treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / arch / mips / sibyte / common / sb_tbprof.c
blobf80d7a7103339e9eaae5e4710df92fa090cd75b1
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
4 * Copyright (C) 2001, 2002, 2003 Broadcom Corporation
5 * Copyright (C) 2007 Ralf Baechle <ralf@linux-mips.org>
6 * Copyright (C) 2007 MIPS Technologies, Inc.
7 * written by Ralf Baechle <ralf@linux-mips.org>
8 */
10 #undef DEBUG
12 #include <linux/device.h>
13 #include <linux/module.h>
14 #include <linux/kernel.h>
15 #include <linux/types.h>
16 #include <linux/init.h>
17 #include <linux/interrupt.h>
18 #include <linux/sched.h>
19 #include <linux/vmalloc.h>
20 #include <linux/fs.h>
21 #include <linux/errno.h>
22 #include <linux/wait.h>
23 #include <asm/io.h>
24 #include <asm/sibyte/sb1250.h>
26 #if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
27 #include <asm/sibyte/bcm1480_regs.h>
28 #include <asm/sibyte/bcm1480_scd.h>
29 #include <asm/sibyte/bcm1480_int.h>
30 #elif defined(CONFIG_SIBYTE_SB1250) || defined(CONFIG_SIBYTE_BCM112X)
31 #include <asm/sibyte/sb1250_regs.h>
32 #include <asm/sibyte/sb1250_scd.h>
33 #include <asm/sibyte/sb1250_int.h>
34 #else
35 #error invalid SiByte UART configuration
36 #endif
38 #if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
39 #undef K_INT_TRACE_FREEZE
40 #define K_INT_TRACE_FREEZE K_BCM1480_INT_TRACE_FREEZE
41 #undef K_INT_PERF_CNT
42 #define K_INT_PERF_CNT K_BCM1480_INT_PERF_CNT
43 #endif
45 #include <linux/uaccess.h>
47 #define SBPROF_TB_MAJOR 240
49 typedef u64 tb_sample_t[6*256];
51 enum open_status {
52 SB_CLOSED,
53 SB_OPENING,
54 SB_OPEN
57 struct sbprof_tb {
58 wait_queue_head_t tb_sync;
59 wait_queue_head_t tb_read;
60 struct mutex lock;
61 enum open_status open;
62 tb_sample_t *sbprof_tbbuf;
63 int next_tb_sample;
65 volatile int tb_enable;
66 volatile int tb_armed;
70 static struct sbprof_tb sbp;
72 #define MAX_SAMPLE_BYTES (24*1024*1024)
73 #define MAX_TBSAMPLE_BYTES (12*1024*1024)
75 #define MAX_SAMPLES (MAX_SAMPLE_BYTES/sizeof(u_int32_t))
76 #define TB_SAMPLE_SIZE (sizeof(tb_sample_t))
77 #define MAX_TB_SAMPLES (MAX_TBSAMPLE_BYTES/TB_SAMPLE_SIZE)
79 /* ioctls */
80 #define SBPROF_ZBSTART _IOW('s', 0, int)
81 #define SBPROF_ZBSTOP _IOW('s', 1, int)
82 #define SBPROF_ZBWAITFULL _IOW('s', 2, int)
85 * Routines for using 40-bit SCD cycle counter
87 * Client responsible for either handling interrupts or making sure
88 * the cycles counter never saturates, e.g., by doing
89 * zclk_timer_init(0) at least every 2^40 - 1 ZCLKs.
93 * Configures SCD counter 0 to count ZCLKs starting from val;
94 * Configures SCD counters1,2,3 to count nothing.
95 * Must not be called while gathering ZBbus profiles.
98 #define zclk_timer_init(val) \
99 __asm__ __volatile__ (".set push;" \
100 ".set mips64;" \
101 "la $8, 0xb00204c0;" /* SCD perf_cnt_cfg */ \
102 "sd %0, 0x10($8);" /* write val to counter0 */ \
103 "sd %1, 0($8);" /* config counter0 for zclks*/ \
104 ".set pop" \
105 : /* no outputs */ \
106 /* enable, counter0 */ \
107 : /* inputs */ "r"(val), "r" ((1ULL << 33) | 1ULL) \
108 : /* modifies */ "$8" )
111 /* Reads SCD counter 0 and puts result in value
112 unsigned long long val; */
113 #define zclk_get(val) \
114 __asm__ __volatile__ (".set push;" \
115 ".set mips64;" \
116 "la $8, 0xb00204c0;" /* SCD perf_cnt_cfg */ \
117 "ld %0, 0x10($8);" /* write val to counter0 */ \
118 ".set pop" \
119 : /* outputs */ "=r"(val) \
120 : /* inputs */ \
121 : /* modifies */ "$8" )
123 #define DEVNAME "sb_tbprof"
125 #define TB_FULL (sbp.next_tb_sample == MAX_TB_SAMPLES)
128 * Support for ZBbus sampling using the trace buffer
130 * We use the SCD performance counter interrupt, caused by a Zclk counter
131 * overflow, to trigger the start of tracing.
133 * We set the trace buffer to sample everything and freeze on
134 * overflow.
136 * We map the interrupt for trace_buffer_freeze to handle it on CPU 0.
140 static u64 tb_period;
142 static void arm_tb(void)
144 u64 scdperfcnt;
145 u64 next = (1ULL << 40) - tb_period;
146 u64 tb_options = M_SCD_TRACE_CFG_FREEZE_FULL;
149 * Generate an SCD_PERFCNT interrupt in TB_PERIOD Zclks to
150 * trigger start of trace. XXX vary sampling period
152 __raw_writeq(0, IOADDR(A_SCD_PERF_CNT_1));
153 scdperfcnt = __raw_readq(IOADDR(A_SCD_PERF_CNT_CFG));
156 * Unfortunately, in Pass 2 we must clear all counters to knock down
157 * a previous interrupt request. This means that bus profiling
158 * requires ALL of the SCD perf counters.
160 #if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
161 __raw_writeq((scdperfcnt & ~M_SPC_CFG_SRC1) |
162 /* keep counters 0,2,3,4,5,6,7 as is */
163 V_SPC_CFG_SRC1(1), /* counter 1 counts cycles */
164 IOADDR(A_BCM1480_SCD_PERF_CNT_CFG0));
165 __raw_writeq(
166 M_SPC_CFG_ENABLE | /* enable counting */
167 M_SPC_CFG_CLEAR | /* clear all counters */
168 V_SPC_CFG_SRC1(1), /* counter 1 counts cycles */
169 IOADDR(A_BCM1480_SCD_PERF_CNT_CFG1));
170 #else
171 __raw_writeq((scdperfcnt & ~M_SPC_CFG_SRC1) |
172 /* keep counters 0,2,3 as is */
173 M_SPC_CFG_ENABLE | /* enable counting */
174 M_SPC_CFG_CLEAR | /* clear all counters */
175 V_SPC_CFG_SRC1(1), /* counter 1 counts cycles */
176 IOADDR(A_SCD_PERF_CNT_CFG));
177 #endif
178 __raw_writeq(next, IOADDR(A_SCD_PERF_CNT_1));
179 /* Reset the trace buffer */
180 __raw_writeq(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
181 #if 0 && defined(M_SCD_TRACE_CFG_FORCECNT)
182 /* XXXKW may want to expose control to the data-collector */
183 tb_options |= M_SCD_TRACE_CFG_FORCECNT;
184 #endif
185 __raw_writeq(tb_options, IOADDR(A_SCD_TRACE_CFG));
186 sbp.tb_armed = 1;
189 static irqreturn_t sbprof_tb_intr(int irq, void *dev_id)
191 int i;
193 pr_debug(DEVNAME ": tb_intr\n");
195 if (sbp.next_tb_sample < MAX_TB_SAMPLES) {
196 /* XXX should use XKPHYS to make writes bypass L2 */
197 u64 *p = sbp.sbprof_tbbuf[sbp.next_tb_sample++];
198 /* Read out trace */
199 __raw_writeq(M_SCD_TRACE_CFG_START_READ,
200 IOADDR(A_SCD_TRACE_CFG));
201 __asm__ __volatile__ ("sync" : : : "memory");
202 /* Loop runs backwards because bundles are read out in reverse order */
203 for (i = 256 * 6; i > 0; i -= 6) {
204 /* Subscripts decrease to put bundle in the order */
205 /* t0 lo, t0 hi, t1 lo, t1 hi, t2 lo, t2 hi */
206 p[i - 1] = __raw_readq(IOADDR(A_SCD_TRACE_READ));
207 /* read t2 hi */
208 p[i - 2] = __raw_readq(IOADDR(A_SCD_TRACE_READ));
209 /* read t2 lo */
210 p[i - 3] = __raw_readq(IOADDR(A_SCD_TRACE_READ));
211 /* read t1 hi */
212 p[i - 4] = __raw_readq(IOADDR(A_SCD_TRACE_READ));
213 /* read t1 lo */
214 p[i - 5] = __raw_readq(IOADDR(A_SCD_TRACE_READ));
215 /* read t0 hi */
216 p[i - 6] = __raw_readq(IOADDR(A_SCD_TRACE_READ));
217 /* read t0 lo */
219 if (!sbp.tb_enable) {
220 pr_debug(DEVNAME ": tb_intr shutdown\n");
221 __raw_writeq(M_SCD_TRACE_CFG_RESET,
222 IOADDR(A_SCD_TRACE_CFG));
223 sbp.tb_armed = 0;
224 wake_up_interruptible(&sbp.tb_sync);
225 } else {
226 /* knock down current interrupt and get another one later */
227 arm_tb();
229 } else {
230 /* No more trace buffer samples */
231 pr_debug(DEVNAME ": tb_intr full\n");
232 __raw_writeq(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
233 sbp.tb_armed = 0;
234 if (!sbp.tb_enable)
235 wake_up_interruptible(&sbp.tb_sync);
236 wake_up_interruptible(&sbp.tb_read);
238 return IRQ_HANDLED;
241 static irqreturn_t sbprof_pc_intr(int irq, void *dev_id)
243 printk(DEVNAME ": unexpected pc_intr");
244 return IRQ_NONE;
248 * Requires: Already called zclk_timer_init with a value that won't
249 * saturate 40 bits. No subsequent use of SCD performance counters
250 * or trace buffer.
253 static int sbprof_zbprof_start(struct file *filp)
255 u64 scdperfcnt;
256 int err;
258 if (xchg(&sbp.tb_enable, 1))
259 return -EBUSY;
261 pr_debug(DEVNAME ": starting\n");
263 sbp.next_tb_sample = 0;
264 filp->f_pos = 0;
266 err = request_irq(K_INT_TRACE_FREEZE, sbprof_tb_intr, 0,
267 DEVNAME " trace freeze", &sbp);
268 if (err)
269 return -EBUSY;
271 /* Make sure there isn't a perf-cnt interrupt waiting */
272 scdperfcnt = __raw_readq(IOADDR(A_SCD_PERF_CNT_CFG));
273 /* Disable and clear counters, override SRC_1 */
274 __raw_writeq((scdperfcnt & ~(M_SPC_CFG_SRC1 | M_SPC_CFG_ENABLE)) |
275 M_SPC_CFG_ENABLE | M_SPC_CFG_CLEAR | V_SPC_CFG_SRC1(1),
276 IOADDR(A_SCD_PERF_CNT_CFG));
279 * We grab this interrupt to prevent others from trying to use
280 * it, even though we don't want to service the interrupts
281 * (they only feed into the trace-on-interrupt mechanism)
283 if (request_irq(K_INT_PERF_CNT, sbprof_pc_intr, 0, DEVNAME " scd perfcnt", &sbp)) {
284 free_irq(K_INT_TRACE_FREEZE, &sbp);
285 return -EBUSY;
289 * I need the core to mask these, but the interrupt mapper to
290 * pass them through. I am exploiting my knowledge that
291 * cp0_status masks out IP[5]. krw
293 #if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
294 __raw_writeq(K_BCM1480_INT_MAP_I3,
295 IOADDR(A_BCM1480_IMR_REGISTER(0, R_BCM1480_IMR_INTERRUPT_MAP_BASE_L) +
296 ((K_BCM1480_INT_PERF_CNT & 0x3f) << 3)));
297 #else
298 __raw_writeq(K_INT_MAP_I3,
299 IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_MAP_BASE) +
300 (K_INT_PERF_CNT << 3)));
301 #endif
303 /* Initialize address traps */
304 __raw_writeq(0, IOADDR(A_ADDR_TRAP_UP_0));
305 __raw_writeq(0, IOADDR(A_ADDR_TRAP_UP_1));
306 __raw_writeq(0, IOADDR(A_ADDR_TRAP_UP_2));
307 __raw_writeq(0, IOADDR(A_ADDR_TRAP_UP_3));
309 __raw_writeq(0, IOADDR(A_ADDR_TRAP_DOWN_0));
310 __raw_writeq(0, IOADDR(A_ADDR_TRAP_DOWN_1));
311 __raw_writeq(0, IOADDR(A_ADDR_TRAP_DOWN_2));
312 __raw_writeq(0, IOADDR(A_ADDR_TRAP_DOWN_3));
314 __raw_writeq(0, IOADDR(A_ADDR_TRAP_CFG_0));
315 __raw_writeq(0, IOADDR(A_ADDR_TRAP_CFG_1));
316 __raw_writeq(0, IOADDR(A_ADDR_TRAP_CFG_2));
317 __raw_writeq(0, IOADDR(A_ADDR_TRAP_CFG_3));
319 /* Initialize Trace Event 0-7 */
320 /* when interrupt */
321 __raw_writeq(M_SCD_TREVT_INTERRUPT, IOADDR(A_SCD_TRACE_EVENT_0));
322 __raw_writeq(0, IOADDR(A_SCD_TRACE_EVENT_1));
323 __raw_writeq(0, IOADDR(A_SCD_TRACE_EVENT_2));
324 __raw_writeq(0, IOADDR(A_SCD_TRACE_EVENT_3));
325 __raw_writeq(0, IOADDR(A_SCD_TRACE_EVENT_4));
326 __raw_writeq(0, IOADDR(A_SCD_TRACE_EVENT_5));
327 __raw_writeq(0, IOADDR(A_SCD_TRACE_EVENT_6));
328 __raw_writeq(0, IOADDR(A_SCD_TRACE_EVENT_7));
330 /* Initialize Trace Sequence 0-7 */
331 /* Start on event 0 (interrupt) */
332 __raw_writeq(V_SCD_TRSEQ_FUNC_START | 0x0fff,
333 IOADDR(A_SCD_TRACE_SEQUENCE_0));
334 /* dsamp when d used | asamp when a used */
335 __raw_writeq(M_SCD_TRSEQ_ASAMPLE | M_SCD_TRSEQ_DSAMPLE |
336 K_SCD_TRSEQ_TRIGGER_ALL,
337 IOADDR(A_SCD_TRACE_SEQUENCE_1));
338 __raw_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_2));
339 __raw_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_3));
340 __raw_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_4));
341 __raw_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_5));
342 __raw_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_6));
343 __raw_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_7));
345 /* Now indicate the PERF_CNT interrupt as a trace-relevant interrupt */
346 #if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
347 __raw_writeq(1ULL << (K_BCM1480_INT_PERF_CNT & 0x3f),
348 IOADDR(A_BCM1480_IMR_REGISTER(0, R_BCM1480_IMR_INTERRUPT_TRACE_L)));
349 #else
350 __raw_writeq(1ULL << K_INT_PERF_CNT,
351 IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_TRACE)));
352 #endif
353 arm_tb();
355 pr_debug(DEVNAME ": done starting\n");
357 return 0;
360 static int sbprof_zbprof_stop(void)
362 int err = 0;
364 pr_debug(DEVNAME ": stopping\n");
366 if (sbp.tb_enable) {
368 * XXXKW there is a window here where the intr handler may run,
369 * see the disable, and do the wake_up before this sleep
370 * happens.
372 pr_debug(DEVNAME ": wait for disarm\n");
373 err = wait_event_interruptible(sbp.tb_sync, !sbp.tb_armed);
374 pr_debug(DEVNAME ": disarm complete, stat %d\n", err);
376 if (err)
377 return err;
379 sbp.tb_enable = 0;
380 free_irq(K_INT_TRACE_FREEZE, &sbp);
381 free_irq(K_INT_PERF_CNT, &sbp);
384 pr_debug(DEVNAME ": done stopping\n");
386 return err;
389 static int sbprof_tb_open(struct inode *inode, struct file *filp)
391 int minor;
393 minor = iminor(inode);
394 if (minor != 0)
395 return -ENODEV;
397 if (xchg(&sbp.open, SB_OPENING) != SB_CLOSED)
398 return -EBUSY;
400 memset(&sbp, 0, sizeof(struct sbprof_tb));
401 sbp.sbprof_tbbuf = vzalloc(MAX_TBSAMPLE_BYTES);
402 if (!sbp.sbprof_tbbuf) {
403 sbp.open = SB_CLOSED;
404 wmb();
405 return -ENOMEM;
408 init_waitqueue_head(&sbp.tb_sync);
409 init_waitqueue_head(&sbp.tb_read);
410 mutex_init(&sbp.lock);
412 sbp.open = SB_OPEN;
413 wmb();
415 return 0;
418 static int sbprof_tb_release(struct inode *inode, struct file *filp)
420 int minor;
422 minor = iminor(inode);
423 if (minor != 0 || sbp.open != SB_CLOSED)
424 return -ENODEV;
426 mutex_lock(&sbp.lock);
428 if (sbp.tb_armed || sbp.tb_enable)
429 sbprof_zbprof_stop();
431 vfree(sbp.sbprof_tbbuf);
432 sbp.open = SB_CLOSED;
433 wmb();
435 mutex_unlock(&sbp.lock);
437 return 0;
440 static ssize_t sbprof_tb_read(struct file *filp, char *buf,
441 size_t size, loff_t *offp)
443 int cur_sample, sample_off, cur_count, sample_left;
444 char *src;
445 int count = 0;
446 char *dest = buf;
447 long cur_off = *offp;
449 if (!access_ok(buf, size))
450 return -EFAULT;
452 mutex_lock(&sbp.lock);
454 count = 0;
455 cur_sample = cur_off / TB_SAMPLE_SIZE;
456 sample_off = cur_off % TB_SAMPLE_SIZE;
457 sample_left = TB_SAMPLE_SIZE - sample_off;
459 while (size && (cur_sample < sbp.next_tb_sample)) {
460 int err;
462 cur_count = size < sample_left ? size : sample_left;
463 src = (char *)(((long)sbp.sbprof_tbbuf[cur_sample])+sample_off);
464 err = __copy_to_user(dest, src, cur_count);
465 if (err) {
466 *offp = cur_off + cur_count - err;
467 mutex_unlock(&sbp.lock);
468 return err;
470 pr_debug(DEVNAME ": read from sample %d, %d bytes\n",
471 cur_sample, cur_count);
472 size -= cur_count;
473 sample_left -= cur_count;
474 if (!sample_left) {
475 cur_sample++;
476 sample_off = 0;
477 sample_left = TB_SAMPLE_SIZE;
478 } else {
479 sample_off += cur_count;
481 cur_off += cur_count;
482 dest += cur_count;
483 count += cur_count;
485 *offp = cur_off;
486 mutex_unlock(&sbp.lock);
488 return count;
491 static long sbprof_tb_ioctl(struct file *filp,
492 unsigned int command,
493 unsigned long arg)
495 int err = 0;
497 switch (command) {
498 case SBPROF_ZBSTART:
499 mutex_lock(&sbp.lock);
500 err = sbprof_zbprof_start(filp);
501 mutex_unlock(&sbp.lock);
502 break;
504 case SBPROF_ZBSTOP:
505 mutex_lock(&sbp.lock);
506 err = sbprof_zbprof_stop();
507 mutex_unlock(&sbp.lock);
508 break;
510 case SBPROF_ZBWAITFULL: {
511 err = wait_event_interruptible(sbp.tb_read, TB_FULL);
512 if (err)
513 break;
515 err = put_user(TB_FULL, (int *) arg);
516 break;
519 default:
520 err = -EINVAL;
521 break;
524 return err;
527 static const struct file_operations sbprof_tb_fops = {
528 .owner = THIS_MODULE,
529 .open = sbprof_tb_open,
530 .release = sbprof_tb_release,
531 .read = sbprof_tb_read,
532 .unlocked_ioctl = sbprof_tb_ioctl,
533 .compat_ioctl = sbprof_tb_ioctl,
534 .mmap = NULL,
535 .llseek = default_llseek,
538 static struct class *tb_class;
539 static struct device *tb_dev;
541 static int __init sbprof_tb_init(void)
543 struct device *dev;
544 struct class *tbc;
545 int err;
547 if (register_chrdev(SBPROF_TB_MAJOR, DEVNAME, &sbprof_tb_fops)) {
548 printk(KERN_WARNING DEVNAME ": initialization failed (dev %d)\n",
549 SBPROF_TB_MAJOR);
550 return -EIO;
553 tbc = class_create(THIS_MODULE, "sb_tracebuffer");
554 if (IS_ERR(tbc)) {
555 err = PTR_ERR(tbc);
556 goto out_chrdev;
559 tb_class = tbc;
561 dev = device_create(tbc, NULL, MKDEV(SBPROF_TB_MAJOR, 0), NULL, "tb");
562 if (IS_ERR(dev)) {
563 err = PTR_ERR(dev);
564 goto out_class;
566 tb_dev = dev;
568 sbp.open = SB_CLOSED;
569 wmb();
570 tb_period = zbbus_mhz * 10000LL;
571 pr_info(DEVNAME ": initialized - tb_period = %lld\n",
572 (long long) tb_period);
573 return 0;
575 out_class:
576 class_destroy(tb_class);
577 out_chrdev:
578 unregister_chrdev(SBPROF_TB_MAJOR, DEVNAME);
580 return err;
583 static void __exit sbprof_tb_cleanup(void)
585 device_destroy(tb_class, MKDEV(SBPROF_TB_MAJOR, 0));
586 unregister_chrdev(SBPROF_TB_MAJOR, DEVNAME);
587 class_destroy(tb_class);
590 module_init(sbprof_tb_init);
591 module_exit(sbprof_tb_cleanup);
593 MODULE_ALIAS_CHARDEV_MAJOR(SBPROF_TB_MAJOR);
594 MODULE_AUTHOR("Ralf Baechle <ralf@linux-mips.org>");
595 MODULE_LICENSE("GPL");