mlxbf_gige: call request_irq() after NAPI initialized

[David Thompson]

SRU Justification:

[Impact]
The mlxbf_gige driver encounters a NULL pointer exception in
mlxbf_gige_open() when kdump is enabled. The exception happens
because there is a pending RX interrupt before the call to
request_irq(RX IRQ) executes. Then, the RX IRQ handler fires
immediately after this request_irq() completes. The RX IRQ handler
runs "napi_schedule()" before NAPI is fully initialized via
"netif_napi_add()" and "napi_enable()", both which happen later
in the open() logic.

[Fix]
The logic in mlxbf_gige_open() must fully initialize NAPI before
any calls to request_irq() execute.

[Test Case]
* Boot BF platform and bring up "oob_net0" interface
* Enable kdump completely
* Trigger kdump via "echo c > /proc/sysrq-trigger"
* There should be no exceptions from mlxbf_gige driver

[Regression Potential]
There is low potential for regression as this brings in upstream content.

[Other]
None

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-bluefield/5.15.0-1040.42 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-jammy-linux-bluefield' to 'verification-done-jammy-linux-bluefield'. If the problem still exists, change the tag 'verification-needed-jammy-linux-bluefield' to 'verification-failed-jammy-linux-bluefield'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Tien Do (tienmdo)]

Verification

#################################
root@bu-lab62v2-oob:~# bfver
--/dev/mmcblk0boot0
BlueField ATF version: v2.2(release):4.7.0-17-g55e782a
BlueField UEFI version: 4.7.0-30-g91cad60
BlueField BSP version: 4.7.0.13101

OS Release Version: bf-bundle-2.7.0-11_24.04_ubuntu-22.04_dev
root@bu-lab62v2-oob:~#

#########################################
root@bu-lab62v2-oob:~# ifconfig oob_net0
oob_net0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
        inet 10.15.1.66 netmask 255.255.255.0 broadcast 10.15.1.255
        inet6 fe80::a288:c2ff:fe0e:865a prefixlen 64 scopeid 0x20<link>
        ether a0:88:c2:0e:86:5a txqueuelen 1000 (Ethernet)
        RX packets 202 bytes 22026 (22.0 KB)
        RX errors 0 dropped 0 overruns 0 frame 0
        TX packets 65 bytes 5360 (5.3 KB)
        TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

root@bu-lab62v2-oob:~#

########################################
root@bu-lab62v2-oob:~# kdump-config show
DUMP_MODE: kdump
USE_KDUMP: 1
KDUMP_COREDIR: /var/crash
crashkernel addr: 0xdd000000
   /var/lib/kdump/vmlinuz: symbolic link to /boot/vmlinuz-5.15.0-1040-bluefield
kdump initrd:
   /var/lib/kdump/initrd.img: symbolic link to /var/lib/kdump/initrd.img-5.15.0-1040-bluefield
current state: ready to kdump

kexec command:
  /sbin/kexec -p --command-line="BOOT_IMAGE=/boot/vmlinuz-5.15.0-1040-bluefield root=UUID=0790b0b1-2540-4819-aed6-0e26caf975f5 ro console=hvc0 console=ttyAMA0 earlycon=pl011,0x13010000 fixrtc net.ifnames=0 biosdevname=0 iommu.passthrough=1 isolcpus=6,7 reset_devices systemd.unit=kdump-tools-dump.service nr_cpus=1" --initrd=/var/lib/kdump/initrd.img /var/lib/kdump/vmlinuz
root@bu-lab62v2-oob:~#

############################################
root@bu-lab62v2-oob:~# echo c > /proc/sysrq-trigger
[ 443.856844] sysrq: Trigger a crash
[ 443.861063] Kernel panic - not syncing: sysrq triggered crash
[ 443.866799] CPU: 0 PID: 10859 Comm: bash Kdump: loaded Tainted: G OE 5.15.0-1040-bluefield #42-Ubuntu
[ 443.877215] Hardware name: https://www.mellanox.com BlueField SoC/BlueField SoC, BIOS 4.7.0.13101 Apr 5 2024
[ 443.887109] Call trace:
[ 443.889540] dump_backtrace+0x0/0x200
[ 443.893194] show_stack+0x20/0x2c
[ 443.896494] dump_stack_lvl+0x68/0x84
[ 443.900145] dump_stack+0x18/0x34
[ 443.903444] panic+0x1b0/0x3a0
[ 443.906486] sysrq_reset_seq_param_set+0x0/0x9c
[ 443.911003] __handle_sysrq+0xc4/0x250
[ 443.914737] write_sysrq_trigger+0xbc/0x1a0
[ 443.918905] proc_reg_write+0xb0/0x10c
[ 443.922640] vfs_write+0xf8/0x2c4
[ 443.925941] ksys_write+0x70/0x100
[ 443.929328] __arm64_sys_write+0x24/0x30
[ 443.933235] invoke_syscall+0x78/0x100
[ 443.936971] el0_svc_common.constprop.0+0x54/0x184
[ 443.941747] do_el0_svc+0x30/0xac
[ 443.945046] el0_svc+0x48/0x160
[ 443.948175] el0t_64_sync_handler+0xa4/0x12c
[ 443.952430] el0t_64_sync+0x1a4/0x1a8
[ 443.956082] SMP: stopping secondary CPUs
[ 443.960307] Starting crashdump kernel...
[ 443.964217] Bye!