staging: vchiq: Factor out bulk transfer for VCHIQ_BULK_MODE_WAITING

staging: vchiq: Factor out bulk transfer for VCHIQ_BULK_MODE_WAITING

The bulk transfer is VCHIQ_BULK_MODE_WAITING is used by VCHIQ ioctl
interface. It is factored out to a separate function from
vchiq_bulk_transfer() to bulk_xfer_waiting_interruptible().

This is a part of vchiq_bulk_transfer refactoring. Each bulk mode
will have their dedicated functions to execute bulk transfers.
Each mode will be handled separately in subsequent patches.

bulk_xfer_waiting_interruptible() is suffixed with "_interruptible"
to denote that it can be interrupted when a signal is received.
-EAGAIN maybe returned in those cases, similar to what
vchiq_bulk_transfer() does.

Adjust the vchiq_irq_queue_bulk_tx_rx() in the vchiq-dev.c to call
bulk_xfer_waiting_interruptible() for waiting mode. A temporary
goto label has been introduced to jump the call execution over
vchiq_bulk_transfer() for waiting mode only. When all dedicated bulk
transfer calls are introduced, this label shall be dropped.

No function changes intended in this patch.

Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
Tested-by: Stefan Wahren <wahrenst@gmx.net>
Link: https://lore.kernel.org/r/20240910051007.297227-2-umang.jain@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>