xref: /netbsd-src/sys/dev/fdt/cpus.c (revision ecd207b422ce9e9d57801379c24c12381d31a7e4)
1 /* $NetBSD: cpus.c,v 1.8 2023/06/12 12:58:17 skrll Exp $ */
2 
3 /*-
4  * Copyright (c) 2017 Jared McNeill <jmcneill@invisible.ca>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: cpus.c,v 1.8 2023/06/12 12:58:17 skrll Exp $");
31 
32 #include <sys/param.h>
33 #include <sys/bus.h>
34 #include <sys/device.h>
35 #include <sys/intr.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/kmem.h>
39 
40 #include <dev/fdt/fdtvar.h>
41 
42 static int	cpus_match(device_t, cfdata_t, void *);
43 static void	cpus_attach(device_t, device_t, void *);
44 
45 static bool	cpus_cpu_enabled(int);
46 
47 CFATTACH_DECL_NEW(cpus, 0, cpus_match, cpus_attach, NULL, NULL);
48 
49 static int
cpus_match(device_t parent,cfdata_t cf,void * aux)50 cpus_match(device_t parent, cfdata_t cf, void *aux)
51 {
52 	struct fdt_attach_args * const faa = aux;
53 
54 	return OF_finddevice("/cpus") == faa->faa_phandle;
55 }
56 
57 static void
cpus_attach(device_t parent,device_t self,void * aux)58 cpus_attach(device_t parent, device_t self, void *aux)
59 {
60 	struct fdt_attach_args * const faa = aux;
61 	const int phandle = faa->faa_phandle;
62 	int child;
63 
64 	aprint_naive("\n");
65 	aprint_normal("\n");
66 
67 	fdtbus_cpus_md_attach(parent, self, faa);
68 
69 	for (child = OF_child(phandle); child; child = OF_peer(child)) {
70 		if (!cpus_cpu_enabled(child))
71 			continue;
72 		fdt_add_child(self, child, faa, 0);
73 	}
74 }
75 
76 static bool
cpus_cpu_enabled(int child)77 cpus_cpu_enabled(int child)
78 {
79 	const char *s;
80 
81 	/* Only match nodes with device_type = "cpu" */
82 	s = fdtbus_get_string(child, "device_type");
83 	if (!s || strcmp(s, "cpu") != 0)
84 		return false;
85 
86 	/* If status is set, it must be either "okay" or "disabled" */
87 	s = fdtbus_get_string(child, "status");
88 	if (s) {
89 		if (strcmp(s, "okay") == 0)
90 			return true;
91 		if (strcmp(s, "disabled") == 0)
92 			return of_hasprop(child, "enable-method");
93 		return false;
94 	} else {
95 		return true;
96 	}
97 }
98