igb: free up irq resources in device shutdown path.

systems, using igb driver, crash while executing poweroff command
as per following call stack:

crash> bt -a
PID: 62583    TASK: ffff97ebbf28dc40  CPU: 0    COMMAND: "poweroff"
 #0 [ffffa7adcd64f8a0] machine_kexec at ffffffffa606c7c1
 #1 [ffffa7adcd64f900] __crash_kexec at ffffffffa613bb52
 #2 [ffffa7adcd64f9d0] panic at ffffffffa6099c45
 #3 [ffffa7adcd64fa50] oops_end at ffffffffa603359a
 #4 [ffffa7adcd64fa78] die at ffffffffa6033c32
 #5 [ffffa7adcd64faa8] do_trap at ffffffffa60309a0
 #6 [ffffa7adcd64faf8] do_error_trap at ffffffffa60311e7
 #7 [ffffa7adcd64fbc0] do_invalid_op at ffffffffa6031320
 #8 [ffffa7adcd64fbd0] invalid_op at ffffffffa6a01f2a
    [exception RIP: free_msi_irqs+408]
    RIP: ffffffffa645d248  RSP: ffffa7adcd64fc88  RFLAGS: 00010286
    RAX: ffff97eb1396fe00  RBX: 0000000000000000  RCX: ffff97eb1396fe00
    RDX: ffff97eb1396fe00  RSI: 0000000000000000  RDI: 0000000000000000
    RBP: ffffa7adcd64fcb0   R8: 0000000000000002   R9: 000000000000fbff
    R10: 0000000000000000  R11: 0000000000000000  R12: ffff98c047af4720
    R13: ffff97eb87cd32a0  R14: ffff97eb87cd3000  R15: ffffa7adcd64fd57
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #9 [ffffa7adcd64fc80] free_msi_irqs at ffffffffa645d0fc
 #10 [ffffa7adcd64fcb8] pci_disable_msix at ffffffffa645d896
 #11 [ffffa7adcd64fce0] igb_reset_interrupt_capability at ffffffffc024f335 [igb]
 #12 [ffffa7adcd64fd08] __igb_shutdown at ffffffffc0258ed7 [igb]
 #13 [ffffa7adcd64fd48] igb_shutdown at ffffffffc025908b [igb]
 #14 [ffffa7adcd64fd70] pci_device_shutdown at ffffffffa6441e3a
 #15 [ffffa7adcd64fd98] device_shutdown at ffffffffa6570260
 #16 [ffffa7adcd64fdc8] kernel_power_off at ffffffffa60c0725
 #17 [ffffa7adcd64fdd8] SYSC_reboot at ffffffffa60c08f1
 #18 [ffffa7adcd64ff18] sys_reboot at ffffffffa60c09ee
 #19 [ffffa7adcd64ff28] do_syscall_64 at ffffffffa6003ca9
 #20 [ffffa7adcd64ff50] entry_SYSCALL_64_after_hwframe at ffffffffa6a001b1

This happens because igb_shutdown has not yet freed up allocated irqs and
free_msi_irqs finds irq_has_action true for involved msi irqs here and this
condition triggers BUG_ON.

Freeing irqs before proceeding further in igb_clear_interrupt_scheme,
fixes this problem.

This issue does not happen in v5.17 or later kernel versions because
'commit 9fb9eb4 ("PCI/MSI: Let core code free MSI descriptors")',
explicitly frees up MSI based irqs and hence indirectly fixes this issue
as well. But this change is dependent on framework for runtime extension
of MSI-X irqs and including these changes will break the kABI because it
changes some core data structures like pci_device, device and others.

So in kernels prior to v5.17 we need to have this change to fix this issue,
without breaking the kABI.

Orabug: 36547249

Signed-off-by: Imran Khan <[email protected]>
Reviewed-by: Junxiao Bi <[email protected]>
Signed-off-by: Brian Maly <[email protected]>

drivers/net/ethernet/intel/igb/igb_main.c

@@ -107,6 +107,7 @@ static int igb_setup_all_rx_resources(struct igb_adapter *);
 static void igb_free_all_tx_resources(struct igb_adapter *);
 static void igb_free_all_rx_resources(struct igb_adapter *);
 static void igb_setup_mrqc(struct igb_adapter *);
+static void igb_free_irq(struct igb_adapter *adapter);
 static int igb_probe(struct pci_dev *, const struct pci_device_id *);
 static void igb_remove(struct pci_dev *pdev);
 static int igb_sw_init(struct igb_adapter *);
@@ -1080,6 +1081,7 @@ static void igb_free_q_vectors(struct igb_adapter *adapter)
  */
 static void igb_clear_interrupt_scheme(struct igb_adapter *adapter)
 {
+	igb_free_irq(adapter);
 	igb_free_q_vectors(adapter);
 	igb_reset_interrupt_capability(adapter);
 }