ia64/linux-2.6.18-xen.hg

view arch/alpha/kernel/smp.c @ 897:329ea0ccb344

balloon: try harder to balloon up under memory pressure.

Currently if the balloon driver is unable to increase the guest's
reservation it assumes the failure was due to reaching its full
allocation, gives up on the ballooning operation and records the limit
it reached as the "hard limit". The driver will not try again until
the target is set again (even to the same value).

However it is possible that ballooning has in fact failed due to
memory pressure in the host and therefore it is desirable to keep
attempting to reach the target in case memory becomes available. The
most likely scenario is that some guests are ballooning down while
others are ballooning up and therefore there is temporary memory
pressure while things stabilise. You would not expect a well behaved
toolstack to ask a domain to balloon to more than its allocation nor
would you expect it to deliberately over-commit memory by setting
balloon targets which exceed the total host memory.

This patch drops the concept of a hard limit and causes the balloon
driver to retry increasing the reservation on a timer in the same
manner as when decreasing the reservation.

Also if we partially succeed in increasing the reservation
(i.e. receive less pages than we asked for) then we may as well keep
those pages rather than returning them to Xen.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Fri Jun 05 14:01:20 2009 +0100 (2009-06-05)
parents 831230e53067
children
line source
1 /*
2 * linux/arch/alpha/kernel/smp.c
3 *
4 * 2001-07-09 Phil Ezolt (Phillip.Ezolt@compaq.com)
5 * Renamed modified smp_call_function to smp_call_function_on_cpu()
6 * Created an function that conforms to the old calling convention
7 * of smp_call_function().
8 *
9 * This is helpful for DCPI.
10 *
11 */
13 #include <linux/errno.h>
14 #include <linux/kernel.h>
15 #include <linux/kernel_stat.h>
16 #include <linux/module.h>
17 #include <linux/sched.h>
18 #include <linux/mm.h>
19 #include <linux/threads.h>
20 #include <linux/smp.h>
21 #include <linux/smp_lock.h>
22 #include <linux/interrupt.h>
23 #include <linux/init.h>
24 #include <linux/delay.h>
25 #include <linux/spinlock.h>
26 #include <linux/irq.h>
27 #include <linux/cache.h>
28 #include <linux/profile.h>
29 #include <linux/bitops.h>
31 #include <asm/hwrpb.h>
32 #include <asm/ptrace.h>
33 #include <asm/atomic.h>
35 #include <asm/io.h>
36 #include <asm/irq.h>
37 #include <asm/pgtable.h>
38 #include <asm/pgalloc.h>
39 #include <asm/mmu_context.h>
40 #include <asm/tlbflush.h>
42 #include "proto.h"
43 #include "irq_impl.h"
46 #define DEBUG_SMP 0
47 #if DEBUG_SMP
48 #define DBGS(args) printk args
49 #else
50 #define DBGS(args)
51 #endif
53 /* A collection of per-processor data. */
54 struct cpuinfo_alpha cpu_data[NR_CPUS];
56 /* A collection of single bit ipi messages. */
57 static struct {
58 unsigned long bits ____cacheline_aligned;
59 } ipi_data[NR_CPUS] __cacheline_aligned;
61 enum ipi_message_type {
62 IPI_RESCHEDULE,
63 IPI_CALL_FUNC,
64 IPI_CPU_STOP,
65 };
67 /* Set to a secondary's cpuid when it comes online. */
68 static int smp_secondary_alive __initdata = 0;
70 /* Which cpus ids came online. */
71 cpumask_t cpu_online_map;
73 EXPORT_SYMBOL(cpu_online_map);
75 int smp_num_probed; /* Internal processor count */
76 int smp_num_cpus = 1; /* Number that came online. */
78 extern void calibrate_delay(void);
82 /*
83 * Called by both boot and secondaries to move global data into
84 * per-processor storage.
85 */
86 static inline void __init
87 smp_store_cpu_info(int cpuid)
88 {
89 cpu_data[cpuid].loops_per_jiffy = loops_per_jiffy;
90 cpu_data[cpuid].last_asn = ASN_FIRST_VERSION;
91 cpu_data[cpuid].need_new_asn = 0;
92 cpu_data[cpuid].asn_lock = 0;
93 }
95 /*
96 * Ideally sets up per-cpu profiling hooks. Doesn't do much now...
97 */
98 static inline void __init
99 smp_setup_percpu_timer(int cpuid)
100 {
101 cpu_data[cpuid].prof_counter = 1;
102 cpu_data[cpuid].prof_multiplier = 1;
103 }
105 static void __init
106 wait_boot_cpu_to_stop(int cpuid)
107 {
108 unsigned long stop = jiffies + 10*HZ;
110 while (time_before(jiffies, stop)) {
111 if (!smp_secondary_alive)
112 return;
113 barrier();
114 }
116 printk("wait_boot_cpu_to_stop: FAILED on CPU %d, hanging now\n", cpuid);
117 for (;;)
118 barrier();
119 }
121 /*
122 * Where secondaries begin a life of C.
123 */
124 void __init
125 smp_callin(void)
126 {
127 int cpuid = hard_smp_processor_id();
129 if (cpu_test_and_set(cpuid, cpu_online_map)) {
130 printk("??, cpu 0x%x already present??\n", cpuid);
131 BUG();
132 }
134 /* Turn on machine checks. */
135 wrmces(7);
137 /* Set trap vectors. */
138 trap_init();
140 /* Set interrupt vector. */
141 wrent(entInt, 0);
143 /* Get our local ticker going. */
144 smp_setup_percpu_timer(cpuid);
146 /* Call platform-specific callin, if specified */
147 if (alpha_mv.smp_callin) alpha_mv.smp_callin();
149 /* All kernel threads share the same mm context. */
150 atomic_inc(&init_mm.mm_count);
151 current->active_mm = &init_mm;
153 /* Must have completely accurate bogos. */
154 local_irq_enable();
156 /* Wait boot CPU to stop with irq enabled before running
157 calibrate_delay. */
158 wait_boot_cpu_to_stop(cpuid);
159 mb();
160 calibrate_delay();
162 smp_store_cpu_info(cpuid);
163 /* Allow master to continue only after we written loops_per_jiffy. */
164 wmb();
165 smp_secondary_alive = 1;
167 DBGS(("smp_callin: commencing CPU %d current %p active_mm %p\n",
168 cpuid, current, current->active_mm));
170 /* Do nothing. */
171 cpu_idle();
172 }
174 /* Wait until hwrpb->txrdy is clear for cpu. Return -1 on timeout. */
175 static int __init
176 wait_for_txrdy (unsigned long cpumask)
177 {
178 unsigned long timeout;
180 if (!(hwrpb->txrdy & cpumask))
181 return 0;
183 timeout = jiffies + 10*HZ;
184 while (time_before(jiffies, timeout)) {
185 if (!(hwrpb->txrdy & cpumask))
186 return 0;
187 udelay(10);
188 barrier();
189 }
191 return -1;
192 }
194 /*
195 * Send a message to a secondary's console. "START" is one such
196 * interesting message. ;-)
197 */
198 static void __init
199 send_secondary_console_msg(char *str, int cpuid)
200 {
201 struct percpu_struct *cpu;
202 register char *cp1, *cp2;
203 unsigned long cpumask;
204 size_t len;
206 cpu = (struct percpu_struct *)
207 ((char*)hwrpb
208 + hwrpb->processor_offset
209 + cpuid * hwrpb->processor_size);
211 cpumask = (1UL << cpuid);
212 if (wait_for_txrdy(cpumask))
213 goto timeout;
215 cp2 = str;
216 len = strlen(cp2);
217 *(unsigned int *)&cpu->ipc_buffer[0] = len;
218 cp1 = (char *) &cpu->ipc_buffer[1];
219 memcpy(cp1, cp2, len);
221 /* atomic test and set */
222 wmb();
223 set_bit(cpuid, &hwrpb->rxrdy);
225 if (wait_for_txrdy(cpumask))
226 goto timeout;
227 return;
229 timeout:
230 printk("Processor %x not ready\n", cpuid);
231 }
233 /*
234 * A secondary console wants to send a message. Receive it.
235 */
236 static void
237 recv_secondary_console_msg(void)
238 {
239 int mycpu, i, cnt;
240 unsigned long txrdy = hwrpb->txrdy;
241 char *cp1, *cp2, buf[80];
242 struct percpu_struct *cpu;
244 DBGS(("recv_secondary_console_msg: TXRDY 0x%lx.\n", txrdy));
246 mycpu = hard_smp_processor_id();
248 for (i = 0; i < NR_CPUS; i++) {
249 if (!(txrdy & (1UL << i)))
250 continue;
252 DBGS(("recv_secondary_console_msg: "
253 "TXRDY contains CPU %d.\n", i));
255 cpu = (struct percpu_struct *)
256 ((char*)hwrpb
257 + hwrpb->processor_offset
258 + i * hwrpb->processor_size);
260 DBGS(("recv_secondary_console_msg: on %d from %d"
261 " HALT_REASON 0x%lx FLAGS 0x%lx\n",
262 mycpu, i, cpu->halt_reason, cpu->flags));
264 cnt = cpu->ipc_buffer[0] >> 32;
265 if (cnt <= 0 || cnt >= 80)
266 strcpy(buf, "<<< BOGUS MSG >>>");
267 else {
268 cp1 = (char *) &cpu->ipc_buffer[11];
269 cp2 = buf;
270 strcpy(cp2, cp1);
272 while ((cp2 = strchr(cp2, '\r')) != 0) {
273 *cp2 = ' ';
274 if (cp2[1] == '\n')
275 cp2[1] = ' ';
276 }
277 }
279 DBGS((KERN_INFO "recv_secondary_console_msg: on %d "
280 "message is '%s'\n", mycpu, buf));
281 }
283 hwrpb->txrdy = 0;
284 }
286 /*
287 * Convince the console to have a secondary cpu begin execution.
288 */
289 static int __init
290 secondary_cpu_start(int cpuid, struct task_struct *idle)
291 {
292 struct percpu_struct *cpu;
293 struct pcb_struct *hwpcb, *ipcb;
294 unsigned long timeout;
296 cpu = (struct percpu_struct *)
297 ((char*)hwrpb
298 + hwrpb->processor_offset
299 + cpuid * hwrpb->processor_size);
300 hwpcb = (struct pcb_struct *) cpu->hwpcb;
301 ipcb = &task_thread_info(idle)->pcb;
303 /* Initialize the CPU's HWPCB to something just good enough for
304 us to get started. Immediately after starting, we'll swpctx
305 to the target idle task's pcb. Reuse the stack in the mean
306 time. Precalculate the target PCBB. */
307 hwpcb->ksp = (unsigned long)ipcb + sizeof(union thread_union) - 16;
308 hwpcb->usp = 0;
309 hwpcb->ptbr = ipcb->ptbr;
310 hwpcb->pcc = 0;
311 hwpcb->asn = 0;
312 hwpcb->unique = virt_to_phys(ipcb);
313 hwpcb->flags = ipcb->flags;
314 hwpcb->res1 = hwpcb->res2 = 0;
316 #if 0
317 DBGS(("KSP 0x%lx PTBR 0x%lx VPTBR 0x%lx UNIQUE 0x%lx\n",
318 hwpcb->ksp, hwpcb->ptbr, hwrpb->vptb, hwpcb->unique));
319 #endif
320 DBGS(("Starting secondary cpu %d: state 0x%lx pal_flags 0x%lx\n",
321 cpuid, idle->state, ipcb->flags));
323 /* Setup HWRPB fields that SRM uses to activate secondary CPU */
324 hwrpb->CPU_restart = __smp_callin;
325 hwrpb->CPU_restart_data = (unsigned long) __smp_callin;
327 /* Recalculate and update the HWRPB checksum */
328 hwrpb_update_checksum(hwrpb);
330 /*
331 * Send a "start" command to the specified processor.
332 */
334 /* SRM III 3.4.1.3 */
335 cpu->flags |= 0x22; /* turn on Context Valid and Restart Capable */
336 cpu->flags &= ~1; /* turn off Bootstrap In Progress */
337 wmb();
339 send_secondary_console_msg("START\r\n", cpuid);
341 /* Wait 10 seconds for an ACK from the console. */
342 timeout = jiffies + 10*HZ;
343 while (time_before(jiffies, timeout)) {
344 if (cpu->flags & 1)
345 goto started;
346 udelay(10);
347 barrier();
348 }
349 printk(KERN_ERR "SMP: Processor %d failed to start.\n", cpuid);
350 return -1;
352 started:
353 DBGS(("secondary_cpu_start: SUCCESS for CPU %d!!!\n", cpuid));
354 return 0;
355 }
357 /*
358 * Bring one cpu online.
359 */
360 static int __init
361 smp_boot_one_cpu(int cpuid)
362 {
363 struct task_struct *idle;
364 unsigned long timeout;
366 /* Cook up an idler for this guy. Note that the address we
367 give to kernel_thread is irrelevant -- it's going to start
368 where HWRPB.CPU_restart says to start. But this gets all
369 the other task-y sort of data structures set up like we
370 wish. We can't use kernel_thread since we must avoid
371 rescheduling the child. */
372 idle = fork_idle(cpuid);
373 if (IS_ERR(idle))
374 panic("failed fork for CPU %d", cpuid);
376 DBGS(("smp_boot_one_cpu: CPU %d state 0x%lx flags 0x%lx\n",
377 cpuid, idle->state, idle->flags));
379 /* Signal the secondary to wait a moment. */
380 smp_secondary_alive = -1;
382 /* Whirrr, whirrr, whirrrrrrrrr... */
383 if (secondary_cpu_start(cpuid, idle))
384 return -1;
386 /* Notify the secondary CPU it can run calibrate_delay. */
387 mb();
388 smp_secondary_alive = 0;
390 /* We've been acked by the console; wait one second for
391 the task to start up for real. */
392 timeout = jiffies + 1*HZ;
393 while (time_before(jiffies, timeout)) {
394 if (smp_secondary_alive == 1)
395 goto alive;
396 udelay(10);
397 barrier();
398 }
400 /* We failed to boot the CPU. */
402 printk(KERN_ERR "SMP: Processor %d is stuck.\n", cpuid);
403 return -1;
405 alive:
406 /* Another "Red Snapper". */
407 return 0;
408 }
410 /*
411 * Called from setup_arch. Detect an SMP system and which processors
412 * are present.
413 */
414 void __init
415 setup_smp(void)
416 {
417 struct percpu_struct *cpubase, *cpu;
418 unsigned long i;
420 if (boot_cpuid != 0) {
421 printk(KERN_WARNING "SMP: Booting off cpu %d instead of 0?\n",
422 boot_cpuid);
423 }
425 if (hwrpb->nr_processors > 1) {
426 int boot_cpu_palrev;
428 DBGS(("setup_smp: nr_processors %ld\n",
429 hwrpb->nr_processors));
431 cpubase = (struct percpu_struct *)
432 ((char*)hwrpb + hwrpb->processor_offset);
433 boot_cpu_palrev = cpubase->pal_revision;
435 for (i = 0; i < hwrpb->nr_processors; i++) {
436 cpu = (struct percpu_struct *)
437 ((char *)cpubase + i*hwrpb->processor_size);
438 if ((cpu->flags & 0x1cc) == 0x1cc) {
439 smp_num_probed++;
440 /* Assume here that "whami" == index */
441 cpu_set(i, cpu_present_map);
442 cpu->pal_revision = boot_cpu_palrev;
443 }
445 DBGS(("setup_smp: CPU %d: flags 0x%lx type 0x%lx\n",
446 i, cpu->flags, cpu->type));
447 DBGS(("setup_smp: CPU %d: PAL rev 0x%lx\n",
448 i, cpu->pal_revision));
449 }
450 } else {
451 smp_num_probed = 1;
452 }
454 printk(KERN_INFO "SMP: %d CPUs probed -- cpu_present_map = %lx\n",
455 smp_num_probed, cpu_present_map.bits[0]);
456 }
458 /*
459 * Called by smp_init prepare the secondaries
460 */
461 void __init
462 smp_prepare_cpus(unsigned int max_cpus)
463 {
464 /* Take care of some initial bookkeeping. */
465 memset(ipi_data, 0, sizeof(ipi_data));
467 current_thread_info()->cpu = boot_cpuid;
469 smp_store_cpu_info(boot_cpuid);
470 smp_setup_percpu_timer(boot_cpuid);
472 /* Nothing to do on a UP box, or when told not to. */
473 if (smp_num_probed == 1 || max_cpus == 0) {
474 cpu_present_map = cpumask_of_cpu(boot_cpuid);
475 printk(KERN_INFO "SMP mode deactivated.\n");
476 return;
477 }
479 printk(KERN_INFO "SMP starting up secondaries.\n");
481 smp_num_cpus = smp_num_probed;
482 }
484 void __devinit
485 smp_prepare_boot_cpu(void)
486 {
487 }
489 int __devinit
490 __cpu_up(unsigned int cpu)
491 {
492 smp_boot_one_cpu(cpu);
494 return cpu_online(cpu) ? 0 : -ENOSYS;
495 }
497 void __init
498 smp_cpus_done(unsigned int max_cpus)
499 {
500 int cpu;
501 unsigned long bogosum = 0;
503 for(cpu = 0; cpu < NR_CPUS; cpu++)
504 if (cpu_online(cpu))
505 bogosum += cpu_data[cpu].loops_per_jiffy;
507 printk(KERN_INFO "SMP: Total of %d processors activated "
508 "(%lu.%02lu BogoMIPS).\n",
509 num_online_cpus(),
510 (bogosum + 2500) / (500000/HZ),
511 ((bogosum + 2500) / (5000/HZ)) % 100);
512 }
515 void
516 smp_percpu_timer_interrupt(struct pt_regs *regs)
517 {
518 int cpu = smp_processor_id();
519 unsigned long user = user_mode(regs);
520 struct cpuinfo_alpha *data = &cpu_data[cpu];
522 /* Record kernel PC. */
523 profile_tick(CPU_PROFILING, regs);
525 if (!--data->prof_counter) {
526 /* We need to make like a normal interrupt -- otherwise
527 timer interrupts ignore the global interrupt lock,
528 which would be a Bad Thing. */
529 irq_enter();
531 update_process_times(user);
533 data->prof_counter = data->prof_multiplier;
535 irq_exit();
536 }
537 }
539 int __init
540 setup_profiling_timer(unsigned int multiplier)
541 {
542 return -EINVAL;
543 }
546 static void
547 send_ipi_message(cpumask_t to_whom, enum ipi_message_type operation)
548 {
549 int i;
551 mb();
552 for_each_cpu_mask(i, to_whom)
553 set_bit(operation, &ipi_data[i].bits);
555 mb();
556 for_each_cpu_mask(i, to_whom)
557 wripir(i);
558 }
560 /* Structure and data for smp_call_function. This is designed to
561 minimize static memory requirements. Plus it looks cleaner. */
563 struct smp_call_struct {
564 void (*func) (void *info);
565 void *info;
566 long wait;
567 atomic_t unstarted_count;
568 atomic_t unfinished_count;
569 };
571 static struct smp_call_struct *smp_call_function_data;
573 /* Atomicly drop data into a shared pointer. The pointer is free if
574 it is initially locked. If retry, spin until free. */
576 static int
577 pointer_lock (void *lock, void *data, int retry)
578 {
579 void *old, *tmp;
581 mb();
582 again:
583 /* Compare and swap with zero. */
584 asm volatile (
585 "1: ldq_l %0,%1\n"
586 " mov %3,%2\n"
587 " bne %0,2f\n"
588 " stq_c %2,%1\n"
589 " beq %2,1b\n"
590 "2:"
591 : "=&r"(old), "=m"(*(void **)lock), "=&r"(tmp)
592 : "r"(data)
593 : "memory");
595 if (old == 0)
596 return 0;
597 if (! retry)
598 return -EBUSY;
600 while (*(void **)lock)
601 barrier();
602 goto again;
603 }
605 void
606 handle_ipi(struct pt_regs *regs)
607 {
608 int this_cpu = smp_processor_id();
609 unsigned long *pending_ipis = &ipi_data[this_cpu].bits;
610 unsigned long ops;
612 #if 0
613 DBGS(("handle_ipi: on CPU %d ops 0x%lx PC 0x%lx\n",
614 this_cpu, *pending_ipis, regs->pc));
615 #endif
617 mb(); /* Order interrupt and bit testing. */
618 while ((ops = xchg(pending_ipis, 0)) != 0) {
619 mb(); /* Order bit clearing and data access. */
620 do {
621 unsigned long which;
623 which = ops & -ops;
624 ops &= ~which;
625 which = __ffs(which);
627 switch (which) {
628 case IPI_RESCHEDULE:
629 /* Reschedule callback. Everything to be done
630 is done by the interrupt return path. */
631 break;
633 case IPI_CALL_FUNC:
634 {
635 struct smp_call_struct *data;
636 void (*func)(void *info);
637 void *info;
638 int wait;
640 data = smp_call_function_data;
641 func = data->func;
642 info = data->info;
643 wait = data->wait;
645 /* Notify the sending CPU that the data has been
646 received, and execution is about to begin. */
647 mb();
648 atomic_dec (&data->unstarted_count);
650 /* At this point the structure may be gone unless
651 wait is true. */
652 (*func)(info);
654 /* Notify the sending CPU that the task is done. */
655 mb();
656 if (wait) atomic_dec (&data->unfinished_count);
657 break;
658 }
660 case IPI_CPU_STOP:
661 halt();
663 default:
664 printk(KERN_CRIT "Unknown IPI on CPU %d: %lu\n",
665 this_cpu, which);
666 break;
667 }
668 } while (ops);
670 mb(); /* Order data access and bit testing. */
671 }
673 cpu_data[this_cpu].ipi_count++;
675 if (hwrpb->txrdy)
676 recv_secondary_console_msg();
677 }
679 void
680 smp_send_reschedule(int cpu)
681 {
682 #ifdef DEBUG_IPI_MSG
683 if (cpu == hard_smp_processor_id())
684 printk(KERN_WARNING
685 "smp_send_reschedule: Sending IPI to self.\n");
686 #endif
687 send_ipi_message(cpumask_of_cpu(cpu), IPI_RESCHEDULE);
688 }
690 void
691 smp_send_stop(void)
692 {
693 cpumask_t to_whom = cpu_possible_map;
694 cpu_clear(smp_processor_id(), to_whom);
695 #ifdef DEBUG_IPI_MSG
696 if (hard_smp_processor_id() != boot_cpu_id)
697 printk(KERN_WARNING "smp_send_stop: Not on boot cpu.\n");
698 #endif
699 send_ipi_message(to_whom, IPI_CPU_STOP);
700 }
702 /*
703 * Run a function on all other CPUs.
704 * <func> The function to run. This must be fast and non-blocking.
705 * <info> An arbitrary pointer to pass to the function.
706 * <retry> If true, keep retrying until ready.
707 * <wait> If true, wait until function has completed on other CPUs.
708 * [RETURNS] 0 on success, else a negative status code.
709 *
710 * Does not return until remote CPUs are nearly ready to execute <func>
711 * or are or have executed.
712 * You must not call this function with disabled interrupts or from a
713 * hardware interrupt handler or from a bottom half handler.
714 */
716 int
717 smp_call_function_on_cpu (void (*func) (void *info), void *info, int retry,
718 int wait, cpumask_t to_whom)
719 {
720 struct smp_call_struct data;
721 unsigned long timeout;
722 int num_cpus_to_call;
724 /* Can deadlock when called with interrupts disabled */
725 WARN_ON(irqs_disabled());
727 data.func = func;
728 data.info = info;
729 data.wait = wait;
731 cpu_clear(smp_processor_id(), to_whom);
732 num_cpus_to_call = cpus_weight(to_whom);
734 atomic_set(&data.unstarted_count, num_cpus_to_call);
735 atomic_set(&data.unfinished_count, num_cpus_to_call);
737 /* Acquire the smp_call_function_data mutex. */
738 if (pointer_lock(&smp_call_function_data, &data, retry))
739 return -EBUSY;
741 /* Send a message to the requested CPUs. */
742 send_ipi_message(to_whom, IPI_CALL_FUNC);
744 /* Wait for a minimal response. */
745 timeout = jiffies + HZ;
746 while (atomic_read (&data.unstarted_count) > 0
747 && time_before (jiffies, timeout))
748 barrier();
750 /* If there's no response yet, log a message but allow a longer
751 * timeout period -- if we get a response this time, log
752 * a message saying when we got it..
753 */
754 if (atomic_read(&data.unstarted_count) > 0) {
755 long start_time = jiffies;
756 printk(KERN_ERR "%s: initial timeout -- trying long wait\n",
757 __FUNCTION__);
758 timeout = jiffies + 30 * HZ;
759 while (atomic_read(&data.unstarted_count) > 0
760 && time_before(jiffies, timeout))
761 barrier();
762 if (atomic_read(&data.unstarted_count) <= 0) {
763 long delta = jiffies - start_time;
764 printk(KERN_ERR
765 "%s: response %ld.%ld seconds into long wait\n",
766 __FUNCTION__, delta / HZ,
767 (100 * (delta - ((delta / HZ) * HZ))) / HZ);
768 }
769 }
771 /* We either got one or timed out -- clear the lock. */
772 mb();
773 smp_call_function_data = NULL;
775 /*
776 * If after both the initial and long timeout periods we still don't
777 * have a response, something is very wrong...
778 */
779 BUG_ON(atomic_read (&data.unstarted_count) > 0);
781 /* Wait for a complete response, if needed. */
782 if (wait) {
783 while (atomic_read (&data.unfinished_count) > 0)
784 barrier();
785 }
787 return 0;
788 }
790 int
791 smp_call_function (void (*func) (void *info), void *info, int retry, int wait)
792 {
793 return smp_call_function_on_cpu (func, info, retry, wait,
794 cpu_online_map);
795 }
797 static void
798 ipi_imb(void *ignored)
799 {
800 imb();
801 }
803 void
804 smp_imb(void)
805 {
806 /* Must wait other processors to flush their icache before continue. */
807 if (on_each_cpu(ipi_imb, NULL, 1, 1))
808 printk(KERN_CRIT "smp_imb: timed out\n");
809 }
811 static void
812 ipi_flush_tlb_all(void *ignored)
813 {
814 tbia();
815 }
817 void
818 flush_tlb_all(void)
819 {
820 /* Although we don't have any data to pass, we do want to
821 synchronize with the other processors. */
822 if (on_each_cpu(ipi_flush_tlb_all, NULL, 1, 1)) {
823 printk(KERN_CRIT "flush_tlb_all: timed out\n");
824 }
825 }
827 #define asn_locked() (cpu_data[smp_processor_id()].asn_lock)
829 static void
830 ipi_flush_tlb_mm(void *x)
831 {
832 struct mm_struct *mm = (struct mm_struct *) x;
833 if (mm == current->active_mm && !asn_locked())
834 flush_tlb_current(mm);
835 else
836 flush_tlb_other(mm);
837 }
839 void
840 flush_tlb_mm(struct mm_struct *mm)
841 {
842 preempt_disable();
844 if (mm == current->active_mm) {
845 flush_tlb_current(mm);
846 if (atomic_read(&mm->mm_users) <= 1) {
847 int cpu, this_cpu = smp_processor_id();
848 for (cpu = 0; cpu < NR_CPUS; cpu++) {
849 if (!cpu_online(cpu) || cpu == this_cpu)
850 continue;
851 if (mm->context[cpu])
852 mm->context[cpu] = 0;
853 }
854 preempt_enable();
855 return;
856 }
857 }
859 if (smp_call_function(ipi_flush_tlb_mm, mm, 1, 1)) {
860 printk(KERN_CRIT "flush_tlb_mm: timed out\n");
861 }
863 preempt_enable();
864 }
866 struct flush_tlb_page_struct {
867 struct vm_area_struct *vma;
868 struct mm_struct *mm;
869 unsigned long addr;
870 };
872 static void
873 ipi_flush_tlb_page(void *x)
874 {
875 struct flush_tlb_page_struct *data = (struct flush_tlb_page_struct *)x;
876 struct mm_struct * mm = data->mm;
878 if (mm == current->active_mm && !asn_locked())
879 flush_tlb_current_page(mm, data->vma, data->addr);
880 else
881 flush_tlb_other(mm);
882 }
884 void
885 flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
886 {
887 struct flush_tlb_page_struct data;
888 struct mm_struct *mm = vma->vm_mm;
890 preempt_disable();
892 if (mm == current->active_mm) {
893 flush_tlb_current_page(mm, vma, addr);
894 if (atomic_read(&mm->mm_users) <= 1) {
895 int cpu, this_cpu = smp_processor_id();
896 for (cpu = 0; cpu < NR_CPUS; cpu++) {
897 if (!cpu_online(cpu) || cpu == this_cpu)
898 continue;
899 if (mm->context[cpu])
900 mm->context[cpu] = 0;
901 }
902 preempt_enable();
903 return;
904 }
905 }
907 data.vma = vma;
908 data.mm = mm;
909 data.addr = addr;
911 if (smp_call_function(ipi_flush_tlb_page, &data, 1, 1)) {
912 printk(KERN_CRIT "flush_tlb_page: timed out\n");
913 }
915 preempt_enable();
916 }
918 void
919 flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
920 {
921 /* On the Alpha we always flush the whole user tlb. */
922 flush_tlb_mm(vma->vm_mm);
923 }
925 static void
926 ipi_flush_icache_page(void *x)
927 {
928 struct mm_struct *mm = (struct mm_struct *) x;
929 if (mm == current->active_mm && !asn_locked())
930 __load_new_mm_context(mm);
931 else
932 flush_tlb_other(mm);
933 }
935 void
936 flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
937 unsigned long addr, int len)
938 {
939 struct mm_struct *mm = vma->vm_mm;
941 if ((vma->vm_flags & VM_EXEC) == 0)
942 return;
944 preempt_disable();
946 if (mm == current->active_mm) {
947 __load_new_mm_context(mm);
948 if (atomic_read(&mm->mm_users) <= 1) {
949 int cpu, this_cpu = smp_processor_id();
950 for (cpu = 0; cpu < NR_CPUS; cpu++) {
951 if (!cpu_online(cpu) || cpu == this_cpu)
952 continue;
953 if (mm->context[cpu])
954 mm->context[cpu] = 0;
955 }
956 preempt_enable();
957 return;
958 }
959 }
961 if (smp_call_function(ipi_flush_icache_page, mm, 1, 1)) {
962 printk(KERN_CRIT "flush_icache_page: timed out\n");
963 }
965 preempt_enable();
966 }