devices.c

该文件是rt_linux

/* devices.c: Initial scan of the prom device tree for important
 *	      Sparc device nodes which we need to find.
 *
 * Copyright (C) 1996 David S. Miller ([e-mail])
 */

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/threads.h>
#include <linux/string.h>
#include <linux/init.h>

#include <asm/page.h>
#include <asm/oplib.h>
#include <asm/smp.h>
#include <asm/system.h>

struct prom_cpuinfo linux_cpus[32];
int linux_num_cpus = 0;

extern void cpu_probe(void);
extern void clock_stop_probe(void); /* tadpole.c */
extern void sun4c_probe_memerr_reg(void);

void __init
device_scan(void)
{
	char node_str[128];
	int thismid;

	prom_getstring(prom_root_node, "device_type", node_str, sizeof(node_str));

	prom_printf("Booting Linux...\n");
	if(strcmp(node_str, "cpu") == 0) {
		linux_num_cpus++;
	} else {
		int scan;
		scan = prom_getchild(prom_root_node);
		/* One can look it up in PROM instead */
		while ((scan = prom_getsibling(scan)) != 0) {
			prom_getstring(scan, "device_type",
				       node_str, sizeof(node_str));
			if (strcmp(node_str, "cpu") == 0) {
				linux_cpus[linux_num_cpus].prom_node = scan;
				prom_getproperty(scan, "mid",
						 (char *) &thismid, sizeof(thismid));
				linux_cpus[linux_num_cpus].mid = thismid;
				printk("Found CPU %d <node=%08lx,mid=%d>\n",
				       linux_num_cpus, (unsigned long) scan, thismid);
				linux_num_cpus++;
			}
		}
		if (linux_num_cpus == 0 && sparc_cpu_model == sun4d) {
			scan = prom_getchild(prom_root_node);
			for (scan = prom_searchsiblings(scan, "cpu-unit"); scan;
			     scan = prom_searchsiblings(prom_getsibling(scan), "cpu-unit")) {
				int node = prom_getchild(scan);

				prom_getstring(node, "device_type",
					       node_str, sizeof(node_str));
				if (strcmp(node_str, "cpu") == 0) {
					prom_getproperty(node, "cpu-id",
							 (char *) &thismid, sizeof(thismid));
					linux_cpus[linux_num_cpus].prom_node = node;
					linux_cpus[linux_num_cpus].mid = thismid;
					printk("Found CPU %d <node=%08lx,mid=%d>\n", 
					       linux_num_cpus, (unsigned long) node, thismid);
					linux_num_cpus++;
				}
			}
		}
		if (linux_num_cpus == 0) {
			printk("No CPU nodes found, cannot continue.\n");
			/* Probably a sun4e, Sun is trying to trick us ;-) */
			halt();
		}
		printk("Found %d CPU prom device tree node(s).\n", linux_num_cpus);
	}

	cpu_probe();
#ifdef CONFIG_SUN_AUXIO
	{
		extern void auxio_probe(void);
		extern void auxio_power_probe(void);
		auxio_probe();
		auxio_power_probe();
	}
#endif
	clock_stop_probe();

	if (ARCH_SUN4C_SUN4)
		sun4c_probe_memerr_reg();

	return;
}