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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 <linux/sched/task_stack.h>
11#include <asm/cpu_ops.h>
12#include <asm/cpu_ops_sbi.h>
13#include <asm/sbi.h>
14#include <asm/smp.h>
15
16extern char secondary_start_sbi[];
17const struct cpu_operations cpu_ops_sbi;
18
19/*
20 * Ordered booting via HSM brings one cpu at a time. However, cpu hotplug can
21 * be invoked from multiple threads in parallel. Define a per cpu data
22 * to handle that.
23 */
24static DEFINE_PER_CPU(struct sbi_hart_boot_data, boot_data);
25
26static int sbi_hsm_hart_start(unsigned long hartid, unsigned long saddr,
27 unsigned long priv)
28{
29 struct sbiret ret;
30
31 ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_START,
32 hartid, saddr, priv, 0, 0, 0);
33 if (ret.error)
34 return sbi_err_map_linux_errno(ret.error);
35 else
36 return 0;
37}
38
39#ifdef CONFIG_HOTPLUG_CPU
40static int sbi_hsm_hart_stop(void)
41{
42 struct sbiret ret;
43
44 ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_STOP, 0, 0, 0, 0, 0, 0);
45
46 if (ret.error)
47 return sbi_err_map_linux_errno(ret.error);
48 else
49 return 0;
50}
51
52static int sbi_hsm_hart_get_status(unsigned long hartid)
53{
54 struct sbiret ret;
55
56 ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_STATUS,
57 hartid, 0, 0, 0, 0, 0);
58 if (ret.error)
59 return sbi_err_map_linux_errno(ret.error);
60 else
61 return ret.value;
62}
63#endif
64
65static int sbi_cpu_start(unsigned int cpuid, struct task_struct *tidle)
66{
67 unsigned long boot_addr = __pa_symbol(secondary_start_sbi);
68 unsigned long hartid = cpuid_to_hartid_map(cpuid);
69 unsigned long hsm_data;
70 struct sbi_hart_boot_data *bdata = &per_cpu(boot_data, cpuid);
71
72 /* Make sure tidle is updated */
73 smp_mb();
74 bdata->task_ptr = tidle;
75 bdata->stack_ptr = task_stack_page(tidle) + THREAD_SIZE;
76 /* Make sure boot data is updated */
77 smp_mb();
78 hsm_data = __pa(bdata);
79 return sbi_hsm_hart_start(hartid, boot_addr, hsm_data);
80}
81
82static int sbi_cpu_prepare(unsigned int cpuid)
83{
84 if (!cpu_ops_sbi.cpu_start) {
85 pr_err("cpu start method not defined for CPU [%d]\n", cpuid);
86 return -ENODEV;
87 }
88 return 0;
89}
90
91#ifdef CONFIG_HOTPLUG_CPU
92static int sbi_cpu_disable(unsigned int cpuid)
93{
94 if (!cpu_ops_sbi.cpu_stop)
95 return -EOPNOTSUPP;
96 return 0;
97}
98
99static void sbi_cpu_stop(void)
100{
101 int ret;
102
103 ret = sbi_hsm_hart_stop();
104 pr_crit("Unable to stop the cpu %u (%d)\n", smp_processor_id(), ret);
105}
106
107static int sbi_cpu_is_stopped(unsigned int cpuid)
108{
109 int rc;
110 unsigned long hartid = cpuid_to_hartid_map(cpuid);
111
112 rc = sbi_hsm_hart_get_status(hartid);
113
114 if (rc == SBI_HSM_STATE_STOPPED)
115 return 0;
116 return rc;
117}
118#endif
119
120const struct cpu_operations cpu_ops_sbi = {
121 .name = "sbi",
122 .cpu_prepare = sbi_cpu_prepare,
123 .cpu_start = sbi_cpu_start,
124#ifdef CONFIG_HOTPLUG_CPU
125 .cpu_disable = sbi_cpu_disable,
126 .cpu_stop = sbi_cpu_stop,
127 .cpu_is_stopped = sbi_cpu_is_stopped,
128#endif
129};
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
14extern char secondary_start_sbi[];
15const struct cpu_operations cpu_ops_sbi;
16
17static 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
31static 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
43static 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
56static 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
68static 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
78static int sbi_cpu_disable(unsigned int cpuid)
79{
80 if (!cpu_ops_sbi.cpu_stop)
81 return -EOPNOTSUPP;
82 return 0;
83}
84
85static 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
93static 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
106const 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};