1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
/*
* Copyright (C) 2012 Regents of the University of California
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/init.h>
#include <linux/seq_file.h>
#include <linux/of.h>
#include <asm/smp.h>
/*
* Returns the hart ID of the given device tree node, or -1 if the device tree
* node isn't a RISC-V hart.
*/
int riscv_of_processor_hartid(struct device_node *node)
{
const char *isa, *status;
u32 hart;
if (!of_device_is_compatible(node, "riscv")) {
pr_warn("Found incompatible CPU\n");
return -(ENODEV);
}
if (of_property_read_u32(node, "reg", &hart)) {
pr_warn("Found CPU without hart ID\n");
return -(ENODEV);
}
if (hart >= NR_CPUS) {
pr_info("Found hart ID %d, which is above NR_CPUs. Disabling this hart\n", hart);
return -(ENODEV);
}
if (of_property_read_string(node, "status", &status)) {
pr_warn("CPU with hartid=%d has no \"status\" property\n", hart);
return -(ENODEV);
}
if (strcmp(status, "okay")) {
pr_info("CPU with hartid=%d has a non-okay status of \"%s\"\n", hart, status);
return -(ENODEV);
}
if (of_property_read_string(node, "riscv,isa", &isa)) {
pr_warn("CPU with hartid=%d has no \"riscv,isa\" property\n", hart);
return -(ENODEV);
}
if (isa[0] != 'r' || isa[1] != 'v') {
pr_warn("CPU with hartid=%d has an invalid ISA of \"%s\"\n", hart, isa);
return -(ENODEV);
}
return hart;
}
#ifdef CONFIG_PROC_FS
static void print_isa(struct seq_file *f, const char *orig_isa)
{
static const char *ext = "mafdcsu";
const char *isa = orig_isa;
const char *e;
/*
* Linux doesn't support rv32e or rv128i, and we only support booting
* kernels on harts with the same ISA that the kernel is compiled for.
*/
#if defined(CONFIG_32BIT)
if (strncmp(isa, "rv32i", 5) != 0)
return;
#elif defined(CONFIG_64BIT)
if (strncmp(isa, "rv64i", 5) != 0)
return;
#endif
/* Print the base ISA, as we already know it's legal. */
seq_puts(f, "isa\t\t: ");
seq_write(f, isa, 5);
isa += 5;
/*
* Check the rest of the ISA string for valid extensions, printing those
* we find. RISC-V ISA strings define an order, so we only print the
* extension bits when they're in order. Hide the supervisor (S)
* extension from userspace as it's not accessible from there.
*/
for (e = ext; *e != '\0'; ++e) {
if (isa[0] == e[0]) {
if (isa[0] != 's')
seq_write(f, isa, 1);
isa++;
}
}
seq_puts(f, "\n");
/*
* If we were given an unsupported ISA in the device tree then print
* a bit of info describing what went wrong.
*/
if (isa[0] != '\0')
pr_info("unsupported ISA \"%s\" in device tree", orig_isa);
}
static void print_mmu(struct seq_file *f, const char *mmu_type)
{
#if defined(CONFIG_32BIT)
if (strcmp(mmu_type, "riscv,sv32") != 0)
return;
#elif defined(CONFIG_64BIT)
if (strcmp(mmu_type, "riscv,sv39") != 0 &&
strcmp(mmu_type, "riscv,sv48") != 0)
return;
#endif
seq_printf(f, "mmu\t\t: %s\n", mmu_type+6);
}
static void *c_start(struct seq_file *m, loff_t *pos)
{
*pos = cpumask_next(*pos - 1, cpu_online_mask);
if ((*pos) < nr_cpu_ids)
return (void *)(uintptr_t)(1 + *pos);
return NULL;
}
static void *c_next(struct seq_file *m, void *v, loff_t *pos)
{
(*pos)++;
return c_start(m, pos);
}
static void c_stop(struct seq_file *m, void *v)
{
}
static int c_show(struct seq_file *m, void *v)
{
unsigned long cpu_id = (unsigned long)v - 1;
struct device_node *node = of_get_cpu_node(cpuid_to_hartid_map(cpu_id),
NULL);
const char *compat, *isa, *mmu;
seq_printf(m, "processor\t: %lu\n", cpu_id);
seq_printf(m, "hart\t\t: %lu\n", cpuid_to_hartid_map(cpu_id));
if (!of_property_read_string(node, "riscv,isa", &isa))
print_isa(m, isa);
if (!of_property_read_string(node, "mmu-type", &mmu))
print_mmu(m, mmu);
if (!of_property_read_string(node, "compatible", &compat)
&& strcmp(compat, "riscv"))
seq_printf(m, "uarch\t\t: %s\n", compat);
seq_puts(m, "\n");
return 0;
}
const struct seq_operations cpuinfo_op = {
.start = c_start,
.next = c_next,
.stop = c_stop,
.show = c_show
};
#endif /* CONFIG_PROC_FS */
|
