aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/smp.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kernel/smp.c')
-rw-r--r--arch/x86/kernel/smp.c158
1 files changed, 20 insertions, 138 deletions
diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
index 0cb7aadc87cd..361b7a4c640c 100644
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -121,132 +121,23 @@ static void native_smp_send_reschedule(int cpu)
121 send_IPI_mask(cpumask_of_cpu(cpu), RESCHEDULE_VECTOR); 121 send_IPI_mask(cpumask_of_cpu(cpu), RESCHEDULE_VECTOR);
122} 122}
123 123
124/* 124void native_send_call_func_single_ipi(int cpu)
125 * Structure and data for smp_call_function(). This is designed to minimise
126 * static memory requirements. It also looks cleaner.
127 */
128static DEFINE_SPINLOCK(call_lock);
129
130struct call_data_struct {
131 void (*func) (void *info);
132 void *info;
133 atomic_t started;
134 atomic_t finished;
135 int wait;
136};
137
138void lock_ipi_call_lock(void)
139{ 125{
140 spin_lock_irq(&call_lock); 126 send_IPI_mask(cpumask_of_cpu(cpu), CALL_FUNCTION_SINGLE_VECTOR);
141}
142
143void unlock_ipi_call_lock(void)
144{
145 spin_unlock_irq(&call_lock);
146}
147
148static struct call_data_struct *call_data;
149
150static void __smp_call_function(void (*func) (void *info), void *info,
151 int nonatomic, int wait)
152{
153 struct call_data_struct data;
154 int cpus = num_online_cpus() - 1;
155
156 if (!cpus)
157 return;
158
159 data.func = func;
160 data.info = info;
161 atomic_set(&data.started, 0);
162 data.wait = wait;
163 if (wait)
164 atomic_set(&data.finished, 0);
165
166 call_data = &data;
167 mb();
168
169 /* Send a message to all other CPUs and wait for them to respond */
170 send_IPI_allbutself(CALL_FUNCTION_VECTOR);
171
172 /* Wait for response */
173 while (atomic_read(&data.started) != cpus)
174 cpu_relax();
175
176 if (wait)
177 while (atomic_read(&data.finished) != cpus)
178 cpu_relax();
179} 127}
180 128
181 129void native_send_call_func_ipi(cpumask_t mask)
182/**
183 * smp_call_function_mask(): Run a function on a set of other CPUs.
184 * @mask: The set of cpus to run on. Must not include the current cpu.
185 * @func: The function to run. This must be fast and non-blocking.
186 * @info: An arbitrary pointer to pass to the function.
187 * @wait: If true, wait (atomically) until function has completed on other CPUs.
188 *
189 * Returns 0 on success, else a negative status code.
190 *
191 * If @wait is true, then returns once @func has returned; otherwise
192 * it returns just before the target cpu calls @func.
193 *
194 * You must not call this function with disabled interrupts or from a
195 * hardware interrupt handler or from a bottom half handler.
196 */
197static int
198native_smp_call_function_mask(cpumask_t mask,
199 void (*func)(void *), void *info,
200 int wait)
201{ 130{
202 struct call_data_struct data;
203 cpumask_t allbutself; 131 cpumask_t allbutself;
204 int cpus;
205
206 /* Can deadlock when called with interrupts disabled */
207 WARN_ON(irqs_disabled());
208
209 /* Holding any lock stops cpus from going down. */
210 spin_lock(&call_lock);
211 132
212 allbutself = cpu_online_map; 133 allbutself = cpu_online_map;
213 cpu_clear(smp_processor_id(), allbutself); 134 cpu_clear(smp_processor_id(), allbutself);
214 135
215 cpus_and(mask, mask, allbutself);
216 cpus = cpus_weight(mask);
217
218 if (!cpus) {
219 spin_unlock(&call_lock);
220 return 0;
221 }
222
223 data.func = func;
224 data.info = info;
225 atomic_set(&data.started, 0);
226 data.wait = wait;
227 if (wait)
228 atomic_set(&data.finished, 0);
229
230 call_data = &data;
231 wmb();
232
233 /* Send a message to other CPUs */
234 if (cpus_equal(mask, allbutself) && 136 if (cpus_equal(mask, allbutself) &&
235 cpus_equal(cpu_online_map, cpu_callout_map)) 137 cpus_equal(cpu_online_map, cpu_callout_map))
236 send_IPI_allbutself(CALL_FUNCTION_VECTOR); 138 send_IPI_allbutself(CALL_FUNCTION_VECTOR);
237 else 139 else
238 send_IPI_mask(mask, CALL_FUNCTION_VECTOR); 140 send_IPI_mask(mask, CALL_FUNCTION_VECTOR);
239
240 /* Wait for response */
241 while (atomic_read(&data.started) != cpus)
242 cpu_relax();
243
244 if (wait)
245 while (atomic_read(&data.finished) != cpus)
246 cpu_relax();
247 spin_unlock(&call_lock);
248
249 return 0;
250} 141}
251 142
252static void stop_this_cpu(void *dummy) 143static void stop_this_cpu(void *dummy)
@@ -268,18 +159,13 @@ static void stop_this_cpu(void *dummy)
268 159
269static void native_smp_send_stop(void) 160static void native_smp_send_stop(void)
270{ 161{
271 int nolock;
272 unsigned long flags; 162 unsigned long flags;
273 163
274 if (reboot_force) 164 if (reboot_force)
275 return; 165 return;
276 166
277 /* Don't deadlock on the call lock in panic */ 167 smp_call_function(stop_this_cpu, NULL, 0);
278 nolock = !spin_trylock(&call_lock);
279 local_irq_save(flags); 168 local_irq_save(flags);
280 __smp_call_function(stop_this_cpu, NULL, 0, 0);
281 if (!nolock)
282 spin_unlock(&call_lock);
283 disable_local_APIC(); 169 disable_local_APIC();
284 local_irq_restore(flags); 170 local_irq_restore(flags);
285} 171}
@@ -301,33 +187,28 @@ void smp_reschedule_interrupt(struct pt_regs *regs)
301 187
302void smp_call_function_interrupt(struct pt_regs *regs) 188void smp_call_function_interrupt(struct pt_regs *regs)
303{ 189{
304 void (*func) (void *info) = call_data->func;
305 void *info = call_data->info;
306 int wait = call_data->wait;
307
308 ack_APIC_irq(); 190 ack_APIC_irq();
309 /*
310 * Notify initiating CPU that I've grabbed the data and am
311 * about to execute the function
312 */
313 mb();
314 atomic_inc(&call_data->started);
315 /*
316 * At this point the info structure may be out of scope unless wait==1
317 */
318 irq_enter(); 191 irq_enter();
319 (*func)(info); 192 generic_smp_call_function_interrupt();
320#ifdef CONFIG_X86_32 193#ifdef CONFIG_X86_32
321 __get_cpu_var(irq_stat).irq_call_count++; 194 __get_cpu_var(irq_stat).irq_call_count++;
322#else 195#else
323 add_pda(irq_call_count, 1); 196 add_pda(irq_call_count, 1);
324#endif 197#endif
325 irq_exit(); 198 irq_exit();
199}
326 200
327 if (wait) { 201void smp_call_function_single_interrupt(struct pt_regs *regs)
328 mb(); 202{
329 atomic_inc(&call_data->finished); 203 ack_APIC_irq();
330 } 204 irq_enter();
205 generic_smp_call_function_single_interrupt();
206#ifdef CONFIG_X86_32
207 __get_cpu_var(irq_stat).irq_call_count++;
208#else
209 add_pda(irq_call_count, 1);
210#endif
211 irq_exit();
331} 212}
332 213
333struct smp_ops smp_ops = { 214struct smp_ops smp_ops = {
@@ -338,7 +219,8 @@ struct smp_ops smp_ops = {
338 219
339 .smp_send_stop = native_smp_send_stop, 220 .smp_send_stop = native_smp_send_stop,
340 .smp_send_reschedule = native_smp_send_reschedule, 221 .smp_send_reschedule = native_smp_send_reschedule,
341 .smp_call_function_mask = native_smp_call_function_mask, 222
223 .send_call_func_ipi = native_send_call_func_ipi,
224 .send_call_func_single_ipi = native_send_call_func_single_ipi,
342}; 225};
343EXPORT_SYMBOL_GPL(smp_ops); 226EXPORT_SYMBOL_GPL(smp_ops);
344