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.lawrynow...@linux.intel.com>
Reviewed-by: Jeff Hugo <jeff.h...@oss.qualcomm.com>