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 23 extern void cpu_probe(void); 24 extern void clock_stop_probe(void); /* tadpole.c */ 25 extern void sun4c_probe_memerr_reg(void); 26 27 static char *cpu_mid_prop(void) 28 { 29 if (sparc_cpu_model == sun4d) 30 return "cpu-id"; 31 return "mid"; 32 } 33 34 static 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 60 static 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 84 static 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 93 int 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 99 static 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 } 110 111 int 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 */ 121 int cpu_get_hwmid(int prom_node) 122 { 123 return prom_getintdefault(prom_node, cpu_mid_prop(), -ENODEV); 124 } 125 126 void __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 } 161