source: mainline/kernel/arch/sparc64/src/smp/sun4u/smp.c

Last change on this file was 7c5320c, checked in by Jiří Zárevúcky <zarevucky.jiri@…>, 2 years ago

Use the semaphore interface instead of waitq in some places

Since we already have an underused semaphore API in the kernel,
it would be worthwhile to use it in places where the baseline
semaphore semantics are needed. It makes the function of the
calls obvious even to people unfamiliar with the details of
waitq API.

  • Property mode set to 100644
File size: 4.0 KB
Line 
1/*
2 * Copyright (c) 2006 Jakub Jermar
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup kernel_sparc64
30 * @{
31 */
32/** @file
33 */
34
35#include <smp/smp.h>
36#include <genarch/ofw/ofw_tree.h>
37#include <cpu.h>
38#include <arch/cpu_family.h>
39#include <arch/cpu.h>
40#include <arch.h>
41#include <config.h>
42#include <macros.h>
43#include <stdint.h>
44#include <synch/waitq.h>
45#include <log.h>
46#include <arch/cpu_node.h>
47
48/**
49 * This global variable is used to pick-up application processors
50 * from their active loop in start.S. When a processor looping in
51 * start.S sees that this variable contains its MID, it can
52 * proceed with its initialization.
53 *
54 * This variable is modified only by the bootstrap processor.
55 * Other processors access it read-only.
56 */
57volatile uint64_t waking_up_mid = (uint64_t) -1;
58
59/** Determine number of processors. */
60void smp_init(void)
61{
62 ofw_tree_node_t *node;
63 unsigned int cnt = 0;
64
65 if (is_us() || is_us_iii()) {
66 node = ofw_tree_find_child_by_device_type(cpus_parent(), "cpu");
67 while (node) {
68 cnt++;
69 node = ofw_tree_find_peer_by_device_type(node, "cpu");
70 }
71 } else if (is_us_iv()) {
72 node = ofw_tree_find_child(cpus_parent(), "cmp");
73 while (node) {
74 cnt += 2;
75 node = ofw_tree_find_peer_by_name(node, "cmp");
76 }
77 }
78
79 config.cpu_count = max(1, cnt);
80}
81
82/**
83 * Wakes up the CPU which is represented by the "node" OFW tree node.
84 * If "node" represents the current CPU, calling the function has
85 * no effect.
86 */
87static void wakeup_cpu(ofw_tree_node_t *node)
88{
89 uint32_t mid;
90 ofw_tree_property_t *prop;
91
92 /* 'upa-portid' for US, 'portid' for US-III, 'cpuid' for US-IV */
93 prop = ofw_tree_getprop(node, "upa-portid");
94 if ((!prop) || (!prop->value))
95 prop = ofw_tree_getprop(node, "portid");
96 if ((!prop) || (!prop->value))
97 prop = ofw_tree_getprop(node, "cpuid");
98
99 if (!prop || prop->value == NULL)
100 return;
101
102 mid = *((uint32_t *) prop->value);
103 if (CPU->arch.mid == mid)
104 return;
105
106 waking_up_mid = mid;
107
108 if (semaphore_down_timeout(&ap_completion_semaphore, 1000000) != EOK)
109 log(LF_ARCH, LVL_NOTE, "%s: waiting for processor (mid = %" PRIu32
110 ") timed out", __func__, mid);
111}
112
113/** Wake application processors up. */
114void kmp(void *arg)
115{
116 ofw_tree_node_t *node;
117 int i;
118
119 if (is_us() || is_us_iii()) {
120 node = ofw_tree_find_child_by_device_type(cpus_parent(), "cpu");
121 for (i = 0; node;
122 node = ofw_tree_find_peer_by_device_type(node, "cpu"), i++)
123 wakeup_cpu(node);
124 } else if (is_us_iv()) {
125 node = ofw_tree_find_child(cpus_parent(), "cmp");
126 while (node) {
127 wakeup_cpu(ofw_tree_find_child(node, "cpu@0"));
128 wakeup_cpu(ofw_tree_find_child(node, "cpu@1"));
129 node = ofw_tree_find_peer_by_name(node, "cmp");
130 }
131 }
132}
133
134/** @}
135 */
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