1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * HSM extension and cpu_ops implementation.
4 *
5 * Copyright (c) 2020 Western Digital Corporation or its affiliates.
6 */
7
8 #include <linux/init.h>
9 #include <linux/mm.h>
10 #include <asm/cpu_ops.h>
11 #include <asm/sbi.h>
12 #include <asm/smp.h>
13
14 extern char secondary_start_sbi[];
15 const struct cpu_operations cpu_ops_sbi;
16
sbi_hsm_hart_start(unsigned long hartid,unsigned long saddr,unsigned long priv)17 static int sbi_hsm_hart_start(unsigned long hartid, unsigned long saddr,
18 unsigned long priv)
19 {
20 struct sbiret ret;
21
22 ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_START,
23 hartid, saddr, priv, 0, 0, 0);
24 if (ret.error)
25 return sbi_err_map_linux_errno(ret.error);
26 else
27 return 0;
28 }
29
30 #ifdef CONFIG_HOTPLUG_CPU
sbi_hsm_hart_stop(void)31 static int sbi_hsm_hart_stop(void)
32 {
33 struct sbiret ret;
34
35 ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_STOP, 0, 0, 0, 0, 0, 0);
36
37 if (ret.error)
38 return sbi_err_map_linux_errno(ret.error);
39 else
40 return 0;
41 }
42
sbi_hsm_hart_get_status(unsigned long hartid)43 static int sbi_hsm_hart_get_status(unsigned long hartid)
44 {
45 struct sbiret ret;
46
47 ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_STATUS,
48 hartid, 0, 0, 0, 0, 0);
49 if (ret.error)
50 return sbi_err_map_linux_errno(ret.error);
51 else
52 return ret.value;
53 }
54 #endif
55
sbi_cpu_start(unsigned int cpuid,struct task_struct * tidle)56 static int sbi_cpu_start(unsigned int cpuid, struct task_struct *tidle)
57 {
58 int rc;
59 unsigned long boot_addr = __pa_symbol(secondary_start_sbi);
60 int hartid = cpuid_to_hartid_map(cpuid);
61
62 cpu_update_secondary_bootdata(cpuid, tidle);
63 rc = sbi_hsm_hart_start(hartid, boot_addr, 0);
64
65 return rc;
66 }
67
sbi_cpu_prepare(unsigned int cpuid)68 static int sbi_cpu_prepare(unsigned int cpuid)
69 {
70 if (!cpu_ops_sbi.cpu_start) {
71 pr_err("cpu start method not defined for CPU [%d]\n", cpuid);
72 return -ENODEV;
73 }
74 return 0;
75 }
76
77 #ifdef CONFIG_HOTPLUG_CPU
sbi_cpu_disable(unsigned int cpuid)78 static int sbi_cpu_disable(unsigned int cpuid)
79 {
80 if (!cpu_ops_sbi.cpu_stop)
81 return -EOPNOTSUPP;
82 return 0;
83 }
84
sbi_cpu_stop(void)85 static void sbi_cpu_stop(void)
86 {
87 int ret;
88
89 ret = sbi_hsm_hart_stop();
90 pr_crit("Unable to stop the cpu %u (%d)\n", smp_processor_id(), ret);
91 }
92
sbi_cpu_is_stopped(unsigned int cpuid)93 static int sbi_cpu_is_stopped(unsigned int cpuid)
94 {
95 int rc;
96 int hartid = cpuid_to_hartid_map(cpuid);
97
98 rc = sbi_hsm_hart_get_status(hartid);
99
100 if (rc == SBI_HSM_HART_STATUS_STOPPED)
101 return 0;
102 return rc;
103 }
104 #endif
105
106 const struct cpu_operations cpu_ops_sbi = {
107 .name = "sbi",
108 .cpu_prepare = sbi_cpu_prepare,
109 .cpu_start = sbi_cpu_start,
110 #ifdef CONFIG_HOTPLUG_CPU
111 .cpu_disable = sbi_cpu_disable,
112 .cpu_stop = sbi_cpu_stop,
113 .cpu_is_stopped = sbi_cpu_is_stopped,
114 #endif
115 };
116