--- /dev/null
+/*
+ * 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.
+ */
+ printk("%s\n", 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;
+}
Code Review / kvmfornfv.git / blobdiff