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1da177e4 LT |
1 | /* |
2 | * PowerPC64 SLB support. | |
3 | * | |
4 | * Copyright (C) 2004 David Gibson <dwg@au.ibm.com>, IBM | |
5 | * Based on earlier code writteh by: | |
6 | * Dave Engebretsen and Mike Corrigan {engebret|mikejc}@us.ibm.com | |
7 | * Copyright (c) 2001 Dave Engebretsen | |
8 | * Copyright (C) 2002 Anton Blanchard <anton@au.ibm.com>, IBM | |
9 | * | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or | |
12 | * modify it under the terms of the GNU General Public License | |
13 | * as published by the Free Software Foundation; either version | |
14 | * 2 of the License, or (at your option) any later version. | |
15 | */ | |
16 | ||
3c726f8d BH |
17 | #undef DEBUG |
18 | ||
1da177e4 LT |
19 | #include <asm/pgtable.h> |
20 | #include <asm/mmu.h> | |
21 | #include <asm/mmu_context.h> | |
22 | #include <asm/paca.h> | |
23 | #include <asm/cputable.h> | |
3c726f8d | 24 | #include <asm/cacheflush.h> |
2f6093c8 | 25 | #include <asm/smp.h> |
56291e19 | 26 | #include <asm/firmware.h> |
2f6093c8 | 27 | #include <linux/compiler.h> |
aa39be09 | 28 | #include <asm/udbg.h> |
3c726f8d BH |
29 | |
30 | #ifdef DEBUG | |
31 | #define DBG(fmt...) udbg_printf(fmt) | |
32 | #else | |
33 | #define DBG(fmt...) | |
34 | #endif | |
1da177e4 | 35 | |
3c726f8d BH |
36 | extern void slb_allocate_realmode(unsigned long ea); |
37 | extern void slb_allocate_user(unsigned long ea); | |
38 | ||
39 | static void slb_allocate(unsigned long ea) | |
40 | { | |
41 | /* Currently, we do real mode for all SLBs including user, but | |
42 | * that will change if we bring back dynamic VSIDs | |
43 | */ | |
44 | slb_allocate_realmode(ea); | |
45 | } | |
1da177e4 | 46 | |
1189be65 PM |
47 | static inline unsigned long mk_esid_data(unsigned long ea, int ssize, |
48 | unsigned long slot) | |
1da177e4 | 49 | { |
1189be65 PM |
50 | unsigned long mask; |
51 | ||
52 | mask = (ssize == MMU_SEGSIZE_256M)? ESID_MASK: ESID_MASK_1T; | |
53 | return (ea & mask) | SLB_ESID_V | slot; | |
1da177e4 LT |
54 | } |
55 | ||
1189be65 PM |
56 | #define slb_vsid_shift(ssize) \ |
57 | ((ssize) == MMU_SEGSIZE_256M? SLB_VSID_SHIFT: SLB_VSID_SHIFT_1T) | |
58 | ||
59 | static inline unsigned long mk_vsid_data(unsigned long ea, int ssize, | |
60 | unsigned long flags) | |
1da177e4 | 61 | { |
1189be65 PM |
62 | return (get_kernel_vsid(ea, ssize) << slb_vsid_shift(ssize)) | flags | |
63 | ((unsigned long) ssize << SLB_VSID_SSIZE_SHIFT); | |
1da177e4 LT |
64 | } |
65 | ||
1189be65 | 66 | static inline void slb_shadow_update(unsigned long ea, int ssize, |
67439b76 | 67 | unsigned long flags, |
2f6093c8 | 68 | unsigned long entry) |
1da177e4 | 69 | { |
2f6093c8 MN |
70 | /* |
71 | * Clear the ESID first so the entry is not valid while we are | |
00efee7d MN |
72 | * updating it. No write barriers are needed here, provided |
73 | * we only update the current CPU's SLB shadow buffer. | |
2f6093c8 MN |
74 | */ |
75 | get_slb_shadow()->save_area[entry].esid = 0; | |
1189be65 PM |
76 | get_slb_shadow()->save_area[entry].vsid = mk_vsid_data(ea, ssize, flags); |
77 | get_slb_shadow()->save_area[entry].esid = mk_esid_data(ea, ssize, entry); | |
2f6093c8 MN |
78 | } |
79 | ||
edd0622b | 80 | static inline void slb_shadow_clear(unsigned long entry) |
2f6093c8 | 81 | { |
edd0622b | 82 | get_slb_shadow()->save_area[entry].esid = 0; |
1da177e4 LT |
83 | } |
84 | ||
1189be65 PM |
85 | static inline void create_shadowed_slbe(unsigned long ea, int ssize, |
86 | unsigned long flags, | |
175587cc PM |
87 | unsigned long entry) |
88 | { | |
89 | /* | |
90 | * Updating the shadow buffer before writing the SLB ensures | |
91 | * we don't get a stale entry here if we get preempted by PHYP | |
92 | * between these two statements. | |
93 | */ | |
1189be65 | 94 | slb_shadow_update(ea, ssize, flags, entry); |
175587cc PM |
95 | |
96 | asm volatile("slbmte %0,%1" : | |
1189be65 PM |
97 | : "r" (mk_vsid_data(ea, ssize, flags)), |
98 | "r" (mk_esid_data(ea, ssize, entry)) | |
175587cc PM |
99 | : "memory" ); |
100 | } | |
101 | ||
bf72aeba | 102 | void slb_flush_and_rebolt(void) |
1da177e4 LT |
103 | { |
104 | /* If you change this make sure you change SLB_NUM_BOLTED | |
105 | * appropriately too. */ | |
bf72aeba | 106 | unsigned long linear_llp, vmalloc_llp, lflags, vflags; |
1189be65 | 107 | unsigned long ksp_esid_data, ksp_vsid_data; |
1da177e4 LT |
108 | |
109 | WARN_ON(!irqs_disabled()); | |
110 | ||
3c726f8d | 111 | linear_llp = mmu_psize_defs[mmu_linear_psize].sllp; |
bf72aeba | 112 | vmalloc_llp = mmu_psize_defs[mmu_vmalloc_psize].sllp; |
3c726f8d | 113 | lflags = SLB_VSID_KERNEL | linear_llp; |
bf72aeba | 114 | vflags = SLB_VSID_KERNEL | vmalloc_llp; |
1da177e4 | 115 | |
1189be65 PM |
116 | ksp_esid_data = mk_esid_data(get_paca()->kstack, mmu_kernel_ssize, 2); |
117 | if ((ksp_esid_data & ~0xfffffffUL) <= PAGE_OFFSET) { | |
1da177e4 | 118 | ksp_esid_data &= ~SLB_ESID_V; |
1189be65 | 119 | ksp_vsid_data = 0; |
edd0622b PM |
120 | slb_shadow_clear(2); |
121 | } else { | |
122 | /* Update stack entry; others don't change */ | |
1189be65 PM |
123 | slb_shadow_update(get_paca()->kstack, mmu_kernel_ssize, lflags, 2); |
124 | ksp_vsid_data = get_slb_shadow()->save_area[2].vsid; | |
edd0622b | 125 | } |
2f6093c8 | 126 | |
1da177e4 LT |
127 | /* We need to do this all in asm, so we're sure we don't touch |
128 | * the stack between the slbia and rebolting it. */ | |
129 | asm volatile("isync\n" | |
130 | "slbia\n" | |
131 | /* Slot 1 - first VMALLOC segment */ | |
132 | "slbmte %0,%1\n" | |
133 | /* Slot 2 - kernel stack */ | |
134 | "slbmte %2,%3\n" | |
135 | "isync" | |
1189be65 PM |
136 | :: "r"(mk_vsid_data(VMALLOC_START, mmu_kernel_ssize, vflags)), |
137 | "r"(mk_esid_data(VMALLOC_START, mmu_kernel_ssize, 1)), | |
138 | "r"(ksp_vsid_data), | |
1da177e4 LT |
139 | "r"(ksp_esid_data) |
140 | : "memory"); | |
141 | } | |
142 | ||
67439b76 MN |
143 | void slb_vmalloc_update(void) |
144 | { | |
145 | unsigned long vflags; | |
146 | ||
147 | vflags = SLB_VSID_KERNEL | mmu_psize_defs[mmu_vmalloc_psize].sllp; | |
1189be65 | 148 | slb_shadow_update(VMALLOC_START, mmu_kernel_ssize, vflags, 1); |
67439b76 MN |
149 | slb_flush_and_rebolt(); |
150 | } | |
151 | ||
465ccab9 | 152 | /* Helper function to compare esids. There are four cases to handle. |
153 | * 1. The system is not 1T segment size capable. Use the GET_ESID compare. | |
154 | * 2. The system is 1T capable, both addresses are < 1T, use the GET_ESID compare. | |
155 | * 3. The system is 1T capable, only one of the two addresses is > 1T. This is not a match. | |
156 | * 4. The system is 1T capable, both addresses are > 1T, use the GET_ESID_1T macro to compare. | |
157 | */ | |
158 | static inline int esids_match(unsigned long addr1, unsigned long addr2) | |
159 | { | |
160 | int esid_1t_count; | |
161 | ||
162 | /* System is not 1T segment size capable. */ | |
163 | if (!cpu_has_feature(CPU_FTR_1T_SEGMENT)) | |
164 | return (GET_ESID(addr1) == GET_ESID(addr2)); | |
165 | ||
166 | esid_1t_count = (((addr1 >> SID_SHIFT_1T) != 0) + | |
167 | ((addr2 >> SID_SHIFT_1T) != 0)); | |
168 | ||
169 | /* both addresses are < 1T */ | |
170 | if (esid_1t_count == 0) | |
171 | return (GET_ESID(addr1) == GET_ESID(addr2)); | |
172 | ||
173 | /* One address < 1T, the other > 1T. Not a match */ | |
174 | if (esid_1t_count == 1) | |
175 | return 0; | |
176 | ||
177 | /* Both addresses are > 1T. */ | |
178 | return (GET_ESID_1T(addr1) == GET_ESID_1T(addr2)); | |
179 | } | |
180 | ||
1da177e4 LT |
181 | /* Flush all user entries from the segment table of the current processor. */ |
182 | void switch_slb(struct task_struct *tsk, struct mm_struct *mm) | |
183 | { | |
184 | unsigned long offset = get_paca()->slb_cache_ptr; | |
1189be65 | 185 | unsigned long slbie_data = 0; |
1da177e4 LT |
186 | unsigned long pc = KSTK_EIP(tsk); |
187 | unsigned long stack = KSTK_ESP(tsk); | |
188 | unsigned long unmapped_base; | |
189 | ||
f66bce5e OJ |
190 | if (!cpu_has_feature(CPU_FTR_NO_SLBIE_B) && |
191 | offset <= SLB_CACHE_ENTRIES) { | |
1da177e4 LT |
192 | int i; |
193 | asm volatile("isync" : : : "memory"); | |
194 | for (i = 0; i < offset; i++) { | |
1189be65 PM |
195 | slbie_data = (unsigned long)get_paca()->slb_cache[i] |
196 | << SID_SHIFT; /* EA */ | |
197 | slbie_data |= user_segment_size(slbie_data) | |
198 | << SLBIE_SSIZE_SHIFT; | |
199 | slbie_data |= SLBIE_C; /* C set for user addresses */ | |
200 | asm volatile("slbie %0" : : "r" (slbie_data)); | |
1da177e4 LT |
201 | } |
202 | asm volatile("isync" : : : "memory"); | |
203 | } else { | |
204 | slb_flush_and_rebolt(); | |
205 | } | |
206 | ||
207 | /* Workaround POWER5 < DD2.1 issue */ | |
208 | if (offset == 1 || offset > SLB_CACHE_ENTRIES) | |
1189be65 | 209 | asm volatile("slbie %0" : : "r" (slbie_data)); |
1da177e4 LT |
210 | |
211 | get_paca()->slb_cache_ptr = 0; | |
212 | get_paca()->context = mm->context; | |
213 | ||
214 | /* | |
215 | * preload some userspace segments into the SLB. | |
216 | */ | |
217 | if (test_tsk_thread_flag(tsk, TIF_32BIT)) | |
218 | unmapped_base = TASK_UNMAPPED_BASE_USER32; | |
219 | else | |
220 | unmapped_base = TASK_UNMAPPED_BASE_USER64; | |
221 | ||
51fae6de | 222 | if (is_kernel_addr(pc)) |
1da177e4 LT |
223 | return; |
224 | slb_allocate(pc); | |
225 | ||
465ccab9 | 226 | if (esids_match(pc,stack)) |
1da177e4 LT |
227 | return; |
228 | ||
51fae6de | 229 | if (is_kernel_addr(stack)) |
1da177e4 LT |
230 | return; |
231 | slb_allocate(stack); | |
232 | ||
465ccab9 | 233 | if (esids_match(pc,unmapped_base) || esids_match(stack,unmapped_base)) |
1da177e4 LT |
234 | return; |
235 | ||
51fae6de | 236 | if (is_kernel_addr(unmapped_base)) |
1da177e4 LT |
237 | return; |
238 | slb_allocate(unmapped_base); | |
239 | } | |
240 | ||
3c726f8d BH |
241 | static inline void patch_slb_encoding(unsigned int *insn_addr, |
242 | unsigned int immed) | |
243 | { | |
244 | /* Assume the instruction had a "0" immediate value, just | |
245 | * "or" in the new value | |
246 | */ | |
247 | *insn_addr |= immed; | |
248 | flush_icache_range((unsigned long)insn_addr, 4+ | |
249 | (unsigned long)insn_addr); | |
250 | } | |
251 | ||
1da177e4 LT |
252 | void slb_initialize(void) |
253 | { | |
bf72aeba | 254 | unsigned long linear_llp, vmalloc_llp, io_llp; |
56291e19 | 255 | unsigned long lflags, vflags; |
3c726f8d BH |
256 | static int slb_encoding_inited; |
257 | extern unsigned int *slb_miss_kernel_load_linear; | |
bf72aeba | 258 | extern unsigned int *slb_miss_kernel_load_io; |
3c726f8d BH |
259 | |
260 | /* Prepare our SLB miss handler based on our page size */ | |
261 | linear_llp = mmu_psize_defs[mmu_linear_psize].sllp; | |
bf72aeba PM |
262 | io_llp = mmu_psize_defs[mmu_io_psize].sllp; |
263 | vmalloc_llp = mmu_psize_defs[mmu_vmalloc_psize].sllp; | |
264 | get_paca()->vmalloc_sllp = SLB_VSID_KERNEL | vmalloc_llp; | |
265 | ||
3c726f8d BH |
266 | if (!slb_encoding_inited) { |
267 | slb_encoding_inited = 1; | |
268 | patch_slb_encoding(slb_miss_kernel_load_linear, | |
269 | SLB_VSID_KERNEL | linear_llp); | |
bf72aeba PM |
270 | patch_slb_encoding(slb_miss_kernel_load_io, |
271 | SLB_VSID_KERNEL | io_llp); | |
3c726f8d BH |
272 | |
273 | DBG("SLB: linear LLP = %04x\n", linear_llp); | |
bf72aeba | 274 | DBG("SLB: io LLP = %04x\n", io_llp); |
3c726f8d BH |
275 | } |
276 | ||
56291e19 SR |
277 | get_paca()->stab_rr = SLB_NUM_BOLTED; |
278 | ||
1da177e4 LT |
279 | /* On iSeries the bolted entries have already been set up by |
280 | * the hypervisor from the lparMap data in head.S */ | |
56291e19 SR |
281 | if (firmware_has_feature(FW_FEATURE_ISERIES)) |
282 | return; | |
1da177e4 | 283 | |
3c726f8d | 284 | lflags = SLB_VSID_KERNEL | linear_llp; |
bf72aeba | 285 | vflags = SLB_VSID_KERNEL | vmalloc_llp; |
1da177e4 | 286 | |
3c726f8d | 287 | /* Invalidate the entire SLB (even slot 0) & all the ERATS */ |
175587cc PM |
288 | asm volatile("isync":::"memory"); |
289 | asm volatile("slbmte %0,%0"::"r" (0) : "memory"); | |
290 | asm volatile("isync; slbia; isync":::"memory"); | |
1189be65 | 291 | create_shadowed_slbe(PAGE_OFFSET, mmu_kernel_ssize, lflags, 0); |
175587cc | 292 | |
1189be65 | 293 | create_shadowed_slbe(VMALLOC_START, mmu_kernel_ssize, vflags, 1); |
175587cc PM |
294 | |
295 | /* We don't bolt the stack for the time being - we're in boot, | |
296 | * so the stack is in the bolted segment. By the time it goes | |
297 | * elsewhere, we'll call _switch() which will bolt in the new | |
298 | * one. */ | |
299 | asm volatile("isync":::"memory"); | |
1da177e4 | 300 | } |