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1/*
2 * Switch a MMU context.
3 *
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
6 * for more details.
7 *
8 * Copyright (C) 1996, 1997, 1998, 1999 by Ralf Baechle
9 * Copyright (C) 1999 Silicon Graphics, Inc.
10 */
11#ifndef _ASM_MMU_CONTEXT_H
12#define _ASM_MMU_CONTEXT_H
13
14#include <linux/errno.h>
15#include <linux/sched.h>
16#include <linux/smp.h>
17#include <linux/slab.h>
18#include <asm/cacheflush.h>
19#include <asm/hazards.h>
20#include <asm/tlbflush.h>
21#ifdef CONFIG_MIPS_MT_SMTC
22#include <asm/mipsmtregs.h>
23#include <asm/smtc.h>
24#endif /* SMTC */
25#include <asm-generic/mm_hooks.h>
26
27#ifdef CONFIG_MIPS_PGD_C0_CONTEXT
28
29#define TLBMISS_HANDLER_SETUP_PGD(pgd) \
30 tlbmiss_handler_setup_pgd((unsigned long)(pgd))
31
32extern void tlbmiss_handler_setup_pgd(unsigned long pgd);
33
34#define TLBMISS_HANDLER_SETUP() \
35 do { \
36 TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir); \
37 write_c0_xcontext((unsigned long) smp_processor_id() << 51); \
38 } while (0)
39
40
41static inline unsigned long get_current_pgd(void)
42{
43 return PHYS_TO_XKSEG_CACHED((read_c0_context() >> 11) & ~0xfffUL);
44}
45
46#else /* CONFIG_MIPS_PGD_C0_CONTEXT: using pgd_current*/
47
48/*
49 * For the fast tlb miss handlers, we keep a per cpu array of pointers
50 * to the current pgd for each processor. Also, the proc. id is stuffed
51 * into the context register.
52 */
53extern unsigned long pgd_current[];
54
55#define TLBMISS_HANDLER_SETUP_PGD(pgd) \
56 pgd_current[smp_processor_id()] = (unsigned long)(pgd)
57
58#ifdef CONFIG_32BIT
59#define TLBMISS_HANDLER_SETUP() \
60 write_c0_context((unsigned long) smp_processor_id() << 25); \
61 back_to_back_c0_hazard(); \
62 TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir)
63#endif
64#ifdef CONFIG_64BIT
65#define TLBMISS_HANDLER_SETUP() \
66 write_c0_context((unsigned long) smp_processor_id() << 26); \
67 back_to_back_c0_hazard(); \
68 TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir)
69#endif
70#endif /* CONFIG_MIPS_PGD_C0_CONTEXT*/
71#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
72
73#define ASID_INC 0x40
74#define ASID_MASK 0xfc0
75
76#elif defined(CONFIG_CPU_R8000)
77
78#define ASID_INC 0x10
79#define ASID_MASK 0xff0
80
81#elif defined(CONFIG_CPU_RM9000)
82
83#define ASID_INC 0x1
84#define ASID_MASK 0xfff
85
86/* SMTC/34K debug hack - but maybe we'll keep it */
87#elif defined(CONFIG_MIPS_MT_SMTC)
88
89#define ASID_INC 0x1
90extern unsigned long smtc_asid_mask;
91#define ASID_MASK (smtc_asid_mask)
92#define HW_ASID_MASK 0xff
93/* End SMTC/34K debug hack */
94#else /* FIXME: not correct for R6000 */
95
96#define ASID_INC 0x1
97#define ASID_MASK 0xff
98
99#endif
100
101#define cpu_context(cpu, mm) ((mm)->context.asid[cpu])
102#define cpu_asid(cpu, mm) (cpu_context((cpu), (mm)) & ASID_MASK)
103#define asid_cache(cpu) (cpu_data[cpu].asid_cache)
104
105static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
106{
107}
108
109/*
110 * All unused by hardware upper bits will be considered
111 * as a software asid extension.
112 */
113#define ASID_VERSION_MASK ((unsigned long)~(ASID_MASK|(ASID_MASK-1)))
114#define ASID_FIRST_VERSION ((unsigned long)(~ASID_VERSION_MASK) + 1)
115
116#ifndef CONFIG_MIPS_MT_SMTC
117/* Normal, classic MIPS get_new_mmu_context */
118static inline void
119get_new_mmu_context(struct mm_struct *mm, unsigned long cpu)
120{
121 unsigned long asid = asid_cache(cpu);
122
123 if (! ((asid += ASID_INC) & ASID_MASK) ) {
124 if (cpu_has_vtag_icache)
125 flush_icache_all();
126 local_flush_tlb_all(); /* start new asid cycle */
127 if (!asid) /* fix version if needed */
128 asid = ASID_FIRST_VERSION;
129 }
130 cpu_context(cpu, mm) = asid_cache(cpu) = asid;
131}
132
133#else /* CONFIG_MIPS_MT_SMTC */
134
135#define get_new_mmu_context(mm, cpu) smtc_get_new_mmu_context((mm), (cpu))
136
137#endif /* CONFIG_MIPS_MT_SMTC */
138
139/*
140 * Initialize the context related info for a new mm_struct
141 * instance.
142 */
143static inline int
144init_new_context(struct task_struct *tsk, struct mm_struct *mm)
145{
146 int i;
147
148 for_each_online_cpu(i)
149 cpu_context(i, mm) = 0;
150
151 return 0;
152}
153
154static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
155 struct task_struct *tsk)
156{
157 unsigned int cpu = smp_processor_id();
158 unsigned long flags;
159#ifdef CONFIG_MIPS_MT_SMTC
160 unsigned long oldasid;
161 unsigned long mtflags;
162 int mytlb = (smtc_status & SMTC_TLB_SHARED) ? 0 : cpu_data[cpu].vpe_id;
163 local_irq_save(flags);
164 mtflags = dvpe();
165#else /* Not SMTC */
166 local_irq_save(flags);
167#endif /* CONFIG_MIPS_MT_SMTC */
168
169 /* Check if our ASID is of an older version and thus invalid */
170 if ((cpu_context(cpu, next) ^ asid_cache(cpu)) & ASID_VERSION_MASK)
171 get_new_mmu_context(next, cpu);
172#ifdef CONFIG_MIPS_MT_SMTC
173 /*
174 * If the EntryHi ASID being replaced happens to be
175 * the value flagged at ASID recycling time as having
176 * an extended life, clear the bit showing it being
177 * in use by this "CPU", and if that's the last bit,
178 * free up the ASID value for use and flush any old
179 * instances of it from the TLB.
180 */
181 oldasid = (read_c0_entryhi() & ASID_MASK);
182 if(smtc_live_asid[mytlb][oldasid]) {
183 smtc_live_asid[mytlb][oldasid] &= ~(0x1 << cpu);
184 if(smtc_live_asid[mytlb][oldasid] == 0)
185 smtc_flush_tlb_asid(oldasid);
186 }
187 /*
188 * Tread softly on EntryHi, and so long as we support
189 * having ASID_MASK smaller than the hardware maximum,
190 * make sure no "soft" bits become "hard"...
191 */
192 write_c0_entryhi((read_c0_entryhi() & ~HW_ASID_MASK) |
193 cpu_asid(cpu, next));
194 ehb(); /* Make sure it propagates to TCStatus */
195 evpe(mtflags);
196#else
197 write_c0_entryhi(cpu_asid(cpu, next));
198#endif /* CONFIG_MIPS_MT_SMTC */
199 TLBMISS_HANDLER_SETUP_PGD(next->pgd);
200
201 /*
202 * Mark current->active_mm as not "active" anymore.
203 * We don't want to mislead possible IPI tlb flush routines.
204 */
205 cpumask_clear_cpu(cpu, mm_cpumask(prev));
206 cpumask_set_cpu(cpu, mm_cpumask(next));
207
208 local_irq_restore(flags);
209}
210
211/*
212 * Destroy context related info for an mm_struct that is about
213 * to be put to rest.
214 */
215static inline void destroy_context(struct mm_struct *mm)
216{
217}
218
219#define deactivate_mm(tsk, mm) do { } while (0)
220
221/*
222 * After we have set current->mm to a new value, this activates
223 * the context for the new mm so we see the new mappings.
224 */
225static inline void
226activate_mm(struct mm_struct *prev, struct mm_struct *next)
227{
228 unsigned long flags;
229 unsigned int cpu = smp_processor_id();
230
231#ifdef CONFIG_MIPS_MT_SMTC
232 unsigned long oldasid;
233 unsigned long mtflags;
234 int mytlb = (smtc_status & SMTC_TLB_SHARED) ? 0 : cpu_data[cpu].vpe_id;
235#endif /* CONFIG_MIPS_MT_SMTC */
236
237 local_irq_save(flags);
238
239 /* Unconditionally get a new ASID. */
240 get_new_mmu_context(next, cpu);
241
242#ifdef CONFIG_MIPS_MT_SMTC
243 /* See comments for similar code above */
244 mtflags = dvpe();
245 oldasid = read_c0_entryhi() & ASID_MASK;
246 if(smtc_live_asid[mytlb][oldasid]) {
247 smtc_live_asid[mytlb][oldasid] &= ~(0x1 << cpu);
248 if(smtc_live_asid[mytlb][oldasid] == 0)
249 smtc_flush_tlb_asid(oldasid);
250 }
251 /* See comments for similar code above */
252 write_c0_entryhi((read_c0_entryhi() & ~HW_ASID_MASK) |
253 cpu_asid(cpu, next));
254 ehb(); /* Make sure it propagates to TCStatus */
255 evpe(mtflags);
256#else
257 write_c0_entryhi(cpu_asid(cpu, next));
258#endif /* CONFIG_MIPS_MT_SMTC */
259 TLBMISS_HANDLER_SETUP_PGD(next->pgd);
260
261 /* mark mmu ownership change */
262 cpumask_clear_cpu(cpu, mm_cpumask(prev));
263 cpumask_set_cpu(cpu, mm_cpumask(next));
264
265 local_irq_restore(flags);
266}
267
268/*
269 * If mm is currently active_mm, we can't really drop it. Instead,
270 * we will get a new one for it.
271 */
272static inline void
273drop_mmu_context(struct mm_struct *mm, unsigned cpu)
274{
275 unsigned long flags;
276#ifdef CONFIG_MIPS_MT_SMTC
277 unsigned long oldasid;
278 /* Can't use spinlock because called from TLB flush within DVPE */
279 unsigned int prevvpe;
280 int mytlb = (smtc_status & SMTC_TLB_SHARED) ? 0 : cpu_data[cpu].vpe_id;
281#endif /* CONFIG_MIPS_MT_SMTC */
282
283 local_irq_save(flags);
284
285 if (cpumask_test_cpu(cpu, mm_cpumask(mm))) {
286 get_new_mmu_context(mm, cpu);
287#ifdef CONFIG_MIPS_MT_SMTC
288 /* See comments for similar code above */
289 prevvpe = dvpe();
290 oldasid = (read_c0_entryhi() & ASID_MASK);
291 if (smtc_live_asid[mytlb][oldasid]) {
292 smtc_live_asid[mytlb][oldasid] &= ~(0x1 << cpu);
293 if(smtc_live_asid[mytlb][oldasid] == 0)
294 smtc_flush_tlb_asid(oldasid);
295 }
296 /* See comments for similar code above */
297 write_c0_entryhi((read_c0_entryhi() & ~HW_ASID_MASK)
298 | cpu_asid(cpu, mm));
299 ehb(); /* Make sure it propagates to TCStatus */
300 evpe(prevvpe);
301#else /* not CONFIG_MIPS_MT_SMTC */
302 write_c0_entryhi(cpu_asid(cpu, mm));
303#endif /* CONFIG_MIPS_MT_SMTC */
304 } else {
305 /* will get a new context next time */
306#ifndef CONFIG_MIPS_MT_SMTC
307 cpu_context(cpu, mm) = 0;
308#else /* SMTC */
309 int i;
310
311 /* SMTC shares the TLB (and ASIDs) across VPEs */
312 for_each_online_cpu(i) {
313 if((smtc_status & SMTC_TLB_SHARED)
314 || (cpu_data[i].vpe_id == cpu_data[cpu].vpe_id))
315 cpu_context(i, mm) = 0;
316 }
317#endif /* CONFIG_MIPS_MT_SMTC */
318 }
319 local_irq_restore(flags);
320}
321
322#endif /* _ASM_MMU_CONTEXT_H */
1/*
2 * Switch a MMU context.
3 *
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
6 * for more details.
7 *
8 * Copyright (C) 1996, 1997, 1998, 1999 by Ralf Baechle
9 * Copyright (C) 1999 Silicon Graphics, Inc.
10 */
11#ifndef _ASM_MMU_CONTEXT_H
12#define _ASM_MMU_CONTEXT_H
13
14#include <linux/errno.h>
15#include <linux/sched.h>
16#include <linux/smp.h>
17#include <linux/slab.h>
18#include <asm/cacheflush.h>
19#include <asm/hazards.h>
20#include <asm/tlbflush.h>
21#include <asm-generic/mm_hooks.h>
22
23#define htw_set_pwbase(pgd) \
24do { \
25 if (cpu_has_htw) { \
26 write_c0_pwbase(pgd); \
27 back_to_back_c0_hazard(); \
28 } \
29} while (0)
30
31#define TLBMISS_HANDLER_SETUP_PGD(pgd) \
32do { \
33 extern void tlbmiss_handler_setup_pgd(unsigned long); \
34 tlbmiss_handler_setup_pgd((unsigned long)(pgd)); \
35 htw_set_pwbase((unsigned long)pgd); \
36} while (0)
37
38#ifdef CONFIG_MIPS_PGD_C0_CONTEXT
39
40#define TLBMISS_HANDLER_RESTORE() \
41 write_c0_xcontext((unsigned long) smp_processor_id() << \
42 SMP_CPUID_REGSHIFT)
43
44#define TLBMISS_HANDLER_SETUP() \
45 do { \
46 TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir); \
47 TLBMISS_HANDLER_RESTORE(); \
48 } while (0)
49
50#else /* !CONFIG_MIPS_PGD_C0_CONTEXT: using pgd_current*/
51
52/*
53 * For the fast tlb miss handlers, we keep a per cpu array of pointers
54 * to the current pgd for each processor. Also, the proc. id is stuffed
55 * into the context register.
56 */
57extern unsigned long pgd_current[];
58
59#define TLBMISS_HANDLER_RESTORE() \
60 write_c0_context((unsigned long) smp_processor_id() << \
61 SMP_CPUID_REGSHIFT)
62
63#define TLBMISS_HANDLER_SETUP() \
64 TLBMISS_HANDLER_RESTORE(); \
65 back_to_back_c0_hazard(); \
66 TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir)
67#endif /* CONFIG_MIPS_PGD_C0_CONTEXT*/
68#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
69
70#define ASID_INC 0x40
71#define ASID_MASK 0xfc0
72
73#elif defined(CONFIG_CPU_R8000)
74
75#define ASID_INC 0x10
76#define ASID_MASK 0xff0
77
78#else /* FIXME: not correct for R6000 */
79
80#define ASID_INC 0x1
81#define ASID_MASK 0xff
82
83#endif
84
85#define cpu_context(cpu, mm) ((mm)->context.asid[cpu])
86#define cpu_asid(cpu, mm) (cpu_context((cpu), (mm)) & ASID_MASK)
87#define asid_cache(cpu) (cpu_data[cpu].asid_cache)
88
89static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
90{
91}
92
93/*
94 * All unused by hardware upper bits will be considered
95 * as a software asid extension.
96 */
97#define ASID_VERSION_MASK ((unsigned long)~(ASID_MASK|(ASID_MASK-1)))
98#define ASID_FIRST_VERSION ((unsigned long)(~ASID_VERSION_MASK) + 1)
99
100/* Normal, classic MIPS get_new_mmu_context */
101static inline void
102get_new_mmu_context(struct mm_struct *mm, unsigned long cpu)
103{
104 extern void kvm_local_flush_tlb_all(void);
105 unsigned long asid = asid_cache(cpu);
106
107 if (! ((asid += ASID_INC) & ASID_MASK) ) {
108 if (cpu_has_vtag_icache)
109 flush_icache_all();
110#ifdef CONFIG_KVM
111 kvm_local_flush_tlb_all(); /* start new asid cycle */
112#else
113 local_flush_tlb_all(); /* start new asid cycle */
114#endif
115 if (!asid) /* fix version if needed */
116 asid = ASID_FIRST_VERSION;
117 }
118
119 cpu_context(cpu, mm) = asid_cache(cpu) = asid;
120}
121
122/*
123 * Initialize the context related info for a new mm_struct
124 * instance.
125 */
126static inline int
127init_new_context(struct task_struct *tsk, struct mm_struct *mm)
128{
129 int i;
130
131 for_each_possible_cpu(i)
132 cpu_context(i, mm) = 0;
133
134 atomic_set(&mm->context.fp_mode_switching, 0);
135
136 return 0;
137}
138
139static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
140 struct task_struct *tsk)
141{
142 unsigned int cpu = smp_processor_id();
143 unsigned long flags;
144 local_irq_save(flags);
145
146 htw_stop();
147 /* Check if our ASID is of an older version and thus invalid */
148 if ((cpu_context(cpu, next) ^ asid_cache(cpu)) & ASID_VERSION_MASK)
149 get_new_mmu_context(next, cpu);
150 write_c0_entryhi(cpu_asid(cpu, next));
151 TLBMISS_HANDLER_SETUP_PGD(next->pgd);
152
153 /*
154 * Mark current->active_mm as not "active" anymore.
155 * We don't want to mislead possible IPI tlb flush routines.
156 */
157 cpumask_clear_cpu(cpu, mm_cpumask(prev));
158 cpumask_set_cpu(cpu, mm_cpumask(next));
159 htw_start();
160
161 local_irq_restore(flags);
162}
163
164/*
165 * Destroy context related info for an mm_struct that is about
166 * to be put to rest.
167 */
168static inline void destroy_context(struct mm_struct *mm)
169{
170}
171
172#define deactivate_mm(tsk, mm) do { } while (0)
173
174/*
175 * After we have set current->mm to a new value, this activates
176 * the context for the new mm so we see the new mappings.
177 */
178static inline void
179activate_mm(struct mm_struct *prev, struct mm_struct *next)
180{
181 unsigned long flags;
182 unsigned int cpu = smp_processor_id();
183
184 local_irq_save(flags);
185
186 htw_stop();
187 /* Unconditionally get a new ASID. */
188 get_new_mmu_context(next, cpu);
189
190 write_c0_entryhi(cpu_asid(cpu, next));
191 TLBMISS_HANDLER_SETUP_PGD(next->pgd);
192
193 /* mark mmu ownership change */
194 cpumask_clear_cpu(cpu, mm_cpumask(prev));
195 cpumask_set_cpu(cpu, mm_cpumask(next));
196 htw_start();
197
198 local_irq_restore(flags);
199}
200
201/*
202 * If mm is currently active_mm, we can't really drop it. Instead,
203 * we will get a new one for it.
204 */
205static inline void
206drop_mmu_context(struct mm_struct *mm, unsigned cpu)
207{
208 unsigned long flags;
209
210 local_irq_save(flags);
211 htw_stop();
212
213 if (cpumask_test_cpu(cpu, mm_cpumask(mm))) {
214 get_new_mmu_context(mm, cpu);
215 write_c0_entryhi(cpu_asid(cpu, mm));
216 } else {
217 /* will get a new context next time */
218 cpu_context(cpu, mm) = 0;
219 }
220 htw_start();
221 local_irq_restore(flags);
222}
223
224#endif /* _ASM_MMU_CONTEXT_H */