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