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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 | |
14cf11af PM |
14 | * |
15 | * Derived from "arch/i386/mm/init.c" | |
16 | * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds | |
17 | * | |
18 | * This program is free software; you can redistribute it and/or | |
19 | * modify it under the terms of the GNU General Public License | |
20 | * as published by the Free Software Foundation; either version | |
21 | * 2 of the License, or (at your option) any later version. | |
22 | * | |
23 | */ | |
24 | ||
14cf11af PM |
25 | #include <linux/kernel.h> |
26 | #include <linux/mm.h> | |
27 | #include <linux/init.h> | |
28 | #include <linux/highmem.h> | |
95f72d1e | 29 | #include <linux/memblock.h> |
14cf11af PM |
30 | |
31 | #include <asm/prom.h> | |
32 | #include <asm/mmu.h> | |
33 | #include <asm/machdep.h> | |
34 | ||
35 | #include "mmu_decl.h" | |
14cf11af | 36 | |
8e561e7e | 37 | struct hash_pte *Hash, *Hash_end; |
14cf11af PM |
38 | unsigned long Hash_size, Hash_mask; |
39 | unsigned long _SDR1; | |
40 | ||
316a4058 | 41 | struct ppc_bat BATS[8][2]; /* 8 pairs of IBAT, DBAT */ |
14cf11af PM |
42 | |
43 | struct batrange { /* stores address ranges mapped by BATs */ | |
44 | unsigned long start; | |
45 | unsigned long limit; | |
7c5c4325 | 46 | phys_addr_t phys; |
ee0339f2 | 47 | } bat_addrs[8]; |
14cf11af PM |
48 | |
49 | /* | |
50 | * Return PA for this VA if it is mapped by a BAT, or 0 | |
51 | */ | |
7c5c4325 | 52 | phys_addr_t v_mapped_by_bats(unsigned long va) |
14cf11af PM |
53 | { |
54 | int b; | |
55 | for (b = 0; b < 4; ++b) | |
56 | if (va >= bat_addrs[b].start && va < bat_addrs[b].limit) | |
57 | return bat_addrs[b].phys + (va - bat_addrs[b].start); | |
58 | return 0; | |
59 | } | |
60 | ||
61 | /* | |
62 | * Return VA for a given PA or 0 if not mapped | |
63 | */ | |
7c5c4325 | 64 | unsigned long p_mapped_by_bats(phys_addr_t pa) |
14cf11af PM |
65 | { |
66 | int b; | |
67 | for (b = 0; b < 4; ++b) | |
68 | if (pa >= bat_addrs[b].phys | |
69 | && pa < (bat_addrs[b].limit-bat_addrs[b].start) | |
70 | +bat_addrs[b].phys) | |
71 | return bat_addrs[b].start+(pa-bat_addrs[b].phys); | |
72 | return 0; | |
73 | } | |
74 | ||
de32400d | 75 | unsigned long __init mmu_mapin_ram(unsigned long top) |
14cf11af | 76 | { |
14cf11af PM |
77 | unsigned long tot, bl, done; |
78 | unsigned long max_size = (256<<20); | |
14cf11af | 79 | |
88df6e90 BH |
80 | if (__map_without_bats) { |
81 | printk(KERN_DEBUG "RAM mapped without BATs\n"); | |
14cf11af | 82 | return 0; |
88df6e90 | 83 | } |
14cf11af PM |
84 | |
85 | /* Set up BAT2 and if necessary BAT3 to cover RAM. */ | |
86 | ||
87 | /* Make sure we don't map a block larger than the | |
88 | smallest alignment of the physical address. */ | |
de32400d | 89 | tot = top; |
14cf11af PM |
90 | for (bl = 128<<10; bl < max_size; bl <<= 1) { |
91 | if (bl * 2 > tot) | |
92 | break; | |
93 | } | |
94 | ||
8d1cf34e | 95 | setbat(2, PAGE_OFFSET, 0, bl, PAGE_KERNEL_X); |
ccdcef72 | 96 | done = (unsigned long)bat_addrs[2].limit - PAGE_OFFSET + 1; |
14cf11af PM |
97 | if ((done < tot) && !bat_addrs[3].limit) { |
98 | /* use BAT3 to cover a bit more */ | |
99 | tot -= done; | |
100 | for (bl = 128<<10; bl < max_size; bl <<= 1) | |
101 | if (bl * 2 > tot) | |
102 | break; | |
8d1cf34e | 103 | setbat(3, PAGE_OFFSET+done, done, bl, PAGE_KERNEL_X); |
ccdcef72 | 104 | done = (unsigned long)bat_addrs[3].limit - PAGE_OFFSET + 1; |
14cf11af PM |
105 | } |
106 | ||
107 | return done; | |
14cf11af PM |
108 | } |
109 | ||
110 | /* | |
111 | * Set up one of the I/D BAT (block address translation) register pairs. | |
112 | * The parameters are not checked; in particular size must be a power | |
113 | * of 2 between 128k and 256M. | |
114 | */ | |
7c5c4325 | 115 | void __init setbat(int index, unsigned long virt, phys_addr_t phys, |
14cf11af PM |
116 | unsigned int size, int flags) |
117 | { | |
118 | unsigned int bl; | |
119 | int wimgxpp; | |
316a4058 | 120 | struct ppc_bat *bat = BATS[index]; |
14cf11af | 121 | |
4c456a67 GP |
122 | if ((flags & _PAGE_NO_CACHE) || |
123 | (cpu_has_feature(CPU_FTR_NEED_COHERENT) == 0)) | |
124 | flags &= ~_PAGE_COHERENT; | |
14cf11af PM |
125 | |
126 | bl = (size >> 17) - 1; | |
127 | if (PVR_VER(mfspr(SPRN_PVR)) != 1) { | |
128 | /* 603, 604, etc. */ | |
129 | /* Do DBAT first */ | |
130 | wimgxpp = flags & (_PAGE_WRITETHRU | _PAGE_NO_CACHE | |
131 | | _PAGE_COHERENT | _PAGE_GUARDED); | |
132 | wimgxpp |= (flags & _PAGE_RW)? BPP_RW: BPP_RX; | |
316a4058 BB |
133 | bat[1].batu = virt | (bl << 2) | 2; /* Vs=1, Vp=0 */ |
134 | bat[1].batl = BAT_PHYS_ADDR(phys) | wimgxpp; | |
14cf11af | 135 | if (flags & _PAGE_USER) |
316a4058 | 136 | bat[1].batu |= 1; /* Vp = 1 */ |
14cf11af PM |
137 | if (flags & _PAGE_GUARDED) { |
138 | /* G bit must be zero in IBATs */ | |
316a4058 | 139 | bat[0].batu = bat[0].batl = 0; |
14cf11af PM |
140 | } else { |
141 | /* make IBAT same as DBAT */ | |
142 | bat[0] = bat[1]; | |
143 | } | |
144 | } else { | |
145 | /* 601 cpu */ | |
146 | if (bl > BL_8M) | |
147 | bl = BL_8M; | |
148 | wimgxpp = flags & (_PAGE_WRITETHRU | _PAGE_NO_CACHE | |
149 | | _PAGE_COHERENT); | |
150 | wimgxpp |= (flags & _PAGE_RW)? | |
151 | ((flags & _PAGE_USER)? PP_RWRW: PP_RWXX): PP_RXRX; | |
316a4058 BB |
152 | bat->batu = virt | wimgxpp | 4; /* Ks=0, Ku=1 */ |
153 | bat->batl = phys | bl | 0x40; /* V=1 */ | |
14cf11af PM |
154 | } |
155 | ||
156 | bat_addrs[index].start = virt; | |
157 | bat_addrs[index].limit = virt + ((bl + 1) << 17) - 1; | |
158 | bat_addrs[index].phys = phys; | |
159 | } | |
160 | ||
3c726f8d BH |
161 | /* |
162 | * Preload a translation in the hash table | |
163 | */ | |
164 | void hash_preload(struct mm_struct *mm, unsigned long ea, | |
165 | unsigned long access, unsigned long trap) | |
166 | { | |
167 | pmd_t *pmd; | |
168 | ||
169 | if (Hash == 0) | |
170 | return; | |
f1a1eb29 | 171 | pmd = pmd_offset(pud_offset(pgd_offset(mm, ea), ea), ea); |
3c726f8d | 172 | if (!pmd_none(*pmd)) |
6218a761 | 173 | add_hash_page(mm->context.id, ea, pmd_val(*pmd)); |
3c726f8d BH |
174 | } |
175 | ||
14cf11af PM |
176 | /* |
177 | * Initialize the hash table and patch the instructions in hashtable.S. | |
178 | */ | |
179 | void __init MMU_init_hw(void) | |
180 | { | |
181 | unsigned int hmask, mb, mb2; | |
182 | unsigned int n_hpteg, lg_n_hpteg; | |
183 | ||
184 | extern unsigned int hash_page_patch_A[]; | |
185 | extern unsigned int hash_page_patch_B[], hash_page_patch_C[]; | |
186 | extern unsigned int hash_page[]; | |
187 | extern unsigned int flush_hash_patch_A[], flush_hash_patch_B[]; | |
188 | ||
7c03d653 | 189 | if (!mmu_has_feature(MMU_FTR_HPTE_TABLE)) { |
14cf11af PM |
190 | /* |
191 | * Put a blr (procedure return) instruction at the | |
192 | * start of hash_page, since we can still get DSI | |
193 | * exceptions on a 603. | |
194 | */ | |
195 | hash_page[0] = 0x4e800020; | |
196 | flush_icache_range((unsigned long) &hash_page[0], | |
197 | (unsigned long) &hash_page[1]); | |
198 | return; | |
199 | } | |
200 | ||
201 | if ( ppc_md.progress ) ppc_md.progress("hash:enter", 0x105); | |
202 | ||
14cf11af PM |
203 | #define LG_HPTEG_SIZE 6 /* 64 bytes per HPTEG */ |
204 | #define SDR1_LOW_BITS ((n_hpteg - 1) >> 10) | |
205 | #define MIN_N_HPTEG 1024 /* min 64kB hash table */ | |
14cf11af | 206 | |
14cf11af PM |
207 | /* |
208 | * Allow 1 HPTE (1/8 HPTEG) for each page of memory. | |
209 | * This is less than the recommended amount, but then | |
210 | * Linux ain't AIX. | |
211 | */ | |
212 | n_hpteg = total_memory / (PAGE_SIZE * 8); | |
213 | if (n_hpteg < MIN_N_HPTEG) | |
214 | n_hpteg = MIN_N_HPTEG; | |
215 | lg_n_hpteg = __ilog2(n_hpteg); | |
216 | if (n_hpteg & (n_hpteg - 1)) { | |
217 | ++lg_n_hpteg; /* round up if not power of 2 */ | |
218 | n_hpteg = 1 << lg_n_hpteg; | |
219 | } | |
220 | Hash_size = n_hpteg << LG_HPTEG_SIZE; | |
221 | ||
222 | /* | |
223 | * Find some memory for the hash table. | |
224 | */ | |
225 | if ( ppc_md.progress ) ppc_md.progress("hash:find piece", 0x322); | |
e63075a3 | 226 | Hash = __va(memblock_alloc(Hash_size, Hash_size)); |
14cf11af PM |
227 | cacheable_memzero(Hash, Hash_size); |
228 | _SDR1 = __pa(Hash) | SDR1_LOW_BITS; | |
14cf11af | 229 | |
8e561e7e | 230 | Hash_end = (struct hash_pte *) ((unsigned long)Hash + Hash_size); |
14cf11af | 231 | |
c7c8eede TB |
232 | printk("Total memory = %lldMB; using %ldkB for hash table (at %p)\n", |
233 | (unsigned long long)(total_memory >> 20), Hash_size >> 10, Hash); | |
14cf11af PM |
234 | |
235 | ||
236 | /* | |
237 | * Patch up the instructions in hashtable.S:create_hpte | |
238 | */ | |
239 | if ( ppc_md.progress ) ppc_md.progress("hash:patch", 0x345); | |
240 | Hash_mask = n_hpteg - 1; | |
241 | hmask = Hash_mask >> (16 - LG_HPTEG_SIZE); | |
242 | mb2 = mb = 32 - LG_HPTEG_SIZE - lg_n_hpteg; | |
243 | if (lg_n_hpteg > 16) | |
244 | mb2 = 16 - LG_HPTEG_SIZE; | |
245 | ||
246 | hash_page_patch_A[0] = (hash_page_patch_A[0] & ~0xffff) | |
247 | | ((unsigned int)(Hash) >> 16); | |
248 | hash_page_patch_A[1] = (hash_page_patch_A[1] & ~0x7c0) | (mb << 6); | |
249 | hash_page_patch_A[2] = (hash_page_patch_A[2] & ~0x7c0) | (mb2 << 6); | |
250 | hash_page_patch_B[0] = (hash_page_patch_B[0] & ~0xffff) | hmask; | |
251 | hash_page_patch_C[0] = (hash_page_patch_C[0] & ~0xffff) | hmask; | |
252 | ||
253 | /* | |
254 | * Ensure that the locations we've patched have been written | |
255 | * out from the data cache and invalidated in the instruction | |
256 | * cache, on those machines with split caches. | |
257 | */ | |
258 | flush_icache_range((unsigned long) &hash_page_patch_A[0], | |
259 | (unsigned long) &hash_page_patch_C[1]); | |
260 | ||
261 | /* | |
262 | * Patch up the instructions in hashtable.S:flush_hash_page | |
263 | */ | |
264 | flush_hash_patch_A[0] = (flush_hash_patch_A[0] & ~0xffff) | |
265 | | ((unsigned int)(Hash) >> 16); | |
266 | flush_hash_patch_A[1] = (flush_hash_patch_A[1] & ~0x7c0) | (mb << 6); | |
267 | flush_hash_patch_A[2] = (flush_hash_patch_A[2] & ~0x7c0) | (mb2 << 6); | |
268 | flush_hash_patch_B[0] = (flush_hash_patch_B[0] & ~0xffff) | hmask; | |
269 | flush_icache_range((unsigned long) &flush_hash_patch_A[0], | |
270 | (unsigned long) &flush_hash_patch_B[1]); | |
271 | ||
272 | if ( ppc_md.progress ) ppc_md.progress("hash:done", 0x205); | |
273 | } |