* Elliot Berman <quic_eberman@xxxxxxxxxxx> [2024-02-22 15:16:30]:
> The resource manager is a special virtual machine which is always
> running on a Gunyah system. It provides APIs for creating and destroying
> VMs, secure memory management, sharing/lending of memory between VMs,
> and setup of inter-VM communication. Calls to the resource manager are
> made via message queues.
>
> This patch implements the basic probing and RPC mechanism to make those
> API calls. Request/response calls can be made with gh_rm_call.
> Drivers can also register to notifications pushed by RM via
> gh_rm_register_notifier
>
> Specific API calls that resource manager supports will be implemented in
> subsequent patches.
>
> Signed-off-by: Elliot Berman <quic_eberman@xxxxxxxxxxx>
Left a minor comment below. LGTM otherwise.
Reviewed-by: Srivatsa Vaddagiri <quic_svaddagi@xxxxxxxxxxx>
> +static irqreturn_t gunyah_rm_rx(int irq, void *data)
> +{
> + enum gunyah_error gunyah_error;
> + struct gunyah_rm_rpc_hdr *hdr;
> + struct gunyah_rm *rm = data;
> + void *msg = &rm->recv_msg[0];
> + size_t len;
> + bool ready;
> +
> + do {
> + gunyah_error = gunyah_hypercall_msgq_recv(rm->rx_ghrsc.capid,
> + msg,
> + sizeof(rm->recv_msg),
> + &len, &ready);
> + if (gunyah_error != GUNYAH_ERROR_OK) {
> + if (gunyah_error != GUNYAH_ERROR_MSGQUEUE_EMPTY)
> + dev_warn(rm->dev,
> + "Failed to receive data: %d\n",
> + gunyah_error);
> + return IRQ_HANDLED;
> + }
> +
> + if (len < sizeof(*hdr)) {
> + dev_err_ratelimited(
> + rm->dev,
> + "Too small message received. size=%ld\n", len);
> + continue;
In practice we should never hit this condition, in case we do encounter, do you
see a reason why continue is preferred over simply breaking the loop?
> + }
> +
> + hdr = msg;
> + if (hdr->api != RM_RPC_API) {
> + dev_err(rm->dev, "Unknown RM RPC API version: %x\n",
> + hdr->api);
> + return IRQ_HANDLED;
> + }
> +
> + switch (FIELD_GET(RM_RPC_TYPE_MASK, hdr->type)) {
> + case RM_RPC_TYPE_NOTIF:
> + gunyah_rm_process_notif(rm, msg, len);
> + break;
> + case RM_RPC_TYPE_REPLY:
> + gunyah_rm_process_reply(rm, msg, len);
> + break;
> + case RM_RPC_TYPE_CONTINUATION:
> + gunyah_rm_process_cont(rm, rm->active_rx_message, msg,
> + len);
> + break;
> + default:
> + dev_err(rm->dev,
> + "Invalid message type (%lu) received\n",
> + FIELD_GET(RM_RPC_TYPE_MASK, hdr->type));
> + return IRQ_HANDLED;
> + }
> + } while (ready);
> +
> + return IRQ_HANDLED;
> +}
