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      1 /* $NetBSD: cpus.c,v 1.8 2023/06/12 12:58:17 skrll Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2017 Jared McNeill <jmcneill (at) 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
     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
     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
     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