1/*
2 * linux/drivers/scsi/esas2r/esas2r_log.c
3 * For use with ATTO ExpressSAS R6xx SAS/SATA RAID controllers
4 *
5 * Copyright (c) 2001-2013 ATTO Technology, Inc.
6 * (mailto:linuxdrivers@attotech.com)
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version 2
11 * of the License, or (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * NO WARRANTY
19 * THE PROGRAM IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OR
20 * CONDITIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED INCLUDING, WITHOUT
21 * LIMITATION, ANY WARRANTIES OR CONDITIONS OF TITLE, NON-INFRINGEMENT,
22 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Each Recipient is
23 * solely responsible for determining the appropriateness of using and
24 * distributing the Program and assumes all risks associated with its
25 * exercise of rights under this Agreement, including but not limited to
26 * the risks and costs of program errors, damage to or loss of data,
27 * programs or equipment, and unavailability or interruption of operations.
28 *
29 * DISCLAIMER OF LIABILITY
30 * NEITHER RECIPIENT NOR ANY CONTRIBUTORS SHALL HAVE ANY LIABILITY FOR ANY
31 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING WITHOUT LIMITATION LOST PROFITS), HOWEVER CAUSED AND
33 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
34 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
35 * USE OR DISTRIBUTION OF THE PROGRAM OR THE EXERCISE OF ANY RIGHTS GRANTED
36 * HEREUNDER, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGES
37 *
38 * You should have received a copy of the GNU General Public License
39 * along with this program; if not, write to the Free Software
40 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
41 * USA.
42 */
43
44#include "esas2r.h"
45
46/*
47 * this module within the driver is tasked with providing logging functionality.
48 * the event_log_level module parameter controls the level of messages that are
49 * written to the system log. the default level of messages that are written
50 * are critical and warning messages. if other types of messages are desired,
51 * one simply needs to load the module with the correct value for the
52 * event_log_level module parameter. for example:
53 *
54 * insmod <module> event_log_level=1
55 *
56 * will load the module and only critical events will be written by this module
57 * to the system log. if critical, warning, and information-level messages are
58 * desired, the correct value for the event_log_level module parameter
59 * would be as follows:
60 *
61 * insmod <module> event_log_level=3
62 */
63
64#define EVENT_LOG_BUFF_SIZE 1024
65
66static long event_log_level = ESAS2R_LOG_DFLT;
67
68module_param(event_log_level, long, S_IRUGO | S_IRUSR);
69MODULE_PARM_DESC(event_log_level,
70 "Specifies the level of events to report to the system log. Critical and warning level events are logged by default.");
71
72/* A shared buffer to use for formatting messages. */
73static char event_buffer[EVENT_LOG_BUFF_SIZE];
74
75/* A lock to protect the shared buffer used for formatting messages. */
76static DEFINE_SPINLOCK(event_buffer_lock);
77
78/*
79 * translates an esas2r-defined logging event level to a kernel logging level.
80 *
81 * @param [in] level the esas2r-defined logging event level to translate
82 *
83 * @return the corresponding kernel logging level.
84 */
85static const char *translate_esas2r_event_level_to_kernel(const long level)
86{
87 switch (level) {
88 case ESAS2R_LOG_CRIT:
89 return KERN_CRIT;
90
91 case ESAS2R_LOG_WARN:
92 return KERN_WARNING;
93
94 case ESAS2R_LOG_INFO:
95 return KERN_INFO;
96
97 case ESAS2R_LOG_DEBG:
98 case ESAS2R_LOG_TRCE:
99 default:
100 return KERN_DEBUG;
101 }
102}
103
104#pragma GCC diagnostic push
105#ifndef __clang__
106#pragma GCC diagnostic ignored "-Wsuggest-attribute=format"
107#endif
108
109/*
110 * the master logging function. this function will format the message as
111 * outlined by the formatting string, the input device information and the
112 * substitution arguments and output the resulting string to the system log.
113 *
114 * @param [in] level the event log level of the message
115 * @param [in] dev the device information
116 * @param [in] format the formatting string for the message
117 * @param [in] args the substition arguments to the formatting string
118 *
119 * @return 0 on success, or -1 if an error occurred.
120 */
121static int esas2r_log_master(const long level,
122 const struct device *dev,
123 const char *format,
124 va_list args)
125{
126 if (level <= event_log_level) {
127 unsigned long flags = 0;
128 int retval = 0;
129 char *buffer = event_buffer;
130 size_t buflen = EVENT_LOG_BUFF_SIZE;
131 const char *fmt_nodev = "%s%s: ";
132 const char *fmt_dev = "%s%s [%s, %s, %s]";
133 const char *slevel =
134 translate_esas2r_event_level_to_kernel(level);
135
136 spin_lock_irqsave(&event_buffer_lock, flags);
137
138 memset(buffer, 0, buflen);
139
140 /*
141 * format the level onto the beginning of the string and do
142 * some pointer arithmetic to move the pointer to the point
143 * where the actual message can be inserted.
144 */
145
146 if (dev == NULL) {
147 snprintf(buf: buffer, size: buflen, fmt: fmt_nodev, slevel,
148 ESAS2R_DRVR_NAME);
149 } else {
150 snprintf(buf: buffer, size: buflen, fmt: fmt_dev, slevel,
151 ESAS2R_DRVR_NAME,
152 (dev->driver ? dev->driver->name : "unknown"),
153 (dev->bus ? dev->bus->name : "unknown"),
154 dev_name(dev));
155 }
156
157 buffer += strlen(event_buffer);
158 buflen -= strlen(event_buffer);
159
160 retval = vsnprintf(buf: buffer, size: buflen, fmt: format, args);
161 if (retval < 0) {
162 spin_unlock_irqrestore(lock: &event_buffer_lock, flags);
163 return -1;
164 }
165
166 /*
167 * Put a line break at the end of the formatted string so that
168 * we don't wind up with run-on messages.
169 */
170 printk("%s\n", event_buffer);
171
172 spin_unlock_irqrestore(lock: &event_buffer_lock, flags);
173 }
174
175 return 0;
176}
177
178#pragma GCC diagnostic pop
179
180/*
181 * formats and logs a message to the system log.
182 *
183 * @param [in] level the event level of the message
184 * @param [in] format the formating string for the message
185 * @param [in] ... the substitution arguments to the formatting string
186 *
187 * @return 0 on success, or -1 if an error occurred.
188 */
189int esas2r_log(const long level, const char *format, ...)
190{
191 int retval = 0;
192 va_list args;
193
194 va_start(args, format);
195
196 retval = esas2r_log_master(level, NULL, format, args);
197
198 va_end(args);
199
200 return retval;
201}
202
203/*
204 * formats and logs a message to the system log. this message will include
205 * device information.
206 *
207 * @param [in] level the event level of the message
208 * @param [in] dev the device information
209 * @param [in] format the formatting string for the message
210 * @param [in] ... the substitution arguments to the formatting string
211 *
212 * @return 0 on success, or -1 if an error occurred.
213 */
214int esas2r_log_dev(const long level,
215 const struct device *dev,
216 const char *format,
217 ...)
218{
219 int retval = 0;
220 va_list args;
221
222 va_start(args, format);
223
224 retval = esas2r_log_master(level, dev, format, args);
225
226 va_end(args);
227
228 return retval;
229}
230
231/*
232 * formats and logs a message to the system log. this message will include
233 * device information.
234 *
235 * @param [in] level the event level of the message
236 * @param [in] buf
237 * @param [in] len
238 *
239 * @return 0 on success, or -1 if an error occurred.
240 */
241int esas2r_log_hexdump(const long level,
242 const void *buf,
243 size_t len)
244{
245 if (level <= event_log_level) {
246 print_hex_dump(level: translate_esas2r_event_level_to_kernel(level),
247 prefix_str: "", prefix_type: DUMP_PREFIX_OFFSET, rowsize: 16, groupsize: 1, buf,
248 len, ascii: true);
249 }
250
251 return 1;
252}
253

source code of linux/drivers/scsi/esas2r/esas2r_log.c