- 根目录:
- drivers
- scsi
- esas2r
- esas2r_log.c
/*
* 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;
}