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1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
4 */
5
6#ifndef __ASM_ARC_SMP_H
7#define __ASM_ARC_SMP_H
8
9#ifdef CONFIG_SMP
10
11#include <linux/types.h>
12#include <linux/init.h>
13#include <linux/threads.h>
14
15#define raw_smp_processor_id() (current_thread_info()->cpu)
16
17/* including cpumask.h leads to cyclic deps hence this Forward declaration */
18struct cpumask;
19
20/*
21 * APIs provided by arch SMP code to generic code
22 */
23extern void arch_send_call_function_single_ipi(int cpu);
24extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
25
26/*
27 * APIs provided by arch SMP code to rest of arch code
28 */
29extern void __init smp_init_cpus(void);
30extern void first_lines_of_secondary(void);
31extern const char *arc_platform_smp_cpuinfo(void);
32extern void arc_platform_smp_wait_to_boot(int);
33extern void start_kernel_secondary(void);
34
35/*
36 * API expected BY platform smp code (FROM arch smp code)
37 *
38 * smp_ipi_irq_setup:
39 * Takes @cpu and @hwirq to which the arch-common ISR is hooked up
40 */
41extern int smp_ipi_irq_setup(int cpu, irq_hw_number_t hwirq);
42
43/*
44 * struct plat_smp_ops - SMP callbacks provided by platform to ARC SMP
45 *
46 * @info: SoC SMP specific info for /proc/cpuinfo etc
47 * @init_early_smp: A SMP specific h/w block can init itself
48 * Could be common across platforms so not covered by
49 * mach_desc->init_early()
50 * @init_per_cpu: Called for each core so SMP h/w block driver can do
51 * any needed setup per cpu (e.g. IPI request)
52 * @cpu_kick: For Master to kickstart a cpu (optionally at a PC)
53 * @ipi_send: To send IPI to a @cpu
54 * @ips_clear: To clear IPI received at @irq
55 */
56struct plat_smp_ops {
57 const char *info;
58 void (*init_early_smp)(void);
59 void (*init_per_cpu)(int cpu);
60 void (*cpu_kick)(int cpu, unsigned long pc);
61 void (*ipi_send)(int cpu);
62 void (*ipi_clear)(int irq);
63};
64
65/* TBD: stop exporting it for direct population by platform */
66extern struct plat_smp_ops plat_smp_ops;
67
68#else /* CONFIG_SMP */
69
70static inline void smp_init_cpus(void) {}
71static inline const char *arc_platform_smp_cpuinfo(void)
72{
73 return "";
74}
75
76#endif /* !CONFIG_SMP */
77
78/*
79 * ARC700 doesn't support atomic Read-Modify-Write ops.
80 * Originally Interrupts had to be disabled around code to gaurantee atomicity.
81 * The LLOCK/SCOND insns allow writing interrupt-hassle-free based atomic ops
82 * based on retry-if-irq-in-atomic (with hardware assist).
83 * However despite these, we provide the IRQ disabling variant
84 *
85 * (1) These insn were introduced only in 4.10 release. So for older released
86 * support needed.
87 *
88 * (2) In a SMP setup, the LLOCK/SCOND atomicity across CPUs needs to be
89 * gaurantted by the platform (not something which core handles).
90 * Assuming a platform won't, SMP Linux needs to use spinlocks + local IRQ
91 * disabling for atomicity.
92 *
93 * However exported spinlock API is not usable due to cyclic hdr deps
94 * (even after system.h disintegration upstream)
95 * asm/bitops.h -> linux/spinlock.h -> linux/preempt.h
96 * -> linux/thread_info.h -> linux/bitops.h -> asm/bitops.h
97 *
98 * So the workaround is to use the lowest level arch spinlock API.
99 * The exported spinlock API is smart enough to be NOP for !CONFIG_SMP,
100 * but same is not true for ARCH backend, hence the need for 2 variants
101 */
102#ifndef CONFIG_ARC_HAS_LLSC
103
104#include <linux/irqflags.h>
105#ifdef CONFIG_SMP
106
107#include <asm/spinlock.h>
108
109extern arch_spinlock_t smp_atomic_ops_lock;
110
111#define atomic_ops_lock(flags) do { \
112 local_irq_save(flags); \
113 arch_spin_lock(&smp_atomic_ops_lock); \
114} while (0)
115
116#define atomic_ops_unlock(flags) do { \
117 arch_spin_unlock(&smp_atomic_ops_lock); \
118 local_irq_restore(flags); \
119} while (0)
120
121#else /* !CONFIG_SMP */
122
123#define atomic_ops_lock(flags) local_irq_save(flags)
124#define atomic_ops_unlock(flags) local_irq_restore(flags)
125
126#endif /* !CONFIG_SMP */
127
128#endif /* !CONFIG_ARC_HAS_LLSC */
129
130#endif
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
4 */
5
6#ifndef __ASM_ARC_SMP_H
7#define __ASM_ARC_SMP_H
8
9#ifdef CONFIG_SMP
10
11#include <linux/types.h>
12#include <linux/init.h>
13#include <linux/threads.h>
14
15#define raw_smp_processor_id() (current_thread_info()->cpu)
16
17/* including cpumask.h leads to cyclic deps hence this Forward declaration */
18struct cpumask;
19
20/*
21 * APIs provided by arch SMP code to generic code
22 */
23extern void arch_send_call_function_single_ipi(int cpu);
24extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
25
26/*
27 * APIs provided by arch SMP code to rest of arch code
28 */
29extern void __init smp_init_cpus(void);
30extern void first_lines_of_secondary(void);
31extern const char *arc_platform_smp_cpuinfo(void);
32
33/*
34 * API expected BY platform smp code (FROM arch smp code)
35 *
36 * smp_ipi_irq_setup:
37 * Takes @cpu and @hwirq to which the arch-common ISR is hooked up
38 */
39extern int smp_ipi_irq_setup(int cpu, irq_hw_number_t hwirq);
40
41/*
42 * struct plat_smp_ops - SMP callbacks provided by platform to ARC SMP
43 *
44 * @info: SoC SMP specific info for /proc/cpuinfo etc
45 * @init_early_smp: A SMP specific h/w block can init itself
46 * Could be common across platforms so not covered by
47 * mach_desc->init_early()
48 * @init_per_cpu: Called for each core so SMP h/w block driver can do
49 * any needed setup per cpu (e.g. IPI request)
50 * @cpu_kick: For Master to kickstart a cpu (optionally at a PC)
51 * @ipi_send: To send IPI to a @cpu
52 * @ips_clear: To clear IPI received at @irq
53 */
54struct plat_smp_ops {
55 const char *info;
56 void (*init_early_smp)(void);
57 void (*init_per_cpu)(int cpu);
58 void (*cpu_kick)(int cpu, unsigned long pc);
59 void (*ipi_send)(int cpu);
60 void (*ipi_clear)(int irq);
61};
62
63/* TBD: stop exporting it for direct population by platform */
64extern struct plat_smp_ops plat_smp_ops;
65
66#else /* CONFIG_SMP */
67
68static inline void smp_init_cpus(void) {}
69static inline const char *arc_platform_smp_cpuinfo(void)
70{
71 return "";
72}
73
74#endif /* !CONFIG_SMP */
75
76/*
77 * ARC700 doesn't support atomic Read-Modify-Write ops.
78 * Originally Interrupts had to be disabled around code to gaurantee atomicity.
79 * The LLOCK/SCOND insns allow writing interrupt-hassle-free based atomic ops
80 * based on retry-if-irq-in-atomic (with hardware assist).
81 * However despite these, we provide the IRQ disabling variant
82 *
83 * (1) These insn were introduced only in 4.10 release. So for older released
84 * support needed.
85 *
86 * (2) In a SMP setup, the LLOCK/SCOND atomicity across CPUs needs to be
87 * gaurantted by the platform (not something which core handles).
88 * Assuming a platform won't, SMP Linux needs to use spinlocks + local IRQ
89 * disabling for atomicity.
90 *
91 * However exported spinlock API is not usable due to cyclic hdr deps
92 * (even after system.h disintegration upstream)
93 * asm/bitops.h -> linux/spinlock.h -> linux/preempt.h
94 * -> linux/thread_info.h -> linux/bitops.h -> asm/bitops.h
95 *
96 * So the workaround is to use the lowest level arch spinlock API.
97 * The exported spinlock API is smart enough to be NOP for !CONFIG_SMP,
98 * but same is not true for ARCH backend, hence the need for 2 variants
99 */
100#ifndef CONFIG_ARC_HAS_LLSC
101
102#include <linux/irqflags.h>
103#ifdef CONFIG_SMP
104
105#include <asm/spinlock.h>
106
107extern arch_spinlock_t smp_atomic_ops_lock;
108
109#define atomic_ops_lock(flags) do { \
110 local_irq_save(flags); \
111 arch_spin_lock(&smp_atomic_ops_lock); \
112} while (0)
113
114#define atomic_ops_unlock(flags) do { \
115 arch_spin_unlock(&smp_atomic_ops_lock); \
116 local_irq_restore(flags); \
117} while (0)
118
119#else /* !CONFIG_SMP */
120
121#define atomic_ops_lock(flags) local_irq_save(flags)
122#define atomic_ops_unlock(flags) local_irq_restore(flags)
123
124#endif /* !CONFIG_SMP */
125
126#endif /* !CONFIG_ARC_HAS_LLSC */
127
128#endif