Index: head/sys/powerpc/powernv/opal_async.c
===================================================================
--- head/sys/powerpc/powernv/opal_async.c	(revision 345789)
+++ head/sys/powerpc/powernv/opal_async.c	(revision 345790)
@@ -1,94 +1,124 @@
 /*-
  * Copyright (C) 2019 Justin Hibbits
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  * $FreeBSD$
  */
 
 #include <sys/cdefs.h>
 #include <sys/param.h>
 #include <sys/types.h>
 #include <sys/malloc.h>
 #include <sys/proc.h>
 #include <sys/vmem.h>
 
 #include <vm/vm.h>
 #include <vm/pmap.h>
 #include "opal.h"
 
+#include <machine/cpufunc.h>
+
 /*
  * Manage asynchronous tokens for the OPAL abstraction layer.
  *
  * Only a finite number of in-flight tokens are supported by OPAL, so we must be
  * careful managing this.  The basic design uses the vmem subsystem as a general
  * purpose allocator, with wrappers to manage expected behaviors and
  * requirements.
  */
 static vmem_t *async_token_pool;
 
+static void opal_handle_async_completion(void *, struct opal_msg *);
+
+struct async_completion {
+	uint64_t rval;
+	bool completed;
+};
+
+struct async_completion *completions;
+
 /* Setup the token pool. */
 int
 opal_init_async_tokens(int count)
 {
 	/* Only allow one initialization */
 	if (async_token_pool != NULL)
 		return (EINVAL);
 
 	async_token_pool = vmem_create("OPAL Async", 0, count, 1, 1,
 	    M_WAITOK | M_FIRSTFIT);
+	completions = malloc(count * sizeof(struct async_completion),
+	    M_DEVBUF, M_WAITOK | M_ZERO);
 
+	EVENTHANDLER_REGISTER(OPAL_ASYNC_COMP, opal_handle_async_completion,
+	    NULL, EVENTHANDLER_PRI_ANY);
+
 	return (0);
 }
 
 int
 opal_alloc_async_token(void)
 {
 	vmem_addr_t token;
 
 	vmem_alloc(async_token_pool, 1, M_FIRSTFIT | M_WAITOK, &token);
+	completions[token].completed = false;
 
 	return (token);
 }
 
 void
 opal_free_async_token(int token)
 {
 
 	vmem_free(async_token_pool, token, 1);
 }
 
 /*
  * Wait for the operation watched by the token to complete.  Return the result
  * of the operation, error if it returns early.
  */
 int
 opal_wait_completion(void *buf, uint64_t size, uint64_t token)
 {
 	int err;
 
 	do {
 		err = opal_call(OPAL_CHECK_ASYNC_COMPLETION,
 		    vtophys(buf), size, token);
+		if (err == OPAL_BUSY)
+			if (completions[token].completed)
+				return (completions[token].rval);
 	} while (err == OPAL_BUSY);
 
 	return (err);
+}
+
+static void opal_handle_async_completion(void *arg, struct opal_msg *msg)
+{
+	int token;
+
+	token = msg->params[0];
+	completions[token].rval = msg->params[1];
+	isync();
+	completions[token].completed = true;
 }