Linus Torvalds | 1da177e | 2005-04-16 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 | |
| 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 | } |