xref: /src/sys/dev/fdt/cpus.c

/* $NetBSD: cpus.c,v 1.6 2022/11/05 10:04:35 skrll Exp $ */

/*-
 * Copyright (c) 2017 Jared McNeill <jmcneill (at) invisible.ca>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: cpus.c,v 1.6 2022/11/05 10:04:35 skrll Exp $");

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/device.h>
#include <sys/intr.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/kmem.h>

#include <dev/fdt/fdtvar.h>

static int	cpus_match(device_t, cfdata_t, void *);
static void	cpus_attach(device_t, device_t, void *);

static bool	cpus_cpu_enabled(int);

CFATTACH_DECL_NEW(cpus, 0, cpus_match, cpus_attach, NULL, NULL);

static int
cpus_match(device_t parent, cfdata_t cf, void *aux)
{
	struct fdt_attach_args * const faa = aux;

	return OF_finddevice("/cpus") == faa->faa_phandle;
}

static void
cpus_attach(device_t parent, device_t self, void *aux)
{
	struct fdt_attach_args * const faa = aux;
	const int phandle = faa->faa_phandle;
	int child;

	aprint_naive("\n");
	aprint_normal("\n");

	for (child = OF_child(phandle); child; child = OF_peer(child)) {
		if (!cpus_cpu_enabled(child))
			continue;
		fdt_add_child(self, child, faa, 0);
	}
}

static bool
cpus_cpu_enabled(int child)
{
	const char *s;

	/* Only match nodes with device_type = "cpu" */
	s = fdtbus_get_string(child, "device_type");
	if (!s || strcmp(s, "cpu") != 0)
		return false;

	/* If status is set, it must be either "okay" or "disabled" */
	s = fdtbus_get_string(child, "status");
	if (s) {
		if (strcmp(s, "okay") == 0)
			return true;
		if (strcmp(s, "disabled") == 0)
			return of_hasprop(child, "enable-method");
		return false;
	} else {
		return true;
	}
}