[PATCH v1 6/6] staging: qlge: add documentation for debugging qlge

Coiby Xu
2020-10-08T11:59:07Z

Instructions and examples on kernel data structures dumping and coredump.

Signed-off-by: Coiby Xu <coiby.xu@gmail.com>
---
.../networking/device_drivers/index.rst | 1 +
.../device_drivers/qlogic/index.rst | 18 +++
.../networking/device_drivers/qlogic/qlge.rst | 118 ++++++++++++++++++
MAINTAINERS | 6 +
4 files changed, 143 insertions(+)
create mode 100644 Documentation/networking/device_drivers/qlogic/index.rst
create mode 100644 Documentation/networking/device_drivers/qlogic/qlge.rst

diff --git a/Documentation/networking/device_drivers/index.rst b/Documentation/networking/device_drivers/index.rst
index a3113ffd7a16..d8279de7bf25 100644
--- a/Documentation/networking/device_drivers/index.rst
+++ b/Documentation/networking/device_drivers/index.rst
@@ -15,6 +15,7 @@ Contents:
ethernet/index
fddi/index
hamradio/index
+ qlogic/index
wan/index
wifi/index

diff --git a/Documentation/networking/device_drivers/qlogic/index.rst b/Documentation/networking/device_drivers/qlogic/index.rst
new file mode 100644
index 000000000000..ad05b04286e4
--- /dev/null
+++ b/Documentation/networking/device_drivers/qlogic/index.rst
@@ -0,0 +1,18 @@
+.. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+
+QLogic QLGE Device Drivers
+===============================================
+
+Contents:
+
+.. toctree::
+ :maxdepth: 2
+
+ qlge
+
+.. only:: subproject and html
+
+ Indices
+ =======
+
+ * :ref:`genindex`
diff --git a/Documentation/networking/device_drivers/qlogic/qlge.rst b/Documentation/networking/device_drivers/qlogic/qlge.rst
new file mode 100644
index 000000000000..0b888253d152
--- /dev/null
+++ b/Documentation/networking/device_drivers/qlogic/qlge.rst
@@ -0,0 +1,118 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=======================================
+QLogic QLGE 10Gb Ethernet device driver
+=======================================
+
+This driver use drgn and devlink for debugging.
+
+Dump kernel data structures in drgn
+-----------------------------------
+
+To dump kernel data structures, the following Python script can be used
+in drgn:
+
+.. code-block:: python
+
+ def align(x, a):
+ """the alignment a should be a power of 2
+ """
+ mask = a - 1
+ return (x+ mask) & ~mask
+
+ def struct_size(struct_type):
+ struct_str = "struct {}".format(struct_type)
+ return sizeof(Object(prog, struct_str, address=0x0))
+
+ def netdev_priv(netdevice):
+ NETDEV_ALIGN = 32
+ return netdevice.value_() + align(struct_size("net_device"), NETDEV_ALIGN)
+
+ name = 'xxx'
+ qlge_device = None
+ netdevices = prog['init_net'].dev_base_head.address_of_()
+ for netdevice in list_for_each_entry("struct net_device", netdevices, "dev_list"):
+ if netdevice.name.string_().decode('ascii') == name:
+ print(netdevice.name)
+
+ ql_adapter = Object(prog, "struct ql_adapter", address=netdev_priv(qlge_device))
+
+The struct ql_adapter will be printed in drgn as follows,
+
+ >>> ql_adapter
+ (struct ql_adapter){
+ .ricb = (struct ricb){
+ .base_cq = (u8)0,
+ .flags = (u8)120,
+ .mask = (__le16)26637,
+ .hash_cq_id = (u8 [1024]){ 172, 142, 255, 255 },
+ .ipv6_hash_key = (__le32 [10]){},
+ .ipv4_hash_key = (__le32 [4]){},
+ },
+ .flags = (unsigned long)0,
+ .wol = (u32)0,
+ .nic_stats = (struct nic_stats){
+ .tx_pkts = (u64)0,
+ .tx_bytes = (u64)0,
+ .tx_mcast_pkts = (u64)0,
+ .tx_bcast_pkts = (u64)0,
+ .tx_ucast_pkts = (u64)0,
+ .tx_ctl_pkts = (u64)0,
+ .tx_pause_pkts = (u64)0,
+ ...
+ },
+ .active_vlans = (unsigned long [64]){
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 52780853100545, 18446744073709551615,
+ 18446619461681283072, 0, 42949673024, 2147483647,
+ },
+ .rx_ring = (struct rx_ring [17]){
+ {
+ .cqicb = (struct cqicb){
+ .msix_vect = (u8)0,
+ .reserved1 = (u8)0,
+ .reserved2 = (u8)0,
+ .flags = (u8)0,
+ .len = (__le16)0,
+ .rid = (__le16)0,
+ ...
+ },
+ .cq_base = (void *)0x0,
+ .cq_base_dma = (dma_addr_t)0,
+ }
+ ...
+ }
+ }
+
+coredump via devlink
+--------------------
+
+
+And the coredump obtained via devlink in json format looks like,
+
+.. code:: shell
+
+ $ devlink health dump show DEVICE reporter coredump -p -j
+ {
+ "Core Registers": {
+ "segment": 1,
+ "values": [ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 ]
+ },
+ "Test Logic Regs": {
+ "segment": 2,
+ "values": [ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 ]
+ },
+ "RMII Registers": {
+ "segment": 3,
+ "values": [ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 ]
+ },
+ ...
+ "Sem Registers": {
+ "segment": 50,
+ "values": [ 0,0,0,0 ]
+ }
+ }
+
+When the module parameter qlge_force_coredump is set to be true, the MPI
+RISC reset before coredumping. So coredumping will much longer since
+devlink tool has to wait for 5 secs for the resetting to be
+finished.
diff --git a/MAINTAINERS b/MAINTAINERS
index 9ecb727f0a8f..d482078e3e88 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14411,6 +14411,12 @@ L: netdev@vger.kernel.org
S: Supported
F: drivers/staging/qlge/

+QLOGIC QLGE 10Gb ETHERNET DRIVER
+M: Coiby Xu <coiby.xu@gmail.com>
+L: netdev@vger.kernel.org
+S: Maintained
+F: Documentation/networking/device_drivers/qlogic/qlge.rst
+
QM1D1B0004 MEDIA DRIVER
M: Akihiro Tsukada <tskd08@gmail.com>
L: linux-media@vger.kernel.org
--
2.28.0