[PATCH 6.6 087/122] accel/ivpu: Fix deadlock in context_xa

Greg Kroah-Hartman
2024-04-15T14:38:22Z

From: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>

commit fd7726e75968b27fe98534ccbf47ccd6fef686f3 upstream.

ivpu_device->context_xa is locked both in kernel thread and IRQ context.
It requires XA_FLAGS_LOCK_IRQ flag to be passed during initialization
otherwise the lock could be acquired from a thread and interrupted by
an IRQ that locks it for the second time causing the deadlock.

This deadlock was reported by lockdep and observed in internal tests.

Fixes: 35b137630f08 ("accel/ivpu: Introduce a new DRM driver for Intel VPU")
Cc: <stable@vger.kernel.org> # v6.3+
Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240402104929.941186-9-jacek.lawrynowicz@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/accel/ivpu/ivpu_drv.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/accel/ivpu/ivpu_drv.c
+++ b/drivers/accel/ivpu/ivpu_drv.c
@@ -517,7 +517,7 @@ static int ivpu_dev_init(struct ivpu_dev
vdev->context_xa_limit.min = IVPU_USER_CONTEXT_MIN_SSID;
vdev->context_xa_limit.max = IVPU_USER_CONTEXT_MAX_SSID;
atomic64_set(&vdev->unique_id_counter, 0);
- xa_init_flags(&vdev->context_xa, XA_FLAGS_ALLOC);
+ xa_init_flags(&vdev->context_xa, XA_FLAGS_ALLOC | XA_FLAGS_LOCK_IRQ);
xa_init_flags(&vdev->submitted_jobs_xa, XA_FLAGS_ALLOC1);
lockdep_set_class(&vdev->submitted_jobs_xa.xa_lock, &submitted_jobs_xa_lock_class_key);