[PATCH] accel/qaic: Add Sahara implementation for firmware loading

[Bjorn Andersson]

On Thu, Mar 21, 2024 at 09:49:17PM -0600, Jeffrey Hugo wrote:
> The AIC100 secondary bootloader uses the Sahara protocol for two
> purposes - loading the runtime firmware images from the host, and
> offloading crashdumps to the host. The crashdump functionality is only
> invoked when the AIC100 device encounters a crash and dumps are enabled.
> Also the collection of the dump is optional - the host can reject
> collecting the dump.
> 
> The Sahara protocol contains many features and modes including firmware
> upload, crashdump download, and client commands. For simplicity,
> implement the parts of the protocol needed for loading firmware to the
> device.
> 
> Fundamentally, the Sahara protocol is an embedded file transfer
> protocol. Both sides negotiate a connection through a simple exchange of
> hello messages. After handshaking through a hello message, the device
> either sends a message requesting images, or a message advertising the
> memory dump available for the host. For image transfer, the remote device
> issues a read data request that provides an image (by ID), an offset, and
> a length. The host has an internal mapping of image IDs to filenames. The
> host is expected to access the image and transfer the requested chunk to
> the device. The device can issue additional read requests, or signal that
> it has consumed enough data from this image with an end of image message.
> The host confirms the end of image, and the device can proceed with
> another image by starting over with the hello exchange again.
> 
> Some images may be optional, and only provided as part of a provisioning
> flow. The host is not aware of this information, and thus should report
> an error to the device when an image is not available. The device will
> evaluate if the image is required or not, and take the appropriate
> action.
> 
> Signed-off-by: Jeffrey Hugo <quic_jhugo at quicinc.com>
> Reviewed-by: Carl Vanderlip <quic_carlv at quicinc.com>
> Reviewed-by: Pranjal Ramajor Asha Kanojiya <quic_pkanojiy at quicinc.com>

Reviewed-by: Bjorn Andersson <andersson at kernel.org>

Regards,
Bjorn