accel/ivpu: Fix deadlock in context_xa

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>

diff --git a/drivers/accel/ivpu/ivpu_drv.c b/drivers/accel/ivpu/ivpu_drv.c
index 8fb70e3c7b9ca1d031f0719d3fb85ed44c92659c..5619980d9edda7de133d806f6515c674b83f58c1 100644 (file)
--- 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_device *vdev)
        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);