dmaengine: idxd: Enable Function Level Reset (FLR) for halt

When DSA/IAA device hits a fatal error, the device enters a halt state.
The driver can reset the device depending on Reset Type required by
hardware to recover the device.

Supported Reset Types are:
0: Reset Device command
1: Function Level Reset (FLR)
2: Warm reset
3: Cold reset

Currently, the driver only supports Reset Type 0.

This patch adds support for FLR recovery Type 1. Before issuing a PCIe
FLR command, IDXD device and WQ states are saved. After the FLR command
execution, the device is recovered to its previous states, allowing
the user can continue using the device.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20241122233028.2762809-6-fenghua.yu@intel.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>