[PATCH] accel/ivpu: Fix pm related deadlocks in cmdq ioctls

[Jeff Hugo]

On 4/25/2025 3:33 AM, Jacek Lawrynowicz wrote:
> Fix deadlocks in ivpu_cmdq_create_ioctl() and ivpu_cmdq_destroy_ioctl()
> related to runtime suspend.
> 
> Runtime suspend acquires file_priv->lock mutex by calling
> ivpu_cmdq_reset_all_contexts(). The same lock is acquired in the cmdq
> ioctls. If one of the cmdq ioctls is called while runtime suspend is in
> progress, it can lead to a deadlock.
> 
> Call stacks from example deadlock below.
> 
> Runtime suspend thread:
> [ 3443.179717] Call Trace:
> [ 3443.179724]  __schedule+0x4b6/0x16b0
> [ 3443.179732]  ? __mod_timer+0x27d/0x3a0
> [ 3443.179738]  schedule+0x2f/0x140
> [ 3443.179741]  schedule_preempt_disabled+0x19/0x30
> [ 3443.179743]  __mutex_lock.constprop.0+0x335/0x7d0
> [ 3443.179745]  ? xas_find+0x1ed/0x260
> [ 3443.179747]  ? xa_find+0x8e/0xf0
> [ 3443.179749]  __mutex_lock_slowpath+0x13/0x20
> [ 3443.179751]  mutex_lock+0x41/0x60
> [ 3443.179757]  ivpu_cmdq_reset_all_contexts+0x82/0x150 [intel_vpu a9bd091a97f28f0235f161316b29f8234f437295]
> [ 3443.179786]  ivpu_pm_runtime_suspend_cb+0x1f1/0x3f0 [intel_vpu a9bd091a97f28f0235f161316b29f8234f437295]
> [ 3443.179850]  pci_pm_runtime_suspend+0x6e/0x1f0
> [ 3443.179870]  ? __pfx_pci_pm_runtime_suspend+0x10/0x10
> [ 3443.179886]  __rpm_callback+0x48/0x130
> [ 3443.179899]  rpm_callback+0x64/0x70
> [ 3443.179911]  rpm_suspend+0x12c/0x630
> [ 3443.179922]  ? __schedule+0x4be/0x16b0
> [ 3443.179941]  pm_runtime_work+0xca/0xf0
> [ 3443.179955]  process_one_work+0x188/0x3d0
> [ 3443.179971]  worker_thread+0x2b9/0x3c0
> [ 3443.179984]  kthread+0xfb/0x220
> [ 3443.180001]  ? __pfx_worker_thread+0x10/0x10
> [ 3443.180013]  ? __pfx_kthread+0x10/0x10
> [ 3443.180029]  ret_from_fork+0x47/0x70
> [ 3443.180044]  ? __pfx_kthread+0x10/0x10
> [ 3443.180059]  ret_from_fork_asm+0x1a/0x30
> 
> User space thread:
> [ 3443.180128] Call Trace:
> [ 3443.180138]  __schedule+0x4b6/0x16b0
> [ 3443.180159]  schedule+0x2f/0x140
> [ 3443.180163]  rpm_resume+0x1a7/0x6a0
> [ 3443.180165]  ? __pfx_autoremove_wake_function+0x10/0x10
> [ 3443.180169]  __pm_runtime_resume+0x56/0x90
> [ 3443.180171]  ivpu_rpm_get+0x28/0xb0 [intel_vpu a9bd091a97f28f0235f161316b29f8234f437295]
> [ 3443.180181]  ivpu_ipc_send_receive+0x6d/0x120 [intel_vpu a9bd091a97f28f0235f161316b29f8234f437295]
> [ 3443.180193]  ? free_frozen_pages+0x395/0x670
> [ 3443.180199]  ? __free_pages+0xa7/0xc0
> [ 3443.180202]  ivpu_jsm_hws_destroy_cmdq+0x76/0xf0 [intel_vpu a9bd091a97f28f0235f161316b29f8234f437295]
> [ 3443.180213]  ? locks_dispose_list+0x6c/0xa0
> [ 3443.180219]  ? kmem_cache_free+0x342/0x470
> [ 3443.180222]  ? vm_area_free+0x19/0x30
> [ 3443.180225]  ? xas_load+0x17/0xf0
> [ 3443.180229]  ? xa_load+0x72/0xb0
> [ 3443.180230]  ivpu_cmdq_unregister.isra.0+0xb1/0x100 [intel_vpu a9bd091a97f28f0235f161316b29f8234f437295]
> [ 3443.180241]  ivpu_cmdq_destroy_ioctl+0x8d/0x130 [intel_vpu a9bd091a97f28f0235f161316b29f8234f437295]
> [ 3443.180251]  ? __pfx_ivpu_cmdq_destroy_ioctl+0x10/0x10 [intel_vpu a9bd091a97f28f0235f161316b29f8234f437295]
> [ 3443.180260]  drm_ioctl_kernel+0xb3/0x110
> [ 3443.180265]  drm_ioctl+0x2ca/0x580
> [ 3443.180266]  ? __pfx_ivpu_cmdq_destroy_ioctl+0x10/0x10 [intel_vpu a9bd091a97f28f0235f161316b29f8234f437295]
> [ 3443.180275]  ? __fput+0x1ae/0x2f0
> [ 3443.180279]  ? kmem_cache_free+0x342/0x470
> [ 3443.180282]  __x64_sys_ioctl+0xa9/0xe0
> [ 3443.180286]  x64_sys_call+0x13b7/0x26f0
> [ 3443.180289]  do_syscall_64+0x62/0x180
> [ 3443.180291]  entry_SYSCALL_64_after_hwframe+0x71/0x79
> 
> Fixes: 465a3914b254 ("accel/ivpu: Add API for command queue create/destroy/submit")
> Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz at linux.intel.com>

Reviewed-by: Jeff Hugo <jeff.hugo at oss.qualcomm.com>