Merge branch 'omap-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind...
[pandora-kernel.git] / arch / sparc / kernel / perf_event.c
1 /* Performance event support for sparc64.
2  *
3  * Copyright (C) 2009, 2010 David S. Miller <davem@davemloft.net>
4  *
5  * This code is based almost entirely upon the x86 perf event
6  * code, which is:
7  *
8  *  Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
9  *  Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
10  *  Copyright (C) 2009 Jaswinder Singh Rajput
11  *  Copyright (C) 2009 Advanced Micro Devices, Inc., Robert Richter
12  *  Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
13  */
14
15 #include <linux/perf_event.h>
16 #include <linux/kprobes.h>
17 #include <linux/ftrace.h>
18 #include <linux/kernel.h>
19 #include <linux/kdebug.h>
20 #include <linux/mutex.h>
21
22 #include <asm/stacktrace.h>
23 #include <asm/cpudata.h>
24 #include <asm/uaccess.h>
25 #include <asm/atomic.h>
26 #include <asm/nmi.h>
27 #include <asm/pcr.h>
28
29 #include "kstack.h"
30
31 /* Sparc64 chips have two performance counters, 32-bits each, with
32  * overflow interrupts generated on transition from 0xffffffff to 0.
33  * The counters are accessed in one go using a 64-bit register.
34  *
35  * Both counters are controlled using a single control register.  The
36  * only way to stop all sampling is to clear all of the context (user,
37  * supervisor, hypervisor) sampling enable bits.  But these bits apply
38  * to both counters, thus the two counters can't be enabled/disabled
39  * individually.
40  *
41  * The control register has two event fields, one for each of the two
42  * counters.  It's thus nearly impossible to have one counter going
43  * while keeping the other one stopped.  Therefore it is possible to
44  * get overflow interrupts for counters not currently "in use" and
45  * that condition must be checked in the overflow interrupt handler.
46  *
47  * So we use a hack, in that we program inactive counters with the
48  * "sw_count0" and "sw_count1" events.  These count how many times
49  * the instruction "sethi %hi(0xfc000), %g0" is executed.  It's an
50  * unusual way to encode a NOP and therefore will not trigger in
51  * normal code.
52  */
53
54 #define MAX_HWEVENTS                    2
55 #define MAX_PERIOD                      ((1UL << 32) - 1)
56
57 #define PIC_UPPER_INDEX                 0
58 #define PIC_LOWER_INDEX                 1
59 #define PIC_NO_INDEX                    -1
60
61 struct cpu_hw_events {
62         /* Number of events currently scheduled onto this cpu.
63          * This tells how many entries in the arrays below
64          * are valid.
65          */
66         int                     n_events;
67
68         /* Number of new events added since the last hw_perf_disable().
69          * This works because the perf event layer always adds new
70          * events inside of a perf_{disable,enable}() sequence.
71          */
72         int                     n_added;
73
74         /* Array of events current scheduled on this cpu.  */
75         struct perf_event       *event[MAX_HWEVENTS];
76
77         /* Array of encoded longs, specifying the %pcr register
78          * encoding and the mask of PIC counters this even can
79          * be scheduled on.  See perf_event_encode() et al.
80          */
81         unsigned long           events[MAX_HWEVENTS];
82
83         /* The current counter index assigned to an event.  When the
84          * event hasn't been programmed into the cpu yet, this will
85          * hold PIC_NO_INDEX.  The event->hw.idx value tells us where
86          * we ought to schedule the event.
87          */
88         int                     current_idx[MAX_HWEVENTS];
89
90         /* Software copy of %pcr register on this cpu.  */
91         u64                     pcr;
92
93         /* Enabled/disable state.  */
94         int                     enabled;
95 };
96 DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events) = { .enabled = 1, };
97
98 /* An event map describes the characteristics of a performance
99  * counter event.  In particular it gives the encoding as well as
100  * a mask telling which counters the event can be measured on.
101  */
102 struct perf_event_map {
103         u16     encoding;
104         u8      pic_mask;
105 #define PIC_NONE        0x00
106 #define PIC_UPPER       0x01
107 #define PIC_LOWER       0x02
108 };
109
110 /* Encode a perf_event_map entry into a long.  */
111 static unsigned long perf_event_encode(const struct perf_event_map *pmap)
112 {
113         return ((unsigned long) pmap->encoding << 16) | pmap->pic_mask;
114 }
115
116 static u8 perf_event_get_msk(unsigned long val)
117 {
118         return val & 0xff;
119 }
120
121 static u64 perf_event_get_enc(unsigned long val)
122 {
123         return val >> 16;
124 }
125
126 #define C(x) PERF_COUNT_HW_CACHE_##x
127
128 #define CACHE_OP_UNSUPPORTED    0xfffe
129 #define CACHE_OP_NONSENSE       0xffff
130
131 typedef struct perf_event_map cache_map_t
132                                 [PERF_COUNT_HW_CACHE_MAX]
133                                 [PERF_COUNT_HW_CACHE_OP_MAX]
134                                 [PERF_COUNT_HW_CACHE_RESULT_MAX];
135
136 struct sparc_pmu {
137         const struct perf_event_map     *(*event_map)(int);
138         const cache_map_t               *cache_map;
139         int                             max_events;
140         int                             upper_shift;
141         int                             lower_shift;
142         int                             event_mask;
143         int                             hv_bit;
144         int                             irq_bit;
145         int                             upper_nop;
146         int                             lower_nop;
147 };
148
149 static const struct perf_event_map ultra3_perfmon_event_map[] = {
150         [PERF_COUNT_HW_CPU_CYCLES] = { 0x0000, PIC_UPPER | PIC_LOWER },
151         [PERF_COUNT_HW_INSTRUCTIONS] = { 0x0001, PIC_UPPER | PIC_LOWER },
152         [PERF_COUNT_HW_CACHE_REFERENCES] = { 0x0009, PIC_LOWER },
153         [PERF_COUNT_HW_CACHE_MISSES] = { 0x0009, PIC_UPPER },
154 };
155
156 static const struct perf_event_map *ultra3_event_map(int event_id)
157 {
158         return &ultra3_perfmon_event_map[event_id];
159 }
160
161 static const cache_map_t ultra3_cache_map = {
162 [C(L1D)] = {
163         [C(OP_READ)] = {
164                 [C(RESULT_ACCESS)] = { 0x09, PIC_LOWER, },
165                 [C(RESULT_MISS)] = { 0x09, PIC_UPPER, },
166         },
167         [C(OP_WRITE)] = {
168                 [C(RESULT_ACCESS)] = { 0x0a, PIC_LOWER },
169                 [C(RESULT_MISS)] = { 0x0a, PIC_UPPER },
170         },
171         [C(OP_PREFETCH)] = {
172                 [C(RESULT_ACCESS)] = { CACHE_OP_UNSUPPORTED },
173                 [C(RESULT_MISS)] = { CACHE_OP_UNSUPPORTED },
174         },
175 },
176 [C(L1I)] = {
177         [C(OP_READ)] = {
178                 [C(RESULT_ACCESS)] = { 0x09, PIC_LOWER, },
179                 [C(RESULT_MISS)] = { 0x09, PIC_UPPER, },
180         },
181         [ C(OP_WRITE) ] = {
182                 [ C(RESULT_ACCESS) ] = { CACHE_OP_NONSENSE },
183                 [ C(RESULT_MISS)   ] = { CACHE_OP_NONSENSE },
184         },
185         [ C(OP_PREFETCH) ] = {
186                 [ C(RESULT_ACCESS) ] = { CACHE_OP_UNSUPPORTED },
187                 [ C(RESULT_MISS)   ] = { CACHE_OP_UNSUPPORTED },
188         },
189 },
190 [C(LL)] = {
191         [C(OP_READ)] = {
192                 [C(RESULT_ACCESS)] = { 0x0c, PIC_LOWER, },
193                 [C(RESULT_MISS)] = { 0x0c, PIC_UPPER, },
194         },
195         [C(OP_WRITE)] = {
196                 [C(RESULT_ACCESS)] = { 0x0c, PIC_LOWER },
197                 [C(RESULT_MISS)] = { 0x0c, PIC_UPPER },
198         },
199         [C(OP_PREFETCH)] = {
200                 [C(RESULT_ACCESS)] = { CACHE_OP_UNSUPPORTED },
201                 [C(RESULT_MISS)] = { CACHE_OP_UNSUPPORTED },
202         },
203 },
204 [C(DTLB)] = {
205         [C(OP_READ)] = {
206                 [C(RESULT_ACCESS)] = { CACHE_OP_UNSUPPORTED },
207                 [C(RESULT_MISS)] = { 0x12, PIC_UPPER, },
208         },
209         [ C(OP_WRITE) ] = {
210                 [ C(RESULT_ACCESS) ] = { CACHE_OP_UNSUPPORTED },
211                 [ C(RESULT_MISS)   ] = { CACHE_OP_UNSUPPORTED },
212         },
213         [ C(OP_PREFETCH) ] = {
214                 [ C(RESULT_ACCESS) ] = { CACHE_OP_UNSUPPORTED },
215                 [ C(RESULT_MISS)   ] = { CACHE_OP_UNSUPPORTED },
216         },
217 },
218 [C(ITLB)] = {
219         [C(OP_READ)] = {
220                 [C(RESULT_ACCESS)] = { CACHE_OP_UNSUPPORTED },
221                 [C(RESULT_MISS)] = { 0x11, PIC_UPPER, },
222         },
223         [ C(OP_WRITE) ] = {
224                 [ C(RESULT_ACCESS) ] = { CACHE_OP_UNSUPPORTED },
225                 [ C(RESULT_MISS)   ] = { CACHE_OP_UNSUPPORTED },
226         },
227         [ C(OP_PREFETCH) ] = {
228                 [ C(RESULT_ACCESS) ] = { CACHE_OP_UNSUPPORTED },
229                 [ C(RESULT_MISS)   ] = { CACHE_OP_UNSUPPORTED },
230         },
231 },
232 [C(BPU)] = {
233         [C(OP_READ)] = {
234                 [C(RESULT_ACCESS)] = { CACHE_OP_UNSUPPORTED },
235                 [C(RESULT_MISS)] = { CACHE_OP_UNSUPPORTED },
236         },
237         [ C(OP_WRITE) ] = {
238                 [ C(RESULT_ACCESS) ] = { CACHE_OP_UNSUPPORTED },
239                 [ C(RESULT_MISS)   ] = { CACHE_OP_UNSUPPORTED },
240         },
241         [ C(OP_PREFETCH) ] = {
242                 [ C(RESULT_ACCESS) ] = { CACHE_OP_UNSUPPORTED },
243                 [ C(RESULT_MISS)   ] = { CACHE_OP_UNSUPPORTED },
244         },
245 },
246 };
247
248 static const struct sparc_pmu ultra3_pmu = {
249         .event_map      = ultra3_event_map,
250         .cache_map      = &ultra3_cache_map,
251         .max_events     = ARRAY_SIZE(ultra3_perfmon_event_map),
252         .upper_shift    = 11,
253         .lower_shift    = 4,
254         .event_mask     = 0x3f,
255         .upper_nop      = 0x1c,
256         .lower_nop      = 0x14,
257 };
258
259 /* Niagara1 is very limited.  The upper PIC is hard-locked to count
260  * only instructions, so it is free running which creates all kinds of
261  * problems.  Some hardware designs make one wonder if the creator
262  * even looked at how this stuff gets used by software.
263  */
264 static const struct perf_event_map niagara1_perfmon_event_map[] = {
265         [PERF_COUNT_HW_CPU_CYCLES] = { 0x00, PIC_UPPER },
266         [PERF_COUNT_HW_INSTRUCTIONS] = { 0x00, PIC_UPPER },
267         [PERF_COUNT_HW_CACHE_REFERENCES] = { 0, PIC_NONE },
268         [PERF_COUNT_HW_CACHE_MISSES] = { 0x03, PIC_LOWER },
269 };
270
271 static const struct perf_event_map *niagara1_event_map(int event_id)
272 {
273         return &niagara1_perfmon_event_map[event_id];
274 }
275
276 static const cache_map_t niagara1_cache_map = {
277 [C(L1D)] = {
278         [C(OP_READ)] = {
279                 [C(RESULT_ACCESS)] = { CACHE_OP_UNSUPPORTED },
280                 [C(RESULT_MISS)] = { 0x03, PIC_LOWER, },
281         },
282         [C(OP_WRITE)] = {
283                 [C(RESULT_ACCESS)] = { CACHE_OP_UNSUPPORTED },
284                 [C(RESULT_MISS)] = { 0x03, PIC_LOWER, },
285         },
286         [C(OP_PREFETCH)] = {
287                 [C(RESULT_ACCESS)] = { CACHE_OP_UNSUPPORTED },
288                 [C(RESULT_MISS)] = { CACHE_OP_UNSUPPORTED },
289         },
290 },
291 [C(L1I)] = {
292         [C(OP_READ)] = {
293                 [C(RESULT_ACCESS)] = { 0x00, PIC_UPPER },
294                 [C(RESULT_MISS)] = { 0x02, PIC_LOWER, },
295         },
296         [ C(OP_WRITE) ] = {
297                 [ C(RESULT_ACCESS) ] = { CACHE_OP_NONSENSE },
298                 [ C(RESULT_MISS)   ] = { CACHE_OP_NONSENSE },
299         },
300         [ C(OP_PREFETCH) ] = {
301                 [ C(RESULT_ACCESS) ] = { CACHE_OP_UNSUPPORTED },
302                 [ C(RESULT_MISS)   ] = { CACHE_OP_UNSUPPORTED },
303         },
304 },
305 [C(LL)] = {
306         [C(OP_READ)] = {
307                 [C(RESULT_ACCESS)] = { CACHE_OP_UNSUPPORTED },
308                 [C(RESULT_MISS)] = { 0x07, PIC_LOWER, },
309         },
310         [C(OP_WRITE)] = {
311                 [C(RESULT_ACCESS)] = { CACHE_OP_UNSUPPORTED },
312                 [C(RESULT_MISS)] = { 0x07, PIC_LOWER, },
313         },
314         [C(OP_PREFETCH)] = {
315                 [C(RESULT_ACCESS)] = { CACHE_OP_UNSUPPORTED },
316                 [C(RESULT_MISS)] = { CACHE_OP_UNSUPPORTED },
317         },
318 },
319 [C(DTLB)] = {
320         [C(OP_READ)] = {
321                 [C(RESULT_ACCESS)] = { CACHE_OP_UNSUPPORTED },
322                 [C(RESULT_MISS)] = { 0x05, PIC_LOWER, },
323         },
324         [ C(OP_WRITE) ] = {
325                 [ C(RESULT_ACCESS) ] = { CACHE_OP_UNSUPPORTED },
326                 [ C(RESULT_MISS)   ] = { CACHE_OP_UNSUPPORTED },
327         },
328         [ C(OP_PREFETCH) ] = {
329                 [ C(RESULT_ACCESS) ] = { CACHE_OP_UNSUPPORTED },
330                 [ C(RESULT_MISS)   ] = { CACHE_OP_UNSUPPORTED },
331         },
332 },
333 [C(ITLB)] = {
334         [C(OP_READ)] = {
335                 [C(RESULT_ACCESS)] = { CACHE_OP_UNSUPPORTED },
336                 [C(RESULT_MISS)] = { 0x04, PIC_LOWER, },
337         },
338         [ C(OP_WRITE) ] = {
339                 [ C(RESULT_ACCESS) ] = { CACHE_OP_UNSUPPORTED },
340                 [ C(RESULT_MISS)   ] = { CACHE_OP_UNSUPPORTED },
341         },
342         [ C(OP_PREFETCH) ] = {
343                 [ C(RESULT_ACCESS) ] = { CACHE_OP_UNSUPPORTED },
344                 [ C(RESULT_MISS)   ] = { CACHE_OP_UNSUPPORTED },
345         },
346 },
347 [C(BPU)] = {
348         [C(OP_READ)] = {
349                 [C(RESULT_ACCESS)] = { CACHE_OP_UNSUPPORTED },
350                 [C(RESULT_MISS)] = { CACHE_OP_UNSUPPORTED },
351         },
352         [ C(OP_WRITE) ] = {
353                 [ C(RESULT_ACCESS) ] = { CACHE_OP_UNSUPPORTED },
354                 [ C(RESULT_MISS)   ] = { CACHE_OP_UNSUPPORTED },
355         },
356         [ C(OP_PREFETCH) ] = {
357                 [ C(RESULT_ACCESS) ] = { CACHE_OP_UNSUPPORTED },
358                 [ C(RESULT_MISS)   ] = { CACHE_OP_UNSUPPORTED },
359         },
360 },
361 };
362
363 static const struct sparc_pmu niagara1_pmu = {
364         .event_map      = niagara1_event_map,
365         .cache_map      = &niagara1_cache_map,
366         .max_events     = ARRAY_SIZE(niagara1_perfmon_event_map),
367         .upper_shift    = 0,
368         .lower_shift    = 4,
369         .event_mask     = 0x7,
370         .upper_nop      = 0x0,
371         .lower_nop      = 0x0,
372 };
373
374 static const struct perf_event_map niagara2_perfmon_event_map[] = {
375         [PERF_COUNT_HW_CPU_CYCLES] = { 0x02ff, PIC_UPPER | PIC_LOWER },
376         [PERF_COUNT_HW_INSTRUCTIONS] = { 0x02ff, PIC_UPPER | PIC_LOWER },
377         [PERF_COUNT_HW_CACHE_REFERENCES] = { 0x0208, PIC_UPPER | PIC_LOWER },
378         [PERF_COUNT_HW_CACHE_MISSES] = { 0x0302, PIC_UPPER | PIC_LOWER },
379         [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = { 0x0201, PIC_UPPER | PIC_LOWER },
380         [PERF_COUNT_HW_BRANCH_MISSES] = { 0x0202, PIC_UPPER | PIC_LOWER },
381 };
382
383 static const struct perf_event_map *niagara2_event_map(int event_id)
384 {
385         return &niagara2_perfmon_event_map[event_id];
386 }
387
388 static const cache_map_t niagara2_cache_map = {
389 [C(L1D)] = {
390         [C(OP_READ)] = {
391                 [C(RESULT_ACCESS)] = { 0x0208, PIC_UPPER | PIC_LOWER, },
392                 [C(RESULT_MISS)] = { 0x0302, PIC_UPPER | PIC_LOWER, },
393         },
394         [C(OP_WRITE)] = {
395                 [C(RESULT_ACCESS)] = { 0x0210, PIC_UPPER | PIC_LOWER, },
396                 [C(RESULT_MISS)] = { 0x0302, PIC_UPPER | PIC_LOWER, },
397         },
398         [C(OP_PREFETCH)] = {
399                 [C(RESULT_ACCESS)] = { CACHE_OP_UNSUPPORTED },
400                 [C(RESULT_MISS)] = { CACHE_OP_UNSUPPORTED },
401         },
402 },
403 [C(L1I)] = {
404         [C(OP_READ)] = {
405                 [C(RESULT_ACCESS)] = { 0x02ff, PIC_UPPER | PIC_LOWER, },
406                 [C(RESULT_MISS)] = { 0x0301, PIC_UPPER | PIC_LOWER, },
407         },
408         [ C(OP_WRITE) ] = {
409                 [ C(RESULT_ACCESS) ] = { CACHE_OP_NONSENSE },
410                 [ C(RESULT_MISS)   ] = { CACHE_OP_NONSENSE },
411         },
412         [ C(OP_PREFETCH) ] = {
413                 [ C(RESULT_ACCESS) ] = { CACHE_OP_UNSUPPORTED },
414                 [ C(RESULT_MISS)   ] = { CACHE_OP_UNSUPPORTED },
415         },
416 },
417 [C(LL)] = {
418         [C(OP_READ)] = {
419                 [C(RESULT_ACCESS)] = { 0x0208, PIC_UPPER | PIC_LOWER, },
420                 [C(RESULT_MISS)] = { 0x0330, PIC_UPPER | PIC_LOWER, },
421         },
422         [C(OP_WRITE)] = {
423                 [C(RESULT_ACCESS)] = { 0x0210, PIC_UPPER | PIC_LOWER, },
424                 [C(RESULT_MISS)] = { 0x0320, PIC_UPPER | PIC_LOWER, },
425         },
426         [C(OP_PREFETCH)] = {
427                 [C(RESULT_ACCESS)] = { CACHE_OP_UNSUPPORTED },
428                 [C(RESULT_MISS)] = { CACHE_OP_UNSUPPORTED },
429         },
430 },
431 [C(DTLB)] = {
432         [C(OP_READ)] = {
433                 [C(RESULT_ACCESS)] = { CACHE_OP_UNSUPPORTED },
434                 [C(RESULT_MISS)] = { 0x0b08, PIC_UPPER | PIC_LOWER, },
435         },
436         [ C(OP_WRITE) ] = {
437                 [ C(RESULT_ACCESS) ] = { CACHE_OP_UNSUPPORTED },
438                 [ C(RESULT_MISS)   ] = { CACHE_OP_UNSUPPORTED },
439         },
440         [ C(OP_PREFETCH) ] = {
441                 [ C(RESULT_ACCESS) ] = { CACHE_OP_UNSUPPORTED },
442                 [ C(RESULT_MISS)   ] = { CACHE_OP_UNSUPPORTED },
443         },
444 },
445 [C(ITLB)] = {
446         [C(OP_READ)] = {
447                 [C(RESULT_ACCESS)] = { CACHE_OP_UNSUPPORTED },
448                 [C(RESULT_MISS)] = { 0xb04, PIC_UPPER | PIC_LOWER, },
449         },
450         [ C(OP_WRITE) ] = {
451                 [ C(RESULT_ACCESS) ] = { CACHE_OP_UNSUPPORTED },
452                 [ C(RESULT_MISS)   ] = { CACHE_OP_UNSUPPORTED },
453         },
454         [ C(OP_PREFETCH) ] = {
455                 [ C(RESULT_ACCESS) ] = { CACHE_OP_UNSUPPORTED },
456                 [ C(RESULT_MISS)   ] = { CACHE_OP_UNSUPPORTED },
457         },
458 },
459 [C(BPU)] = {
460         [C(OP_READ)] = {
461                 [C(RESULT_ACCESS)] = { CACHE_OP_UNSUPPORTED },
462                 [C(RESULT_MISS)] = { CACHE_OP_UNSUPPORTED },
463         },
464         [ C(OP_WRITE) ] = {
465                 [ C(RESULT_ACCESS) ] = { CACHE_OP_UNSUPPORTED },
466                 [ C(RESULT_MISS)   ] = { CACHE_OP_UNSUPPORTED },
467         },
468         [ C(OP_PREFETCH) ] = {
469                 [ C(RESULT_ACCESS) ] = { CACHE_OP_UNSUPPORTED },
470                 [ C(RESULT_MISS)   ] = { CACHE_OP_UNSUPPORTED },
471         },
472 },
473 };
474
475 static const struct sparc_pmu niagara2_pmu = {
476         .event_map      = niagara2_event_map,
477         .cache_map      = &niagara2_cache_map,
478         .max_events     = ARRAY_SIZE(niagara2_perfmon_event_map),
479         .upper_shift    = 19,
480         .lower_shift    = 6,
481         .event_mask     = 0xfff,
482         .hv_bit         = 0x8,
483         .irq_bit        = 0x30,
484         .upper_nop      = 0x220,
485         .lower_nop      = 0x220,
486 };
487
488 static const struct sparc_pmu *sparc_pmu __read_mostly;
489
490 static u64 event_encoding(u64 event_id, int idx)
491 {
492         if (idx == PIC_UPPER_INDEX)
493                 event_id <<= sparc_pmu->upper_shift;
494         else
495                 event_id <<= sparc_pmu->lower_shift;
496         return event_id;
497 }
498
499 static u64 mask_for_index(int idx)
500 {
501         return event_encoding(sparc_pmu->event_mask, idx);
502 }
503
504 static u64 nop_for_index(int idx)
505 {
506         return event_encoding(idx == PIC_UPPER_INDEX ?
507                               sparc_pmu->upper_nop :
508                               sparc_pmu->lower_nop, idx);
509 }
510
511 static inline void sparc_pmu_enable_event(struct cpu_hw_events *cpuc, struct hw_perf_event *hwc, int idx)
512 {
513         u64 val, mask = mask_for_index(idx);
514
515         val = cpuc->pcr;
516         val &= ~mask;
517         val |= hwc->config;
518         cpuc->pcr = val;
519
520         pcr_ops->write(cpuc->pcr);
521 }
522
523 static inline void sparc_pmu_disable_event(struct cpu_hw_events *cpuc, struct hw_perf_event *hwc, int idx)
524 {
525         u64 mask = mask_for_index(idx);
526         u64 nop = nop_for_index(idx);
527         u64 val;
528
529         val = cpuc->pcr;
530         val &= ~mask;
531         val |= nop;
532         cpuc->pcr = val;
533
534         pcr_ops->write(cpuc->pcr);
535 }
536
537 static u32 read_pmc(int idx)
538 {
539         u64 val;
540
541         read_pic(val);
542         if (idx == PIC_UPPER_INDEX)
543                 val >>= 32;
544
545         return val & 0xffffffff;
546 }
547
548 static void write_pmc(int idx, u64 val)
549 {
550         u64 shift, mask, pic;
551
552         shift = 0;
553         if (idx == PIC_UPPER_INDEX)
554                 shift = 32;
555
556         mask = ((u64) 0xffffffff) << shift;
557         val <<= shift;
558
559         read_pic(pic);
560         pic &= ~mask;
561         pic |= val;
562         write_pic(pic);
563 }
564
565 static u64 sparc_perf_event_update(struct perf_event *event,
566                                    struct hw_perf_event *hwc, int idx)
567 {
568         int shift = 64 - 32;
569         u64 prev_raw_count, new_raw_count;
570         s64 delta;
571
572 again:
573         prev_raw_count = atomic64_read(&hwc->prev_count);
574         new_raw_count = read_pmc(idx);
575
576         if (atomic64_cmpxchg(&hwc->prev_count, prev_raw_count,
577                              new_raw_count) != prev_raw_count)
578                 goto again;
579
580         delta = (new_raw_count << shift) - (prev_raw_count << shift);
581         delta >>= shift;
582
583         atomic64_add(delta, &event->count);
584         atomic64_sub(delta, &hwc->period_left);
585
586         return new_raw_count;
587 }
588
589 static int sparc_perf_event_set_period(struct perf_event *event,
590                                        struct hw_perf_event *hwc, int idx)
591 {
592         s64 left = atomic64_read(&hwc->period_left);
593         s64 period = hwc->sample_period;
594         int ret = 0;
595
596         if (unlikely(left <= -period)) {
597                 left = period;
598                 atomic64_set(&hwc->period_left, left);
599                 hwc->last_period = period;
600                 ret = 1;
601         }
602
603         if (unlikely(left <= 0)) {
604                 left += period;
605                 atomic64_set(&hwc->period_left, left);
606                 hwc->last_period = period;
607                 ret = 1;
608         }
609         if (left > MAX_PERIOD)
610                 left = MAX_PERIOD;
611
612         atomic64_set(&hwc->prev_count, (u64)-left);
613
614         write_pmc(idx, (u64)(-left) & 0xffffffff);
615
616         perf_event_update_userpage(event);
617
618         return ret;
619 }
620
621 /* If performance event entries have been added, move existing
622  * events around (if necessary) and then assign new entries to
623  * counters.
624  */
625 static u64 maybe_change_configuration(struct cpu_hw_events *cpuc, u64 pcr)
626 {
627         int i;
628
629         if (!cpuc->n_added)
630                 goto out;
631
632         /* Read in the counters which are moving.  */
633         for (i = 0; i < cpuc->n_events; i++) {
634                 struct perf_event *cp = cpuc->event[i];
635
636                 if (cpuc->current_idx[i] != PIC_NO_INDEX &&
637                     cpuc->current_idx[i] != cp->hw.idx) {
638                         sparc_perf_event_update(cp, &cp->hw,
639                                                 cpuc->current_idx[i]);
640                         cpuc->current_idx[i] = PIC_NO_INDEX;
641                 }
642         }
643
644         /* Assign to counters all unassigned events.  */
645         for (i = 0; i < cpuc->n_events; i++) {
646                 struct perf_event *cp = cpuc->event[i];
647                 struct hw_perf_event *hwc = &cp->hw;
648                 int idx = hwc->idx;
649                 u64 enc;
650
651                 if (cpuc->current_idx[i] != PIC_NO_INDEX)
652                         continue;
653
654                 sparc_perf_event_set_period(cp, hwc, idx);
655                 cpuc->current_idx[i] = idx;
656
657                 enc = perf_event_get_enc(cpuc->events[i]);
658                 pcr |= event_encoding(enc, idx);
659         }
660 out:
661         return pcr;
662 }
663
664 void hw_perf_enable(void)
665 {
666         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
667         u64 pcr;
668
669         if (cpuc->enabled)
670                 return;
671
672         cpuc->enabled = 1;
673         barrier();
674
675         pcr = cpuc->pcr;
676         if (!cpuc->n_events) {
677                 pcr = 0;
678         } else {
679                 pcr = maybe_change_configuration(cpuc, pcr);
680
681                 /* We require that all of the events have the same
682                  * configuration, so just fetch the settings from the
683                  * first entry.
684                  */
685                 cpuc->pcr = pcr | cpuc->event[0]->hw.config_base;
686         }
687
688         pcr_ops->write(cpuc->pcr);
689 }
690
691 void hw_perf_disable(void)
692 {
693         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
694         u64 val;
695
696         if (!cpuc->enabled)
697                 return;
698
699         cpuc->enabled = 0;
700         cpuc->n_added = 0;
701
702         val = cpuc->pcr;
703         val &= ~(PCR_UTRACE | PCR_STRACE |
704                  sparc_pmu->hv_bit | sparc_pmu->irq_bit);
705         cpuc->pcr = val;
706
707         pcr_ops->write(cpuc->pcr);
708 }
709
710 static void sparc_pmu_disable(struct perf_event *event)
711 {
712         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
713         struct hw_perf_event *hwc = &event->hw;
714         unsigned long flags;
715         int i;
716
717         local_irq_save(flags);
718         perf_disable();
719
720         for (i = 0; i < cpuc->n_events; i++) {
721                 if (event == cpuc->event[i]) {
722                         int idx = cpuc->current_idx[i];
723
724                         /* Shift remaining entries down into
725                          * the existing slot.
726                          */
727                         while (++i < cpuc->n_events) {
728                                 cpuc->event[i - 1] = cpuc->event[i];
729                                 cpuc->events[i - 1] = cpuc->events[i];
730                                 cpuc->current_idx[i - 1] =
731                                         cpuc->current_idx[i];
732                         }
733
734                         /* Absorb the final count and turn off the
735                          * event.
736                          */
737                         sparc_pmu_disable_event(cpuc, hwc, idx);
738                         barrier();
739                         sparc_perf_event_update(event, hwc, idx);
740
741                         perf_event_update_userpage(event);
742
743                         cpuc->n_events--;
744                         break;
745                 }
746         }
747
748         perf_enable();
749         local_irq_restore(flags);
750 }
751
752 static int active_event_index(struct cpu_hw_events *cpuc,
753                               struct perf_event *event)
754 {
755         int i;
756
757         for (i = 0; i < cpuc->n_events; i++) {
758                 if (cpuc->event[i] == event)
759                         break;
760         }
761         BUG_ON(i == cpuc->n_events);
762         return cpuc->current_idx[i];
763 }
764
765 static void sparc_pmu_read(struct perf_event *event)
766 {
767         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
768         int idx = active_event_index(cpuc, event);
769         struct hw_perf_event *hwc = &event->hw;
770
771         sparc_perf_event_update(event, hwc, idx);
772 }
773
774 static void sparc_pmu_unthrottle(struct perf_event *event)
775 {
776         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
777         int idx = active_event_index(cpuc, event);
778         struct hw_perf_event *hwc = &event->hw;
779
780         sparc_pmu_enable_event(cpuc, hwc, idx);
781 }
782
783 static atomic_t active_events = ATOMIC_INIT(0);
784 static DEFINE_MUTEX(pmc_grab_mutex);
785
786 static void perf_stop_nmi_watchdog(void *unused)
787 {
788         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
789
790         stop_nmi_watchdog(NULL);
791         cpuc->pcr = pcr_ops->read();
792 }
793
794 void perf_event_grab_pmc(void)
795 {
796         if (atomic_inc_not_zero(&active_events))
797                 return;
798
799         mutex_lock(&pmc_grab_mutex);
800         if (atomic_read(&active_events) == 0) {
801                 if (atomic_read(&nmi_active) > 0) {
802                         on_each_cpu(perf_stop_nmi_watchdog, NULL, 1);
803                         BUG_ON(atomic_read(&nmi_active) != 0);
804                 }
805                 atomic_inc(&active_events);
806         }
807         mutex_unlock(&pmc_grab_mutex);
808 }
809
810 void perf_event_release_pmc(void)
811 {
812         if (atomic_dec_and_mutex_lock(&active_events, &pmc_grab_mutex)) {
813                 if (atomic_read(&nmi_active) == 0)
814                         on_each_cpu(start_nmi_watchdog, NULL, 1);
815                 mutex_unlock(&pmc_grab_mutex);
816         }
817 }
818
819 static const struct perf_event_map *sparc_map_cache_event(u64 config)
820 {
821         unsigned int cache_type, cache_op, cache_result;
822         const struct perf_event_map *pmap;
823
824         if (!sparc_pmu->cache_map)
825                 return ERR_PTR(-ENOENT);
826
827         cache_type = (config >>  0) & 0xff;
828         if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
829                 return ERR_PTR(-EINVAL);
830
831         cache_op = (config >>  8) & 0xff;
832         if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX)
833                 return ERR_PTR(-EINVAL);
834
835         cache_result = (config >> 16) & 0xff;
836         if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
837                 return ERR_PTR(-EINVAL);
838
839         pmap = &((*sparc_pmu->cache_map)[cache_type][cache_op][cache_result]);
840
841         if (pmap->encoding == CACHE_OP_UNSUPPORTED)
842                 return ERR_PTR(-ENOENT);
843
844         if (pmap->encoding == CACHE_OP_NONSENSE)
845                 return ERR_PTR(-EINVAL);
846
847         return pmap;
848 }
849
850 static void hw_perf_event_destroy(struct perf_event *event)
851 {
852         perf_event_release_pmc();
853 }
854
855 /* Make sure all events can be scheduled into the hardware at
856  * the same time.  This is simplified by the fact that we only
857  * need to support 2 simultaneous HW events.
858  *
859  * As a side effect, the evts[]->hw.idx values will be assigned
860  * on success.  These are pending indexes.  When the events are
861  * actually programmed into the chip, these values will propagate
862  * to the per-cpu cpuc->current_idx[] slots, see the code in
863  * maybe_change_configuration() for details.
864  */
865 static int sparc_check_constraints(struct perf_event **evts,
866                                    unsigned long *events, int n_ev)
867 {
868         u8 msk0 = 0, msk1 = 0;
869         int idx0 = 0;
870
871         /* This case is possible when we are invoked from
872          * hw_perf_group_sched_in().
873          */
874         if (!n_ev)
875                 return 0;
876
877         if (n_ev > perf_max_events)
878                 return -1;
879
880         msk0 = perf_event_get_msk(events[0]);
881         if (n_ev == 1) {
882                 if (msk0 & PIC_LOWER)
883                         idx0 = 1;
884                 goto success;
885         }
886         BUG_ON(n_ev != 2);
887         msk1 = perf_event_get_msk(events[1]);
888
889         /* If both events can go on any counter, OK.  */
890         if (msk0 == (PIC_UPPER | PIC_LOWER) &&
891             msk1 == (PIC_UPPER | PIC_LOWER))
892                 goto success;
893
894         /* If one event is limited to a specific counter,
895          * and the other can go on both, OK.
896          */
897         if ((msk0 == PIC_UPPER || msk0 == PIC_LOWER) &&
898             msk1 == (PIC_UPPER | PIC_LOWER)) {
899                 if (msk0 & PIC_LOWER)
900                         idx0 = 1;
901                 goto success;
902         }
903
904         if ((msk1 == PIC_UPPER || msk1 == PIC_LOWER) &&
905             msk0 == (PIC_UPPER | PIC_LOWER)) {
906                 if (msk1 & PIC_UPPER)
907                         idx0 = 1;
908                 goto success;
909         }
910
911         /* If the events are fixed to different counters, OK.  */
912         if ((msk0 == PIC_UPPER && msk1 == PIC_LOWER) ||
913             (msk0 == PIC_LOWER && msk1 == PIC_UPPER)) {
914                 if (msk0 & PIC_LOWER)
915                         idx0 = 1;
916                 goto success;
917         }
918
919         /* Otherwise, there is a conflict.  */
920         return -1;
921
922 success:
923         evts[0]->hw.idx = idx0;
924         if (n_ev == 2)
925                 evts[1]->hw.idx = idx0 ^ 1;
926         return 0;
927 }
928
929 static int check_excludes(struct perf_event **evts, int n_prev, int n_new)
930 {
931         int eu = 0, ek = 0, eh = 0;
932         struct perf_event *event;
933         int i, n, first;
934
935         n = n_prev + n_new;
936         if (n <= 1)
937                 return 0;
938
939         first = 1;
940         for (i = 0; i < n; i++) {
941                 event = evts[i];
942                 if (first) {
943                         eu = event->attr.exclude_user;
944                         ek = event->attr.exclude_kernel;
945                         eh = event->attr.exclude_hv;
946                         first = 0;
947                 } else if (event->attr.exclude_user != eu ||
948                            event->attr.exclude_kernel != ek ||
949                            event->attr.exclude_hv != eh) {
950                         return -EAGAIN;
951                 }
952         }
953
954         return 0;
955 }
956
957 static int collect_events(struct perf_event *group, int max_count,
958                           struct perf_event *evts[], unsigned long *events,
959                           int *current_idx)
960 {
961         struct perf_event *event;
962         int n = 0;
963
964         if (!is_software_event(group)) {
965                 if (n >= max_count)
966                         return -1;
967                 evts[n] = group;
968                 events[n] = group->hw.event_base;
969                 current_idx[n++] = PIC_NO_INDEX;
970         }
971         list_for_each_entry(event, &group->sibling_list, group_entry) {
972                 if (!is_software_event(event) &&
973                     event->state != PERF_EVENT_STATE_OFF) {
974                         if (n >= max_count)
975                                 return -1;
976                         evts[n] = event;
977                         events[n] = event->hw.event_base;
978                         current_idx[n++] = PIC_NO_INDEX;
979                 }
980         }
981         return n;
982 }
983
984 static void event_sched_in(struct perf_event *event)
985 {
986         event->state = PERF_EVENT_STATE_ACTIVE;
987         event->oncpu = smp_processor_id();
988         event->tstamp_running += event->ctx->time - event->tstamp_stopped;
989         if (is_software_event(event))
990                 event->pmu->enable(event);
991 }
992
993 int hw_perf_group_sched_in(struct perf_event *group_leader,
994                            struct perf_cpu_context *cpuctx,
995                            struct perf_event_context *ctx)
996 {
997         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
998         struct perf_event *sub;
999         int n0, n;
1000
1001         if (!sparc_pmu)
1002                 return 0;
1003
1004         n0 = cpuc->n_events;
1005         n = collect_events(group_leader, perf_max_events - n0,
1006                            &cpuc->event[n0], &cpuc->events[n0],
1007                            &cpuc->current_idx[n0]);
1008         if (n < 0)
1009                 return -EAGAIN;
1010         if (check_excludes(cpuc->event, n0, n))
1011                 return -EINVAL;
1012         if (sparc_check_constraints(cpuc->event, cpuc->events, n + n0))
1013                 return -EAGAIN;
1014         cpuc->n_events = n0 + n;
1015         cpuc->n_added += n;
1016
1017         cpuctx->active_oncpu += n;
1018         n = 1;
1019         event_sched_in(group_leader);
1020         list_for_each_entry(sub, &group_leader->sibling_list, group_entry) {
1021                 if (sub->state != PERF_EVENT_STATE_OFF) {
1022                         event_sched_in(sub);
1023                         n++;
1024                 }
1025         }
1026         ctx->nr_active += n;
1027
1028         return 1;
1029 }
1030
1031 static int sparc_pmu_enable(struct perf_event *event)
1032 {
1033         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
1034         int n0, ret = -EAGAIN;
1035         unsigned long flags;
1036
1037         local_irq_save(flags);
1038         perf_disable();
1039
1040         n0 = cpuc->n_events;
1041         if (n0 >= perf_max_events)
1042                 goto out;
1043
1044         cpuc->event[n0] = event;
1045         cpuc->events[n0] = event->hw.event_base;
1046         cpuc->current_idx[n0] = PIC_NO_INDEX;
1047
1048         if (check_excludes(cpuc->event, n0, 1))
1049                 goto out;
1050         if (sparc_check_constraints(cpuc->event, cpuc->events, n0 + 1))
1051                 goto out;
1052
1053         cpuc->n_events++;
1054         cpuc->n_added++;
1055
1056         ret = 0;
1057 out:
1058         perf_enable();
1059         local_irq_restore(flags);
1060         return ret;
1061 }
1062
1063 static int __hw_perf_event_init(struct perf_event *event)
1064 {
1065         struct perf_event_attr *attr = &event->attr;
1066         struct perf_event *evts[MAX_HWEVENTS];
1067         struct hw_perf_event *hwc = &event->hw;
1068         unsigned long events[MAX_HWEVENTS];
1069         int current_idx_dmy[MAX_HWEVENTS];
1070         const struct perf_event_map *pmap;
1071         int n;
1072
1073         if (atomic_read(&nmi_active) < 0)
1074                 return -ENODEV;
1075
1076         if (attr->type == PERF_TYPE_HARDWARE) {
1077                 if (attr->config >= sparc_pmu->max_events)
1078                         return -EINVAL;
1079                 pmap = sparc_pmu->event_map(attr->config);
1080         } else if (attr->type == PERF_TYPE_HW_CACHE) {
1081                 pmap = sparc_map_cache_event(attr->config);
1082                 if (IS_ERR(pmap))
1083                         return PTR_ERR(pmap);
1084         } else
1085                 return -EOPNOTSUPP;
1086
1087         /* We save the enable bits in the config_base.  */
1088         hwc->config_base = sparc_pmu->irq_bit;
1089         if (!attr->exclude_user)
1090                 hwc->config_base |= PCR_UTRACE;
1091         if (!attr->exclude_kernel)
1092                 hwc->config_base |= PCR_STRACE;
1093         if (!attr->exclude_hv)
1094                 hwc->config_base |= sparc_pmu->hv_bit;
1095
1096         hwc->event_base = perf_event_encode(pmap);
1097
1098         n = 0;
1099         if (event->group_leader != event) {
1100                 n = collect_events(event->group_leader,
1101                                    perf_max_events - 1,
1102                                    evts, events, current_idx_dmy);
1103                 if (n < 0)
1104                         return -EINVAL;
1105         }
1106         events[n] = hwc->event_base;
1107         evts[n] = event;
1108
1109         if (check_excludes(evts, n, 1))
1110                 return -EINVAL;
1111
1112         if (sparc_check_constraints(evts, events, n + 1))
1113                 return -EINVAL;
1114
1115         hwc->idx = PIC_NO_INDEX;
1116
1117         /* Try to do all error checking before this point, as unwinding
1118          * state after grabbing the PMC is difficult.
1119          */
1120         perf_event_grab_pmc();
1121         event->destroy = hw_perf_event_destroy;
1122
1123         if (!hwc->sample_period) {
1124                 hwc->sample_period = MAX_PERIOD;
1125                 hwc->last_period = hwc->sample_period;
1126                 atomic64_set(&hwc->period_left, hwc->sample_period);
1127         }
1128
1129         return 0;
1130 }
1131
1132 static const struct pmu pmu = {
1133         .enable         = sparc_pmu_enable,
1134         .disable        = sparc_pmu_disable,
1135         .read           = sparc_pmu_read,
1136         .unthrottle     = sparc_pmu_unthrottle,
1137 };
1138
1139 const struct pmu *hw_perf_event_init(struct perf_event *event)
1140 {
1141         int err = __hw_perf_event_init(event);
1142
1143         if (err)
1144                 return ERR_PTR(err);
1145         return &pmu;
1146 }
1147
1148 void perf_event_print_debug(void)
1149 {
1150         unsigned long flags;
1151         u64 pcr, pic;
1152         int cpu;
1153
1154         if (!sparc_pmu)
1155                 return;
1156
1157         local_irq_save(flags);
1158
1159         cpu = smp_processor_id();
1160
1161         pcr = pcr_ops->read();
1162         read_pic(pic);
1163
1164         pr_info("\n");
1165         pr_info("CPU#%d: PCR[%016llx] PIC[%016llx]\n",
1166                 cpu, pcr, pic);
1167
1168         local_irq_restore(flags);
1169 }
1170
1171 static int __kprobes perf_event_nmi_handler(struct notifier_block *self,
1172                                             unsigned long cmd, void *__args)
1173 {
1174         struct die_args *args = __args;
1175         struct perf_sample_data data;
1176         struct cpu_hw_events *cpuc;
1177         struct pt_regs *regs;
1178         int i;
1179
1180         if (!atomic_read(&active_events))
1181                 return NOTIFY_DONE;
1182
1183         switch (cmd) {
1184         case DIE_NMI:
1185                 break;
1186
1187         default:
1188                 return NOTIFY_DONE;
1189         }
1190
1191         regs = args->regs;
1192
1193         perf_sample_data_init(&data, 0);
1194
1195         cpuc = &__get_cpu_var(cpu_hw_events);
1196
1197         /* If the PMU has the TOE IRQ enable bits, we need to do a
1198          * dummy write to the %pcr to clear the overflow bits and thus
1199          * the interrupt.
1200          *
1201          * Do this before we peek at the counters to determine
1202          * overflow so we don't lose any events.
1203          */
1204         if (sparc_pmu->irq_bit)
1205                 pcr_ops->write(cpuc->pcr);
1206
1207         for (i = 0; i < cpuc->n_events; i++) {
1208                 struct perf_event *event = cpuc->event[i];
1209                 int idx = cpuc->current_idx[i];
1210                 struct hw_perf_event *hwc;
1211                 u64 val;
1212
1213                 hwc = &event->hw;
1214                 val = sparc_perf_event_update(event, hwc, idx);
1215                 if (val & (1ULL << 31))
1216                         continue;
1217
1218                 data.period = event->hw.last_period;
1219                 if (!sparc_perf_event_set_period(event, hwc, idx))
1220                         continue;
1221
1222                 if (perf_event_overflow(event, 1, &data, regs))
1223                         sparc_pmu_disable_event(cpuc, hwc, idx);
1224         }
1225
1226         return NOTIFY_STOP;
1227 }
1228
1229 static __read_mostly struct notifier_block perf_event_nmi_notifier = {
1230         .notifier_call          = perf_event_nmi_handler,
1231 };
1232
1233 static bool __init supported_pmu(void)
1234 {
1235         if (!strcmp(sparc_pmu_type, "ultra3") ||
1236             !strcmp(sparc_pmu_type, "ultra3+") ||
1237             !strcmp(sparc_pmu_type, "ultra3i") ||
1238             !strcmp(sparc_pmu_type, "ultra4+")) {
1239                 sparc_pmu = &ultra3_pmu;
1240                 return true;
1241         }
1242         if (!strcmp(sparc_pmu_type, "niagara")) {
1243                 sparc_pmu = &niagara1_pmu;
1244                 return true;
1245         }
1246         if (!strcmp(sparc_pmu_type, "niagara2")) {
1247                 sparc_pmu = &niagara2_pmu;
1248                 return true;
1249         }
1250         return false;
1251 }
1252
1253 void __init init_hw_perf_events(void)
1254 {
1255         pr_info("Performance events: ");
1256
1257         if (!supported_pmu()) {
1258                 pr_cont("No support for PMU type '%s'\n", sparc_pmu_type);
1259                 return;
1260         }
1261
1262         pr_cont("Supported PMU type is '%s'\n", sparc_pmu_type);
1263
1264         /* All sparc64 PMUs currently have 2 events.  */
1265         perf_max_events = 2;
1266
1267         register_die_notifier(&perf_event_nmi_notifier);
1268 }
1269
1270 static inline void callchain_store(struct perf_callchain_entry *entry, u64 ip)
1271 {
1272         if (entry->nr < PERF_MAX_STACK_DEPTH)
1273                 entry->ip[entry->nr++] = ip;
1274 }
1275
1276 static void perf_callchain_kernel(struct pt_regs *regs,
1277                                   struct perf_callchain_entry *entry)
1278 {
1279         unsigned long ksp, fp;
1280 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1281         int graph = 0;
1282 #endif
1283
1284         callchain_store(entry, PERF_CONTEXT_KERNEL);
1285         callchain_store(entry, regs->tpc);
1286
1287         ksp = regs->u_regs[UREG_I6];
1288         fp = ksp + STACK_BIAS;
1289         do {
1290                 struct sparc_stackf *sf;
1291                 struct pt_regs *regs;
1292                 unsigned long pc;
1293
1294                 if (!kstack_valid(current_thread_info(), fp))
1295                         break;
1296
1297                 sf = (struct sparc_stackf *) fp;
1298                 regs = (struct pt_regs *) (sf + 1);
1299
1300                 if (kstack_is_trap_frame(current_thread_info(), regs)) {
1301                         if (user_mode(regs))
1302                                 break;
1303                         pc = regs->tpc;
1304                         fp = regs->u_regs[UREG_I6] + STACK_BIAS;
1305                 } else {
1306                         pc = sf->callers_pc;
1307                         fp = (unsigned long)sf->fp + STACK_BIAS;
1308                 }
1309                 callchain_store(entry, pc);
1310 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1311                 if ((pc + 8UL) == (unsigned long) &return_to_handler) {
1312                         int index = current->curr_ret_stack;
1313                         if (current->ret_stack && index >= graph) {
1314                                 pc = current->ret_stack[index - graph].ret;
1315                                 callchain_store(entry, pc);
1316                                 graph++;
1317                         }
1318                 }
1319 #endif
1320         } while (entry->nr < PERF_MAX_STACK_DEPTH);
1321 }
1322
1323 static void perf_callchain_user_64(struct pt_regs *regs,
1324                                    struct perf_callchain_entry *entry)
1325 {
1326         unsigned long ufp;
1327
1328         callchain_store(entry, PERF_CONTEXT_USER);
1329         callchain_store(entry, regs->tpc);
1330
1331         ufp = regs->u_regs[UREG_I6] + STACK_BIAS;
1332         do {
1333                 struct sparc_stackf *usf, sf;
1334                 unsigned long pc;
1335
1336                 usf = (struct sparc_stackf *) ufp;
1337                 if (__copy_from_user_inatomic(&sf, usf, sizeof(sf)))
1338                         break;
1339
1340                 pc = sf.callers_pc;
1341                 ufp = (unsigned long)sf.fp + STACK_BIAS;
1342                 callchain_store(entry, pc);
1343         } while (entry->nr < PERF_MAX_STACK_DEPTH);
1344 }
1345
1346 static void perf_callchain_user_32(struct pt_regs *regs,
1347                                    struct perf_callchain_entry *entry)
1348 {
1349         unsigned long ufp;
1350
1351         callchain_store(entry, PERF_CONTEXT_USER);
1352         callchain_store(entry, regs->tpc);
1353
1354         ufp = regs->u_regs[UREG_I6] & 0xffffffffUL;
1355         do {
1356                 struct sparc_stackf32 *usf, sf;
1357                 unsigned long pc;
1358
1359                 usf = (struct sparc_stackf32 *) ufp;
1360                 if (__copy_from_user_inatomic(&sf, usf, sizeof(sf)))
1361                         break;
1362
1363                 pc = sf.callers_pc;
1364                 ufp = (unsigned long)sf.fp;
1365                 callchain_store(entry, pc);
1366         } while (entry->nr < PERF_MAX_STACK_DEPTH);
1367 }
1368
1369 /* Like powerpc we can't get PMU interrupts within the PMU handler,
1370  * so no need for separate NMI and IRQ chains as on x86.
1371  */
1372 static DEFINE_PER_CPU(struct perf_callchain_entry, callchain);
1373
1374 struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
1375 {
1376         struct perf_callchain_entry *entry = &__get_cpu_var(callchain);
1377
1378         entry->nr = 0;
1379         if (!user_mode(regs)) {
1380                 stack_trace_flush();
1381                 perf_callchain_kernel(regs, entry);
1382                 if (current->mm)
1383                         regs = task_pt_regs(current);
1384                 else
1385                         regs = NULL;
1386         }
1387         if (regs) {
1388                 flushw_user();
1389                 if (test_thread_flag(TIF_32BIT))
1390                         perf_callchain_user_32(regs, entry);
1391                 else
1392                         perf_callchain_user_64(regs, entry);
1393         }
1394         return entry;
1395 }