2 * IPI management based on arch/arm/kernel/smp.c (Copyright 2002 ARM Limited)
4 * Copyright 2007-2009 Analog Devices Inc.
5 * Philippe Gerum <rpm@xenomai.org>
7 * Licensed under the GPL-2.
10 #include <linux/module.h>
11 #include <linux/delay.h>
12 #include <linux/init.h>
13 #include <linux/spinlock.h>
14 #include <linux/sched.h>
15 #include <linux/interrupt.h>
16 #include <linux/cache.h>
17 #include <linux/profile.h>
18 #include <linux/errno.h>
20 #include <linux/cpu.h>
21 #include <linux/smp.h>
22 #include <linux/cpumask.h>
23 #include <linux/seq_file.h>
24 #include <linux/irq.h>
25 #include <linux/slab.h>
26 #include <linux/atomic.h>
27 #include <asm/cacheflush.h>
28 #include <asm/irq_handler.h>
29 #include <asm/mmu_context.h>
30 #include <asm/pgtable.h>
31 #include <asm/pgalloc.h>
32 #include <asm/processor.h>
33 #include <asm/ptrace.h>
36 #include <linux/err.h>
40 * 05000120 - we always define corelock as 32-bit integer in L2
42 struct corelock_slot corelock
__attribute__ ((__section__(".l2.bss")));
44 #ifdef CONFIG_ICACHE_FLUSH_L1
45 unsigned long blackfin_iflush_l1_entry
[NR_CPUS
];
48 struct blackfin_initial_pda __cpuinitdata initial_pda_coreb
;
50 #define BFIN_IPI_RESCHEDULE 0
51 #define BFIN_IPI_CALL_FUNC 1
52 #define BFIN_IPI_CPU_STOP 2
54 struct blackfin_flush_data
{
59 void *secondary_stack
;
62 struct smp_call_struct
{
63 void (*func
)(void *info
);
69 static struct blackfin_flush_data smp_flush_data
;
71 static DEFINE_SPINLOCK(stop_lock
);
75 struct smp_call_struct call_struct
;
78 /* A magic number - stress test shows this is safe for common cases */
79 #define BFIN_IPI_MSGQ_LEN 5
81 /* Simple FIFO buffer, overflow leads to panic */
82 struct ipi_message_queue
{
85 unsigned long head
; /* head of the queue */
86 struct ipi_message ipi_message
[BFIN_IPI_MSGQ_LEN
];
89 static DEFINE_PER_CPU(struct ipi_message_queue
, ipi_msg_queue
);
91 static void ipi_cpu_stop(unsigned int cpu
)
93 spin_lock(&stop_lock
);
94 printk(KERN_CRIT
"CPU%u: stopping\n", cpu
);
96 spin_unlock(&stop_lock
);
98 set_cpu_online(cpu
, false);
106 static void ipi_flush_icache(void *info
)
108 struct blackfin_flush_data
*fdata
= info
;
110 /* Invalidate the memory holding the bounds of the flushed region. */
111 blackfin_dcache_invalidate_range((unsigned long)fdata
,
112 (unsigned long)fdata
+ sizeof(*fdata
));
114 /* Make sure all write buffers in the data side of the core
115 * are flushed before trying to invalidate the icache. This
116 * needs to be after the data flush and before the icache
117 * flush so that the SSYNC does the right thing in preventing
118 * the instruction prefetcher from hitting things in cached
119 * memory at the wrong time -- it runs much further ahead than
124 /* ipi_flaush_icache is invoked by generic flush_icache_range,
125 * so call blackfin arch icache flush directly here.
127 blackfin_icache_flush_range(fdata
->start
, fdata
->end
);
130 static void ipi_call_function(unsigned int cpu
, struct ipi_message
*msg
)
133 void (*func
)(void *info
);
135 func
= msg
->call_struct
.func
;
136 info
= msg
->call_struct
.info
;
137 wait
= msg
->call_struct
.wait
;
140 #ifdef __ARCH_SYNC_CORE_DCACHE
142 * 'wait' usually means synchronization between CPUs.
143 * Invalidate D cache in case shared data was changed
144 * by func() to ensure cache coherence.
146 resync_core_dcache();
148 cpumask_clear_cpu(cpu
, msg
->call_struct
.waitmask
);
152 /* Use IRQ_SUPPLE_0 to request reschedule.
153 * When returning from interrupt to user space,
154 * there is chance to reschedule */
155 static irqreturn_t
ipi_handler_int0(int irq
, void *dev_instance
)
157 unsigned int cpu
= smp_processor_id();
159 platform_clear_ipi(cpu
, IRQ_SUPPLE_0
);
163 static irqreturn_t
ipi_handler_int1(int irq
, void *dev_instance
)
165 struct ipi_message
*msg
;
166 struct ipi_message_queue
*msg_queue
;
167 unsigned int cpu
= smp_processor_id();
170 platform_clear_ipi(cpu
, IRQ_SUPPLE_1
);
172 msg_queue
= &__get_cpu_var(ipi_msg_queue
);
174 spin_lock_irqsave(&msg_queue
->lock
, flags
);
176 while (msg_queue
->count
) {
177 msg
= &msg_queue
->ipi_message
[msg_queue
->head
];
179 case BFIN_IPI_RESCHEDULE
:
182 case BFIN_IPI_CALL_FUNC
:
183 spin_unlock_irqrestore(&msg_queue
->lock
, flags
);
184 ipi_call_function(cpu
, msg
);
185 spin_lock_irqsave(&msg_queue
->lock
, flags
);
187 case BFIN_IPI_CPU_STOP
:
188 spin_unlock_irqrestore(&msg_queue
->lock
, flags
);
190 spin_lock_irqsave(&msg_queue
->lock
, flags
);
193 printk(KERN_CRIT
"CPU%u: Unknown IPI message 0x%lx\n",
198 msg_queue
->head
%= BFIN_IPI_MSGQ_LEN
;
201 spin_unlock_irqrestore(&msg_queue
->lock
, flags
);
205 static void ipi_queue_init(void)
208 struct ipi_message_queue
*msg_queue
;
209 for_each_possible_cpu(cpu
) {
210 msg_queue
= &per_cpu(ipi_msg_queue
, cpu
);
211 spin_lock_init(&msg_queue
->lock
);
212 msg_queue
->count
= 0;
217 static inline void smp_send_message(cpumask_t callmap
, unsigned long type
,
218 void (*func
) (void *info
), void *info
, int wait
)
221 struct ipi_message_queue
*msg_queue
;
222 struct ipi_message
*msg
;
223 unsigned long flags
, next_msg
;
224 cpumask_t waitmask
; /* waitmask is shared by all cpus */
226 cpumask_copy(&waitmask
, &callmap
);
227 for_each_cpu(cpu
, &callmap
) {
228 msg_queue
= &per_cpu(ipi_msg_queue
, cpu
);
229 spin_lock_irqsave(&msg_queue
->lock
, flags
);
230 if (msg_queue
->count
< BFIN_IPI_MSGQ_LEN
) {
231 next_msg
= (msg_queue
->head
+ msg_queue
->count
)
233 msg
= &msg_queue
->ipi_message
[next_msg
];
235 if (type
== BFIN_IPI_CALL_FUNC
) {
236 msg
->call_struct
.func
= func
;
237 msg
->call_struct
.info
= info
;
238 msg
->call_struct
.wait
= wait
;
239 msg
->call_struct
.waitmask
= &waitmask
;
243 panic("IPI message queue overflow\n");
244 spin_unlock_irqrestore(&msg_queue
->lock
, flags
);
245 platform_send_ipi_cpu(cpu
, IRQ_SUPPLE_1
);
249 while (!cpumask_empty(&waitmask
))
250 blackfin_dcache_invalidate_range(
251 (unsigned long)(&waitmask
),
252 (unsigned long)(&waitmask
));
253 #ifdef __ARCH_SYNC_CORE_DCACHE
255 * Invalidate D cache in case shared data was changed by
256 * other processors to ensure cache coherence.
258 resync_core_dcache();
263 int smp_call_function(void (*func
)(void *info
), void *info
, int wait
)
268 cpumask_copy(&callmap
, cpu_online_mask
);
269 cpumask_clear_cpu(smp_processor_id(), &callmap
);
270 if (!cpumask_empty(&callmap
))
271 smp_send_message(callmap
, BFIN_IPI_CALL_FUNC
, func
, info
, wait
);
277 EXPORT_SYMBOL_GPL(smp_call_function
);
279 int smp_call_function_single(int cpuid
, void (*func
) (void *info
), void *info
,
282 unsigned int cpu
= cpuid
;
285 if (cpu_is_offline(cpu
))
287 cpumask_clear(&callmap
);
288 cpumask_set_cpu(cpu
, &callmap
);
290 smp_send_message(callmap
, BFIN_IPI_CALL_FUNC
, func
, info
, wait
);
294 EXPORT_SYMBOL_GPL(smp_call_function_single
);
296 void smp_send_reschedule(int cpu
)
298 /* simply trigger an ipi */
299 if (cpu_is_offline(cpu
))
301 platform_send_ipi_cpu(cpu
, IRQ_SUPPLE_0
);
306 void smp_send_stop(void)
311 cpumask_copy(&callmap
, cpu_online_mask
);
312 cpumask_clear_cpu(smp_processor_id(), &callmap
);
313 if (!cpumask_empty(&callmap
))
314 smp_send_message(callmap
, BFIN_IPI_CPU_STOP
, NULL
, NULL
, 0);
321 int __cpuinit
__cpu_up(unsigned int cpu
)
324 static struct task_struct
*idle
;
329 idle
= fork_idle(cpu
);
331 printk(KERN_ERR
"CPU%u: fork() failed\n", cpu
);
332 return PTR_ERR(idle
);
335 secondary_stack
= task_stack_page(idle
) + THREAD_SIZE
;
337 ret
= platform_boot_secondary(cpu
, idle
);
339 secondary_stack
= NULL
;
344 static void __cpuinit
setup_secondary(unsigned int cpu
)
350 ilat
= bfin_read_ILAT();
352 bfin_write_ILAT(ilat
);
355 /* Enable interrupt levels IVG7-15. IARs have been already
356 * programmed by the boot CPU. */
357 bfin_irq_flags
|= IMASK_IVG15
|
358 IMASK_IVG14
| IMASK_IVG13
| IMASK_IVG12
| IMASK_IVG11
|
359 IMASK_IVG10
| IMASK_IVG9
| IMASK_IVG8
| IMASK_IVG7
| IMASK_IVGHW
;
362 void __cpuinit
secondary_start_kernel(void)
364 unsigned int cpu
= smp_processor_id();
365 struct mm_struct
*mm
= &init_mm
;
367 if (_bfin_swrst
& SWRST_DBL_FAULT_B
) {
368 printk(KERN_EMERG
"CoreB Recovering from DOUBLE FAULT event\n");
369 #ifdef CONFIG_DEBUG_DOUBLEFAULT
370 printk(KERN_EMERG
" While handling exception (EXCAUSE = %#x) at %pF\n",
371 initial_pda_coreb
.seqstat_doublefault
& SEQSTAT_EXCAUSE
,
372 initial_pda_coreb
.retx_doublefault
);
373 printk(KERN_NOTICE
" DCPLB_FAULT_ADDR: %pF\n",
374 initial_pda_coreb
.dcplb_doublefault_addr
);
375 printk(KERN_NOTICE
" ICPLB_FAULT_ADDR: %pF\n",
376 initial_pda_coreb
.icplb_doublefault_addr
);
378 printk(KERN_NOTICE
" The instruction at %pF caused a double exception\n",
379 initial_pda_coreb
.retx
);
383 * We want the D-cache to be enabled early, in case the atomic
384 * support code emulates cache coherence (see
385 * __ARCH_SYNC_CORE_DCACHE).
387 init_exception_vectors();
391 /* Attach the new idle task to the global mm. */
392 atomic_inc(&mm
->mm_users
);
393 atomic_inc(&mm
->mm_count
);
394 current
->active_mm
= mm
;
398 setup_secondary(cpu
);
400 platform_secondary_init(cpu
);
402 /* setup local core timer */
403 bfin_local_timer_setup();
407 bfin_setup_caches(cpu
);
410 * Calibrate loops per jiffy value.
411 * IRQs need to be enabled here - D-cache can be invalidated
412 * in timer irq handler, so core B can read correct jiffies.
419 void __init
smp_prepare_boot_cpu(void)
423 void __init
smp_prepare_cpus(unsigned int max_cpus
)
425 platform_prepare_cpus(max_cpus
);
427 platform_request_ipi(IRQ_SUPPLE_0
, ipi_handler_int0
);
428 platform_request_ipi(IRQ_SUPPLE_1
, ipi_handler_int1
);
431 void __init
smp_cpus_done(unsigned int max_cpus
)
433 unsigned long bogosum
= 0;
436 for_each_online_cpu(cpu
)
437 bogosum
+= loops_per_jiffy
;
439 printk(KERN_INFO
"SMP: Total of %d processors activated "
440 "(%lu.%02lu BogoMIPS).\n",
442 bogosum
/ (500000/HZ
),
443 (bogosum
/ (5000/HZ
)) % 100);
446 void smp_icache_flush_range_others(unsigned long start
, unsigned long end
)
448 smp_flush_data
.start
= start
;
449 smp_flush_data
.end
= end
;
451 if (smp_call_function(&ipi_flush_icache
, &smp_flush_data
, 0))
452 printk(KERN_WARNING
"SMP: failed to run I-cache flush request on other CPUs\n");
454 EXPORT_SYMBOL_GPL(smp_icache_flush_range_others
);
456 #ifdef __ARCH_SYNC_CORE_ICACHE
457 unsigned long icache_invld_count
[NR_CPUS
];
458 void resync_core_icache(void)
460 unsigned int cpu
= get_cpu();
461 blackfin_invalidate_entire_icache();
462 icache_invld_count
[cpu
]++;
465 EXPORT_SYMBOL(resync_core_icache
);
468 #ifdef __ARCH_SYNC_CORE_DCACHE
469 unsigned long dcache_invld_count
[NR_CPUS
];
470 unsigned long barrier_mask
__attribute__ ((__section__(".l2.bss")));
472 void resync_core_dcache(void)
474 unsigned int cpu
= get_cpu();
475 blackfin_invalidate_entire_dcache();
476 dcache_invld_count
[cpu
]++;
479 EXPORT_SYMBOL(resync_core_dcache
);
482 #ifdef CONFIG_HOTPLUG_CPU
483 int __cpuexit
__cpu_disable(void)
485 unsigned int cpu
= smp_processor_id();
490 set_cpu_online(cpu
, false);
494 static DECLARE_COMPLETION(cpu_killed
);
496 int __cpuexit
__cpu_die(unsigned int cpu
)
498 return wait_for_completion_timeout(&cpu_killed
, 5000);
503 complete(&cpu_killed
);
505 atomic_dec(&init_mm
.mm_users
);
506 atomic_dec(&init_mm
.mm_count
);