1 // SPDX-License-Identifier: GPL-2.0 2 /* devices.c: Initial scan of the prom device tree for important 3 * Sparc device nodes which we need to find. 4 * 5 * This is based on the sparc64 version, but sun4m doesn't always use 6 * the hardware MIDs, so be careful. 7 * 8 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu) 9 */ 10 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/prom.h> 20 #include <asm/smp.h> 21 #include <asm/cpudata.h> 22 #include <asm/cpu_type.h> 23 #include <asm/setup.h> 24 25 #include "kernel.h" 26 cpu_mid_prop(void)27 static char *cpu_mid_prop(void) 28 { 29 if (sparc_cpu_model == sun4d) 30 return "cpu-id"; 31 return "mid"; 32 } 33 check_cpu_node(phandle nd,int * cur_inst,int (* compare)(phandle,int,void *),void * compare_arg,phandle * prom_node,int * mid)34 static int check_cpu_node(phandle nd, int *cur_inst, 35 int (*compare)(phandle, int, void *), void *compare_arg, 36 phandle *prom_node, int *mid) 37 { 38 if (!compare(nd, *cur_inst, compare_arg)) { 39 if (prom_node) 40 *prom_node = nd; 41 if (mid) { 42 *mid = prom_getintdefault(nd, cpu_mid_prop(), 0); 43 if (sparc_cpu_model == sun4m) 44 *mid &= 3; 45 } 46 return 0; 47 } 48 49 (*cur_inst)++; 50 51 return -ENODEV; 52 } 53 __cpu_find_by(int (* compare)(phandle,int,void *),void * compare_arg,phandle * prom_node,int * mid)54 static int __cpu_find_by(int (*compare)(phandle, int, void *), 55 void *compare_arg, phandle *prom_node, int *mid) 56 { 57 struct device_node *dp; 58 int cur_inst; 59 60 cur_inst = 0; 61 for_each_node_by_type(dp, "cpu") { 62 int err = check_cpu_node(dp->phandle, &cur_inst, 63 compare, compare_arg, 64 prom_node, mid); 65 if (!err) { 66 of_node_put(dp); 67 return 0; 68 } 69 } 70 71 return -ENODEV; 72 } 73 cpu_instance_compare(phandle nd,int instance,void * _arg)74 static int cpu_instance_compare(phandle nd, int instance, void *_arg) 75 { 76 int desired_instance = (int) _arg; 77 78 if (instance == desired_instance) 79 return 0; 80 return -ENODEV; 81 } 82 cpu_find_by_instance(int instance,phandle * prom_node,int * mid)83 int cpu_find_by_instance(int instance, phandle *prom_node, int *mid) 84 { 85 return __cpu_find_by(cpu_instance_compare, (void *)instance, 86 prom_node, mid); 87 } 88 cpu_mid_compare(phandle nd,int instance,void * _arg)89 static int cpu_mid_compare(phandle nd, int instance, void *_arg) 90 { 91 int desired_mid = (int) _arg; 92 int this_mid; 93 94 this_mid = prom_getintdefault(nd, cpu_mid_prop(), 0); 95 if (this_mid == desired_mid 96 || (sparc_cpu_model == sun4m && (this_mid & 3) == desired_mid)) 97 return 0; 98 return -ENODEV; 99 } 100 cpu_find_by_mid(int mid,phandle * prom_node)101 int cpu_find_by_mid(int mid, phandle *prom_node) 102 { 103 return __cpu_find_by(cpu_mid_compare, (void *)mid, 104 prom_node, NULL); 105 } 106 107 /* sun4m uses truncated mids since we base the cpuid on the ttable/irqset 108 * address (0-3). This gives us the true hardware mid, which might have 109 * some other bits set. On 4d hardware and software mids are the same. 110 */ cpu_get_hwmid(phandle prom_node)111 int cpu_get_hwmid(phandle prom_node) 112 { 113 return prom_getintdefault(prom_node, cpu_mid_prop(), -ENODEV); 114 } 115 device_scan(void)116 void __init device_scan(void) 117 { 118 printk(KERN_NOTICE "Booting Linux...\n"); 119 120 #ifndef CONFIG_SMP 121 { 122 phandle cpu_node; 123 int err; 124 err = cpu_find_by_instance(0, &cpu_node, NULL); 125 if (err) { 126 /* Probably a sun4e, Sun is trying to trick us ;-) */ 127 prom_printf("No cpu nodes, cannot continue\n"); 128 prom_halt(); 129 } 130 cpu_data(0).clock_tick = prom_getintdefault(cpu_node, 131 "clock-frequency", 132 0); 133 } 134 #endif /* !CONFIG_SMP */ 135 136 auxio_probe(); 137 auxio_power_probe(); 138 } 139