blob: c4fb211dcd25bef135c78ea0683e71d9259a8c20 (
plain)
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
|
/*
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __ASM_ARC_SMP_H
#define __ASM_ARC_SMP_H
#ifdef CONFIG_SMP
#include <linux/types.h>
#include <linux/init.h>
#include <linux/threads.h>
#define raw_smp_processor_id() (current_thread_info()->cpu)
/* including cpumask.h leads to cyclic deps hence this Forward declaration */
struct cpumask;
/*
* APIs provided by arch SMP code to generic code
*/
extern void arch_send_call_function_single_ipi(int cpu);
extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
/*
* APIs provided by arch SMP code to rest of arch code
*/
extern void __init smp_init_cpus(void);
extern void __init first_lines_of_secondary(void);
extern const char *arc_platform_smp_cpuinfo(void);
/*
* API expected BY platform smp code (FROM arch smp code)
*
* smp_ipi_irq_setup:
* Takes @cpu and @irq to which the arch-common ISR is hooked up
*/
extern int smp_ipi_irq_setup(int cpu, int irq);
/*
* struct plat_smp_ops - SMP callbacks provided by platform to ARC SMP
*
* @info: SoC SMP specific info for /proc/cpuinfo etc
* @cpu_kick: For Master to kickstart a cpu (optionally at a PC)
* @ipi_send: To send IPI to a @cpumask
* @ips_clear: To clear IPI received by @cpu at @irq
*/
struct plat_smp_ops {
const char *info;
void (*cpu_kick)(int cpu, unsigned long pc);
void (*ipi_send)(void *callmap);
void (*ipi_clear)(int cpu, int irq);
};
/* TBD: stop exporting it for direct population by platform */
extern struct plat_smp_ops plat_smp_ops;
#endif /* CONFIG_SMP */
/*
* ARC700 doesn't support atomic Read-Modify-Write ops.
* Originally Interrupts had to be disabled around code to gaurantee atomicity.
* The LLOCK/SCOND insns allow writing interrupt-hassle-free based atomic ops
* based on retry-if-irq-in-atomic (with hardware assist).
* However despite these, we provide the IRQ disabling variant
*
* (1) These insn were introduced only in 4.10 release. So for older released
* support needed.
*
* (2) In a SMP setup, the LLOCK/SCOND atomiticity across CPUs needs to be
* gaurantted by the platform (not something which core handles).
* Assuming a platform won't, SMP Linux needs to use spinlocks + local IRQ
* disabling for atomicity.
*
* However exported spinlock API is not usable due to cyclic hdr deps
* (even after system.h disintegration upstream)
* asm/bitops.h -> linux/spinlock.h -> linux/preempt.h
* -> linux/thread_info.h -> linux/bitops.h -> asm/bitops.h
*
* So the workaround is to use the lowest level arch spinlock API.
* The exported spinlock API is smart enough to be NOP for !CONFIG_SMP,
* but same is not true for ARCH backend, hence the need for 2 variants
*/
#ifndef CONFIG_ARC_HAS_LLSC
#include <linux/irqflags.h>
#ifdef CONFIG_SMP
#include <asm/spinlock.h>
extern arch_spinlock_t smp_atomic_ops_lock;
extern arch_spinlock_t smp_bitops_lock;
#define atomic_ops_lock(flags) do { \
local_irq_save(flags); \
arch_spin_lock(&smp_atomic_ops_lock); \
} while (0)
#define atomic_ops_unlock(flags) do { \
arch_spin_unlock(&smp_atomic_ops_lock); \
local_irq_restore(flags); \
} while (0)
#define bitops_lock(flags) do { \
local_irq_save(flags); \
arch_spin_lock(&smp_bitops_lock); \
} while (0)
#define bitops_unlock(flags) do { \
arch_spin_unlock(&smp_bitops_lock); \
local_irq_restore(flags); \
} while (0)
#else /* !CONFIG_SMP */
#define atomic_ops_lock(flags) local_irq_save(flags)
#define atomic_ops_unlock(flags) local_irq_restore(flags)
#define bitops_lock(flags) local_irq_save(flags)
#define bitops_unlock(flags) local_irq_restore(flags)
#endif /* !CONFIG_SMP */
#endif /* !CONFIG_ARC_HAS_LLSC */
#endif
|
