This source file includes following definitions.
- smp_prepare_boot_cpu
- arc_get_cpu_map
- arc_init_cpu_possible
- smp_init_cpus
- smp_prepare_cpus
- smp_cpus_done
- arc_default_smp_cpu_kick
- arc_platform_smp_wait_to_boot
- arc_platform_smp_cpuinfo
- start_kernel_secondary
- __cpu_up
- setup_profiling_timer
- ipi_send_msg_one
- ipi_send_msg
- smp_send_reschedule
- smp_send_stop
- arch_send_call_function_single_ipi
- arch_send_call_function_ipi_mask
- ipi_cpu_stop
- __do_IPI
- do_IPI
- smp_ipi_irq_setup
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12 #include <linux/spinlock.h>
13 #include <linux/sched/mm.h>
14 #include <linux/interrupt.h>
15 #include <linux/profile.h>
16 #include <linux/mm.h>
17 #include <linux/cpu.h>
18 #include <linux/irq.h>
19 #include <linux/atomic.h>
20 #include <linux/cpumask.h>
21 #include <linux/reboot.h>
22 #include <linux/irqdomain.h>
23 #include <linux/export.h>
24 #include <linux/of_fdt.h>
25
26 #include <asm/processor.h>
27 #include <asm/setup.h>
28 #include <asm/mach_desc.h>
29
30 #ifndef CONFIG_ARC_HAS_LLSC
31 arch_spinlock_t smp_atomic_ops_lock = __ARCH_SPIN_LOCK_UNLOCKED;
32 arch_spinlock_t smp_bitops_lock = __ARCH_SPIN_LOCK_UNLOCKED;
33
34 EXPORT_SYMBOL_GPL(smp_atomic_ops_lock);
35 EXPORT_SYMBOL_GPL(smp_bitops_lock);
36 #endif
37
38 struct plat_smp_ops __weak plat_smp_ops;
39
40
41 struct task_struct *secondary_idle_tsk;
42
43
44 void __init smp_prepare_boot_cpu(void)
45 {
46 }
47
48 static int __init arc_get_cpu_map(const char *name, struct cpumask *cpumask)
49 {
50 unsigned long dt_root = of_get_flat_dt_root();
51 const char *buf;
52
53 buf = of_get_flat_dt_prop(dt_root, name, NULL);
54 if (!buf)
55 return -EINVAL;
56
57 if (cpulist_parse(buf, cpumask))
58 return -EINVAL;
59
60 return 0;
61 }
62
63
64
65
66
67 static void __init arc_init_cpu_possible(void)
68 {
69 struct cpumask cpumask;
70
71 if (arc_get_cpu_map("possible-cpus", &cpumask)) {
72 pr_warn("Failed to get possible-cpus from dtb, pretending all %u cpus exist\n",
73 NR_CPUS);
74
75 cpumask_setall(&cpumask);
76 }
77
78 if (!cpumask_test_cpu(0, &cpumask))
79 panic("Master cpu (cpu[0]) is missed in cpu possible mask!");
80
81 init_cpu_possible(&cpumask);
82 }
83
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91
92
93 void __init smp_init_cpus(void)
94 {
95 arc_init_cpu_possible();
96
97 if (plat_smp_ops.init_early_smp)
98 plat_smp_ops.init_early_smp();
99 }
100
101
102 void __init smp_prepare_cpus(unsigned int max_cpus)
103 {
104
105
106
107
108 if (num_present_cpus() <= 1)
109 init_cpu_present(cpu_possible_mask);
110 }
111
112 void __init smp_cpus_done(unsigned int max_cpus)
113 {
114
115 }
116
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121
122
123 static volatile int wake_flag;
124
125 #ifdef CONFIG_ISA_ARCOMPACT
126
127 #define __boot_read(f) f
128 #define __boot_write(f, v) f = v
129
130 #else
131
132 #define __boot_read(f) arc_read_uncached_32(&f)
133 #define __boot_write(f, v) arc_write_uncached_32(&f, v)
134
135 #endif
136
137 static void arc_default_smp_cpu_kick(int cpu, unsigned long pc)
138 {
139 BUG_ON(cpu == 0);
140
141 __boot_write(wake_flag, cpu);
142 }
143
144 void arc_platform_smp_wait_to_boot(int cpu)
145 {
146
147 if (IS_ENABLED(CONFIG_ARC_SMP_HALT_ON_RESET))
148 return;
149
150 while (__boot_read(wake_flag) != cpu)
151 ;
152
153 __boot_write(wake_flag, 0);
154 }
155
156 const char *arc_platform_smp_cpuinfo(void)
157 {
158 return plat_smp_ops.info ? : "";
159 }
160
161
162
163
164
165
166 void start_kernel_secondary(void)
167 {
168 struct mm_struct *mm = &init_mm;
169 unsigned int cpu = smp_processor_id();
170
171
172 setup_processor();
173
174 mmget(mm);
175 mmgrab(mm);
176 current->active_mm = mm;
177 cpumask_set_cpu(cpu, mm_cpumask(mm));
178
179
180 if (plat_smp_ops.init_per_cpu)
181 plat_smp_ops.init_per_cpu(cpu);
182
183 if (machine_desc->init_per_cpu)
184 machine_desc->init_per_cpu(cpu);
185
186 notify_cpu_starting(cpu);
187 set_cpu_online(cpu, true);
188
189 pr_info("## CPU%u LIVE ##: Executing Code...\n", cpu);
190
191 local_irq_enable();
192 preempt_disable();
193 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
194 }
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205
206 int __cpu_up(unsigned int cpu, struct task_struct *idle)
207 {
208 unsigned long wait_till;
209
210 secondary_idle_tsk = idle;
211
212 pr_info("Idle Task [%d] %p", cpu, idle);
213 pr_info("Trying to bring up CPU%u ...\n", cpu);
214
215 if (plat_smp_ops.cpu_kick)
216 plat_smp_ops.cpu_kick(cpu,
217 (unsigned long)first_lines_of_secondary);
218 else
219 arc_default_smp_cpu_kick(cpu, (unsigned long)NULL);
220
221
222 wait_till = jiffies + HZ;
223 while (time_before(jiffies, wait_till)) {
224 if (cpu_online(cpu))
225 break;
226 }
227
228 if (!cpu_online(cpu)) {
229 pr_info("Timeout: CPU%u FAILED to comeup !!!\n", cpu);
230 return -1;
231 }
232
233 secondary_idle_tsk = NULL;
234
235 return 0;
236 }
237
238
239
240
241 int setup_profiling_timer(unsigned int multiplier)
242 {
243 return -EINVAL;
244 }
245
246
247
248
249
250 enum ipi_msg_type {
251 IPI_EMPTY = 0,
252 IPI_RESCHEDULE = 1,
253 IPI_CALL_FUNC,
254 IPI_CPU_STOP,
255 };
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261
262
263 static DEFINE_PER_CPU(unsigned long, ipi_data);
264
265 static void ipi_send_msg_one(int cpu, enum ipi_msg_type msg)
266 {
267 unsigned long __percpu *ipi_data_ptr = per_cpu_ptr(&ipi_data, cpu);
268 unsigned long old, new;
269 unsigned long flags;
270
271 pr_debug("%d Sending msg [%d] to %d\n", smp_processor_id(), msg, cpu);
272
273 local_irq_save(flags);
274
275
276
277
278
279 do {
280 new = old = READ_ONCE(*ipi_data_ptr);
281 new |= 1U << msg;
282 } while (cmpxchg(ipi_data_ptr, old, new) != old);
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290
291
292 if (plat_smp_ops.ipi_send && !old)
293 plat_smp_ops.ipi_send(cpu);
294
295 local_irq_restore(flags);
296 }
297
298 static void ipi_send_msg(const struct cpumask *callmap, enum ipi_msg_type msg)
299 {
300 unsigned int cpu;
301
302 for_each_cpu(cpu, callmap)
303 ipi_send_msg_one(cpu, msg);
304 }
305
306 void smp_send_reschedule(int cpu)
307 {
308 ipi_send_msg_one(cpu, IPI_RESCHEDULE);
309 }
310
311 void smp_send_stop(void)
312 {
313 struct cpumask targets;
314 cpumask_copy(&targets, cpu_online_mask);
315 cpumask_clear_cpu(smp_processor_id(), &targets);
316 ipi_send_msg(&targets, IPI_CPU_STOP);
317 }
318
319 void arch_send_call_function_single_ipi(int cpu)
320 {
321 ipi_send_msg_one(cpu, IPI_CALL_FUNC);
322 }
323
324 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
325 {
326 ipi_send_msg(mask, IPI_CALL_FUNC);
327 }
328
329
330
331
332 static void ipi_cpu_stop(void)
333 {
334 machine_halt();
335 }
336
337 static inline int __do_IPI(unsigned long msg)
338 {
339 int rc = 0;
340
341 switch (msg) {
342 case IPI_RESCHEDULE:
343 scheduler_ipi();
344 break;
345
346 case IPI_CALL_FUNC:
347 generic_smp_call_function_interrupt();
348 break;
349
350 case IPI_CPU_STOP:
351 ipi_cpu_stop();
352 break;
353
354 default:
355 rc = 1;
356 }
357
358 return rc;
359 }
360
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364
365 irqreturn_t do_IPI(int irq, void *dev_id)
366 {
367 unsigned long pending;
368 unsigned long __maybe_unused copy;
369
370 pr_debug("IPI [%ld] received on cpu %d\n",
371 *this_cpu_ptr(&ipi_data), smp_processor_id());
372
373 if (plat_smp_ops.ipi_clear)
374 plat_smp_ops.ipi_clear(irq);
375
376
377
378
379
380 copy = pending = xchg(this_cpu_ptr(&ipi_data), 0);
381
382 do {
383 unsigned long msg = __ffs(pending);
384 int rc;
385
386 rc = __do_IPI(msg);
387 if (rc)
388 pr_info("IPI with bogus msg %ld in %ld\n", msg, copy);
389 pending &= ~(1U << msg);
390 } while (pending);
391
392 return IRQ_HANDLED;
393 }
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401
402 static DEFINE_PER_CPU(int, ipi_dev);
403
404 int smp_ipi_irq_setup(int cpu, irq_hw_number_t hwirq)
405 {
406 int *dev = per_cpu_ptr(&ipi_dev, cpu);
407 unsigned int virq = irq_find_mapping(NULL, hwirq);
408
409 if (!virq)
410 panic("Cannot find virq for root domain and hwirq=%lu", hwirq);
411
412
413 if (!cpu) {
414 int rc;
415
416 rc = request_percpu_irq(virq, do_IPI, "IPI Interrupt", dev);
417 if (rc)
418 panic("Percpu IRQ request failed for %u\n", virq);
419 }
420
421 enable_percpu_irq(virq, 0);
422
423 return 0;
424 }