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android-review.linaro.org / kernel / new-features / 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 / . / arch / sparc / kernel / devices.c
blob: fcb0c049c3feb7e4d4c4be6ae0701d6c16ac760f [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame^]1/* devices.c: Initial scan of the prom device tree for important
2 * Sparc device nodes which we need to find.
3 *
4 * This is based on the sparc64 version, but sun4m doesn't always use
5 * the hardware MIDs, so be careful.
6 *
7 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
8 */
9
10#include <linux/config.h>
11#include <linux/kernel.h>
12#include <linux/threads.h>
13#include <linux/string.h>
14#include <linux/init.h>
15#include <linux/errno.h>
16
17#include <asm/page.h>
18#include <asm/oplib.h>
19#include <asm/smp.h>
20#include <asm/system.h>
21#include <asm/cpudata.h>
22
23extern void cpu_probe(void);
24extern void clock_stop_probe(void); /* tadpole.c */
25extern void sun4c_probe_memerr_reg(void);
26
27static char *cpu_mid_prop(void)
28{
29 if (sparc_cpu_model == sun4d)
30 return "cpu-id";
31 return "mid";
32}
33
34static int check_cpu_node(int nd, int *cur_inst,
35 int (*compare)(int, int, void *), void *compare_arg,
36 int *prom_node, int *mid)
37{
38 char node_str[128];
39
40 prom_getstring(nd, "device_type", node_str, sizeof(node_str));
41 if (strcmp(node_str, "cpu"))
42 return -ENODEV;
43
44 if (!compare(nd, *cur_inst, compare_arg)) {
45 if (prom_node)
46 *prom_node = nd;
47 if (mid) {
48 *mid = prom_getintdefault(nd, cpu_mid_prop(), 0);
49 if (sparc_cpu_model == sun4m)
50 *mid &= 3;
51 }
52 return 0;
53 }
54
55 (*cur_inst)++;
56
57 return -ENODEV;
58}
59
60static int __cpu_find_by(int (*compare)(int, int, void *), void *compare_arg,
61 int *prom_node, int *mid)
62{
63 int nd, cur_inst, err;
64
65 nd = prom_root_node;
66 cur_inst = 0;
67
68 err = check_cpu_node(nd, &cur_inst, compare, compare_arg,
69 prom_node, mid);
70 if (!err)
71 return 0;
72
73 nd = prom_getchild(nd);
74 while ((nd = prom_getsibling(nd)) != 0) {
75 err = check_cpu_node(nd, &cur_inst, compare, compare_arg,
76 prom_node, mid);
77 if (!err)
78 return 0;
79 }
80
81 return -ENODEV;
82}
83
84static int cpu_instance_compare(int nd, int instance, void *_arg)
85{
86 int desired_instance = (int) _arg;
87
88 if (instance == desired_instance)
89 return 0;
90 return -ENODEV;
91}
92
93int cpu_find_by_instance(int instance, int *prom_node, int *mid)
94{
95 return __cpu_find_by(cpu_instance_compare, (void *)instance,
96 prom_node, mid);
97}
98
99static int cpu_mid_compare(int nd, int instance, void *_arg)
100{
101 int desired_mid = (int) _arg;
102 int this_mid;
103
104 this_mid = prom_getintdefault(nd, cpu_mid_prop(), 0);
105 if (this_mid == desired_mid
106 || (sparc_cpu_model == sun4m && (this_mid & 3) == desired_mid))
107 return 0;
108 return -ENODEV;
109}
110
111int cpu_find_by_mid(int mid, int *prom_node)
112{
113 return __cpu_find_by(cpu_mid_compare, (void *)mid,
114 prom_node, NULL);
115}
116
117/* sun4m uses truncated mids since we base the cpuid on the ttable/irqset
118 * address (0-3). This gives us the true hardware mid, which might have
119 * some other bits set. On 4d hardware and software mids are the same.
120 */
121int cpu_get_hwmid(int prom_node)
122{
123 return prom_getintdefault(prom_node, cpu_mid_prop(), -ENODEV);
124}
125
126void __init device_scan(void)
127{
128 prom_printf("Booting Linux...\n");
129
130#ifndef CONFIG_SMP
131 {
132 int err, cpu_node;
133 err = cpu_find_by_instance(0, &cpu_node, NULL);
134 if (err) {
135 /* Probably a sun4e, Sun is trying to trick us ;-) */
136 prom_printf("No cpu nodes, cannot continue\n");
137 prom_halt();
138 }
139 cpu_data(0).clock_tick = prom_getintdefault(cpu_node,
140 "clock-frequency",
141 0);
142 }
143#endif /* !CONFIG_SMP */
144
145 cpu_probe();
146#ifdef CONFIG_SUN_AUXIO
147 {
148 extern void auxio_probe(void);
149 extern void auxio_power_probe(void);
150 auxio_probe();
151 auxio_power_probe();
152 }
153#endif
154 clock_stop_probe();
155
156 if (ARCH_SUN4C_SUN4)
157 sun4c_probe_memerr_reg();
158
159 return;
160}