Eric Lee / linux-smarc-t335x-v3.2

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Commit 087a4eb55971dfcc8df18312faf9393d0a479f3a

Authored by Masami Hiramatsu
Committed by Ingo Molnar
1 parent fd02e6f7ae
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

stopmachine: Define __stop_machine when CONFIG_STOP_MACHINE=n 

Define dummy __stop_machine() function even when
CONFIG_STOP_MACHINE=n. This getcpu-required version of
stop_machine() will be used from poke_text_smp().

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: 2nddept-manager@sdl.hitachi.co.jp
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20101014031030.4100.34156.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Showing 1 changed file with 8 additions and 2 deletions Inline Diff

include/linux/stop_machine.h
Diff comments   View file @ 087a4eb
1 #ifndef _LINUX_STOP_MACHINE 1 #ifndef _LINUX_STOP_MACHINE
2 #define _LINUX_STOP_MACHINE 2 #define _LINUX_STOP_MACHINE
3 3
4 #include <linux/cpu.h> 4 #include <linux/cpu.h>
5 #include <linux/cpumask.h> 5 #include <linux/cpumask.h>
6 #include <linux/list.h> 6 #include <linux/list.h>
7 #include <asm/system.h> 7 #include <asm/system.h>
8 8
9 /* 9 /*
10 * stop_cpu[s]() is simplistic per-cpu maximum priority cpu 10 * stop_cpu[s]() is simplistic per-cpu maximum priority cpu
11 * monopolization mechanism. The caller can specify a non-sleeping 11 * monopolization mechanism. The caller can specify a non-sleeping
12 * function to be executed on a single or multiple cpus preempting all 12 * function to be executed on a single or multiple cpus preempting all
13 * other processes and monopolizing those cpus until it finishes. 13 * other processes and monopolizing those cpus until it finishes.
14 * 14 *
15 * Resources for this mechanism are preallocated when a cpu is brought 15 * Resources for this mechanism are preallocated when a cpu is brought
16 * up and requests are guaranteed to be served as long as the target 16 * up and requests are guaranteed to be served as long as the target
17 * cpus are online. 17 * cpus are online.
18 */ 18 */
19 typedef int (*cpu_stop_fn_t)(void *arg); 19 typedef int (*cpu_stop_fn_t)(void *arg);
20 20
21 #ifdef CONFIG_SMP 21 #ifdef CONFIG_SMP
22 22
23 struct cpu_stop_work { 23 struct cpu_stop_work {
24 struct list_head list; /* cpu_stopper->works */ 24 struct list_head list; /* cpu_stopper->works */
25 cpu_stop_fn_t fn; 25 cpu_stop_fn_t fn;
26 void *arg; 26 void *arg;
27 struct cpu_stop_done *done; 27 struct cpu_stop_done *done;
28 }; 28 };
29 29
30 int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg); 30 int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg);
31 void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg, 31 void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg,
32 struct cpu_stop_work *work_buf); 32 struct cpu_stop_work *work_buf);
33 int stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg); 33 int stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg);
34 int try_stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg); 34 int try_stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg);
35 35
36 #else /* CONFIG_SMP */ 36 #else /* CONFIG_SMP */
37 37
38 #include <linux/workqueue.h> 38 #include <linux/workqueue.h>
39 39
40 struct cpu_stop_work { 40 struct cpu_stop_work {
41 struct work_struct work; 41 struct work_struct work;
42 cpu_stop_fn_t fn; 42 cpu_stop_fn_t fn;
43 void *arg; 43 void *arg;
44 }; 44 };
45 45
46 static inline int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg) 46 static inline int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg)
47 { 47 {
48 int ret = -ENOENT; 48 int ret = -ENOENT;
49 preempt_disable(); 49 preempt_disable();
50 if (cpu == smp_processor_id()) 50 if (cpu == smp_processor_id())
51 ret = fn(arg); 51 ret = fn(arg);
52 preempt_enable(); 52 preempt_enable();
53 return ret; 53 return ret;
54 } 54 }
55 55
56 static void stop_one_cpu_nowait_workfn(struct work_struct *work) 56 static void stop_one_cpu_nowait_workfn(struct work_struct *work)
57 { 57 {
58 struct cpu_stop_work *stwork = 58 struct cpu_stop_work *stwork =
59 container_of(work, struct cpu_stop_work, work); 59 container_of(work, struct cpu_stop_work, work);
60 preempt_disable(); 60 preempt_disable();
61 stwork->fn(stwork->arg); 61 stwork->fn(stwork->arg);
62 preempt_enable(); 62 preempt_enable();
63 } 63 }
64 64
65 static inline void stop_one_cpu_nowait(unsigned int cpu, 65 static inline void stop_one_cpu_nowait(unsigned int cpu,
66 cpu_stop_fn_t fn, void *arg, 66 cpu_stop_fn_t fn, void *arg,
67 struct cpu_stop_work *work_buf) 67 struct cpu_stop_work *work_buf)
68 { 68 {
69 if (cpu == smp_processor_id()) { 69 if (cpu == smp_processor_id()) {
70 INIT_WORK(&work_buf->work, stop_one_cpu_nowait_workfn); 70 INIT_WORK(&work_buf->work, stop_one_cpu_nowait_workfn);
71 work_buf->fn = fn; 71 work_buf->fn = fn;
72 work_buf->arg = arg; 72 work_buf->arg = arg;
73 schedule_work(&work_buf->work); 73 schedule_work(&work_buf->work);
74 } 74 }
75 } 75 }
76 76
77 static inline int stop_cpus(const struct cpumask *cpumask, 77 static inline int stop_cpus(const struct cpumask *cpumask,
78 cpu_stop_fn_t fn, void *arg) 78 cpu_stop_fn_t fn, void *arg)
79 { 79 {
80 if (cpumask_test_cpu(raw_smp_processor_id(), cpumask)) 80 if (cpumask_test_cpu(raw_smp_processor_id(), cpumask))
81 return stop_one_cpu(raw_smp_processor_id(), fn, arg); 81 return stop_one_cpu(raw_smp_processor_id(), fn, arg);
82 return -ENOENT; 82 return -ENOENT;
83 } 83 }
84 84
85 static inline int try_stop_cpus(const struct cpumask *cpumask, 85 static inline int try_stop_cpus(const struct cpumask *cpumask,
86 cpu_stop_fn_t fn, void *arg) 86 cpu_stop_fn_t fn, void *arg)
87 { 87 {
88 return stop_cpus(cpumask, fn, arg); 88 return stop_cpus(cpumask, fn, arg);
89 } 89 }
90 90
91 #endif /* CONFIG_SMP */ 91 #endif /* CONFIG_SMP */
92 92
93 /* 93 /*
94 * stop_machine "Bogolock": stop the entire machine, disable 94 * stop_machine "Bogolock": stop the entire machine, disable
95 * interrupts. This is a very heavy lock, which is equivalent to 95 * interrupts. This is a very heavy lock, which is equivalent to
96 * grabbing every spinlock (and more). So the "read" side to such a 96 * grabbing every spinlock (and more). So the "read" side to such a
97 * lock is anything which disables preeempt. 97 * lock is anything which disables preeempt.
98 */ 98 */
99 #if defined(CONFIG_STOP_MACHINE) && defined(CONFIG_SMP) 99 #if defined(CONFIG_STOP_MACHINE) && defined(CONFIG_SMP)
100 100
101 /** 101 /**
102 * stop_machine: freeze the machine on all CPUs and run this function 102 * stop_machine: freeze the machine on all CPUs and run this function
103 * @fn: the function to run 103 * @fn: the function to run
104 * @data: the data ptr for the @fn() 104 * @data: the data ptr for the @fn()
105 * @cpus: the cpus to run the @fn() on (NULL = any online cpu) 105 * @cpus: the cpus to run the @fn() on (NULL = any online cpu)
106 * 106 *
107 * Description: This causes a thread to be scheduled on every cpu, 107 * Description: This causes a thread to be scheduled on every cpu,
108 * each of which disables interrupts. The result is that noone is 108 * each of which disables interrupts. The result is that noone is
109 * holding a spinlock or inside any other preempt-disabled region when 109 * holding a spinlock or inside any other preempt-disabled region when
110 * @fn() runs. 110 * @fn() runs.
111 * 111 *
112 * This can be thought of as a very heavy write lock, equivalent to 112 * This can be thought of as a very heavy write lock, equivalent to
113 * grabbing every spinlock in the kernel. */ 113 * grabbing every spinlock in the kernel. */
114 int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus); 114 int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus);
115 115
116 /** 116 /**
117 * __stop_machine: freeze the machine on all CPUs and run this function 117 * __stop_machine: freeze the machine on all CPUs and run this function
118 * @fn: the function to run 118 * @fn: the function to run
119 * @data: the data ptr for the @fn 119 * @data: the data ptr for the @fn
120 * @cpus: the cpus to run the @fn() on (NULL = any online cpu) 120 * @cpus: the cpus to run the @fn() on (NULL = any online cpu)
121 * 121 *
122 * Description: This is a special version of the above, which assumes cpus 122 * Description: This is a special version of the above, which assumes cpus
123 * won't come or go while it's being called. Used by hotplug cpu. 123 * won't come or go while it's being called. Used by hotplug cpu.
124 */ 124 */
125 int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus); 125 int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus);
126 126
127 #else /* CONFIG_STOP_MACHINE && CONFIG_SMP */ 127 #else /* CONFIG_STOP_MACHINE && CONFIG_SMP */
128 128
129 static inline int stop_machine(int (*fn)(void *), void *data, 129 static inline int __stop_machine(int (*fn)(void *), void *data,
130 const struct cpumask *cpus) 130 const struct cpumask *cpus)
131 { 131 {
132 int ret; 132 int ret;
133 local_irq_disable(); 133 local_irq_disable();
134 ret = fn(data); 134 ret = fn(data);
135 local_irq_enable(); 135 local_irq_enable();
136 return ret; 136 return ret;
137 }
138
139 static inline int stop_machine(int (*fn)(void *), void *data,
140 const struct cpumask *cpus)
141 {
142 return __stop_machine(fn, data, cpus);
137 } 143 }
138 144
139 #endif /* CONFIG_STOP_MACHINE && CONFIG_SMP */ 145 #endif /* CONFIG_STOP_MACHINE && CONFIG_SMP */
140 #endif /* _LINUX_STOP_MACHINE */ 146 #endif /* _LINUX_STOP_MACHINE */
141 147