2 * Copyright (c) 2003,2004 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
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18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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34 * $DragonFly: src/sys/kern/lwkt_ipiq.c,v 1.26 2008/05/01 09:37:48 sephe Exp $
38 * This module implements IPI message queueing and the MI portion of IPI
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/kernel.h>
50 #include <sys/rtprio.h>
51 #include <sys/queue.h>
52 #include <sys/thread2.h>
53 #include <sys/sysctl.h>
55 #include <sys/kthread.h>
56 #include <machine/cpu.h>
61 #include <vm/vm_param.h>
62 #include <vm/vm_kern.h>
63 #include <vm/vm_object.h>
64 #include <vm/vm_page.h>
65 #include <vm/vm_map.h>
66 #include <vm/vm_pager.h>
67 #include <vm/vm_extern.h>
68 #include <vm/vm_zone.h>
70 #include <machine/stdarg.h>
71 #include <machine/smp.h>
72 #include <machine/atomic.h>
76 #include <sys/stdint.h>
77 #include <libcaps/thread.h>
78 #include <sys/thread.h>
79 #include <sys/msgport.h>
80 #include <sys/errno.h>
81 #include <libcaps/globaldata.h>
82 #include <machine/cpufunc.h>
83 #include <sys/thread2.h>
84 #include <sys/msgport2.h>
88 #include <machine/lock.h>
89 #include <machine/cpu.h>
90 #include <machine/atomic.h>
95 static __int64_t ipiq_count; /* total calls to lwkt_send_ipiq*() */
96 static __int64_t ipiq_fifofull; /* number of fifo full conditions detected */
97 static __int64_t ipiq_avoided; /* interlock with target avoids cpu ipi */
98 static __int64_t ipiq_passive; /* passive IPI messages */
99 static __int64_t ipiq_cscount; /* number of cpu synchronizations */
100 static int ipiq_optimized = 1; /* XXX temporary sysctl */
102 static int panic_ipiq_cpu = -1;
103 static int panic_ipiq_count = 100;
110 SYSCTL_QUAD(_lwkt, OID_AUTO, ipiq_count, CTLFLAG_RW, &ipiq_count, 0, "");
111 SYSCTL_QUAD(_lwkt, OID_AUTO, ipiq_fifofull, CTLFLAG_RW, &ipiq_fifofull, 0, "");
112 SYSCTL_QUAD(_lwkt, OID_AUTO, ipiq_avoided, CTLFLAG_RW, &ipiq_avoided, 0, "");
113 SYSCTL_QUAD(_lwkt, OID_AUTO, ipiq_passive, CTLFLAG_RW, &ipiq_passive, 0, "");
114 SYSCTL_QUAD(_lwkt, OID_AUTO, ipiq_cscount, CTLFLAG_RW, &ipiq_cscount, 0, "");
115 SYSCTL_INT(_lwkt, OID_AUTO, ipiq_optimized, CTLFLAG_RW, &ipiq_optimized, 0, "");
117 SYSCTL_INT(_lwkt, OID_AUTO, panic_ipiq_cpu, CTLFLAG_RW, &panic_ipiq_cpu, 0, "");
118 SYSCTL_INT(_lwkt, OID_AUTO, panic_ipiq_count, CTLFLAG_RW, &panic_ipiq_count, 0, "");
121 #define IPIQ_STRING "func=%p arg1=%p arg2=%d scpu=%d dcpu=%d"
122 #define IPIQ_ARG_SIZE (sizeof(void *) * 2 + sizeof(int) * 3)
124 #if !defined(KTR_IPIQ)
125 #define KTR_IPIQ KTR_ALL
127 KTR_INFO_MASTER(ipiq);
128 KTR_INFO(KTR_IPIQ, ipiq, send_norm, 0, IPIQ_STRING, IPIQ_ARG_SIZE);
129 KTR_INFO(KTR_IPIQ, ipiq, send_pasv, 1, IPIQ_STRING, IPIQ_ARG_SIZE);
130 KTR_INFO(KTR_IPIQ, ipiq, send_nbio, 2, IPIQ_STRING, IPIQ_ARG_SIZE);
131 KTR_INFO(KTR_IPIQ, ipiq, send_fail, 3, IPIQ_STRING, IPIQ_ARG_SIZE);
132 KTR_INFO(KTR_IPIQ, ipiq, receive, 4, IPIQ_STRING, IPIQ_ARG_SIZE);
133 KTR_INFO(KTR_IPIQ, ipiq, sync_start, 5, "cpumask=%08x", sizeof(cpumask_t));
134 KTR_INFO(KTR_IPIQ, ipiq, sync_add, 6, "cpumask=%08x", sizeof(cpumask_t));
135 KTR_INFO(KTR_IPIQ, ipiq, cpu_send, 7, IPIQ_STRING, IPIQ_ARG_SIZE);
136 KTR_INFO(KTR_IPIQ, ipiq, send_end, 8, IPIQ_STRING, IPIQ_ARG_SIZE);
138 #define logipiq(name, func, arg1, arg2, sgd, dgd) \
139 KTR_LOG(ipiq_ ## name, func, arg1, arg2, sgd->gd_cpuid, dgd->gd_cpuid)
140 #define logipiq2(name, arg) \
141 KTR_LOG(ipiq_ ## name, arg)
148 static int lwkt_process_ipiq_core(globaldata_t sgd, lwkt_ipiq_t ip,
149 struct intrframe *frame);
150 static void lwkt_cpusync_remote1(lwkt_cpusync_t poll);
151 static void lwkt_cpusync_remote2(lwkt_cpusync_t poll);
154 * Send a function execution request to another cpu. The request is queued
155 * on the cpu<->cpu ipiq matrix. Each cpu owns a unique ipiq FIFO for every
156 * possible target cpu. The FIFO can be written.
158 * If the FIFO fills up we have to enable interrupts to avoid an APIC
159 * deadlock and process pending IPIQs while waiting for it to empty.
160 * Otherwise we may soft-deadlock with another cpu whos FIFO is also full.
162 * We can safely bump gd_intr_nesting_level because our crit_exit() at the
163 * end will take care of any pending interrupts.
165 * The actual hardware IPI is avoided if the target cpu is already processing
166 * the queue from a prior IPI. It is possible to pipeline IPI messages
167 * very quickly between cpus due to the FIFO hysteresis.
169 * Need not be called from a critical section.
172 lwkt_send_ipiq3(globaldata_t target, ipifunc3_t func, void *arg1, int arg2)
176 struct globaldata *gd = mycpu;
178 logipiq(send_norm, func, arg1, arg2, gd, target);
181 func(arg1, arg2, NULL);
182 logipiq(send_end, func, arg1, arg2, gd, target);
186 ++gd->gd_intr_nesting_level;
188 if (gd->gd_intr_nesting_level > 20)
189 panic("lwkt_send_ipiq: TOO HEAVILY NESTED!");
191 KKASSERT(curthread->td_pri >= TDPRI_CRIT);
193 ip = &gd->gd_ipiq[target->gd_cpuid];
196 * Do not allow the FIFO to become full. Interrupts must be physically
197 * enabled while we liveloop to avoid deadlocking the APIC.
199 if (ip->ip_windex - ip->ip_rindex > MAXCPUFIFO / 2) {
200 unsigned int eflags = read_eflags();
202 if (atomic_poll_acquire_int(&ip->ip_npoll) || ipiq_optimized == 0) {
203 logipiq(cpu_send, func, arg1, arg2, gd, target);
204 cpu_send_ipiq(target->gd_cpuid);
208 while (ip->ip_windex - ip->ip_rindex > MAXCPUFIFO / 4) {
209 KKASSERT(ip->ip_windex - ip->ip_rindex != MAXCPUFIFO - 1);
212 write_eflags(eflags);
216 * Queue the new message
218 windex = ip->ip_windex & MAXCPUFIFO_MASK;
219 ip->ip_func[windex] = func;
220 ip->ip_arg1[windex] = arg1;
221 ip->ip_arg2[windex] = arg2;
224 --gd->gd_intr_nesting_level;
227 * signal the target cpu that there is work pending.
229 if (atomic_poll_acquire_int(&ip->ip_npoll)) {
230 logipiq(cpu_send, func, arg1, arg2, gd, target);
231 cpu_send_ipiq(target->gd_cpuid);
233 if (ipiq_optimized == 0) {
234 logipiq(cpu_send, func, arg1, arg2, gd, target);
235 cpu_send_ipiq(target->gd_cpuid);
242 logipiq(send_end, func, arg1, arg2, gd, target);
243 return(ip->ip_windex);
247 * Similar to lwkt_send_ipiq() but this function does not actually initiate
248 * the IPI to the target cpu unless the FIFO has become too full, so it is
251 * This function is used for non-critical IPI messages, such as memory
252 * deallocations. The queue will typically be flushed by the target cpu at
253 * the next clock interrupt.
255 * Need not be called from a critical section.
258 lwkt_send_ipiq3_passive(globaldata_t target, ipifunc3_t func,
259 void *arg1, int arg2)
263 struct globaldata *gd = mycpu;
265 KKASSERT(target != gd);
267 logipiq(send_pasv, func, arg1, arg2, gd, target);
268 ++gd->gd_intr_nesting_level;
270 if (gd->gd_intr_nesting_level > 20)
271 panic("lwkt_send_ipiq: TOO HEAVILY NESTED!");
273 KKASSERT(curthread->td_pri >= TDPRI_CRIT);
276 ip = &gd->gd_ipiq[target->gd_cpuid];
279 * Do not allow the FIFO to become full. Interrupts must be physically
280 * enabled while we liveloop to avoid deadlocking the APIC.
282 if (ip->ip_windex - ip->ip_rindex > MAXCPUFIFO / 2) {
283 unsigned int eflags = read_eflags();
285 if (atomic_poll_acquire_int(&ip->ip_npoll) || ipiq_optimized == 0) {
286 logipiq(cpu_send, func, arg1, arg2, gd, target);
287 cpu_send_ipiq(target->gd_cpuid);
291 while (ip->ip_windex - ip->ip_rindex > MAXCPUFIFO / 4) {
292 KKASSERT(ip->ip_windex - ip->ip_rindex != MAXCPUFIFO - 1);
295 write_eflags(eflags);
299 * Queue the new message
301 windex = ip->ip_windex & MAXCPUFIFO_MASK;
302 ip->ip_func[windex] = func;
303 ip->ip_arg1[windex] = arg1;
304 ip->ip_arg2[windex] = arg2;
307 --gd->gd_intr_nesting_level;
310 * Do not signal the target cpu, it will pick up the IPI when it next
311 * polls (typically on the next tick).
315 logipiq(send_end, func, arg1, arg2, gd, target);
316 return(ip->ip_windex);
320 * Send an IPI request without blocking, return 0 on success, ENOENT on
321 * failure. The actual queueing of the hardware IPI may still force us
322 * to spin and process incoming IPIs but that will eventually go away
323 * when we've gotten rid of the other general IPIs.
326 lwkt_send_ipiq3_nowait(globaldata_t target, ipifunc3_t func,
327 void *arg1, int arg2)
331 struct globaldata *gd = mycpu;
333 logipiq(send_nbio, func, arg1, arg2, gd, target);
334 KKASSERT(curthread->td_pri >= TDPRI_CRIT);
336 func(arg1, arg2, NULL);
337 logipiq(send_end, func, arg1, arg2, gd, target);
341 ip = &gd->gd_ipiq[target->gd_cpuid];
343 if (ip->ip_windex - ip->ip_rindex >= MAXCPUFIFO * 2 / 3) {
344 logipiq(send_fail, func, arg1, arg2, gd, target);
347 windex = ip->ip_windex & MAXCPUFIFO_MASK;
348 ip->ip_func[windex] = func;
349 ip->ip_arg1[windex] = arg1;
350 ip->ip_arg2[windex] = arg2;
355 * This isn't a passive IPI, we still have to signal the target cpu.
357 if (atomic_poll_acquire_int(&ip->ip_npoll)) {
358 logipiq(cpu_send, func, arg1, arg2, gd, target);
359 cpu_send_ipiq(target->gd_cpuid);
361 if (ipiq_optimized == 0) {
362 logipiq(cpu_send, func, arg1, arg2, gd, target);
363 cpu_send_ipiq(target->gd_cpuid);
369 logipiq(send_end, func, arg1, arg2, gd, target);
374 * deprecated, used only by fast int forwarding.
377 lwkt_send_ipiq3_bycpu(int dcpu, ipifunc3_t func, void *arg1, int arg2)
379 return(lwkt_send_ipiq3(globaldata_find(dcpu), func, arg1, arg2));
383 * Send a message to several target cpus. Typically used for scheduling.
384 * The message will not be sent to stopped cpus.
387 lwkt_send_ipiq3_mask(u_int32_t mask, ipifunc3_t func, void *arg1, int arg2)
392 mask &= ~stopped_cpus;
395 lwkt_send_ipiq3(globaldata_find(cpuid), func, arg1, arg2);
396 mask &= ~(1 << cpuid);
403 * Wait for the remote cpu to finish processing a function.
405 * YYY we have to enable interrupts and process the IPIQ while waiting
406 * for it to empty or we may deadlock with another cpu. Create a CPU_*()
407 * function to do this! YYY we really should 'block' here.
409 * MUST be called from a critical section. This routine may be called
410 * from an interrupt (for example, if an interrupt wakes a foreign thread
414 lwkt_wait_ipiq(globaldata_t target, int seq)
417 int maxc = 100000000;
419 if (target != mycpu) {
420 ip = &mycpu->gd_ipiq[target->gd_cpuid];
421 if ((int)(ip->ip_xindex - seq) < 0) {
422 unsigned int eflags = read_eflags();
424 while ((int)(ip->ip_xindex - seq) < 0) {
429 kprintf("LWKT_WAIT_IPIQ WARNING! %d wait %d (%d)\n", mycpu->gd_cpuid, target->gd_cpuid, ip->ip_xindex - seq);
431 panic("LWKT_WAIT_IPIQ");
433 * xindex may be modified by another cpu, use a load fence
434 * to ensure that the loop does not use a speculative value
435 * (which may improve performance).
439 write_eflags(eflags);
445 lwkt_seq_ipiq(globaldata_t target)
449 ip = &mycpu->gd_ipiq[target->gd_cpuid];
450 return(ip->ip_windex);
454 * Called from IPI interrupt (like a fast interrupt), which has placed
455 * us in a critical section. The MP lock may or may not be held.
456 * May also be called from doreti or splz, or be reentrantly called
457 * indirectly through the ip_func[] we run.
459 * There are two versions, one where no interrupt frame is available (when
460 * called from the send code and from splz, and one where an interrupt
461 * frame is available.
464 lwkt_process_ipiq(void)
466 globaldata_t gd = mycpu;
472 for (n = 0; n < ncpus; ++n) {
473 if (n != gd->gd_cpuid) {
474 sgd = globaldata_find(n);
477 while (lwkt_process_ipiq_core(sgd, &ip[gd->gd_cpuid], NULL))
482 if (gd->gd_cpusyncq.ip_rindex != gd->gd_cpusyncq.ip_windex) {
483 if (lwkt_process_ipiq_core(gd, &gd->gd_cpusyncq, NULL)) {
484 if (gd->gd_curthread->td_cscount == 0)
493 lwkt_process_ipiq_frame(struct intrframe *frame)
495 globaldata_t gd = mycpu;
501 for (n = 0; n < ncpus; ++n) {
502 if (n != gd->gd_cpuid) {
503 sgd = globaldata_find(n);
506 while (lwkt_process_ipiq_core(sgd, &ip[gd->gd_cpuid], frame))
511 if (gd->gd_cpusyncq.ip_rindex != gd->gd_cpusyncq.ip_windex) {
512 if (lwkt_process_ipiq_core(gd, &gd->gd_cpusyncq, frame)) {
513 if (gd->gd_curthread->td_cscount == 0)
522 lwkt_process_ipiq_core(globaldata_t sgd, lwkt_ipiq_t ip,
523 struct intrframe *frame)
527 ipifunc3_t copy_func;
532 * Obtain the current write index, which is modified by a remote cpu.
533 * Issue a load fence to prevent speculative reads of e.g. data written
534 * by the other cpu prior to it updating the index.
536 KKASSERT(curthread->td_pri >= TDPRI_CRIT);
541 * Note: xindex is only updated after we are sure the function has
542 * finished execution. Beware lwkt_process_ipiq() reentrancy! The
543 * function may send an IPI which may block/drain.
545 * Note: due to additional IPI operations that the callback function
546 * may make, it is possible for both rindex and windex to advance and
547 * thus for rindex to advance passed our cached windex.
549 while (wi - (ri = ip->ip_rindex) > 0) {
550 ri &= MAXCPUFIFO_MASK;
551 copy_func = ip->ip_func[ri];
552 copy_arg1 = ip->ip_arg1[ri];
553 copy_arg2 = ip->ip_arg2[ri];
556 KKASSERT((ip->ip_rindex & MAXCPUFIFO_MASK) == ((ri + 1) & MAXCPUFIFO_MASK));
557 logipiq(receive, copy_func, copy_arg1, copy_arg2, sgd, mycpu);
558 copy_func(copy_arg1, copy_arg2, frame);
560 ip->ip_xindex = ip->ip_rindex;
564 * Simulate panics during the processing of an IPI
566 if (mycpu->gd_cpuid == panic_ipiq_cpu && panic_ipiq_count) {
567 if (--panic_ipiq_count == 0) {
569 Debugger("PANIC_DEBUG");
571 panic("PANIC_DEBUG");
579 * Return non-zero if there are more IPI messages pending on this
580 * ipiq. ip_npoll is left set as long as possible to reduce the
581 * number of IPIs queued by the originating cpu, but must be cleared
582 * *BEFORE* checking windex.
584 atomic_poll_release_int(&ip->ip_npoll);
585 return(wi != ip->ip_windex);
589 lwkt_sync_ipiq(void *arg)
591 cpumask_t *cpumask = arg;
593 atomic_clear_int(cpumask, mycpu->gd_cpumask);
599 lwkt_synchronize_ipiqs(const char *wmesg)
601 cpumask_t other_cpumask;
603 other_cpumask = mycpu->gd_other_cpus & smp_active_mask;
604 lwkt_send_ipiq_mask(other_cpumask, lwkt_sync_ipiq, &other_cpumask);
607 while (other_cpumask != 0) {
608 tsleep_interlock(&other_cpumask);
609 if (other_cpumask != 0)
610 tsleep(&other_cpumask, 0, wmesg, 0);
618 * CPU Synchronization Support
620 * lwkt_cpusync_simple()
622 * The function is executed synchronously before return on remote cpus.
623 * A lwkt_cpusync_t pointer is passed as an argument. The data can
624 * be accessed via arg->cs_data.
626 * XXX should I just pass the data as an argument to be consistent?
630 lwkt_cpusync_simple(cpumask_t mask, cpusync_func_t func, void *data)
632 struct lwkt_cpusync cmd;
634 cmd.cs_run_func = NULL;
635 cmd.cs_fin1_func = func;
636 cmd.cs_fin2_func = NULL;
638 lwkt_cpusync_start(mask & mycpu->gd_other_cpus, &cmd);
639 if (mask & (1 << mycpu->gd_cpuid))
641 lwkt_cpusync_finish(&cmd);
645 * lwkt_cpusync_fastdata()
647 * The function is executed in tandem with return on remote cpus.
648 * The data is directly passed as an argument. Do not pass pointers to
649 * temporary storage as the storage might have
650 * gone poof by the time the target cpu executes
653 * At the moment lwkt_cpusync is declared on the stack and we must wait
654 * for all remote cpus to ack in lwkt_cpusync_finish(), but as a future
655 * optimization we should be able to put a counter in the globaldata
656 * structure (if it is not otherwise being used) and just poke it and
657 * return without waiting. XXX
660 lwkt_cpusync_fastdata(cpumask_t mask, cpusync_func2_t func, void *data)
662 struct lwkt_cpusync cmd;
664 cmd.cs_run_func = NULL;
665 cmd.cs_fin1_func = NULL;
666 cmd.cs_fin2_func = func;
668 lwkt_cpusync_start(mask & mycpu->gd_other_cpus, &cmd);
669 if (mask & (1 << mycpu->gd_cpuid))
671 lwkt_cpusync_finish(&cmd);
675 * lwkt_cpusync_start()
677 * Start synchronization with a set of target cpus, return once they are
678 * known to be in a synchronization loop. The target cpus will execute
679 * poll->cs_run_func() IN TANDEM WITH THE RETURN.
681 * XXX future: add lwkt_cpusync_start_quick() and require a call to
682 * lwkt_cpusync_add() or lwkt_cpusync_wait(), allowing the caller to
683 * potentially absorb the IPI latency doing something useful.
686 lwkt_cpusync_start(cpumask_t mask, lwkt_cpusync_t poll)
688 globaldata_t gd = mycpu;
691 poll->cs_mask = mask;
693 logipiq2(sync_start, mask & gd->gd_other_cpus);
694 poll->cs_maxcount = lwkt_send_ipiq_mask(
695 mask & gd->gd_other_cpus & smp_active_mask,
696 (ipifunc1_t)lwkt_cpusync_remote1, poll);
698 if (mask & gd->gd_cpumask) {
699 if (poll->cs_run_func)
700 poll->cs_run_func(poll);
703 if (poll->cs_maxcount) {
705 ++gd->gd_curthread->td_cscount;
706 while (poll->cs_count != poll->cs_maxcount) {
716 lwkt_cpusync_add(cpumask_t mask, lwkt_cpusync_t poll)
718 globaldata_t gd = mycpu;
723 mask &= ~poll->cs_mask;
724 poll->cs_mask |= mask;
726 logipiq2(sync_add, mask & gd->gd_other_cpus);
727 count = lwkt_send_ipiq_mask(
728 mask & gd->gd_other_cpus & smp_active_mask,
729 (ipifunc1_t)lwkt_cpusync_remote1, poll);
731 if (mask & gd->gd_cpumask) {
732 if (poll->cs_run_func)
733 poll->cs_run_func(poll);
736 poll->cs_maxcount += count;
737 if (poll->cs_maxcount) {
738 if (poll->cs_maxcount == count)
739 ++gd->gd_curthread->td_cscount;
740 while (poll->cs_count != poll->cs_maxcount) {
750 * Finish synchronization with a set of target cpus. The target cpus will
751 * execute cs_fin1_func(poll) prior to this function returning, and will
752 * execute cs_fin2_func(data) IN TANDEM WITH THIS FUNCTION'S RETURN.
754 * If cs_maxcount is non-zero then we are mastering a cpusync with one or
755 * more remote cpus and must account for it in our thread structure.
758 lwkt_cpusync_finish(lwkt_cpusync_t poll)
760 globaldata_t gd = mycpu;
763 if (poll->cs_mask & gd->gd_cpumask) {
764 if (poll->cs_fin1_func)
765 poll->cs_fin1_func(poll);
766 if (poll->cs_fin2_func)
767 poll->cs_fin2_func(poll->cs_data);
770 if (poll->cs_maxcount) {
771 while (poll->cs_count != -(poll->cs_maxcount + 1)) {
776 --gd->gd_curthread->td_cscount;
784 * helper IPI remote messaging function.
786 * Called on remote cpu when a new cpu synchronization request has been
787 * sent to us. Execute the run function and adjust cs_count, then requeue
788 * the request so we spin on it.
791 lwkt_cpusync_remote1(lwkt_cpusync_t poll)
793 atomic_add_int(&poll->cs_count, 1);
794 if (poll->cs_run_func)
795 poll->cs_run_func(poll);
796 lwkt_cpusync_remote2(poll);
800 * helper IPI remote messaging function.
802 * Poll for the originator telling us to finish. If it hasn't, requeue
803 * our request so we spin on it. When the originator requests that we
804 * finish we execute cs_fin1_func(poll) synchronously and cs_fin2_func(data)
805 * in tandem with the release.
808 lwkt_cpusync_remote2(lwkt_cpusync_t poll)
810 if (poll->cs_count < 0) {
811 cpusync_func2_t savef;
814 if (poll->cs_fin1_func)
815 poll->cs_fin1_func(poll);
816 if (poll->cs_fin2_func) {
817 savef = poll->cs_fin2_func;
818 saved = poll->cs_data;
819 atomic_add_int(&poll->cs_count, -1);
822 atomic_add_int(&poll->cs_count, -1);
825 globaldata_t gd = mycpu;
829 ip = &gd->gd_cpusyncq;
830 wi = ip->ip_windex & MAXCPUFIFO_MASK;
831 ip->ip_func[wi] = (ipifunc3_t)(ipifunc1_t)lwkt_cpusync_remote2;
832 ip->ip_arg1[wi] = poll;