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1/*
2 * Copyright (C) 2012 Regents of the University of California
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation, version 2.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 */
13
14#include <linux/init.h>
15#include <linux/seq_file.h>
16#include <linux/of.h>
17
18/* Return -1 if not a valid hart */
19int riscv_of_processor_hart(struct device_node *node)
20{
21 const char *isa, *status;
22 u32 hart;
23
24 if (!of_device_is_compatible(node, "riscv")) {
25 pr_warn("Found incompatible CPU\n");
26 return -(ENODEV);
27 }
28
29 if (of_property_read_u32(node, "reg", &hart)) {
30 pr_warn("Found CPU without hart ID\n");
31 return -(ENODEV);
32 }
33 if (hart >= NR_CPUS) {
34 pr_info("Found hart ID %d, which is above NR_CPUs. Disabling this hart\n", hart);
35 return -(ENODEV);
36 }
37
38 if (of_property_read_string(node, "status", &status)) {
39 pr_warn("CPU with hartid=%d has no \"status\" property\n", hart);
40 return -(ENODEV);
41 }
42 if (strcmp(status, "okay")) {
43 pr_info("CPU with hartid=%d has a non-okay status of \"%s\"\n", hart, status);
44 return -(ENODEV);
45 }
46
47 if (of_property_read_string(node, "riscv,isa", &isa)) {
48 pr_warn("CPU with hartid=%d has no \"riscv,isa\" property\n", hart);
49 return -(ENODEV);
50 }
51 if (isa[0] != 'r' || isa[1] != 'v') {
52 pr_warn("CPU with hartid=%d has an invalid ISA of \"%s\"\n", hart, isa);
53 return -(ENODEV);
54 }
55
56 return hart;
57}
58
59#ifdef CONFIG_PROC_FS
60
61static void *c_start(struct seq_file *m, loff_t *pos)
62{
63 *pos = cpumask_next(*pos - 1, cpu_online_mask);
64 if ((*pos) < nr_cpu_ids)
65 return (void *)(uintptr_t)(1 + *pos);
66 return NULL;
67}
68
69static void *c_next(struct seq_file *m, void *v, loff_t *pos)
70{
71 (*pos)++;
72 return c_start(m, pos);
73}
74
75static void c_stop(struct seq_file *m, void *v)
76{
77}
78
79static int c_show(struct seq_file *m, void *v)
80{
81 unsigned long hart_id = (unsigned long)v - 1;
82 struct device_node *node = of_get_cpu_node(hart_id, NULL);
83 const char *compat, *isa, *mmu;
84
85 seq_printf(m, "hart\t: %lu\n", hart_id);
86 if (!of_property_read_string(node, "riscv,isa", &isa)
87 && isa[0] == 'r'
88 && isa[1] == 'v')
89 seq_printf(m, "isa\t: %s\n", isa);
90 if (!of_property_read_string(node, "mmu-type", &mmu)
91 && !strncmp(mmu, "riscv,", 6))
92 seq_printf(m, "mmu\t: %s\n", mmu+6);
93 if (!of_property_read_string(node, "compatible", &compat)
94 && strcmp(compat, "riscv"))
95 seq_printf(m, "uarch\t: %s\n", compat);
96 seq_puts(m, "\n");
97
98 return 0;
99}
100
101const struct seq_operations cpuinfo_op = {
102 .start = c_start,
103 .next = c_next,
104 .stop = c_stop,
105 .show = c_show
106};
107
108#endif /* CONFIG_PROC_FS */
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 */
15int 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
49static void print_isa(struct seq_file *f, const char *orig_isa)
50{
51 static const char *ext = "mafdcsu";
52 const char *isa = orig_isa;
53 const char *e;
54
55 /*
56 * Linux doesn't support rv32e or rv128i, and we only support booting
57 * kernels on harts with the same ISA that the kernel is compiled for.
58 */
59#if defined(CONFIG_32BIT)
60 if (strncmp(isa, "rv32i", 5) != 0)
61 return;
62#elif defined(CONFIG_64BIT)
63 if (strncmp(isa, "rv64i", 5) != 0)
64 return;
65#endif
66
67 /* Print the base ISA, as we already know it's legal. */
68 seq_puts(f, "isa\t\t: ");
69 seq_write(f, isa, 5);
70 isa += 5;
71
72 /*
73 * Check the rest of the ISA string for valid extensions, printing those
74 * we find. RISC-V ISA strings define an order, so we only print the
75 * extension bits when they're in order. Hide the supervisor (S)
76 * extension from userspace as it's not accessible from there.
77 */
78 for (e = ext; *e != '\0'; ++e) {
79 if (isa[0] == e[0]) {
80 if (isa[0] != 's')
81 seq_write(f, isa, 1);
82
83 isa++;
84 }
85 }
86 seq_puts(f, "\n");
87
88 /*
89 * If we were given an unsupported ISA in the device tree then print
90 * a bit of info describing what went wrong.
91 */
92 if (isa[0] != '\0')
93 pr_info("unsupported ISA \"%s\" in device tree\n", orig_isa);
94}
95
96static void print_mmu(struct seq_file *f, const char *mmu_type)
97{
98#if defined(CONFIG_32BIT)
99 if (strcmp(mmu_type, "riscv,sv32") != 0)
100 return;
101#elif defined(CONFIG_64BIT)
102 if (strcmp(mmu_type, "riscv,sv39") != 0 &&
103 strcmp(mmu_type, "riscv,sv48") != 0)
104 return;
105#endif
106
107 seq_printf(f, "mmu\t\t: %s\n", mmu_type+6);
108}
109
110static void *c_start(struct seq_file *m, loff_t *pos)
111{
112 *pos = cpumask_next(*pos - 1, cpu_online_mask);
113 if ((*pos) < nr_cpu_ids)
114 return (void *)(uintptr_t)(1 + *pos);
115 return NULL;
116}
117
118static void *c_next(struct seq_file *m, void *v, loff_t *pos)
119{
120 (*pos)++;
121 return c_start(m, pos);
122}
123
124static void c_stop(struct seq_file *m, void *v)
125{
126}
127
128static int c_show(struct seq_file *m, void *v)
129{
130 unsigned long cpu_id = (unsigned long)v - 1;
131 struct device_node *node = of_get_cpu_node(cpu_id, NULL);
132 const char *compat, *isa, *mmu;
133
134 seq_printf(m, "processor\t: %lu\n", cpu_id);
135 seq_printf(m, "hart\t\t: %lu\n", cpuid_to_hartid_map(cpu_id));
136 if (!of_property_read_string(node, "riscv,isa", &isa))
137 print_isa(m, isa);
138 if (!of_property_read_string(node, "mmu-type", &mmu))
139 print_mmu(m, mmu);
140 if (!of_property_read_string(node, "compatible", &compat)
141 && strcmp(compat, "riscv"))
142 seq_printf(m, "uarch\t\t: %s\n", compat);
143 seq_puts(m, "\n");
144 of_node_put(node);
145
146 return 0;
147}
148
149const struct seq_operations cpuinfo_op = {
150 .start = c_start,
151 .next = c_next,
152 .stop = c_stop,
153 .show = c_show
154};
155
156#endif /* CONFIG_PROC_FS */