1 /*-
2 * Copyright (C) 2019 Justin Hibbits
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
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.
12 *
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,
20 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
21 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
22 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 */
24
25 #include <sys/cdefs.h>
26 #include <sys/param.h>
27 #include <sys/eventhandler.h>
28 #include <sys/malloc.h>
29 #include <sys/proc.h>
30 #include <sys/vmem.h>
31
32 #include <vm/vm.h>
33 #include <vm/pmap.h>
34 #include "opal.h"
35
36 #include <machine/cpufunc.h>
37
38 /*
39 * Manage asynchronous tokens for the OPAL abstraction layer.
40 *
41 * Only a finite number of in-flight tokens are supported by OPAL, so we must be
42 * careful managing this. The basic design uses the vmem subsystem as a general
43 * purpose allocator, with wrappers to manage expected behaviors and
44 * requirements.
45 */
46 static vmem_t *async_token_pool;
47
48 static void opal_handle_async_completion(void *, struct opal_msg *);
49
50 struct async_completion {
51 volatile uint64_t completed;
52 struct opal_msg msg;
53 };
54
55 struct async_completion *completions;
56
57 /* Setup the token pool. */
58 int
opal_init_async_tokens(int count)59 opal_init_async_tokens(int count)
60 {
61 /* Only allow one initialization */
62 if (async_token_pool != NULL)
63 return (EINVAL);
64
65 async_token_pool = vmem_create("OPAL Async", 0, count, 1, 1,
66 M_WAITOK | M_FIRSTFIT);
67 completions = malloc(count * sizeof(struct async_completion),
68 M_DEVBUF, M_WAITOK | M_ZERO);
69
70 EVENTHANDLER_REGISTER(OPAL_ASYNC_COMP, opal_handle_async_completion,
71 NULL, EVENTHANDLER_PRI_ANY);
72
73 return (0);
74 }
75
76 int
opal_alloc_async_token(void)77 opal_alloc_async_token(void)
78 {
79 vmem_addr_t token;
80
81 vmem_alloc(async_token_pool, 1, M_FIRSTFIT | M_WAITOK, &token);
82 completions[token].completed = false;
83
84 return (token);
85 }
86
87 void
opal_free_async_token(int token)88 opal_free_async_token(int token)
89 {
90
91 vmem_free(async_token_pool, token, 1);
92 }
93
94 /*
95 * Wait for the operation watched by the token to complete. Return the result
96 * of the operation, error if it returns early.
97 */
98 int
opal_wait_completion(void * buf,uint64_t size,int token)99 opal_wait_completion(void *buf, uint64_t size, int token)
100 {
101 int err;
102
103 do {
104 err = opal_call(OPAL_CHECK_ASYNC_COMPLETION,
105 vtophys(buf), size, token);
106 if (err == OPAL_BUSY) {
107 if (completions[token].completed) {
108 atomic_thread_fence_acq();
109 memcpy(buf, &completions[token].msg, size);
110 return (OPAL_SUCCESS);
111 }
112 }
113 DELAY(100);
114 } while (err == OPAL_BUSY);
115
116 return (err);
117 }
118
opal_handle_async_completion(void * arg,struct opal_msg * msg)119 static void opal_handle_async_completion(void *arg, struct opal_msg *msg)
120 {
121 int token;
122
123 token = msg->params[0];
124 memcpy(&completions[token].msg, msg, sizeof(*msg));
125 atomic_thread_fence_rel();
126 completions[token].completed = true;
127 }
128