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 */
riscv_of_processor_hartid(struct device_node * node)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 hart = of_get_cpu_hwid(node, 0);
26 if (hart == ~0U) {
27 pr_warn("Found CPU without hart ID\n");
28 return -ENODEV;
29 }
30
31 if (!of_device_is_available(node)) {
32 pr_info("CPU with hartid=%d is not available\n", hart);
33 return -ENODEV;
34 }
35
36 if (of_property_read_string(node, "riscv,isa", &isa)) {
37 pr_warn("CPU with hartid=%d has no \"riscv,isa\" property\n", hart);
38 return -ENODEV;
39 }
40 if (isa[0] != 'r' || isa[1] != 'v') {
41 pr_warn("CPU with hartid=%d has an invalid ISA of \"%s\"\n", hart, isa);
42 return -ENODEV;
43 }
44
45 return hart;
46 }
47
48 /*
49 * Find hart ID of the CPU DT node under which given DT node falls.
50 *
51 * To achieve this, we walk up the DT tree until we find an active
52 * RISC-V core (HART) node and extract the cpuid from it.
53 */
riscv_of_parent_hartid(struct device_node * node)54 int riscv_of_parent_hartid(struct device_node *node)
55 {
56 for (; node; node = node->parent) {
57 if (of_device_is_compatible(node, "riscv"))
58 return riscv_of_processor_hartid(node);
59 }
60
61 return -1;
62 }
63
64 #ifdef CONFIG_PROC_FS
65
print_isa(struct seq_file * f,const char * isa)66 static void print_isa(struct seq_file *f, const char *isa)
67 {
68 /* Print the entire ISA as it is */
69 seq_puts(f, "isa\t\t: ");
70 seq_write(f, isa, strlen(isa));
71 seq_puts(f, "\n");
72 }
73
print_mmu(struct seq_file * f,const char * mmu_type)74 static void print_mmu(struct seq_file *f, const char *mmu_type)
75 {
76 #if defined(CONFIG_32BIT)
77 if (strcmp(mmu_type, "riscv,sv32") != 0)
78 return;
79 #elif defined(CONFIG_64BIT)
80 if (strcmp(mmu_type, "riscv,sv39") != 0 &&
81 strcmp(mmu_type, "riscv,sv48") != 0)
82 return;
83 #endif
84
85 seq_printf(f, "mmu\t\t: %s\n", mmu_type+6);
86 }
87
c_start(struct seq_file * m,loff_t * pos)88 static void *c_start(struct seq_file *m, loff_t *pos)
89 {
90 *pos = cpumask_next(*pos - 1, cpu_online_mask);
91 if ((*pos) < nr_cpu_ids)
92 return (void *)(uintptr_t)(1 + *pos);
93 return NULL;
94 }
95
c_next(struct seq_file * m,void * v,loff_t * pos)96 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
97 {
98 (*pos)++;
99 return c_start(m, pos);
100 }
101
c_stop(struct seq_file * m,void * v)102 static void c_stop(struct seq_file *m, void *v)
103 {
104 }
105
c_show(struct seq_file * m,void * v)106 static int c_show(struct seq_file *m, void *v)
107 {
108 unsigned long cpu_id = (unsigned long)v - 1;
109 struct device_node *node = of_get_cpu_node(cpu_id, NULL);
110 const char *compat, *isa, *mmu;
111
112 seq_printf(m, "processor\t: %lu\n", cpu_id);
113 seq_printf(m, "hart\t\t: %lu\n", cpuid_to_hartid_map(cpu_id));
114 if (!of_property_read_string(node, "riscv,isa", &isa))
115 print_isa(m, isa);
116 if (!of_property_read_string(node, "mmu-type", &mmu))
117 print_mmu(m, mmu);
118 if (!of_property_read_string(node, "compatible", &compat)
119 && strcmp(compat, "riscv"))
120 seq_printf(m, "uarch\t\t: %s\n", compat);
121 seq_puts(m, "\n");
122 of_node_put(node);
123
124 return 0;
125 }
126
127 const struct seq_operations cpuinfo_op = {
128 .start = c_start,
129 .next = c_next,
130 .stop = c_stop,
131 .show = c_show
132 };
133
134 #endif /* CONFIG_PROC_FS */
135