |
166 | ((flags & _PAGE_USER)? PP_RWRW: PP_RWXX): PP_RXRX; | |
167 | bat->word[0] = virt | wimgxpp | 4; /* Ks=0, Ku=1 */ | |
168 | bat->word[1] = phys | bl | 0x40; /* V=1 */ | |
169 | } | |
170 | ||
171 | bat_addrs[index].start = virt; | |
172 | bat_addrs[index].limit = virt + ((bl + 1) << 17) - 1; | |
173 | bat_addrs[index].phys = phys; | |
174 | } | |
175 | ||
3c726f8d BH |
176 | /* |
177 | * Preload a translation in the hash table | |
178 | */ | |
179 | void hash_preload(struct mm_struct *mm, unsigned long ea, | |
180 | unsigned long access, unsigned long trap) | |
181 | { | |
182 | pmd_t *pmd; | |
183 | ||
184 | if (Hash == 0) | |
185 | return; | |
863c84b9 | 186 | pmd = pmd_offset(pgd_offset(mm, ea), ea); |
3c726f8d | 187 | if (!pmd_none(*pmd)) |
6218a761 | 188 | add_hash_page(mm->context.id, ea, pmd_val(*pmd)); |
3c726f8d BH |
189 | } |
190 | ||
14cf11af PM |
191 | /* |
192 | * Initialize the hash table and patch the instructions in hashtable.S. | |
193 | */ | |
194 | void __init MMU_init_hw(void) | |
195 | { | |
196 | unsigned int hmask, mb, mb2; | |
197 | unsigned int n_hpteg, lg_n_hpteg; | |
198 | ||
199 | extern unsigned int hash_page_patch_A[]; | |
200 | extern unsigned int hash_page_patch_B[], hash_page_patch_C[]; | |
201 | extern unsigned int hash_page[]; | |
202 | extern unsigned int flush_hash_patch_A[], flush_hash_patch_B[]; | |
203 | ||
204 | if (!cpu_has_feature(CPU_FTR_HPTE_TABLE)) { | |
205 | /* | |
206 | * Put a blr (procedure return) instruction at the | |
207 | * start of hash_page, since we can still get DSI | |
208 | * exceptions on a 603. | |
209 | */ | |
210 | hash_page[0] = 0x4e800020; | |
211 | flush_icache_range((unsigned long) &hash_page[0], | |
212 | (unsigned long) &hash_page[1]); | |
213 | return; | |
214 | } | |
215 | ||
216 | if ( ppc_md.progress ) ppc_md.progress("hash:enter", 0x105); | |
217 | ||
14cf11af PM |
218 | #define LG_HPTEG_SIZE 6 /* 64 bytes per HPTEG */ |
219 | #define SDR1_LOW_BITS ((n_hpteg - 1) >> 10) | |
220 | #define MIN_N_HPTEG 1024 /* min 64kB hash table */ | |
14cf11af | 221 | |
14cf11af PM |
222 | /* |
223 | * Allow 1 HPTE (1/8 HPTEG) for each page of memory. | |
224 | * This is less than the recommended amount, but then | |
225 | * Linux ain't AIX. | |
226 | */ | |
227 | n_hpteg = total_memory / (PAGE_SIZE * 8); | |
228 | if (n_hpteg < MIN_N_HPTEG) | |
229 | n_hpteg = MIN_N_HPTEG; | |
230 | lg_n_hpteg = __ilog2(n_hpteg); | |
231 | if (n_hpteg & (n_hpteg - 1)) { | |
232 | ++lg_n_hpteg; /* round up if not power of 2 */ | |
233 | n_hpteg = 1 << lg_n_hpteg; | |
234 | } | |
235 | Hash_size = n_hpteg << LG_HPTEG_SIZE; | |
236 | ||
237 | /* | |
238 | * Find some memory for the hash table. | |
239 | */ | |
240 | if ( ppc_md.progress ) ppc_md.progress("hash:find piece", 0x322); | |
7c8c6b97 PM |
241 | Hash = __va(lmb_alloc_base(Hash_size, Hash_size, |
242 | __initial_memory_limit)); | |
14cf11af PM |
243 | cacheable_memzero(Hash, Hash_size); |
244 | _SDR1 = __pa(Hash) | SDR1_LOW_BITS; | |
14cf11af PM |
245 | |
246 | Hash_end = (PTE *) ((unsigned long)Hash + Hash_size); | |
247 | ||
248 | printk("Total memory = %ldMB; using %ldkB for hash table (at %p)\n", | |
249 | total_memory >> 20, Hash_size >> 10, Hash); | |
250 | ||
251 | ||
252 | /* | |
253 | * Patch up the instructions in hashtable.S:create_hpte | |
254 | */ | |
255 | if ( ppc_md.progress ) ppc_md.progress("hash:patch", 0x345); | |
256 | Hash_mask = n_hpteg - 1; | |
257 | hmask = Hash_mask >> (16 - LG_HPTEG_SIZE); | |
258 | mb2 = mb = 32 - LG_HPTEG_SIZE - lg_n_hpteg; | |
259 | if (lg_n_hpteg > 16) | |
260 | mb2 = 16 - LG_HPTEG_SIZE; | |
261 | ||
262 | hash_page_patch_A[0] = (hash_page_patch_A[0] & ~0xffff) | |
263 | | ((unsigned int)(Hash) >> 16); | |
264 | hash_page_patch_A[1] = (hash_page_patch_A[1] & ~0x7c0) | (mb << 6); | |
265 | hash_page_patch_A[2] = (hash_page_patch_A[2] & ~0x7c0) | (mb2 << 6); | |
266 | hash_page_patch_B[0] = (hash_page_patch_B[0] & ~0xffff) | hmask; | |
267 | hash_page_patch_C[0] = (hash_page_patch_C[0] & ~0xffff) | hmask; | |
268 | ||
269 | /* | |
270 | * Ensure that the locations we've patched have been written | |
271 | * out from the data cache and invalidated in the instruction | |
272 | * cache, on those machines with split caches. | |
273 | */ | |
274 | flush_icache_range((unsigned long) &hash_page_patch_A[0], | |
275 | (unsigned long) &hash_page_patch_C[1]); | |
276 | ||
277 | /* | |
278 | * Patch up the instructions in hashtable.S:flush_hash_page | |
279 | */ | |
280 | flush_hash_patch_A[0] = (flush_hash_patch_A[0] & ~0xffff) | |
281 | | ((unsigned int)(Hash) >> 16); | |
282 | flush_hash_patch_A[1] = (flush_hash_patch_A[1] & ~0x7c0) | (mb << 6); | |
283 | flush_hash_patch_A[2] = (flush_hash_patch_A[2] & ~0x7c0) | (mb2 << 6); | |
284 | flush_hash_patch_B[0] = (flush_hash_patch_B[0] & ~0xffff) | hmask; | |
285 | flush_icache_range((unsigned long) &flush_hash_patch_A[0], | |
286 | (unsigned long) &flush_hash_patch_B[1]); | |
287 | ||
288 | if ( ppc_md.progress ) ppc_md.progress("hash:done", 0x205); | |
289 | } |