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
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
|
/*
* SMP support for PowerNV machines.
*
* Copyright 2011 IBM Corp.
*
* 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; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/cpu.h>
#include <asm/irq.h>
#include <asm/smp.h>
#include <asm/paca.h>
#include <asm/machdep.h>
#include <asm/cputable.h>
#include <asm/firmware.h>
#include <asm/rtas.h>
#include <asm/vdso_datapage.h>
#include <asm/cputhreads.h>
#include <asm/xics.h>
#include <asm/opal.h>
#include <asm/runlatch.h>
#include <asm/code-patching.h>
#include <asm/dbell.h>
#include "powernv.h"
#ifdef DEBUG
#include <asm/udbg.h>
#define DBG(fmt...) udbg_printf(fmt)
#else
#define DBG(fmt...)
#endif
static void pnv_smp_setup_cpu(int cpu)
{
if (cpu != boot_cpuid)
xics_setup_cpu();
#ifdef CONFIG_PPC_DOORBELL
if (cpu_has_feature(CPU_FTR_DBELL))
doorbell_setup_this_cpu();
#endif
}
static int pnv_smp_kick_cpu(int nr)
{
unsigned int pcpu = get_hard_smp_processor_id(nr);
unsigned long start_here =
__pa(ppc_function_entry(generic_secondary_smp_init));
long rc;
BUG_ON(nr < 0 || nr >= NR_CPUS);
/*
* If we already started or OPALv2 is not supported, we just
* kick the CPU via the PACA
*/
if (paca[nr].cpu_start || !firmware_has_feature(FW_FEATURE_OPALv2))
goto kick;
/*
* At this point, the CPU can either be spinning on the way in
* from kexec or be inside OPAL waiting to be started for the
* first time. OPAL v3 allows us to query OPAL to know if it
* has the CPUs, so we do that
*/
if (firmware_has_feature(FW_FEATURE_OPALv3)) {
uint8_t status;
rc = opal_query_cpu_status(pcpu, &status);
if (rc != OPAL_SUCCESS) {
pr_warn("OPAL Error %ld querying CPU %d state\n",
rc, nr);
return -ENODEV;
}
/*
* Already started, just kick it, probably coming from
* kexec and spinning
*/
if (status == OPAL_THREAD_STARTED)
goto kick;
/*
* Available/inactive, let's kick it
*/
if (status == OPAL_THREAD_INACTIVE) {
pr_devel("OPAL: Starting CPU %d (HW 0x%x)...\n",
nr, pcpu);
rc = opal_start_cpu(pcpu, start_here);
if (rc != OPAL_SUCCESS) {
pr_warn("OPAL Error %ld starting CPU %d\n",
rc, nr);
return -ENODEV;
}
} else {
/*
* An unavailable CPU (or any other unknown status)
* shouldn't be started. It should also
* not be in the possible map but currently it can
* happen
*/
pr_devel("OPAL: CPU %d (HW 0x%x) is unavailable"
" (status %d)...\n", nr, pcpu, status);
return -ENODEV;
}
} else {
/*
* On OPAL v2, we just kick it and hope for the best,
* we must not test the error from opal_start_cpu() or
* we would fail to get CPUs from kexec.
*/
opal_start_cpu(pcpu, start_here);
}
kick:
return smp_generic_kick_cpu(nr);
}
#ifdef CONFIG_HOTPLUG_CPU
static int pnv_smp_cpu_disable(void)
{
int cpu = smp_processor_id();
/* This is identical to pSeries... might consolidate by
* moving migrate_irqs_away to a ppc_md with default to
* the generic fixup_irqs. --BenH.
*/
set_cpu_online(cpu, false);
vdso_data->processorCount--;
if (cpu == boot_cpuid)
boot_cpuid = cpumask_any(cpu_online_mask);
xics_migrate_irqs_away();
return 0;
}
static void pnv_smp_cpu_kill_self(void)
{
unsigned int cpu;
/* Standard hot unplug procedure */
local_irq_disable();
idle_task_exit();
current->active_mm = NULL; /* for sanity */
cpu = smp_processor_id();
DBG("CPU%d offline\n", cpu);
generic_set_cpu_dead(cpu);
smp_wmb();
/* We don't want to take decrementer interrupts while we are offline,
* so clear LPCR:PECE1. We keep PECE2 enabled.
*/
mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~(u64)LPCR_PECE1);
while (!generic_check_cpu_restart(cpu)) {
ppc64_runlatch_off();
power7_nap(1);
ppc64_runlatch_on();
/* Reenable IRQs briefly to clear the IPI that woke us */
local_irq_enable();
local_irq_disable();
mb();
if (cpu_core_split_required())
continue;
if (!generic_check_cpu_restart(cpu))
DBG("CPU%d Unexpected exit while offline !\n", cpu);
}
mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) | LPCR_PECE1);
DBG("CPU%d coming online...\n", cpu);
}
#endif /* CONFIG_HOTPLUG_CPU */
static struct smp_ops_t pnv_smp_ops = {
.message_pass = smp_muxed_ipi_message_pass,
.cause_ipi = NULL, /* Filled at runtime by xics_smp_probe() */
.probe = xics_smp_probe,
.kick_cpu = pnv_smp_kick_cpu,
.setup_cpu = pnv_smp_setup_cpu,
.cpu_bootable = smp_generic_cpu_bootable,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_disable = pnv_smp_cpu_disable,
.cpu_die = generic_cpu_die,
#endif /* CONFIG_HOTPLUG_CPU */
};
/* This is called very early during platform setup_arch */
void __init pnv_smp_init(void)
{
smp_ops = &pnv_smp_ops;
/* XXX We don't yet have a proper entry point from HAL, for
* now we rely on kexec-style entry from BML
*/
#ifdef CONFIG_PPC_RTAS
/* Non-lpar has additional take/give timebase */
if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) {
smp_ops->give_timebase = rtas_give_timebase;
smp_ops->take_timebase = rtas_take_timebase;
}
#endif /* CONFIG_PPC_RTAS */
#ifdef CONFIG_HOTPLUG_CPU
ppc_md.cpu_die = pnv_smp_cpu_kill_self;
#endif
}
|
