1 files changed, 126 insertions, 0 deletions
diff --git a/sys/powerpc/powernv/opal_async.c b/sys/powerpc/powernv/opal_async.c
new file mode 100644
index 000000000000..781a56a4de79
--- /dev/null
+++ b/sys/powerpc/powernv/opal_async.c
@@ -0,0 +1,126 @@
+/*-
+ * 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.
+ */
+
+#include <sys/param.h>
+#include <sys/eventhandler.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 {
+	volatile uint64_t 	completed;
+	struct opal_msg 	msg;
+};
+
+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, int token)
+{
+	int err;
+
+	do {
+		err = opal_call(OPAL_CHECK_ASYNC_COMPLETION,
+		    vtophys(buf), size, token);
+		if (err == OPAL_BUSY) {
+			if (completions[token].completed) {
+				atomic_thread_fence_acq();
+				memcpy(buf, &completions[token].msg, size);
+				return (OPAL_SUCCESS);
+			}
+		}
+		DELAY(100);
+	} while (err == OPAL_BUSY);
+
+	return (err);
+}
+
+static void opal_handle_async_completion(void *arg, struct opal_msg *msg)
+{
+	int token;
+
+	token = msg->params[0];
+	memcpy(&completions[token].msg, msg, sizeof(*msg));
+	atomic_thread_fence_rel();
+	completions[token].completed = true;
+}