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 */
15 struct snic_trc_data *
snic_get_trc_buf(void)16 snic_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
42 end:
43
44 return td;
45 } /* end of snic_get_trc_buf */
46
47 /*
48 * snic_fmt_trc_data : Formats trace data for printing.
49 */
50 static int
snic_fmt_trc_data(struct snic_trc_data * td,char * buf,int buf_sz)51 snic_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 */
73 int
snic_get_trc_data(char * buf,int buf_sz)74 snic_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 */
106 int
snic_trc_init(void)107 snic_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 */
141 void
snic_trc_free(void)142 snic_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 */
156