// SPDX-License-Identifier: GPL-2.0/* devices.c: Initial scan of the prom device tree for important *	      Sparc device nodes which we need to find. * * This is based on the sparc64 version, but sun4m doesn't always use * the hardware MIDs, so be careful. * * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu) */ #include <linux/kernel.h>#include <linux/threads.h>#include <linux/string.h>#include <linux/init.h>#include <linux/errno.h> #include <asm/page.h>#include <asm/oplib.h>#include <asm/prom.h>#include <asm/smp.h>#include <asm/cpudata.h>#include <asm/cpu_type.h>#include <asm/setup.h> #include "kernel.h" static char *cpu_mid_prop(void){	if (sparc_cpu_model == sun4d)		return "cpu-id";	return "mid";} static int check_cpu_node(phandle nd, int *cur_inst,		int (*compare)(phandle, int, void *), void *compare_arg,		phandle *prom_node, int *mid){	if (!compare(nd, *cur_inst, compare_arg)) {		if (prom_node)			*prom_node = nd;		if (mid) {			*mid = prom_getintdefault(nd, cpu_mid_prop(), 0);			if (sparc_cpu_model == sun4m)				*mid &= 3;		}		return 0;	} 	(*cur_inst)++; 	return -ENODEV;} static int __cpu_find_by(int (*compare)(phandle, int, void *),		void *compare_arg, phandle *prom_node, int *mid){	struct device_node *dp;	int cur_inst; 	cur_inst = 0;	for_each_node_by_type(dp, "cpu") {		int err = check_cpu_node(dp->phandle, &cur_inst,					 compare, compare_arg,					 prom_node, mid);		if (!err) {			of_node_put(dp);			return 0;		}	} 	return -ENODEV;} static int cpu_instance_compare(phandle nd, int instance, void *_arg){	int desired_instance = (int) _arg; 	if (instance == desired_instance)		return 0;	return -ENODEV;} int cpu_find_by_instance(int instance, phandle *prom_node, int *mid){	return __cpu_find_by(cpu_instance_compare, (void *)instance,			     prom_node, mid);} static int cpu_mid_compare(phandle nd, int instance, void *_arg){	int desired_mid = (int) _arg;	int this_mid; 	this_mid = prom_getintdefault(nd, cpu_mid_prop(), 0);	if (this_mid == desired_mid	    || (sparc_cpu_model == sun4m && (this_mid & 3) == desired_mid))		return 0;	return -ENODEV;} int cpu_find_by_mid(int mid, phandle *prom_node){	return __cpu_find_by(cpu_mid_compare, (void *)mid,			     prom_node, NULL);} /* sun4m uses truncated mids since we base the cpuid on the ttable/irqset * address (0-3).  This gives us the true hardware mid, which might have * some other bits set.  On 4d hardware and software mids are the same. */int cpu_get_hwmid(phandle prom_node){	return prom_getintdefault(prom_node, cpu_mid_prop(), -ENODEV);} void __init device_scan(void){	printk(KERN_NOTICE "Booting Linux...\n"); #ifndef CONFIG_SMP	{		phandle cpu_node;		int err;		err = cpu_find_by_instance(0, &cpu_node, NULL);		if (err) {			/* Probably a sun4e, Sun is trying to trick us ;-) */			prom_printf("No cpu nodes, cannot continue\n");			prom_halt();		}		cpu_data(0).clock_tick = prom_getintdefault(cpu_node,							    "clock-frequency",							    0);	}#endif /* !CONFIG_SMP */ 	auxio_probe();	auxio_power_probe();}