2 * Copyright (C) 2019 Justin Hibbits
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
17 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
18 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
19 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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25 #include <sys/param.h>
26 #include <sys/eventhandler.h>
27 #include <sys/malloc.h>
35 #include <machine/cpufunc.h>
38 * Manage asynchronous tokens for the OPAL abstraction layer.
40 * Only a finite number of in-flight tokens are supported by OPAL, so we must be
41 * careful managing this. The basic design uses the vmem subsystem as a general
42 * purpose allocator, with wrappers to manage expected behaviors and
45 static vmem_t *async_token_pool;
47 static void opal_handle_async_completion(void *, struct opal_msg *);
49 struct async_completion {
50 volatile uint64_t completed;
54 struct async_completion *completions;
56 /* Setup the token pool. */
58 opal_init_async_tokens(int count)
60 /* Only allow one initialization */
61 if (async_token_pool != NULL)
64 async_token_pool = vmem_create("OPAL Async", 0, count, 1, 1,
65 M_WAITOK | M_FIRSTFIT);
66 completions = malloc(count * sizeof(struct async_completion),
67 M_DEVBUF, M_WAITOK | M_ZERO);
69 EVENTHANDLER_REGISTER(OPAL_ASYNC_COMP, opal_handle_async_completion,
70 NULL, EVENTHANDLER_PRI_ANY);
76 opal_alloc_async_token(void)
80 vmem_alloc(async_token_pool, 1, M_FIRSTFIT | M_WAITOK, &token);
81 completions[token].completed = false;
87 opal_free_async_token(int token)
90 vmem_free(async_token_pool, token, 1);
94 * Wait for the operation watched by the token to complete. Return the result
95 * of the operation, error if it returns early.
98 opal_wait_completion(void *buf, uint64_t size, int token)
103 err = opal_call(OPAL_CHECK_ASYNC_COMPLETION,
104 vtophys(buf), size, token);
105 if (err == OPAL_BUSY) {
106 if (completions[token].completed) {
107 atomic_thread_fence_acq();
108 memcpy(buf, &completions[token].msg, size);
109 return (OPAL_SUCCESS);
113 } while (err == OPAL_BUSY);
118 static void opal_handle_async_completion(void *arg, struct opal_msg *msg)
122 token = msg->params[0];
123 memcpy(&completions[token].msg, msg, sizeof(*msg));
124 atomic_thread_fence_rel();
125 completions[token].completed = true;