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/smp.h> 19 #include <asm/system.h> 20 #include <asm/cpudata.h> 21 22 extern void cpu_probe(void); 23 extern void clock_stop_probe(void); /* tadpole.c */ 24 extern void sun4c_probe_memerr_reg(void); 25 26 static char *cpu_mid_prop(void) 27 { 28 if (sparc_cpu_model == sun4d) 29 return "cpu-id"; 30 return "mid"; 31 } 32 33 static int check_cpu_node(int nd, int *cur_inst, 34 int (*compare)(int, int, void *), void *compare_arg, 35 int *prom_node, int *mid) 36 { 37 char node_str[128]; 38 39 prom_getstring(nd, "device_type", node_str, sizeof(node_str)); 40 if (strcmp(node_str, "cpu")) 41 return -ENODEV; 42 43 if (!compare(nd, *cur_inst, compare_arg)) { 44 if (prom_node) 45 *prom_node = nd; 46 if (mid) { 47 *mid = prom_getintdefault(nd, cpu_mid_prop(), 0); 48 if (sparc_cpu_model == sun4m) 49 *mid &= 3; 50 } 51 return 0; 52 } 53 54 (*cur_inst)++; 55 56 return -ENODEV; 57 } 58 59 static int __cpu_find_by(int (*compare)(int, int, void *), void *compare_arg, 60 int *prom_node, int *mid) 61 { 62 int nd, cur_inst, err; 63 64 nd = prom_root_node; 65 cur_inst = 0; 66 67 err = check_cpu_node(nd, &cur_inst, compare, compare_arg, 68 prom_node, mid); 69 if (!err) 70 return 0; 71 72 nd = prom_getchild(nd); 73 while ((nd = prom_getsibling(nd)) != 0) { 74 err = check_cpu_node(nd, &cur_inst, compare, compare_arg, 75 prom_node, mid); 76 if (!err) 77 return 0; 78 } 79 80 return -ENODEV; 81 } 82 83 static int cpu_instance_compare(int nd, int instance, void *_arg) 84 { 85 int desired_instance = (int) _arg; 86 87 if (instance == desired_instance) 88 return 0; 89 return -ENODEV; 90 } 91 92 int cpu_find_by_instance(int instance, int *prom_node, int *mid) 93 { 94 return __cpu_find_by(cpu_instance_compare, (void *)instance, 95 prom_node, mid); 96 } 97 98 static int cpu_mid_compare(int nd, int instance, void *_arg) 99 { 100 int desired_mid = (int) _arg; 101 int this_mid; 102 103 this_mid = prom_getintdefault(nd, cpu_mid_prop(), 0); 104 if (this_mid == desired_mid 105 || (sparc_cpu_model == sun4m && (this_mid & 3) == desired_mid)) 106 return 0; 107 return -ENODEV; 108 } 109 110 int cpu_find_by_mid(int mid, int *prom_node) 111 { 112 return __cpu_find_by(cpu_mid_compare, (void *)mid, 113 prom_node, NULL); 114 } 115 116 /* sun4m uses truncated mids since we base the cpuid on the ttable/irqset 117 * address (0-3). This gives us the true hardware mid, which might have 118 * some other bits set. On 4d hardware and software mids are the same. 119 */ 120 int cpu_get_hwmid(int prom_node) 121 { 122 return prom_getintdefault(prom_node, cpu_mid_prop(), -ENODEV); 123 } 124 125 void __init device_scan(void) 126 { 127 prom_printf("Booting Linux...\n"); 128 129 #ifndef CONFIG_SMP 130 { 131 int err, cpu_node; 132 err = cpu_find_by_instance(0, &cpu_node, NULL); 133 if (err) { 134 /* Probably a sun4e, Sun is trying to trick us ;-) */ 135 prom_printf("No cpu nodes, cannot continue\n"); 136 prom_halt(); 137 } 138 cpu_data(0).clock_tick = prom_getintdefault(cpu_node, 139 "clock-frequency", 140 0); 141 } 142 #endif /* !CONFIG_SMP */ 143 144 cpu_probe(); 145 #ifdef CONFIG_SUN_AUXIO 146 { 147 extern void auxio_probe(void); 148 extern void auxio_power_probe(void); 149 auxio_probe(); 150 auxio_power_probe(); 151 } 152 #endif 153 clock_stop_probe(); 154 155 if (ARCH_SUN4C_SUN4) 156 sun4c_probe_memerr_reg(); 157 158 return; 159 } 160