1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2012 Regents of the University of California 4 */ 5 6 #include <linux/init.h> 7 #include <linux/seq_file.h> 8 #include <linux/of.h> 9 #include <asm/smp.h> 10 11 /* 12 * Returns the hart ID of the given device tree node, or -ENODEV if the node 13 * isn't an enabled and valid RISC-V hart node. 14 */ 15 int riscv_of_processor_hartid(struct device_node *node) 16 { 17 const char *isa; 18 u32 hart; 19 20 if (!of_device_is_compatible(node, "riscv")) { 21 pr_warn("Found incompatible CPU\n"); 22 return -ENODEV; 23 } 24 25 if (of_property_read_u32(node, "reg", &hart)) { 26 pr_warn("Found CPU without hart ID\n"); 27 return -ENODEV; 28 } 29 30 if (!of_device_is_available(node)) { 31 pr_info("CPU with hartid=%d is not available\n", hart); 32 return -ENODEV; 33 } 34 35 if (of_property_read_string(node, "riscv,isa", &isa)) { 36 pr_warn("CPU with hartid=%d has no \"riscv,isa\" property\n", hart); 37 return -ENODEV; 38 } 39 if (isa[0] != 'r' || isa[1] != 'v') { 40 pr_warn("CPU with hartid=%d has an invalid ISA of \"%s\"\n", hart, isa); 41 return -ENODEV; 42 } 43 44 return hart; 45 } 46 47 #ifdef CONFIG_PROC_FS 48 49 static void print_isa(struct seq_file *f, const char *isa) 50 { 51 /* Print the entire ISA as it is */ 52 seq_puts(f, "isa\t\t: "); 53 seq_write(f, isa, strlen(isa)); 54 seq_puts(f, "\n"); 55 } 56 57 static void print_mmu(struct seq_file *f, const char *mmu_type) 58 { 59 #if defined(CONFIG_32BIT) 60 if (strcmp(mmu_type, "riscv,sv32") != 0) 61 return; 62 #elif defined(CONFIG_64BIT) 63 if (strcmp(mmu_type, "riscv,sv39") != 0 && 64 strcmp(mmu_type, "riscv,sv48") != 0) 65 return; 66 #endif 67 68 seq_printf(f, "mmu\t\t: %s\n", mmu_type+6); 69 } 70 71 static void *c_start(struct seq_file *m, loff_t *pos) 72 { 73 *pos = cpumask_next(*pos - 1, cpu_online_mask); 74 if ((*pos) < nr_cpu_ids) 75 return (void *)(uintptr_t)(1 + *pos); 76 return NULL; 77 } 78 79 static void *c_next(struct seq_file *m, void *v, loff_t *pos) 80 { 81 (*pos)++; 82 return c_start(m, pos); 83 } 84 85 static void c_stop(struct seq_file *m, void *v) 86 { 87 } 88 89 static int c_show(struct seq_file *m, void *v) 90 { 91 unsigned long cpu_id = (unsigned long)v - 1; 92 struct device_node *node = of_get_cpu_node(cpu_id, NULL); 93 const char *compat, *isa, *mmu; 94 95 seq_printf(m, "processor\t: %lu\n", cpu_id); 96 seq_printf(m, "hart\t\t: %lu\n", cpuid_to_hartid_map(cpu_id)); 97 if (!of_property_read_string(node, "riscv,isa", &isa)) 98 print_isa(m, isa); 99 if (!of_property_read_string(node, "mmu-type", &mmu)) 100 print_mmu(m, mmu); 101 if (!of_property_read_string(node, "compatible", &compat) 102 && strcmp(compat, "riscv")) 103 seq_printf(m, "uarch\t\t: %s\n", compat); 104 seq_puts(m, "\n"); 105 of_node_put(node); 106 107 return 0; 108 } 109 110 const struct seq_operations cpuinfo_op = { 111 .start = c_start, 112 .next = c_next, 113 .stop = c_stop, 114 .show = c_show 115 }; 116 117 #endif /* CONFIG_PROC_FS */ 118