diff options
Diffstat (limited to 'drivers/scsi/esas2r/esas2r_log.c')
| -rw-r--r-- | drivers/scsi/esas2r/esas2r_log.c | 254 |
1 files changed, 254 insertions, 0 deletions
diff --git a/drivers/scsi/esas2r/esas2r_log.c b/drivers/scsi/esas2r/esas2r_log.c new file mode 100644 index 000000000000..9bf285df58dd --- /dev/null +++ b/drivers/scsi/esas2r/esas2r_log.c @@ -0,0 +1,254 @@ +/* + * linux/drivers/scsi/esas2r/esas2r_log.c + * For use with ATTO ExpressSAS R6xx SAS/SATA RAID controllers + * + * Copyright (c) 2001-2013 ATTO Technology, Inc. + * (mailto:linuxdrivers@attotech.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * NO WARRANTY + * THE PROGRAM IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OR + * CONDITIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED INCLUDING, WITHOUT + * LIMITATION, ANY WARRANTIES OR CONDITIONS OF TITLE, NON-INFRINGEMENT, + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Each Recipient is + * solely responsible for determining the appropriateness of using and + * distributing the Program and assumes all risks associated with its + * exercise of rights under this Agreement, including but not limited to + * the risks and costs of program errors, damage to or loss of data, + * programs or equipment, and unavailability or interruption of operations. + * + * DISCLAIMER OF LIABILITY + * NEITHER RECIPIENT NOR ANY CONTRIBUTORS SHALL HAVE ANY LIABILITY FOR ANY + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING WITHOUT LIMITATION LOST PROFITS), HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR + * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE + * USE OR DISTRIBUTION OF THE PROGRAM OR THE EXERCISE OF ANY RIGHTS GRANTED + * HEREUNDER, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGES + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, + * USA. + */ + +#include "esas2r.h" + +/* + * this module within the driver is tasked with providing logging functionality. + * the event_log_level module parameter controls the level of messages that are + * written to the system log. the default level of messages that are written + * are critical and warning messages. if other types of messages are desired, + * one simply needs to load the module with the correct value for the + * event_log_level module parameter. for example: + * + * insmod <module> event_log_level=1 + * + * will load the module and only critical events will be written by this module + * to the system log. if critical, warning, and information-level messages are + * desired, the correct value for the event_log_level module parameter + * would be as follows: + * + * insmod <module> event_log_level=3 + */ + +#define EVENT_LOG_BUFF_SIZE 1024 + +static long event_log_level = ESAS2R_LOG_DFLT; + +module_param(event_log_level, long, S_IRUGO | S_IRUSR); +MODULE_PARM_DESC(event_log_level, + "Specifies the level of events to report to the system log. Critical and warning level events are logged by default."); + +/* A shared buffer to use for formatting messages. */ +static char event_buffer[EVENT_LOG_BUFF_SIZE]; + +/* A lock to protect the shared buffer used for formatting messages. */ +static DEFINE_SPINLOCK(event_buffer_lock); + +/** + * translates an esas2r-defined logging event level to a kernel logging level. + * + * @param [in] level the esas2r-defined logging event level to translate + * + * @return the corresponding kernel logging level. + */ +static const char *translate_esas2r_event_level_to_kernel(const long level) +{ + switch (level) { + case ESAS2R_LOG_CRIT: + return KERN_CRIT; + + case ESAS2R_LOG_WARN: + return KERN_WARNING; + + case ESAS2R_LOG_INFO: + return KERN_INFO; + + case ESAS2R_LOG_DEBG: + case ESAS2R_LOG_TRCE: + default: + return KERN_DEBUG; + } +} + +/** + * the master logging function. this function will format the message as + * outlined by the formatting string, the input device information and the + * substitution arguments and output the resulting string to the system log. + * + * @param [in] level the event log level of the message + * @param [in] dev the device information + * @param [in] format the formatting string for the message + * @param [in] args the substition arguments to the formatting string + * + * @return 0 on success, or -1 if an error occurred. + */ +static int esas2r_log_master(const long level, + const struct device *dev, + const char *format, + va_list args) +{ + if (level <= event_log_level) { + unsigned long flags = 0; + int retval = 0; + char *buffer = event_buffer; + size_t buflen = EVENT_LOG_BUFF_SIZE; + const char *fmt_nodev = "%s%s: "; + const char *fmt_dev = "%s%s [%s, %s, %s]"; + const char *slevel = + translate_esas2r_event_level_to_kernel(level); + + spin_lock_irqsave(&event_buffer_lock, flags); + + if (buffer == NULL) { + spin_unlock_irqrestore(&event_buffer_lock, flags); + return -1; + } + + memset(buffer, 0, buflen); + + /* + * format the level onto the beginning of the string and do + * some pointer arithmetic to move the pointer to the point + * where the actual message can be inserted. + */ + + if (dev == NULL) { + snprintf(buffer, buflen, fmt_nodev, slevel, + ESAS2R_DRVR_NAME); + } else { + snprintf(buffer, buflen, fmt_dev, slevel, + ESAS2R_DRVR_NAME, + (dev->driver ? dev->driver->name : "unknown"), + (dev->bus ? dev->bus->name : "unknown"), + dev_name(dev)); + } + + buffer += strlen(event_buffer); + buflen -= strlen(event_buffer); + + retval = vsnprintf(buffer, buflen, format, args); + if (retval < 0) { + spin_unlock_irqrestore(&event_buffer_lock, flags); + return -1; + } + + /* + * Put a line break at the end of the formatted string so that + * we don't wind up with run-on messages. only append if there + * is enough space in the buffer. + */ + if (strlen(event_buffer) < buflen) + strcat(buffer, "\n"); + + printk(event_buffer); + + spin_unlock_irqrestore(&event_buffer_lock, flags); + } + + return 0; +} + +/** + * formats and logs a message to the system log. + * + * @param [in] level the event level of the message + * @param [in] format the formating string for the message + * @param [in] ... the substitution arguments to the formatting string + * + * @return 0 on success, or -1 if an error occurred. + */ +int esas2r_log(const long level, const char *format, ...) +{ + int retval = 0; + va_list args; + + va_start(args, format); + + retval = esas2r_log_master(level, NULL, format, args); + + va_end(args); + + return retval; +} + +/** + * formats and logs a message to the system log. this message will include + * device information. + * + * @param [in] level the event level of the message + * @param [in] dev the device information + * @param [in] format the formatting string for the message + * @param [in] ... the substitution arguments to the formatting string + * + * @return 0 on success, or -1 if an error occurred. + */ +int esas2r_log_dev(const long level, + const struct device *dev, + const char *format, + ...) +{ + int retval = 0; + va_list args; + + va_start(args, format); + + retval = esas2r_log_master(level, dev, format, args); + + va_end(args); + + return retval; +} + +/** + * formats and logs a message to the system log. this message will include + * device information. + * + * @param [in] level the event level of the message + * @param [in] buf + * @param [in] len + * + * @return 0 on success, or -1 if an error occurred. + */ +int esas2r_log_hexdump(const long level, + const void *buf, + size_t len) +{ + if (level <= event_log_level) { + print_hex_dump(translate_esas2r_event_level_to_kernel(level), + "", DUMP_PREFIX_OFFSET, 16, 1, buf, + len, true); + } + + return 1; +} |