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[linux-2.6-omap-h63xx.git] / arch / mips / mm / tlb-r4k.c
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
7  * Copyright (C) 1997, 1998, 1999, 2000 Ralf Baechle ralf@gnu.org
8  * Carsten Langgaard, carstenl@mips.com
9  * Copyright (C) 2002 MIPS Technologies, Inc.  All rights reserved.
10  */
11 #include <linux/init.h>
12 #include <linux/sched.h>
13 #include <linux/mm.h>
14
15 #include <asm/cpu.h>
16 #include <asm/bootinfo.h>
17 #include <asm/mmu_context.h>
18 #include <asm/pgtable.h>
19 #include <asm/system.h>
20
21 extern void build_tlb_refill_handler(void);
22
23 /*
24  * Make sure all entries differ.  If they're not different
25  * MIPS32 will take revenge ...
26  */
27 #define UNIQUE_ENTRYHI(idx) (CKSEG0 + ((idx) << (PAGE_SHIFT + 1)))
28
29 /* Atomicity and interruptability */
30 #ifdef CONFIG_MIPS_MT_SMTC
31
32 #include <asm/smtc.h>
33 #include <asm/mipsmtregs.h>
34
35 #define ENTER_CRITICAL(flags) \
36         { \
37         unsigned int mvpflags; \
38         local_irq_save(flags);\
39         mvpflags = dvpe()
40 #define EXIT_CRITICAL(flags) \
41         evpe(mvpflags); \
42         local_irq_restore(flags); \
43         }
44 #else
45
46 #define ENTER_CRITICAL(flags) local_irq_save(flags)
47 #define EXIT_CRITICAL(flags) local_irq_restore(flags)
48
49 #endif /* CONFIG_MIPS_MT_SMTC */
50
51 #if defined(CONFIG_CPU_LOONGSON2)
52 /*
53  * LOONGSON2 has a 4 entry itlb which is a subset of dtlb,
54  * unfortrunately, itlb is not totally transparent to software.
55  */
56 #define FLUSH_ITLB write_c0_diag(4);
57
58 #define FLUSH_ITLB_VM(vma) { if ((vma)->vm_flags & VM_EXEC)  write_c0_diag(4); }
59
60 #else
61
62 #define FLUSH_ITLB
63 #define FLUSH_ITLB_VM(vma)
64
65 #endif
66
67 void local_flush_tlb_all(void)
68 {
69         unsigned long flags;
70         unsigned long old_ctx;
71         int entry;
72
73         ENTER_CRITICAL(flags);
74         /* Save old context and create impossible VPN2 value */
75         old_ctx = read_c0_entryhi();
76         write_c0_entrylo0(0);
77         write_c0_entrylo1(0);
78
79         entry = read_c0_wired();
80
81         /* Blast 'em all away. */
82         while (entry < current_cpu_data.tlbsize) {
83                 /* Make sure all entries differ. */
84                 write_c0_entryhi(UNIQUE_ENTRYHI(entry));
85                 write_c0_index(entry);
86                 mtc0_tlbw_hazard();
87                 tlb_write_indexed();
88                 entry++;
89         }
90         tlbw_use_hazard();
91         write_c0_entryhi(old_ctx);
92         FLUSH_ITLB;
93         EXIT_CRITICAL(flags);
94 }
95
96 /* All entries common to a mm share an asid.  To effectively flush
97    these entries, we just bump the asid. */
98 void local_flush_tlb_mm(struct mm_struct *mm)
99 {
100         int cpu;
101
102         preempt_disable();
103
104         cpu = smp_processor_id();
105
106         if (cpu_context(cpu, mm) != 0) {
107                 drop_mmu_context(mm, cpu);
108         }
109
110         preempt_enable();
111 }
112
113 void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
114         unsigned long end)
115 {
116         struct mm_struct *mm = vma->vm_mm;
117         int cpu = smp_processor_id();
118
119         if (cpu_context(cpu, mm) != 0) {
120                 unsigned long flags;
121                 int size;
122
123                 ENTER_CRITICAL(flags);
124                 size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
125                 size = (size + 1) >> 1;
126                 if (size <= current_cpu_data.tlbsize/2) {
127                         int oldpid = read_c0_entryhi();
128                         int newpid = cpu_asid(cpu, mm);
129
130                         start &= (PAGE_MASK << 1);
131                         end += ((PAGE_SIZE << 1) - 1);
132                         end &= (PAGE_MASK << 1);
133                         while (start < end) {
134                                 int idx;
135
136                                 write_c0_entryhi(start | newpid);
137                                 start += (PAGE_SIZE << 1);
138                                 mtc0_tlbw_hazard();
139                                 tlb_probe();
140                                 tlb_probe_hazard();
141                                 idx = read_c0_index();
142                                 write_c0_entrylo0(0);
143                                 write_c0_entrylo1(0);
144                                 if (idx < 0)
145                                         continue;
146                                 /* Make sure all entries differ. */
147                                 write_c0_entryhi(UNIQUE_ENTRYHI(idx));
148                                 mtc0_tlbw_hazard();
149                                 tlb_write_indexed();
150                         }
151                         tlbw_use_hazard();
152                         write_c0_entryhi(oldpid);
153                 } else {
154                         drop_mmu_context(mm, cpu);
155                 }
156                 FLUSH_ITLB;
157                 EXIT_CRITICAL(flags);
158         }
159 }
160
161 void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
162 {
163         unsigned long flags;
164         int size;
165
166         ENTER_CRITICAL(flags);
167         size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
168         size = (size + 1) >> 1;
169         if (size <= current_cpu_data.tlbsize / 2) {
170                 int pid = read_c0_entryhi();
171
172                 start &= (PAGE_MASK << 1);
173                 end += ((PAGE_SIZE << 1) - 1);
174                 end &= (PAGE_MASK << 1);
175
176                 while (start < end) {
177                         int idx;
178
179                         write_c0_entryhi(start);
180                         start += (PAGE_SIZE << 1);
181                         mtc0_tlbw_hazard();
182                         tlb_probe();
183                         tlb_probe_hazard();
184                         idx = read_c0_index();
185                         write_c0_entrylo0(0);
186                         write_c0_entrylo1(0);
187                         if (idx < 0)
188                                 continue;
189                         /* Make sure all entries differ. */
190                         write_c0_entryhi(UNIQUE_ENTRYHI(idx));
191                         mtc0_tlbw_hazard();
192                         tlb_write_indexed();
193                 }
194                 tlbw_use_hazard();
195                 write_c0_entryhi(pid);
196         } else {
197                 local_flush_tlb_all();
198         }
199         FLUSH_ITLB;
200         EXIT_CRITICAL(flags);
201 }
202
203 void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
204 {
205         int cpu = smp_processor_id();
206
207         if (cpu_context(cpu, vma->vm_mm) != 0) {
208                 unsigned long flags;
209                 int oldpid, newpid, idx;
210
211                 newpid = cpu_asid(cpu, vma->vm_mm);
212                 page &= (PAGE_MASK << 1);
213                 ENTER_CRITICAL(flags);
214                 oldpid = read_c0_entryhi();
215                 write_c0_entryhi(page | newpid);
216                 mtc0_tlbw_hazard();
217                 tlb_probe();
218                 tlb_probe_hazard();
219                 idx = read_c0_index();
220                 write_c0_entrylo0(0);
221                 write_c0_entrylo1(0);
222                 if (idx < 0)
223                         goto finish;
224                 /* Make sure all entries differ. */
225                 write_c0_entryhi(UNIQUE_ENTRYHI(idx));
226                 mtc0_tlbw_hazard();
227                 tlb_write_indexed();
228                 tlbw_use_hazard();
229
230         finish:
231                 write_c0_entryhi(oldpid);
232                 FLUSH_ITLB_VM(vma);
233                 EXIT_CRITICAL(flags);
234         }
235 }
236
237 /*
238  * This one is only used for pages with the global bit set so we don't care
239  * much about the ASID.
240  */
241 void local_flush_tlb_one(unsigned long page)
242 {
243         unsigned long flags;
244         int oldpid, idx;
245
246         ENTER_CRITICAL(flags);
247         oldpid = read_c0_entryhi();
248         page &= (PAGE_MASK << 1);
249         write_c0_entryhi(page);
250         mtc0_tlbw_hazard();
251         tlb_probe();
252         tlb_probe_hazard();
253         idx = read_c0_index();
254         write_c0_entrylo0(0);
255         write_c0_entrylo1(0);
256         if (idx >= 0) {
257                 /* Make sure all entries differ. */
258                 write_c0_entryhi(UNIQUE_ENTRYHI(idx));
259                 mtc0_tlbw_hazard();
260                 tlb_write_indexed();
261                 tlbw_use_hazard();
262         }
263         write_c0_entryhi(oldpid);
264         FLUSH_ITLB;
265         EXIT_CRITICAL(flags);
266 }
267
268 /*
269  * We will need multiple versions of update_mmu_cache(), one that just
270  * updates the TLB with the new pte(s), and another which also checks
271  * for the R4k "end of page" hardware bug and does the needy.
272  */
273 void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
274 {
275         unsigned long flags;
276         pgd_t *pgdp;
277         pud_t *pudp;
278         pmd_t *pmdp;
279         pte_t *ptep;
280         int idx, pid;
281
282         /*
283          * Handle debugger faulting in for debugee.
284          */
285         if (current->active_mm != vma->vm_mm)
286                 return;
287
288         ENTER_CRITICAL(flags);
289
290         pid = read_c0_entryhi() & ASID_MASK;
291         address &= (PAGE_MASK << 1);
292         write_c0_entryhi(address | pid);
293         pgdp = pgd_offset(vma->vm_mm, address);
294         mtc0_tlbw_hazard();
295         tlb_probe();
296         tlb_probe_hazard();
297         pudp = pud_offset(pgdp, address);
298         pmdp = pmd_offset(pudp, address);
299         idx = read_c0_index();
300         ptep = pte_offset_map(pmdp, address);
301
302 #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
303         write_c0_entrylo0(ptep->pte_high);
304         ptep++;
305         write_c0_entrylo1(ptep->pte_high);
306 #else
307         write_c0_entrylo0(pte_val(*ptep++) >> 6);
308         write_c0_entrylo1(pte_val(*ptep) >> 6);
309 #endif
310         mtc0_tlbw_hazard();
311         if (idx < 0)
312                 tlb_write_random();
313         else
314                 tlb_write_indexed();
315         tlbw_use_hazard();
316         FLUSH_ITLB_VM(vma);
317         EXIT_CRITICAL(flags);
318 }
319
320 #if 0
321 static void r4k_update_mmu_cache_hwbug(struct vm_area_struct * vma,
322                                        unsigned long address, pte_t pte)
323 {
324         unsigned long flags;
325         unsigned int asid;
326         pgd_t *pgdp;
327         pmd_t *pmdp;
328         pte_t *ptep;
329         int idx;
330
331         ENTER_CRITICAL(flags);
332         address &= (PAGE_MASK << 1);
333         asid = read_c0_entryhi() & ASID_MASK;
334         write_c0_entryhi(address | asid);
335         pgdp = pgd_offset(vma->vm_mm, address);
336         mtc0_tlbw_hazard();
337         tlb_probe();
338         tlb_probe_hazard();
339         pmdp = pmd_offset(pgdp, address);
340         idx = read_c0_index();
341         ptep = pte_offset_map(pmdp, address);
342         write_c0_entrylo0(pte_val(*ptep++) >> 6);
343         write_c0_entrylo1(pte_val(*ptep) >> 6);
344         mtc0_tlbw_hazard();
345         if (idx < 0)
346                 tlb_write_random();
347         else
348                 tlb_write_indexed();
349         tlbw_use_hazard();
350         EXIT_CRITICAL(flags);
351 }
352 #endif
353
354 void __init add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
355         unsigned long entryhi, unsigned long pagemask)
356 {
357         unsigned long flags;
358         unsigned long wired;
359         unsigned long old_pagemask;
360         unsigned long old_ctx;
361
362         ENTER_CRITICAL(flags);
363         /* Save old context and create impossible VPN2 value */
364         old_ctx = read_c0_entryhi();
365         old_pagemask = read_c0_pagemask();
366         wired = read_c0_wired();
367         write_c0_wired(wired + 1);
368         write_c0_index(wired);
369         tlbw_use_hazard();      /* What is the hazard here? */
370         write_c0_pagemask(pagemask);
371         write_c0_entryhi(entryhi);
372         write_c0_entrylo0(entrylo0);
373         write_c0_entrylo1(entrylo1);
374         mtc0_tlbw_hazard();
375         tlb_write_indexed();
376         tlbw_use_hazard();
377
378         write_c0_entryhi(old_ctx);
379         tlbw_use_hazard();      /* What is the hazard here? */
380         write_c0_pagemask(old_pagemask);
381         local_flush_tlb_all();
382         EXIT_CRITICAL(flags);
383 }
384
385 /*
386  * Used for loading TLB entries before trap_init() has started, when we
387  * don't actually want to add a wired entry which remains throughout the
388  * lifetime of the system
389  */
390
391 static int temp_tlb_entry __cpuinitdata;
392
393 __init int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1,
394                                unsigned long entryhi, unsigned long pagemask)
395 {
396         int ret = 0;
397         unsigned long flags;
398         unsigned long wired;
399         unsigned long old_pagemask;
400         unsigned long old_ctx;
401
402         ENTER_CRITICAL(flags);
403         /* Save old context and create impossible VPN2 value */
404         old_ctx = read_c0_entryhi();
405         old_pagemask = read_c0_pagemask();
406         wired = read_c0_wired();
407         if (--temp_tlb_entry < wired) {
408                 printk(KERN_WARNING
409                        "No TLB space left for add_temporary_entry\n");
410                 ret = -ENOSPC;
411                 goto out;
412         }
413
414         write_c0_index(temp_tlb_entry);
415         write_c0_pagemask(pagemask);
416         write_c0_entryhi(entryhi);
417         write_c0_entrylo0(entrylo0);
418         write_c0_entrylo1(entrylo1);
419         mtc0_tlbw_hazard();
420         tlb_write_indexed();
421         tlbw_use_hazard();
422
423         write_c0_entryhi(old_ctx);
424         write_c0_pagemask(old_pagemask);
425 out:
426         EXIT_CRITICAL(flags);
427         return ret;
428 }
429
430 static void __cpuinit probe_tlb(unsigned long config)
431 {
432         struct cpuinfo_mips *c = &current_cpu_data;
433         unsigned int reg;
434
435         /*
436          * If this isn't a MIPS32 / MIPS64 compliant CPU.  Config 1 register
437          * is not supported, we assume R4k style.  Cpu probing already figured
438          * out the number of tlb entries.
439          */
440         if ((c->processor_id & 0xff0000) == PRID_COMP_LEGACY)
441                 return;
442 #ifdef CONFIG_MIPS_MT_SMTC
443         /*
444          * If TLB is shared in SMTC system, total size already
445          * has been calculated and written into cpu_data tlbsize
446          */
447         if((smtc_status & SMTC_TLB_SHARED) == SMTC_TLB_SHARED)
448                 return;
449 #endif /* CONFIG_MIPS_MT_SMTC */
450
451         reg = read_c0_config1();
452         if (!((config >> 7) & 3))
453                 panic("No TLB present");
454
455         c->tlbsize = ((reg >> 25) & 0x3f) + 1;
456 }
457
458 static int __cpuinitdata ntlb = 0;
459 static int __init set_ntlb(char *str)
460 {
461         get_option(&str, &ntlb);
462         return 1;
463 }
464
465 __setup("ntlb=", set_ntlb);
466
467 void __cpuinit tlb_init(void)
468 {
469         unsigned int config = read_c0_config();
470
471         /*
472          * You should never change this register:
473          *   - On R4600 1.7 the tlbp never hits for pages smaller than
474          *     the value in the c0_pagemask register.
475          *   - The entire mm handling assumes the c0_pagemask register to
476          *     be set to fixed-size pages.
477          */
478         probe_tlb(config);
479         write_c0_pagemask(PM_DEFAULT_MASK);
480         write_c0_wired(0);
481         if (current_cpu_type() == CPU_R10000 ||
482             current_cpu_type() == CPU_R12000 ||
483             current_cpu_type() == CPU_R14000)
484                 write_c0_framemask(0);
485         temp_tlb_entry = current_cpu_data.tlbsize - 1;
486
487         /* From this point on the ARC firmware is dead.  */
488         local_flush_tlb_all();
489
490         /* Did I tell you that ARC SUCKS?  */
491
492         if (ntlb) {
493                 if (ntlb > 1 && ntlb <= current_cpu_data.tlbsize) {
494                         int wired = current_cpu_data.tlbsize - ntlb;
495                         write_c0_wired(wired);
496                         write_c0_index(wired-1);
497                         printk("Restricting TLB to %d entries\n", ntlb);
498                 } else
499                         printk("Ignoring invalid argument ntlb=%d\n", ntlb);
500         }
501
502         build_tlb_refill_handler();
503 }