iwlwifi: mvm: send udev event upon firmware error to dump logs

When the firmware asserts, the driver will dump the firmware
state to an internal buffer. This buffer is kept aside until
it is dumped through debugfs. Once an external application
fetched the data, the buffer is freed and a new buffer can
be allocated in case another assert occurs.

A udev event is sent to trigger an external application.

A simple rule like:
DRIVER=="iwlwifi", ACTION=="change", RUN+="/sbin/dump_sram.sh"

can fetch the data from debugfs.

Here is my dump_sram.sh:

phyname=$(basename ${DEVPATH})
date=$(date +%F_%H_%M)
filename=/var/log/iwl-sram-${phyname}-${date}.bin
cat /sys/kernel/debug/ieee80211/${phyname}/iwlwifi/iwlmvm/fw_error_dump > ${filename}

The current SRAM size is 80KB so, currently:
$ ls -lh iwl-sram-phy0-2014-03-16_13_14.bin
-rw-r--r-- 1 emmanuel emmanuel 81K Mar 16 13:15 iwl-sram-phy0-2014-03-16_13_14.bin

and after compression:
$ ls -lh iwl-sram-phy0-2014-03-16_13_14.bin.xz
-rw-r--r-- 1 emmanuel emmanuel 13K Mar 16 13:15 iwl-sram-phy0-2014-03-16_13_14.bin.xz

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

1 files changed, 106 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/mvm/fw-error-dump.h b/drivers/net/wireless/iwlwifi/mvm/fw-error-dump.h
new file mode 100644
index 000000000000..58c8941c0d95
--- /dev/null
+++ b/drivers/net/wireless/iwlwifi/mvm/fw-error-dump.h
@@ -0,0 +1,106 @@
+/******************************************************************************
+ *
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2014 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ * 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,
+ * USA
+ *
+ * The full GNU General Public License is included in this distribution
+ * in the file called COPYING.
+ *
+ * Contact Information:
+ *  Intel Linux Wireless <ilw@linux.intel.com>
+ * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
+ *
+ * BSD LICENSE
+ *
+ * Copyright(c) 2014 Intel Corporation. All rights reserved.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *  * Neither the name Intel Corporation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 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
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *****************************************************************************/
+
+#ifndef __fw_error_dump_h__
+#define __fw_error_dump_h__
+
+#include <linux/types.h>
+
+#define IWL_FW_ERROR_DUMP_BARKER        0x14789632
+
+/**
+ * enum iwl_fw_error_dump_type - types of data in the dump file
+ * @IWL_FW_ERROR_DUMP_SRAM:
+ * @IWL_FW_ERROR_DUMP_REG:
+ */
+enum iwl_fw_error_dump_type {
+        IWL_FW_ERROR_DUMP_SRAM = 0,
+        IWL_FW_ERROR_DUMP_REG = 1,
+
+        IWL_FW_ERROR_DUMP_MAX,
+};
+
+/**
+ * struct iwl_fw_error_dump_data - data for one type
+ * @type: %enum iwl_fw_error_dump_type
+ * @len: the length starting from %data - must be a multiplier of 4.
+ * @data: the data itself padded to be a multiplier of 4.
+ */
+struct iwl_fw_error_dump_data {
+        __le32 type;
+        __le32 len;
+        __u8 data[];
+} __packed __aligned(4);
+
+/**
+ * struct iwl_fw_error_dump_file - the layout of the header of the file
+ * @barker: must be %IWL_FW_ERROR_DUMP_BARKER
+ * @file_len: the length of all the file starting from %barker
+ * @data: array of %struct iwl_fw_error_dump_data
+ */
+struct iwl_fw_error_dump_file {
+        __le32 barker;
+        __le32 file_len;
+        u8 data[0];
+} __packed __aligned(4);
+
+#endif /* __fw_error_dump_h__ */