x86/oprofile: Fix uninitialized variable use in debug printk
[pandora-kernel.git] / arch / x86 / oprofile / op_model_amd.c
1 /*
2  * @file op_model_amd.c
3  * athlon / K7 / K8 / Family 10h model-specific MSR operations
4  *
5  * @remark Copyright 2002-2009 OProfile authors
6  * @remark Read the file COPYING
7  *
8  * @author John Levon
9  * @author Philippe Elie
10  * @author Graydon Hoare
11  * @author Robert Richter <robert.richter@amd.com>
12  * @author Barry Kasindorf <barry.kasindorf@amd.com>
13  * @author Jason Yeh <jason.yeh@amd.com>
14  * @author Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
15  */
16
17 #include <linux/oprofile.h>
18 #include <linux/device.h>
19 #include <linux/pci.h>
20 #include <linux/percpu.h>
21
22 #include <asm/ptrace.h>
23 #include <asm/msr.h>
24 #include <asm/nmi.h>
25 #include <asm/apic.h>
26 #include <asm/processor.h>
27 #include <asm/cpufeature.h>
28
29 #include "op_x86_model.h"
30 #include "op_counter.h"
31
32 #define NUM_COUNTERS 4
33 #ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
34 #define NUM_VIRT_COUNTERS 32
35 #else
36 #define NUM_VIRT_COUNTERS NUM_COUNTERS
37 #endif
38
39 #define OP_EVENT_MASK                   0x0FFF
40 #define OP_CTR_OVERFLOW                 (1ULL<<31)
41
42 #define MSR_AMD_EVENTSEL_RESERVED       ((0xFFFFFCF0ULL<<32)|(1ULL<<21))
43
44 static unsigned long reset_value[NUM_VIRT_COUNTERS];
45
46 #define IBS_FETCH_SIZE                  6
47 #define IBS_OP_SIZE                     12
48
49 static u32 ibs_caps;
50
51 struct op_ibs_config {
52         unsigned long op_enabled;
53         unsigned long fetch_enabled;
54         unsigned long max_cnt_fetch;
55         unsigned long max_cnt_op;
56         unsigned long rand_en;
57         unsigned long dispatched_ops;
58 };
59
60 static struct op_ibs_config ibs_config;
61 static u64 ibs_op_ctl;
62
63 /*
64  * IBS cpuid feature detection
65  */
66
67 #define IBS_CPUID_FEATURES              0x8000001b
68
69 /*
70  * Same bit mask as for IBS cpuid feature flags (Fn8000_001B_EAX), but
71  * bit 0 is used to indicate the existence of IBS.
72  */
73 #define IBS_CAPS_AVAIL                  (1U<<0)
74 #define IBS_CAPS_RDWROPCNT              (1U<<3)
75 #define IBS_CAPS_OPCNT                  (1U<<4)
76
77 /*
78  * IBS APIC setup
79  */
80 #define IBSCTL                          0x1cc
81 #define IBSCTL_LVT_OFFSET_VALID         (1ULL<<8)
82 #define IBSCTL_LVT_OFFSET_MASK          0x0F
83
84 /*
85  * IBS randomization macros
86  */
87 #define IBS_RANDOM_BITS                 12
88 #define IBS_RANDOM_MASK                 ((1ULL << IBS_RANDOM_BITS) - 1)
89 #define IBS_RANDOM_MAXCNT_OFFSET        (1ULL << (IBS_RANDOM_BITS - 5))
90
91 static u32 get_ibs_caps(void)
92 {
93         u32 ibs_caps;
94         unsigned int max_level;
95
96         if (!boot_cpu_has(X86_FEATURE_IBS))
97                 return 0;
98
99         /* check IBS cpuid feature flags */
100         max_level = cpuid_eax(0x80000000);
101         if (max_level < IBS_CPUID_FEATURES)
102                 return IBS_CAPS_AVAIL;
103
104         ibs_caps = cpuid_eax(IBS_CPUID_FEATURES);
105         if (!(ibs_caps & IBS_CAPS_AVAIL))
106                 /* cpuid flags not valid */
107                 return IBS_CAPS_AVAIL;
108
109         return ibs_caps;
110 }
111
112 /*
113  * 16-bit Linear Feedback Shift Register (LFSR)
114  *
115  *                       16   14   13    11
116  * Feedback polynomial = X  + X  + X  +  X  + 1
117  */
118 static unsigned int lfsr_random(void)
119 {
120         static unsigned int lfsr_value = 0xF00D;
121         unsigned int bit;
122
123         /* Compute next bit to shift in */
124         bit = ((lfsr_value >> 0) ^
125                (lfsr_value >> 2) ^
126                (lfsr_value >> 3) ^
127                (lfsr_value >> 5)) & 0x0001;
128
129         /* Advance to next register value */
130         lfsr_value = (lfsr_value >> 1) | (bit << 15);
131
132         return lfsr_value;
133 }
134
135 /*
136  * IBS software randomization
137  *
138  * The IBS periodic op counter is randomized in software. The lower 12
139  * bits of the 20 bit counter are randomized. IbsOpCurCnt is
140  * initialized with a 12 bit random value.
141  */
142 static inline u64 op_amd_randomize_ibs_op(u64 val)
143 {
144         unsigned int random = lfsr_random();
145
146         if (!(ibs_caps & IBS_CAPS_RDWROPCNT))
147                 /*
148                  * Work around if the hw can not write to IbsOpCurCnt
149                  *
150                  * Randomize the lower 8 bits of the 16 bit
151                  * IbsOpMaxCnt [15:0] value in the range of -128 to
152                  * +127 by adding/subtracting an offset to the
153                  * maximum count (IbsOpMaxCnt).
154                  *
155                  * To avoid over or underflows and protect upper bits
156                  * starting at bit 16, the initial value for
157                  * IbsOpMaxCnt must fit in the range from 0x0081 to
158                  * 0xff80.
159                  */
160                 val += (s8)(random >> 4);
161         else
162                 val |= (u64)(random & IBS_RANDOM_MASK) << 32;
163
164         return val;
165 }
166
167 static inline void
168 op_amd_handle_ibs(struct pt_regs * const regs,
169                   struct op_msrs const * const msrs)
170 {
171         u64 val, ctl;
172         struct op_entry entry;
173
174         if (!ibs_caps)
175                 return;
176
177         if (ibs_config.fetch_enabled) {
178                 rdmsrl(MSR_AMD64_IBSFETCHCTL, ctl);
179                 if (ctl & IBS_FETCH_VAL) {
180                         rdmsrl(MSR_AMD64_IBSFETCHLINAD, val);
181                         oprofile_write_reserve(&entry, regs, val,
182                                                IBS_FETCH_CODE, IBS_FETCH_SIZE);
183                         oprofile_add_data64(&entry, val);
184                         oprofile_add_data64(&entry, ctl);
185                         rdmsrl(MSR_AMD64_IBSFETCHPHYSAD, val);
186                         oprofile_add_data64(&entry, val);
187                         oprofile_write_commit(&entry);
188
189                         /* reenable the IRQ */
190                         ctl &= ~(IBS_FETCH_VAL | IBS_FETCH_CNT);
191                         ctl |= IBS_FETCH_ENABLE;
192                         wrmsrl(MSR_AMD64_IBSFETCHCTL, ctl);
193                 }
194         }
195
196         if (ibs_config.op_enabled) {
197                 rdmsrl(MSR_AMD64_IBSOPCTL, ctl);
198                 if (ctl & IBS_OP_VAL) {
199                         rdmsrl(MSR_AMD64_IBSOPRIP, val);
200                         oprofile_write_reserve(&entry, regs, val,
201                                                IBS_OP_CODE, IBS_OP_SIZE);
202                         oprofile_add_data64(&entry, val);
203                         rdmsrl(MSR_AMD64_IBSOPDATA, val);
204                         oprofile_add_data64(&entry, val);
205                         rdmsrl(MSR_AMD64_IBSOPDATA2, val);
206                         oprofile_add_data64(&entry, val);
207                         rdmsrl(MSR_AMD64_IBSOPDATA3, val);
208                         oprofile_add_data64(&entry, val);
209                         rdmsrl(MSR_AMD64_IBSDCLINAD, val);
210                         oprofile_add_data64(&entry, val);
211                         rdmsrl(MSR_AMD64_IBSDCPHYSAD, val);
212                         oprofile_add_data64(&entry, val);
213                         oprofile_write_commit(&entry);
214
215                         /* reenable the IRQ */
216                         ctl = op_amd_randomize_ibs_op(ibs_op_ctl);
217                         wrmsrl(MSR_AMD64_IBSOPCTL, ctl);
218                 }
219         }
220 }
221
222 static inline void op_amd_start_ibs(void)
223 {
224         u64 val;
225
226         if (!ibs_caps)
227                 return;
228
229         if (ibs_config.fetch_enabled) {
230                 val = (ibs_config.max_cnt_fetch >> 4) & IBS_FETCH_MAX_CNT;
231                 val |= ibs_config.rand_en ? IBS_FETCH_RAND_EN : 0;
232                 val |= IBS_FETCH_ENABLE;
233                 wrmsrl(MSR_AMD64_IBSFETCHCTL, val);
234         }
235
236         if (ibs_config.op_enabled) {
237                 ibs_op_ctl = ibs_config.max_cnt_op >> 4;
238                 if (!(ibs_caps & IBS_CAPS_RDWROPCNT)) {
239                         /*
240                          * IbsOpCurCnt not supported.  See
241                          * op_amd_randomize_ibs_op() for details.
242                          */
243                         ibs_op_ctl = clamp(ibs_op_ctl, 0x0081ULL, 0xFF80ULL);
244                 } else {
245                         /*
246                          * The start value is randomized with a
247                          * positive offset, we need to compensate it
248                          * with the half of the randomized range. Also
249                          * avoid underflows.
250                          */
251                         ibs_op_ctl = min(ibs_op_ctl + IBS_RANDOM_MAXCNT_OFFSET,
252                                          IBS_OP_MAX_CNT);
253                 }
254                 if (ibs_caps & IBS_CAPS_OPCNT && ibs_config.dispatched_ops)
255                         ibs_op_ctl |= IBS_OP_CNT_CTL;
256                 ibs_op_ctl |= IBS_OP_ENABLE;
257                 val = op_amd_randomize_ibs_op(ibs_op_ctl);
258                 wrmsrl(MSR_AMD64_IBSOPCTL, val);
259         }
260 }
261
262 static void op_amd_stop_ibs(void)
263 {
264         if (!ibs_caps)
265                 return;
266
267         if (ibs_config.fetch_enabled)
268                 /* clear max count and enable */
269                 wrmsrl(MSR_AMD64_IBSFETCHCTL, 0);
270
271         if (ibs_config.op_enabled)
272                 /* clear max count and enable */
273                 wrmsrl(MSR_AMD64_IBSOPCTL, 0);
274 }
275
276 static inline int eilvt_is_available(int offset)
277 {
278         /* check if we may assign a vector */
279         return !setup_APIC_eilvt(offset, 0, APIC_EILVT_MSG_NMI, 1);
280 }
281
282 static inline int ibs_eilvt_valid(void)
283 {
284         int offset;
285         u64 val;
286
287         rdmsrl(MSR_AMD64_IBSCTL, val);
288         offset = val & IBSCTL_LVT_OFFSET_MASK;
289
290         if (!(val & IBSCTL_LVT_OFFSET_VALID)) {
291                 pr_err(FW_BUG "cpu %d, invalid IBS interrupt offset %d (MSR%08X=0x%016llx)\n",
292                        smp_processor_id(), offset, MSR_AMD64_IBSCTL, val);
293                 return 0;
294         }
295
296         if (!eilvt_is_available(offset)) {
297                 pr_err(FW_BUG "cpu %d, IBS interrupt offset %d not available (MSR%08X=0x%016llx)\n",
298                        smp_processor_id(), offset, MSR_AMD64_IBSCTL, val);
299                 return 0;
300         }
301
302         return 1;
303 }
304
305 static inline int get_ibs_offset(void)
306 {
307         u64 val;
308
309         rdmsrl(MSR_AMD64_IBSCTL, val);
310         if (!(val & IBSCTL_LVT_OFFSET_VALID))
311                 return -EINVAL;
312
313         return val & IBSCTL_LVT_OFFSET_MASK;
314 }
315
316 static void setup_APIC_ibs(void)
317 {
318         int offset;
319
320         offset = get_ibs_offset();
321         if (offset < 0)
322                 goto failed;
323
324         if (!setup_APIC_eilvt(offset, 0, APIC_EILVT_MSG_NMI, 0))
325                 return;
326 failed:
327         pr_warn("oprofile: IBS APIC setup failed on cpu #%d\n",
328                 smp_processor_id());
329 }
330
331 static void clear_APIC_ibs(void)
332 {
333         int offset;
334
335         offset = get_ibs_offset();
336         if (offset >= 0)
337                 setup_APIC_eilvt(offset, 0, APIC_EILVT_MSG_FIX, 1);
338 }
339
340 #ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
341
342 static void op_mux_switch_ctrl(struct op_x86_model_spec const *model,
343                                struct op_msrs const * const msrs)
344 {
345         u64 val;
346         int i;
347
348         /* enable active counters */
349         for (i = 0; i < NUM_COUNTERS; ++i) {
350                 int virt = op_x86_phys_to_virt(i);
351                 if (!reset_value[virt])
352                         continue;
353                 rdmsrl(msrs->controls[i].addr, val);
354                 val &= model->reserved;
355                 val |= op_x86_get_ctrl(model, &counter_config[virt]);
356                 wrmsrl(msrs->controls[i].addr, val);
357         }
358 }
359
360 #endif
361
362 /* functions for op_amd_spec */
363
364 static void op_amd_shutdown(struct op_msrs const * const msrs)
365 {
366         int i;
367
368         for (i = 0; i < NUM_COUNTERS; ++i) {
369                 if (!msrs->counters[i].addr)
370                         continue;
371                 release_perfctr_nmi(MSR_K7_PERFCTR0 + i);
372                 release_evntsel_nmi(MSR_K7_EVNTSEL0 + i);
373         }
374 }
375
376 static int op_amd_fill_in_addresses(struct op_msrs * const msrs)
377 {
378         int i;
379
380         for (i = 0; i < NUM_COUNTERS; i++) {
381                 if (!reserve_perfctr_nmi(MSR_K7_PERFCTR0 + i))
382                         goto fail;
383                 if (!reserve_evntsel_nmi(MSR_K7_EVNTSEL0 + i)) {
384                         release_perfctr_nmi(MSR_K7_PERFCTR0 + i);
385                         goto fail;
386                 }
387                 /* both registers must be reserved */
388                 msrs->counters[i].addr = MSR_K7_PERFCTR0 + i;
389                 msrs->controls[i].addr = MSR_K7_EVNTSEL0 + i;
390                 continue;
391         fail:
392                 if (!counter_config[i].enabled)
393                         continue;
394                 op_x86_warn_reserved(i);
395                 op_amd_shutdown(msrs);
396                 return -EBUSY;
397         }
398
399         return 0;
400 }
401
402 static void op_amd_setup_ctrs(struct op_x86_model_spec const *model,
403                               struct op_msrs const * const msrs)
404 {
405         u64 val;
406         int i;
407
408         /* setup reset_value */
409         for (i = 0; i < NUM_VIRT_COUNTERS; ++i) {
410                 if (counter_config[i].enabled
411                     && msrs->counters[op_x86_virt_to_phys(i)].addr)
412                         reset_value[i] = counter_config[i].count;
413                 else
414                         reset_value[i] = 0;
415         }
416
417         /* clear all counters */
418         for (i = 0; i < NUM_COUNTERS; ++i) {
419                 if (!msrs->controls[i].addr)
420                         continue;
421                 rdmsrl(msrs->controls[i].addr, val);
422                 if (val & ARCH_PERFMON_EVENTSEL_ENABLE)
423                         op_x86_warn_in_use(i);
424                 val &= model->reserved;
425                 wrmsrl(msrs->controls[i].addr, val);
426                 /*
427                  * avoid a false detection of ctr overflows in NMI
428                  * handler
429                  */
430                 wrmsrl(msrs->counters[i].addr, -1LL);
431         }
432
433         /* enable active counters */
434         for (i = 0; i < NUM_COUNTERS; ++i) {
435                 int virt = op_x86_phys_to_virt(i);
436                 if (!reset_value[virt])
437                         continue;
438
439                 /* setup counter registers */
440                 wrmsrl(msrs->counters[i].addr, -(u64)reset_value[virt]);
441
442                 /* setup control registers */
443                 rdmsrl(msrs->controls[i].addr, val);
444                 val &= model->reserved;
445                 val |= op_x86_get_ctrl(model, &counter_config[virt]);
446                 wrmsrl(msrs->controls[i].addr, val);
447         }
448
449         if (ibs_caps)
450                 setup_APIC_ibs();
451 }
452
453 static void op_amd_cpu_shutdown(void)
454 {
455         if (ibs_caps)
456                 clear_APIC_ibs();
457 }
458
459 static int op_amd_check_ctrs(struct pt_regs * const regs,
460                              struct op_msrs const * const msrs)
461 {
462         u64 val;
463         int i;
464
465         for (i = 0; i < NUM_COUNTERS; ++i) {
466                 int virt = op_x86_phys_to_virt(i);
467                 if (!reset_value[virt])
468                         continue;
469                 rdmsrl(msrs->counters[i].addr, val);
470                 /* bit is clear if overflowed: */
471                 if (val & OP_CTR_OVERFLOW)
472                         continue;
473                 oprofile_add_sample(regs, virt);
474                 wrmsrl(msrs->counters[i].addr, -(u64)reset_value[virt]);
475         }
476
477         op_amd_handle_ibs(regs, msrs);
478
479         /* See op_model_ppro.c */
480         return 1;
481 }
482
483 static void op_amd_start(struct op_msrs const * const msrs)
484 {
485         u64 val;
486         int i;
487
488         for (i = 0; i < NUM_COUNTERS; ++i) {
489                 if (!reset_value[op_x86_phys_to_virt(i)])
490                         continue;
491                 rdmsrl(msrs->controls[i].addr, val);
492                 val |= ARCH_PERFMON_EVENTSEL_ENABLE;
493                 wrmsrl(msrs->controls[i].addr, val);
494         }
495
496         op_amd_start_ibs();
497 }
498
499 static void op_amd_stop(struct op_msrs const * const msrs)
500 {
501         u64 val;
502         int i;
503
504         /*
505          * Subtle: stop on all counters to avoid race with setting our
506          * pm callback
507          */
508         for (i = 0; i < NUM_COUNTERS; ++i) {
509                 if (!reset_value[op_x86_phys_to_virt(i)])
510                         continue;
511                 rdmsrl(msrs->controls[i].addr, val);
512                 val &= ~ARCH_PERFMON_EVENTSEL_ENABLE;
513                 wrmsrl(msrs->controls[i].addr, val);
514         }
515
516         op_amd_stop_ibs();
517 }
518
519 static int setup_ibs_ctl(int ibs_eilvt_off)
520 {
521         struct pci_dev *cpu_cfg;
522         int nodes;
523         u32 value = 0;
524
525         nodes = 0;
526         cpu_cfg = NULL;
527         do {
528                 cpu_cfg = pci_get_device(PCI_VENDOR_ID_AMD,
529                                          PCI_DEVICE_ID_AMD_10H_NB_MISC,
530                                          cpu_cfg);
531                 if (!cpu_cfg)
532                         break;
533                 ++nodes;
534                 pci_write_config_dword(cpu_cfg, IBSCTL, ibs_eilvt_off
535                                        | IBSCTL_LVT_OFFSET_VALID);
536                 pci_read_config_dword(cpu_cfg, IBSCTL, &value);
537                 if (value != (ibs_eilvt_off | IBSCTL_LVT_OFFSET_VALID)) {
538                         pci_dev_put(cpu_cfg);
539                         printk(KERN_DEBUG "Failed to setup IBS LVT offset, "
540                                "IBSCTL = 0x%08x\n", value);
541                         return -EINVAL;
542                 }
543         } while (1);
544
545         if (!nodes) {
546                 printk(KERN_DEBUG "No CPU node configured for IBS\n");
547                 return -ENODEV;
548         }
549
550         return 0;
551 }
552
553 static int force_ibs_eilvt_setup(void)
554 {
555         int i;
556         int ret;
557
558         /* find the next free available EILVT entry */
559         for (i = 1; i < 4; i++) {
560                 if (!eilvt_is_available(i))
561                         continue;
562                 ret = setup_ibs_ctl(i);
563                 if (ret)
564                         return ret;
565                 return 0;
566         }
567
568         printk(KERN_DEBUG "No EILVT entry available\n");
569
570         return -EBUSY;
571 }
572
573 static int __init_ibs_nmi(void)
574 {
575         int ret;
576
577         if (ibs_eilvt_valid())
578                 return 0;
579
580         ret = force_ibs_eilvt_setup();
581         if (ret)
582                 return ret;
583
584         if (!ibs_eilvt_valid())
585                 return -EFAULT;
586
587         pr_err(FW_BUG "workaround enabled for IBS LVT offset\n");
588
589         return 0;
590 }
591
592 /* initialize the APIC for the IBS interrupts if available */
593 static void init_ibs(void)
594 {
595         ibs_caps = get_ibs_caps();
596
597         if (!ibs_caps)
598                 return;
599
600         if (__init_ibs_nmi()) {
601                 ibs_caps = 0;
602                 return;
603         }
604
605         printk(KERN_INFO "oprofile: AMD IBS detected (0x%08x)\n",
606                (unsigned)ibs_caps);
607 }
608
609 static int (*create_arch_files)(struct super_block *sb, struct dentry *root);
610
611 static int setup_ibs_files(struct super_block *sb, struct dentry *root)
612 {
613         struct dentry *dir;
614         int ret = 0;
615
616         /* architecture specific files */
617         if (create_arch_files)
618                 ret = create_arch_files(sb, root);
619
620         if (ret)
621                 return ret;
622
623         if (!ibs_caps)
624                 return ret;
625
626         /* model specific files */
627
628         /* setup some reasonable defaults */
629         ibs_config.max_cnt_fetch = 250000;
630         ibs_config.fetch_enabled = 0;
631         ibs_config.max_cnt_op = 250000;
632         ibs_config.op_enabled = 0;
633         ibs_config.dispatched_ops = 0;
634
635         dir = oprofilefs_mkdir(sb, root, "ibs_fetch");
636         oprofilefs_create_ulong(sb, dir, "enable",
637                                 &ibs_config.fetch_enabled);
638         oprofilefs_create_ulong(sb, dir, "max_count",
639                                 &ibs_config.max_cnt_fetch);
640         oprofilefs_create_ulong(sb, dir, "rand_enable",
641                                 &ibs_config.rand_en);
642
643         dir = oprofilefs_mkdir(sb, root, "ibs_op");
644         oprofilefs_create_ulong(sb, dir, "enable",
645                                 &ibs_config.op_enabled);
646         oprofilefs_create_ulong(sb, dir, "max_count",
647                                 &ibs_config.max_cnt_op);
648         if (ibs_caps & IBS_CAPS_OPCNT)
649                 oprofilefs_create_ulong(sb, dir, "dispatched_ops",
650                                         &ibs_config.dispatched_ops);
651
652         return 0;
653 }
654
655 static int op_amd_init(struct oprofile_operations *ops)
656 {
657         init_ibs();
658         create_arch_files = ops->create_files;
659         ops->create_files = setup_ibs_files;
660         return 0;
661 }
662
663 struct op_x86_model_spec op_amd_spec = {
664         .num_counters           = NUM_COUNTERS,
665         .num_controls           = NUM_COUNTERS,
666         .num_virt_counters      = NUM_VIRT_COUNTERS,
667         .reserved               = MSR_AMD_EVENTSEL_RESERVED,
668         .event_mask             = OP_EVENT_MASK,
669         .init                   = op_amd_init,
670         .fill_in_addresses      = &op_amd_fill_in_addresses,
671         .setup_ctrs             = &op_amd_setup_ctrs,
672         .cpu_down               = &op_amd_cpu_shutdown,
673         .check_ctrs             = &op_amd_check_ctrs,
674         .start                  = &op_amd_start,
675         .stop                   = &op_amd_stop,
676         .shutdown               = &op_amd_shutdown,
677 #ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
678         .switch_ctrl            = &op_mux_switch_ctrl,
679 #endif
680 };