Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * PowerPC64 Segment Translation Support. | |
3 | * | |
4 | * Dave Engebretsen and Mike Corrigan {engebret|mikejc}@us.ibm.com | |
5 | * Copyright (c) 2001 Dave Engebretsen | |
6 | * | |
7 | * Copyright (C) 2002 Anton Blanchard <anton@au.ibm.com>, IBM | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License | |
11 | * as published by the Free Software Foundation; either version | |
12 | * 2 of the License, or (at your option) any later version. | |
13 | */ | |
14 | ||
d9b2b2a2 DM |
15 | #include <linux/lmb.h> |
16 | ||
1da177e4 LT |
17 | #include <asm/pgtable.h> |
18 | #include <asm/mmu.h> | |
19 | #include <asm/mmu_context.h> | |
20 | #include <asm/paca.h> | |
21 | #include <asm/cputable.h> | |
d9b2b2a2 | 22 | #include <asm/prom.h> |
533f0817 | 23 | #include <asm/abs_addr.h> |
799d6046 | 24 | #include <asm/firmware.h> |
f9b6c1de | 25 | #include <asm/iseries/hv_call.h> |
1da177e4 | 26 | |
1f8d419e DG |
27 | struct stab_entry { |
28 | unsigned long esid_data; | |
29 | unsigned long vsid_data; | |
30 | }; | |
31 | ||
1da177e4 | 32 | #define NR_STAB_CACHE_ENTRIES 8 |
09de9ff8 ME |
33 | static DEFINE_PER_CPU(long, stab_cache_ptr); |
34 | static DEFINE_PER_CPU(long, stab_cache[NR_STAB_CACHE_ENTRIES]); | |
1da177e4 LT |
35 | |
36 | /* | |
37 | * Create a segment table entry for the given esid/vsid pair. | |
38 | */ | |
39 | static int make_ste(unsigned long stab, unsigned long esid, unsigned long vsid) | |
40 | { | |
41 | unsigned long esid_data, vsid_data; | |
42 | unsigned long entry, group, old_esid, castout_entry, i; | |
43 | unsigned int global_entry; | |
44 | struct stab_entry *ste, *castout_ste; | |
b5666f70 | 45 | unsigned long kernel_segment = (esid << SID_SHIFT) >= PAGE_OFFSET; |
1da177e4 LT |
46 | |
47 | vsid_data = vsid << STE_VSID_SHIFT; | |
48 | esid_data = esid << SID_SHIFT | STE_ESID_KP | STE_ESID_V; | |
49 | if (! kernel_segment) | |
50 | esid_data |= STE_ESID_KS; | |
51 | ||
52 | /* Search the primary group first. */ | |
53 | global_entry = (esid & 0x1f) << 3; | |
54 | ste = (struct stab_entry *)(stab | ((esid & 0x1f) << 7)); | |
55 | ||
56 | /* Find an empty entry, if one exists. */ | |
57 | for (group = 0; group < 2; group++) { | |
58 | for (entry = 0; entry < 8; entry++, ste++) { | |
59 | if (!(ste->esid_data & STE_ESID_V)) { | |
60 | ste->vsid_data = vsid_data; | |
74a0ba61 | 61 | eieio(); |
1da177e4 LT |
62 | ste->esid_data = esid_data; |
63 | return (global_entry | entry); | |
64 | } | |
65 | } | |
66 | /* Now search the secondary group. */ | |
67 | global_entry = ((~esid) & 0x1f) << 3; | |
68 | ste = (struct stab_entry *)(stab | (((~esid) & 0x1f) << 7)); | |
69 | } | |
70 | ||
71 | /* | |
72 | * Could not find empty entry, pick one with a round robin selection. | |
73 | * Search all entries in the two groups. | |
74 | */ | |
75 | castout_entry = get_paca()->stab_rr; | |
76 | for (i = 0; i < 16; i++) { | |
77 | if (castout_entry < 8) { | |
78 | global_entry = (esid & 0x1f) << 3; | |
79 | ste = (struct stab_entry *)(stab | ((esid & 0x1f) << 7)); | |
80 | castout_ste = ste + castout_entry; | |
81 | } else { | |
82 | global_entry = ((~esid) & 0x1f) << 3; | |
83 | ste = (struct stab_entry *)(stab | (((~esid) & 0x1f) << 7)); | |
84 | castout_ste = ste + (castout_entry - 8); | |
85 | } | |
86 | ||
87 | /* Dont cast out the first kernel segment */ | |
b5666f70 | 88 | if ((castout_ste->esid_data & ESID_MASK) != PAGE_OFFSET) |
1da177e4 LT |
89 | break; |
90 | ||
91 | castout_entry = (castout_entry + 1) & 0xf; | |
92 | } | |
93 | ||
94 | get_paca()->stab_rr = (castout_entry + 1) & 0xf; | |
95 | ||
96 | /* Modify the old entry to the new value. */ | |
97 | ||
98 | /* Force previous translations to complete. DRENG */ | |
99 | asm volatile("isync" : : : "memory"); | |
100 | ||
101 | old_esid = castout_ste->esid_data >> SID_SHIFT; | |
102 | castout_ste->esid_data = 0; /* Invalidate old entry */ | |
103 | ||
104 | asm volatile("sync" : : : "memory"); /* Order update */ | |
105 | ||
106 | castout_ste->vsid_data = vsid_data; | |
74a0ba61 | 107 | eieio(); /* Order update */ |
1da177e4 LT |
108 | castout_ste->esid_data = esid_data; |
109 | ||
110 | asm volatile("slbie %0" : : "r" (old_esid << SID_SHIFT)); | |
111 | /* Ensure completion of slbie */ | |
112 | asm volatile("sync" : : : "memory"); | |
113 | ||
114 | return (global_entry | (castout_entry & 0x7)); | |
115 | } | |
116 | ||
117 | /* | |
118 | * Allocate a segment table entry for the given ea and mm | |
119 | */ | |
120 | static int __ste_allocate(unsigned long ea, struct mm_struct *mm) | |
121 | { | |
122 | unsigned long vsid; | |
123 | unsigned char stab_entry; | |
124 | unsigned long offset; | |
125 | ||
126 | /* Kernel or user address? */ | |
51fae6de | 127 | if (is_kernel_addr(ea)) { |
1189be65 | 128 | vsid = get_kernel_vsid(ea, MMU_SEGSIZE_256M); |
1da177e4 LT |
129 | } else { |
130 | if ((ea >= TASK_SIZE_USER64) || (! mm)) | |
131 | return 1; | |
132 | ||
1189be65 | 133 | vsid = get_vsid(mm->context.id, ea, MMU_SEGSIZE_256M); |
1da177e4 LT |
134 | } |
135 | ||
136 | stab_entry = make_ste(get_paca()->stab_addr, GET_ESID(ea), vsid); | |
137 | ||
51fae6de | 138 | if (!is_kernel_addr(ea)) { |
1da177e4 LT |
139 | offset = __get_cpu_var(stab_cache_ptr); |
140 | if (offset < NR_STAB_CACHE_ENTRIES) | |
141 | __get_cpu_var(stab_cache[offset++]) = stab_entry; | |
142 | else | |
143 | offset = NR_STAB_CACHE_ENTRIES+1; | |
144 | __get_cpu_var(stab_cache_ptr) = offset; | |
145 | ||
146 | /* Order update */ | |
147 | asm volatile("sync":::"memory"); | |
148 | } | |
149 | ||
150 | return 0; | |
151 | } | |
152 | ||
153 | int ste_allocate(unsigned long ea) | |
154 | { | |
155 | return __ste_allocate(ea, current->mm); | |
156 | } | |
157 | ||
158 | /* | |
159 | * Do the segment table work for a context switch: flush all user | |
160 | * entries from the table, then preload some probably useful entries | |
161 | * for the new task | |
162 | */ | |
163 | void switch_stab(struct task_struct *tsk, struct mm_struct *mm) | |
164 | { | |
165 | struct stab_entry *stab = (struct stab_entry *) get_paca()->stab_addr; | |
166 | struct stab_entry *ste; | |
167 | unsigned long offset = __get_cpu_var(stab_cache_ptr); | |
168 | unsigned long pc = KSTK_EIP(tsk); | |
169 | unsigned long stack = KSTK_ESP(tsk); | |
170 | unsigned long unmapped_base; | |
171 | ||
172 | /* Force previous translations to complete. DRENG */ | |
173 | asm volatile("isync" : : : "memory"); | |
174 | ||
175 | if (offset <= NR_STAB_CACHE_ENTRIES) { | |
176 | int i; | |
177 | ||
178 | for (i = 0; i < offset; i++) { | |
179 | ste = stab + __get_cpu_var(stab_cache[i]); | |
180 | ste->esid_data = 0; /* invalidate entry */ | |
181 | } | |
182 | } else { | |
183 | unsigned long entry; | |
184 | ||
185 | /* Invalidate all entries. */ | |
186 | ste = stab; | |
187 | ||
188 | /* Never flush the first entry. */ | |
189 | ste += 1; | |
190 | for (entry = 1; | |
3c726f8d | 191 | entry < (HW_PAGE_SIZE / sizeof(struct stab_entry)); |
1da177e4 LT |
192 | entry++, ste++) { |
193 | unsigned long ea; | |
194 | ea = ste->esid_data & ESID_MASK; | |
51fae6de | 195 | if (!is_kernel_addr(ea)) { |
1da177e4 LT |
196 | ste->esid_data = 0; |
197 | } | |
198 | } | |
199 | } | |
200 | ||
201 | asm volatile("sync; slbia; sync":::"memory"); | |
202 | ||
203 | __get_cpu_var(stab_cache_ptr) = 0; | |
204 | ||
205 | /* Now preload some entries for the new task */ | |
206 | if (test_tsk_thread_flag(tsk, TIF_32BIT)) | |
207 | unmapped_base = TASK_UNMAPPED_BASE_USER32; | |
208 | else | |
209 | unmapped_base = TASK_UNMAPPED_BASE_USER64; | |
210 | ||
211 | __ste_allocate(pc, mm); | |
212 | ||
213 | if (GET_ESID(pc) == GET_ESID(stack)) | |
214 | return; | |
215 | ||
216 | __ste_allocate(stack, mm); | |
217 | ||
218 | if ((GET_ESID(pc) == GET_ESID(unmapped_base)) | |
219 | || (GET_ESID(stack) == GET_ESID(unmapped_base))) | |
220 | return; | |
221 | ||
222 | __ste_allocate(unmapped_base, mm); | |
223 | ||
224 | /* Order update */ | |
225 | asm volatile("sync" : : : "memory"); | |
226 | } | |
227 | ||
533f0817 DG |
228 | /* |
229 | * Allocate segment tables for secondary CPUs. These must all go in | |
230 | * the first (bolted) segment, so that do_stab_bolted won't get a | |
231 | * recursive segment miss on the segment table itself. | |
232 | */ | |
0108d3fe | 233 | void __init stabs_alloc(void) |
533f0817 DG |
234 | { |
235 | int cpu; | |
236 | ||
237 | if (cpu_has_feature(CPU_FTR_SLB)) | |
238 | return; | |
239 | ||
0e551954 | 240 | for_each_possible_cpu(cpu) { |
533f0817 DG |
241 | unsigned long newstab; |
242 | ||
243 | if (cpu == 0) | |
244 | continue; /* stab for CPU 0 is statically allocated */ | |
245 | ||
3c726f8d BH |
246 | newstab = lmb_alloc_base(HW_PAGE_SIZE, HW_PAGE_SIZE, |
247 | 1<<SID_SHIFT); | |
b5666f70 | 248 | newstab = (unsigned long)__va(newstab); |
533f0817 | 249 | |
3c726f8d | 250 | memset((void *)newstab, 0, HW_PAGE_SIZE); |
533f0817 DG |
251 | |
252 | paca[cpu].stab_addr = newstab; | |
253 | paca[cpu].stab_real = virt_to_abs(newstab); | |
fe333321 IM |
254 | printk(KERN_INFO "Segment table for CPU %d at 0x%llx " |
255 | "virtual, 0x%llx absolute\n", | |
3c726f8d | 256 | cpu, paca[cpu].stab_addr, paca[cpu].stab_real); |
533f0817 DG |
257 | } |
258 | } | |
259 | ||
1da177e4 LT |
260 | /* |
261 | * Build an entry for the base kernel segment and put it into | |
262 | * the segment table or SLB. All other segment table or SLB | |
263 | * entries are faulted in. | |
264 | */ | |
265 | void stab_initialize(unsigned long stab) | |
266 | { | |
1189be65 | 267 | unsigned long vsid = get_kernel_vsid(PAGE_OFFSET, MMU_SEGSIZE_256M); |
799d6046 | 268 | unsigned long stabreal; |
1da177e4 | 269 | |
3c726f8d | 270 | asm volatile("isync; slbia; isync":::"memory"); |
b5666f70 | 271 | make_ste(stab, GET_ESID(PAGE_OFFSET), vsid); |
1da177e4 | 272 | |
3c726f8d BH |
273 | /* Order update */ |
274 | asm volatile("sync":::"memory"); | |
799d6046 PM |
275 | |
276 | /* Set ASR */ | |
277 | stabreal = get_paca()->stab_real | 0x1ul; | |
278 | ||
279 | #ifdef CONFIG_PPC_ISERIES | |
280 | if (firmware_has_feature(FW_FEATURE_ISERIES)) { | |
281 | HvCall1(HvCallBaseSetASR, stabreal); | |
282 | return; | |
283 | } | |
284 | #endif /* CONFIG_PPC_ISERIES */ | |
ca507eaf | 285 | |
799d6046 | 286 | mtspr(SPRN_ASR, stabreal); |
1da177e4 | 287 | } |