snic_trc.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2// Copyright 2014 Cisco Systems, Inc.  All rights reserved.
  3
  4#include <linux/module.h>
  5#include <linux/mempool.h>
  6#include <linux/errno.h>
  7#include <linux/vmalloc.h>
  8
  9#include "snic_io.h"
 10#include "snic.h"
 11
 12/*
 13 * snic_get_trc_buf : Allocates a trace record and returns.
 14 */
 15struct snic_trc_data *
 16snic_get_trc_buf(void)
 17{
 18	struct snic_trc *trc = &snic_glob->trc;
 19	struct snic_trc_data *td = NULL;
 20	unsigned long flags;
 21
 22	spin_lock_irqsave(&trc->lock, flags);
 23	td = &trc->buf[trc->wr_idx];
 24	trc->wr_idx++;
 25
 26	if (trc->wr_idx == trc->max_idx)
 27		trc->wr_idx = 0;
 28
 29	if (trc->wr_idx != trc->rd_idx) {
 30		spin_unlock_irqrestore(&trc->lock, flags);
 31
 32		goto end;
 33	}
 34
 35	trc->rd_idx++;
 36	if (trc->rd_idx == trc->max_idx)
 37		trc->rd_idx = 0;
 38
 39	td->ts = 0;	/* Marker for checking the record, for complete data*/
 40	spin_unlock_irqrestore(&trc->lock, flags);
 41
 42end:
 43
 44	return td;
 45} /* end of snic_get_trc_buf */
 46
 47/*
 48 * snic_fmt_trc_data : Formats trace data for printing.
 49 */
 50static int
 51snic_fmt_trc_data(struct snic_trc_data *td, char *buf, int buf_sz)
 52{
 53	int len = 0;
 54	struct timespec64 tmspec;
 55
 56	jiffies_to_timespec64(td->ts, &tmspec);
 57
 58	len += snprintf(buf, buf_sz,
 59			"%ptSp %-25s %3d %4x %16llx %16llx %16llx %16llx %16llx\n",
 60			&tmspec,
 61			td->fn,
 62			td->hno,
 63			td->tag,
 64			td->data[0], td->data[1], td->data[2], td->data[3],
 65			td->data[4]);
 66
 67	return len;
 68} /* end of snic_fmt_trc_data */
 69
 70/*
 71 * snic_get_trc_data : Returns a formatted trace buffer.
 72 */
 73int
 74snic_get_trc_data(char *buf, int buf_sz)
 75{
 76	struct snic_trc_data *td = NULL;
 77	struct snic_trc *trc = &snic_glob->trc;
 78	unsigned long flags;
 79
 80	spin_lock_irqsave(&trc->lock, flags);
 81	if (trc->rd_idx == trc->wr_idx) {
 82		spin_unlock_irqrestore(&trc->lock, flags);
 83
 84		return -1;
 85	}
 86	td = &trc->buf[trc->rd_idx];
 87
 88	if (td->ts == 0) {
 89		/* write in progress. */
 90		spin_unlock_irqrestore(&trc->lock, flags);
 91
 92		return -1;
 93	}
 94
 95	trc->rd_idx++;
 96	if (trc->rd_idx == trc->max_idx)
 97		trc->rd_idx = 0;
 98	spin_unlock_irqrestore(&trc->lock, flags);
 99
100	return snic_fmt_trc_data(td, buf, buf_sz);
101} /* end of snic_get_trc_data */
102
103/*
104 * snic_trc_init() : Configures Trace Functionality for snic.
105 */
106int
107snic_trc_init(void)
108{
109	struct snic_trc *trc = &snic_glob->trc;
110	void *tbuf = NULL;
111	int tbuf_sz = 0, ret;
112
113	tbuf_sz = (snic_trace_max_pages * PAGE_SIZE);
114	tbuf = vzalloc(tbuf_sz);
115	if (!tbuf) {
116		SNIC_ERR("Failed to Allocate Trace Buffer Size. %d\n", tbuf_sz);
117		SNIC_ERR("Trace Facility not enabled.\n");
118		ret = -ENOMEM;
119
120		return ret;
121	}
122
123	trc->buf = (struct snic_trc_data *) tbuf;
124	spin_lock_init(&trc->lock);
125
126	snic_trc_debugfs_init();
127
128	trc->max_idx = (tbuf_sz / SNIC_TRC_ENTRY_SZ);
129	trc->rd_idx = trc->wr_idx = 0;
130	trc->enable = true;
131	SNIC_INFO("Trace Facility Enabled.\n Trace Buffer SZ %lu Pages.\n",
132		  tbuf_sz / PAGE_SIZE);
133	ret = 0;
134
135	return ret;
136} /* end of snic_trc_init */
137
138/*
139 * snic_trc_free : Releases the trace buffer and disables the tracing.
140 */
141void
142snic_trc_free(void)
143{
144	struct snic_trc *trc = &snic_glob->trc;
145
146	trc->enable = false;
147	snic_trc_debugfs_term();
148
149	if (trc->buf) {
150		vfree(trc->buf);
151		trc->buf = NULL;
152	}
153
154	SNIC_INFO("Trace Facility Disabled.\n");
155} /* end of snic_trc_free */