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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/errno.h>
15#include <linux/sched.h>
16#include <linux/slab.h>
17#include <asm/cacheflush.h>
18#include <asm/tlbflush.h>
Ralf Baechle41c594a2006-04-05 09:45:45 +010019#ifdef CONFIG_MIPS_MT_SMTC
20#include <asm/mipsmtregs.h>
21#include <asm/smtc.h>
22#endif /* SMTC */
Jeremy Fitzhardinged6dd61c2007-05-02 19:27:14 +020023#include <asm-generic/mm_hooks.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
25/*
26 * For the fast tlb miss handlers, we keep a per cpu array of pointers
27 * to the current pgd for each processor. Also, the proc. id is stuffed
28 * into the context register.
29 */
30extern unsigned long pgd_current[];
31
32#define TLBMISS_HANDLER_SETUP_PGD(pgd) \
33 pgd_current[smp_processor_id()] = (unsigned long)(pgd)
34
Ralf Baechle875d43e2005-09-03 15:56:16 -070035#ifdef CONFIG_32BIT
Linus Torvalds1da177e2005-04-16 15:20:36 -070036#define TLBMISS_HANDLER_SETUP() \
Thiemo Seufer1b3a6e92005-04-01 14:07:13 +000037 write_c0_context((unsigned long) smp_processor_id() << 25); \
Linus Torvalds1da177e2005-04-16 15:20:36 -070038 TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir)
39#endif
Ralf Baechle81450952006-02-22 23:06:55 +000040#ifdef CONFIG_64BIT
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#define TLBMISS_HANDLER_SETUP() \
Thiemo Seufer1b3a6e92005-04-01 14:07:13 +000042 write_c0_context((unsigned long) smp_processor_id() << 26); \
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir)
44#endif
45
46#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
47
48#define ASID_INC 0x40
49#define ASID_MASK 0xfc0
50
51#elif defined(CONFIG_CPU_R8000)
52
53#define ASID_INC 0x10
54#define ASID_MASK 0xff0
55
56#elif defined(CONFIG_CPU_RM9000)
57
58#define ASID_INC 0x1
59#define ASID_MASK 0xfff
60
Ralf Baechle41c594a2006-04-05 09:45:45 +010061/* SMTC/34K debug hack - but maybe we'll keep it */
62#elif defined(CONFIG_MIPS_MT_SMTC)
63
64#define ASID_INC 0x1
65extern unsigned long smtc_asid_mask;
66#define ASID_MASK (smtc_asid_mask)
67#define HW_ASID_MASK 0xff
68/* End SMTC/34K debug hack */
Linus Torvalds1da177e2005-04-16 15:20:36 -070069#else /* FIXME: not correct for R6000 */
70
71#define ASID_INC 0x1
72#define ASID_MASK 0xff
73
74#endif
75
76#define cpu_context(cpu, mm) ((mm)->context[cpu])
77#define cpu_asid(cpu, mm) (cpu_context((cpu), (mm)) & ASID_MASK)
78#define asid_cache(cpu) (cpu_data[cpu].asid_cache)
79
80static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
81{
82}
83
84/*
85 * All unused by hardware upper bits will be considered
86 * as a software asid extension.
87 */
88#define ASID_VERSION_MASK ((unsigned long)~(ASID_MASK|(ASID_MASK-1)))
89#define ASID_FIRST_VERSION ((unsigned long)(~ASID_VERSION_MASK) + 1)
90
Ralf Baechle41c594a2006-04-05 09:45:45 +010091#ifndef CONFIG_MIPS_MT_SMTC
92/* Normal, classic MIPS get_new_mmu_context */
Linus Torvalds1da177e2005-04-16 15:20:36 -070093static inline void
94get_new_mmu_context(struct mm_struct *mm, unsigned long cpu)
95{
96 unsigned long asid = asid_cache(cpu);
97
98 if (! ((asid += ASID_INC) & ASID_MASK) ) {
99 if (cpu_has_vtag_icache)
100 flush_icache_all();
101 local_flush_tlb_all(); /* start new asid cycle */
102 if (!asid) /* fix version if needed */
103 asid = ASID_FIRST_VERSION;
104 }
105 cpu_context(cpu, mm) = asid_cache(cpu) = asid;
106}
107
Ralf Baechle41c594a2006-04-05 09:45:45 +0100108#else /* CONFIG_MIPS_MT_SMTC */
109
Ralf Baechle21a151d2007-10-11 23:46:15 +0100110#define get_new_mmu_context(mm, cpu) smtc_get_new_mmu_context((mm), (cpu))
Ralf Baechle41c594a2006-04-05 09:45:45 +0100111
112#endif /* CONFIG_MIPS_MT_SMTC */
113
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114/*
115 * Initialize the context related info for a new mm_struct
116 * instance.
117 */
118static inline int
119init_new_context(struct task_struct *tsk, struct mm_struct *mm)
120{
121 int i;
122
Ralf Baechleb5eb5512007-10-03 19:16:57 +0100123 for_each_online_cpu(i)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 cpu_context(i, mm) = 0;
125
126 return 0;
127}
128
129static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
130 struct task_struct *tsk)
131{
132 unsigned int cpu = smp_processor_id();
133 unsigned long flags;
Ralf Baechle41c594a2006-04-05 09:45:45 +0100134#ifdef CONFIG_MIPS_MT_SMTC
135 unsigned long oldasid;
136 unsigned long mtflags;
137 int mytlb = (smtc_status & SMTC_TLB_SHARED) ? 0 : cpu_data[cpu].vpe_id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 local_irq_save(flags);
Ralf Baechle41c594a2006-04-05 09:45:45 +0100139 mtflags = dvpe();
140#else /* Not SMTC */
141 local_irq_save(flags);
142#endif /* CONFIG_MIPS_MT_SMTC */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143
144 /* Check if our ASID is of an older version and thus invalid */
145 if ((cpu_context(cpu, next) ^ asid_cache(cpu)) & ASID_VERSION_MASK)
146 get_new_mmu_context(next, cpu);
Ralf Baechle41c594a2006-04-05 09:45:45 +0100147#ifdef CONFIG_MIPS_MT_SMTC
148 /*
149 * If the EntryHi ASID being replaced happens to be
150 * the value flagged at ASID recycling time as having
151 * an extended life, clear the bit showing it being
152 * in use by this "CPU", and if that's the last bit,
153 * free up the ASID value for use and flush any old
154 * instances of it from the TLB.
155 */
156 oldasid = (read_c0_entryhi() & ASID_MASK);
157 if(smtc_live_asid[mytlb][oldasid]) {
158 smtc_live_asid[mytlb][oldasid] &= ~(0x1 << cpu);
159 if(smtc_live_asid[mytlb][oldasid] == 0)
160 smtc_flush_tlb_asid(oldasid);
161 }
162 /*
163 * Tread softly on EntryHi, and so long as we support
164 * having ASID_MASK smaller than the hardware maximum,
165 * make sure no "soft" bits become "hard"...
166 */
167 write_c0_entryhi((read_c0_entryhi() & ~HW_ASID_MASK)
168 | (cpu_context(cpu, next) & ASID_MASK));
169 ehb(); /* Make sure it propagates to TCStatus */
170 evpe(mtflags);
171#else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 write_c0_entryhi(cpu_context(cpu, next));
Ralf Baechle41c594a2006-04-05 09:45:45 +0100173#endif /* CONFIG_MIPS_MT_SMTC */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 TLBMISS_HANDLER_SETUP_PGD(next->pgd);
175
176 /*
177 * Mark current->active_mm as not "active" anymore.
178 * We don't want to mislead possible IPI tlb flush routines.
179 */
180 cpu_clear(cpu, prev->cpu_vm_mask);
181 cpu_set(cpu, next->cpu_vm_mask);
182
183 local_irq_restore(flags);
184}
185
186/*
187 * Destroy context related info for an mm_struct that is about
188 * to be put to rest.
189 */
190static inline void destroy_context(struct mm_struct *mm)
191{
192}
193
Ralf Baechle21a151d2007-10-11 23:46:15 +0100194#define deactivate_mm(tsk, mm) do { } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195
196/*
197 * After we have set current->mm to a new value, this activates
198 * the context for the new mm so we see the new mappings.
199 */
200static inline void
201activate_mm(struct mm_struct *prev, struct mm_struct *next)
202{
203 unsigned long flags;
204 unsigned int cpu = smp_processor_id();
205
Ralf Baechle41c594a2006-04-05 09:45:45 +0100206#ifdef CONFIG_MIPS_MT_SMTC
207 unsigned long oldasid;
208 unsigned long mtflags;
209 int mytlb = (smtc_status & SMTC_TLB_SHARED) ? 0 : cpu_data[cpu].vpe_id;
210#endif /* CONFIG_MIPS_MT_SMTC */
211
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 local_irq_save(flags);
213
214 /* Unconditionally get a new ASID. */
215 get_new_mmu_context(next, cpu);
216
Ralf Baechle41c594a2006-04-05 09:45:45 +0100217#ifdef CONFIG_MIPS_MT_SMTC
218 /* See comments for similar code above */
219 mtflags = dvpe();
220 oldasid = read_c0_entryhi() & ASID_MASK;
221 if(smtc_live_asid[mytlb][oldasid]) {
222 smtc_live_asid[mytlb][oldasid] &= ~(0x1 << cpu);
223 if(smtc_live_asid[mytlb][oldasid] == 0)
224 smtc_flush_tlb_asid(oldasid);
225 }
226 /* See comments for similar code above */
227 write_c0_entryhi((read_c0_entryhi() & ~HW_ASID_MASK) |
228 (cpu_context(cpu, next) & ASID_MASK));
229 ehb(); /* Make sure it propagates to TCStatus */
230 evpe(mtflags);
231#else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 write_c0_entryhi(cpu_context(cpu, next));
Ralf Baechle41c594a2006-04-05 09:45:45 +0100233#endif /* CONFIG_MIPS_MT_SMTC */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 TLBMISS_HANDLER_SETUP_PGD(next->pgd);
235
236 /* mark mmu ownership change */
237 cpu_clear(cpu, prev->cpu_vm_mask);
238 cpu_set(cpu, next->cpu_vm_mask);
239
240 local_irq_restore(flags);
241}
242
243/*
244 * If mm is currently active_mm, we can't really drop it. Instead,
245 * we will get a new one for it.
246 */
247static inline void
248drop_mmu_context(struct mm_struct *mm, unsigned cpu)
249{
250 unsigned long flags;
Ralf Baechle41c594a2006-04-05 09:45:45 +0100251#ifdef CONFIG_MIPS_MT_SMTC
252 unsigned long oldasid;
253 /* Can't use spinlock because called from TLB flush within DVPE */
254 unsigned int prevvpe;
255 int mytlb = (smtc_status & SMTC_TLB_SHARED) ? 0 : cpu_data[cpu].vpe_id;
256#endif /* CONFIG_MIPS_MT_SMTC */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
258 local_irq_save(flags);
259
260 if (cpu_isset(cpu, mm->cpu_vm_mask)) {
261 get_new_mmu_context(mm, cpu);
Ralf Baechle41c594a2006-04-05 09:45:45 +0100262#ifdef CONFIG_MIPS_MT_SMTC
263 /* See comments for similar code above */
264 prevvpe = dvpe();
265 oldasid = (read_c0_entryhi() & ASID_MASK);
Ralf Baechle6b8aab02006-08-25 12:34:33 +0100266 if (smtc_live_asid[mytlb][oldasid]) {
267 smtc_live_asid[mytlb][oldasid] &= ~(0x1 << cpu);
268 if(smtc_live_asid[mytlb][oldasid] == 0)
269 smtc_flush_tlb_asid(oldasid);
Ralf Baechle41c594a2006-04-05 09:45:45 +0100270 }
271 /* See comments for similar code above */
272 write_c0_entryhi((read_c0_entryhi() & ~HW_ASID_MASK)
273 | cpu_asid(cpu, mm));
274 ehb(); /* Make sure it propagates to TCStatus */
275 evpe(prevvpe);
276#else /* not CONFIG_MIPS_MT_SMTC */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 write_c0_entryhi(cpu_asid(cpu, mm));
Ralf Baechle41c594a2006-04-05 09:45:45 +0100278#endif /* CONFIG_MIPS_MT_SMTC */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 } else {
280 /* will get a new context next time */
Ralf Baechle41c594a2006-04-05 09:45:45 +0100281#ifndef CONFIG_MIPS_MT_SMTC
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 cpu_context(cpu, mm) = 0;
Ralf Baechle41c594a2006-04-05 09:45:45 +0100283#else /* SMTC */
284 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285
Ralf Baechle41c594a2006-04-05 09:45:45 +0100286 /* SMTC shares the TLB (and ASIDs) across VPEs */
Ralf Baechleb5eb5512007-10-03 19:16:57 +0100287 for_each_online_cpu(i) {
Ralf Baechle41c594a2006-04-05 09:45:45 +0100288 if((smtc_status & SMTC_TLB_SHARED)
289 || (cpu_data[i].vpe_id == cpu_data[cpu].vpe_id))
290 cpu_context(i, mm) = 0;
291 }
292#endif /* CONFIG_MIPS_MT_SMTC */
293 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 local_irq_restore(flags);
295}
296
297#endif /* _ASM_MMU_CONTEXT_H */