Comment 0 for bug 2048966

When running an SVA case, the following soft lockup is triggered:
    --------------------------------------------------------------------
    watchdog: BUG: soft lockup - CPU#244 stuck for 26s!
    pstate: 83400009 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
    pc : arm_smmu_cmdq_issue_cmdlist+0x178/0xa50
    lr : arm_smmu_cmdq_issue_cmdlist+0x150/0xa50
    sp : ffff8000d83ef290
    x29: ffff8000d83ef290 x28: 000000003b9aca00 x27: 0000000000000000
    x26: ffff8000d83ef3c0 x25: da86c0812194a0e8 x24: 0000000000000000
    x23: 0000000000000040 x22: ffff8000d83ef340 x21: ffff0000c63980c0
    x20: 0000000000000001 x19: ffff0000c6398080 x18: 0000000000000000
    x17: 0000000000000000 x16: 0000000000000000 x15: ffff3000b4a3bbb0
    x14: ffff3000b4a30888 x13: ffff3000b4a3cf60 x12: 0000000000000000
    x11: 0000000000000000 x10: 0000000000000000 x9 : ffffc08120e4d6bc
    x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000048cfa
    x5 : 0000000000000000 x4 : 0000000000000001 x3 : 000000000000000a
    x2 : 0000000080000000 x1 : 0000000000000000 x0 : 0000000000000001
    Call trace:
     arm_smmu_cmdq_issue_cmdlist+0x178/0xa50
     __arm_smmu_tlb_inv_range+0x118/0x254
     arm_smmu_tlb_inv_range_asid+0x6c/0x130
     arm_smmu_mm_invalidate_range+0xa0/0xa4
     __mmu_notifier_invalidate_range_end+0x88/0x120
     unmap_vmas+0x194/0x1e0
     unmap_region+0xb4/0x144
     do_mas_align_munmap+0x290/0x490
     do_mas_munmap+0xbc/0x124
     __vm_munmap+0xa8/0x19c
     __arm64_sys_munmap+0x28/0x50
     invoke_syscall+0x78/0x11c
     el0_svc_common.constprop.0+0x58/0x1c0
     do_el0_svc+0x34/0x60
     el0_svc+0x2c/0xd4
     el0t_64_sync_handler+0x114/0x140
     el0t_64_sync+0x1a4/0x1a8
    --------------------------------------------------------------------