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/kernel.h>
11 #include <linux/threads.h>
12 #include <linux/string.h>
13 #include <linux/init.h>
14 #include <linux/errno.h>
15
16 #include <asm/page.h>
17 #include <asm/oplib.h>
18 #include <asm/prom.h>
19 #include <asm/smp.h>
20 #include <asm/cpudata.h>
21 #include <asm/cpu_type.h>
22 #include <asm/setup.h>
23
24 #include "kernel.h"
25
cpu_mid_prop(void)26 static char *cpu_mid_prop(void)
27 {
28 if (sparc_cpu_model == sun4d)
29 return "cpu-id";
30 return "mid";
31 }
32
check_cpu_node(phandle nd,int * cur_inst,int (* compare)(phandle,int,void *),void * compare_arg,phandle * prom_node,int * mid)33 static int check_cpu_node(phandle nd, int *cur_inst,
34 int (*compare)(phandle, int, void *), void *compare_arg,
35 phandle *prom_node, int *mid)
36 {
37 if (!compare(nd, *cur_inst, compare_arg)) {
38 if (prom_node)
39 *prom_node = nd;
40 if (mid) {
41 *mid = prom_getintdefault(nd, cpu_mid_prop(), 0);
42 if (sparc_cpu_model == sun4m)
43 *mid &= 3;
44 }
45 return 0;
46 }
47
48 (*cur_inst)++;
49
50 return -ENODEV;
51 }
52
__cpu_find_by(int (* compare)(phandle,int,void *),void * compare_arg,phandle * prom_node,int * mid)53 static int __cpu_find_by(int (*compare)(phandle, int, void *),
54 void *compare_arg, phandle *prom_node, int *mid)
55 {
56 struct device_node *dp;
57 int cur_inst;
58
59 cur_inst = 0;
60 for_each_node_by_type(dp, "cpu") {
61 int err = check_cpu_node(dp->phandle, &cur_inst,
62 compare, compare_arg,
63 prom_node, mid);
64 if (!err) {
65 of_node_put(dp);
66 return 0;
67 }
68 }
69
70 return -ENODEV;
71 }
72
cpu_instance_compare(phandle nd,int instance,void * _arg)73 static int cpu_instance_compare(phandle nd, int instance, void *_arg)
74 {
75 int desired_instance = (int) _arg;
76
77 if (instance == desired_instance)
78 return 0;
79 return -ENODEV;
80 }
81
cpu_find_by_instance(int instance,phandle * prom_node,int * mid)82 int cpu_find_by_instance(int instance, phandle *prom_node, int *mid)
83 {
84 return __cpu_find_by(cpu_instance_compare, (void *)instance,
85 prom_node, mid);
86 }
87
cpu_mid_compare(phandle nd,int instance,void * _arg)88 static int cpu_mid_compare(phandle nd, int instance, void *_arg)
89 {
90 int desired_mid = (int) _arg;
91 int this_mid;
92
93 this_mid = prom_getintdefault(nd, cpu_mid_prop(), 0);
94 if (this_mid == desired_mid
95 || (sparc_cpu_model == sun4m && (this_mid & 3) == desired_mid))
96 return 0;
97 return -ENODEV;
98 }
99
cpu_find_by_mid(int mid,phandle * prom_node)100 int cpu_find_by_mid(int mid, phandle *prom_node)
101 {
102 return __cpu_find_by(cpu_mid_compare, (void *)mid,
103 prom_node, NULL);
104 }
105
106 /* sun4m uses truncated mids since we base the cpuid on the ttable/irqset
107 * address (0-3). This gives us the true hardware mid, which might have
108 * some other bits set. On 4d hardware and software mids are the same.
109 */
cpu_get_hwmid(phandle prom_node)110 int cpu_get_hwmid(phandle prom_node)
111 {
112 return prom_getintdefault(prom_node, cpu_mid_prop(), -ENODEV);
113 }
114
device_scan(void)115 void __init device_scan(void)
116 {
117 printk(KERN_NOTICE "Booting Linux...\n");
118
119 #ifndef CONFIG_SMP
120 {
121 phandle cpu_node;
122 int err;
123 err = cpu_find_by_instance(0, &cpu_node, NULL);
124 if (err) {
125 /* Probably a sun4e, Sun is trying to trick us ;-) */
126 prom_printf("No cpu nodes, cannot continue\n");
127 prom_halt();
128 }
129 cpu_data(0).clock_tick = prom_getintdefault(cpu_node,
130 "clock-frequency",
131 0);
132 }
133 #endif /* !CONFIG_SMP */
134
135 auxio_probe();
136 auxio_power_probe();
137 }
138