1 /* smp.c: Sparc64 SMP support.
3 * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
6 #include <linux/module.h>
7 #include <linux/kernel.h>
8 #include <linux/sched.h>
10 #include <linux/pagemap.h>
11 #include <linux/threads.h>
12 #include <linux/smp.h>
13 #include <linux/smp_lock.h>
14 #include <linux/interrupt.h>
15 #include <linux/kernel_stat.h>
16 #include <linux/delay.h>
17 #include <linux/init.h>
18 #include <linux/spinlock.h>
20 #include <linux/seq_file.h>
21 #include <linux/cache.h>
22 #include <linux/jiffies.h>
23 #include <linux/profile.h>
24 #include <linux/bootmem.h>
27 #include <asm/ptrace.h>
28 #include <asm/atomic.h>
29 #include <asm/tlbflush.h>
30 #include <asm/mmu_context.h>
31 #include <asm/cpudata.h>
35 #include <asm/pgtable.h>
36 #include <asm/oplib.h>
37 #include <asm/uaccess.h>
38 #include <asm/timer.h>
39 #include <asm/starfire.h>
41 #include <asm/sections.h>
43 extern void calibrate_delay(void);
45 /* Please don't make this stuff initdata!!! --DaveM */
46 static unsigned char boot_cpu_id;
48 cpumask_t cpu_online_map __read_mostly = CPU_MASK_NONE;
49 cpumask_t phys_cpu_present_map __read_mostly = CPU_MASK_NONE;
50 static cpumask_t smp_commenced_mask;
51 static cpumask_t cpu_callout_map;
53 void smp_info(struct seq_file *m)
57 seq_printf(m, "State:\n");
58 for (i = 0; i < NR_CPUS; i++) {
61 "CPU%d:\t\tonline\n", i);
65 void smp_bogo(struct seq_file *m)
69 for (i = 0; i < NR_CPUS; i++)
72 "Cpu%dBogo\t: %lu.%02lu\n"
73 "Cpu%dClkTck\t: %016lx\n",
74 i, cpu_data(i).udelay_val / (500000/HZ),
75 (cpu_data(i).udelay_val / (5000/HZ)) % 100,
76 i, cpu_data(i).clock_tick);
79 void __init smp_store_cpu_info(int id)
83 /* multiplier and counter set by
84 smp_setup_percpu_timer() */
85 cpu_data(id).udelay_val = loops_per_jiffy;
87 cpu_find_by_mid(id, &cpu_node);
88 cpu_data(id).clock_tick = prom_getintdefault(cpu_node,
89 "clock-frequency", 0);
91 cpu_data(id).idle_volume = 1;
93 def = ((tlb_type == hypervisor) ? (8 * 1024) : (16 * 1024));
94 cpu_data(id).dcache_size = prom_getintdefault(cpu_node, "dcache-size",
98 cpu_data(id).dcache_line_size =
99 prom_getintdefault(cpu_node, "dcache-line-size", def);
102 cpu_data(id).icache_size = prom_getintdefault(cpu_node, "icache-size",
106 cpu_data(id).icache_line_size =
107 prom_getintdefault(cpu_node, "icache-line-size", def);
109 def = ((tlb_type == hypervisor) ?
112 cpu_data(id).ecache_size = prom_getintdefault(cpu_node, "ecache-size",
116 cpu_data(id).ecache_line_size =
117 prom_getintdefault(cpu_node, "ecache-line-size", def);
119 printk("CPU[%d]: Caches "
120 "D[sz(%d):line_sz(%d)] "
121 "I[sz(%d):line_sz(%d)] "
122 "E[sz(%d):line_sz(%d)]\n",
124 cpu_data(id).dcache_size, cpu_data(id).dcache_line_size,
125 cpu_data(id).icache_size, cpu_data(id).icache_line_size,
126 cpu_data(id).ecache_size, cpu_data(id).ecache_line_size);
129 static void smp_setup_percpu_timer(void);
131 static volatile unsigned long callin_flag = 0;
133 void __init smp_callin(void)
135 int cpuid = hard_smp_processor_id();
137 __local_per_cpu_offset = __per_cpu_offset(cpuid);
139 if (tlb_type == hypervisor)
140 sun4v_ktsb_register();
144 smp_setup_percpu_timer();
146 if (cheetah_pcache_forced_on)
147 cheetah_enable_pcache();
152 smp_store_cpu_info(cpuid);
154 __asm__ __volatile__("membar #Sync\n\t"
155 "flush %%g6" : : : "memory");
157 /* Clear this or we will die instantly when we
158 * schedule back to this idler...
160 current_thread_info()->new_child = 0;
162 /* Attach to the address space of init_task. */
163 atomic_inc(&init_mm.mm_count);
164 current->active_mm = &init_mm;
166 while (!cpu_isset(cpuid, smp_commenced_mask))
169 cpu_set(cpuid, cpu_online_map);
171 /* idle thread is expected to have preempt disabled */
177 printk("CPU[%d]: Returns from cpu_idle!\n", smp_processor_id());
178 panic("SMP bolixed\n");
181 static unsigned long current_tick_offset __read_mostly;
183 /* This tick register synchronization scheme is taken entirely from
184 * the ia64 port, see arch/ia64/kernel/smpboot.c for details and credit.
186 * The only change I've made is to rework it so that the master
187 * initiates the synchonization instead of the slave. -DaveM
191 #define SLAVE (SMP_CACHE_BYTES/sizeof(unsigned long))
193 #define NUM_ROUNDS 64 /* magic value */
194 #define NUM_ITERS 5 /* likewise */
196 static DEFINE_SPINLOCK(itc_sync_lock);
197 static unsigned long go[SLAVE + 1];
199 #define DEBUG_TICK_SYNC 0
201 static inline long get_delta (long *rt, long *master)
203 unsigned long best_t0 = 0, best_t1 = ~0UL, best_tm = 0;
204 unsigned long tcenter, t0, t1, tm;
207 for (i = 0; i < NUM_ITERS; i++) {
208 t0 = tick_ops->get_tick();
211 while (!(tm = go[SLAVE]))
215 t1 = tick_ops->get_tick();
217 if (t1 - t0 < best_t1 - best_t0)
218 best_t0 = t0, best_t1 = t1, best_tm = tm;
221 *rt = best_t1 - best_t0;
222 *master = best_tm - best_t0;
224 /* average best_t0 and best_t1 without overflow: */
225 tcenter = (best_t0/2 + best_t1/2);
226 if (best_t0 % 2 + best_t1 % 2 == 2)
228 return tcenter - best_tm;
231 void smp_synchronize_tick_client(void)
233 long i, delta, adj, adjust_latency = 0, done = 0;
234 unsigned long flags, rt, master_time_stamp, bound;
237 long rt; /* roundtrip time */
238 long master; /* master's timestamp */
239 long diff; /* difference between midpoint and master's timestamp */
240 long lat; /* estimate of itc adjustment latency */
249 local_irq_save(flags);
251 for (i = 0; i < NUM_ROUNDS; i++) {
252 delta = get_delta(&rt, &master_time_stamp);
254 done = 1; /* let's lock on to this... */
260 adjust_latency += -delta;
261 adj = -delta + adjust_latency/4;
265 tick_ops->add_tick(adj, current_tick_offset);
269 t[i].master = master_time_stamp;
271 t[i].lat = adjust_latency/4;
275 local_irq_restore(flags);
278 for (i = 0; i < NUM_ROUNDS; i++)
279 printk("rt=%5ld master=%5ld diff=%5ld adjlat=%5ld\n",
280 t[i].rt, t[i].master, t[i].diff, t[i].lat);
283 printk(KERN_INFO "CPU %d: synchronized TICK with master CPU (last diff %ld cycles,"
284 "maxerr %lu cycles)\n", smp_processor_id(), delta, rt);
287 static void smp_start_sync_tick_client(int cpu);
289 static void smp_synchronize_one_tick(int cpu)
291 unsigned long flags, i;
295 smp_start_sync_tick_client(cpu);
297 /* wait for client to be ready */
301 /* now let the client proceed into his loop */
305 spin_lock_irqsave(&itc_sync_lock, flags);
307 for (i = 0; i < NUM_ROUNDS*NUM_ITERS; i++) {
312 go[SLAVE] = tick_ops->get_tick();
316 spin_unlock_irqrestore(&itc_sync_lock, flags);
319 extern unsigned long sparc64_cpu_startup;
321 /* The OBP cpu startup callback truncates the 3rd arg cookie to
322 * 32-bits (I think) so to be safe we have it read the pointer
323 * contained here so we work on >4GB machines. -DaveM
325 static struct thread_info *cpu_new_thread = NULL;
327 static int __devinit smp_boot_one_cpu(unsigned int cpu)
329 unsigned long entry =
330 (unsigned long)(&sparc64_cpu_startup);
331 unsigned long cookie =
332 (unsigned long)(&cpu_new_thread);
333 struct task_struct *p;
338 cpu_new_thread = task_thread_info(p);
339 cpu_set(cpu, cpu_callout_map);
341 if (tlb_type == hypervisor) {
342 prom_startcpu_cpuid(cpu, entry, cookie);
346 cpu_find_by_mid(cpu, &cpu_node);
347 prom_startcpu(cpu_node, entry, cookie);
350 for (timeout = 0; timeout < 5000000; timeout++) {
358 printk("Processor %d is stuck.\n", cpu);
359 cpu_clear(cpu, cpu_callout_map);
362 cpu_new_thread = NULL;
367 static void spitfire_xcall_helper(u64 data0, u64 data1, u64 data2, u64 pstate, unsigned long cpu)
372 if (this_is_starfire) {
373 /* map to real upaid */
374 cpu = (((cpu & 0x3c) << 1) |
375 ((cpu & 0x40) >> 4) |
379 target = (cpu << 14) | 0x70;
381 /* Ok, this is the real Spitfire Errata #54.
382 * One must read back from a UDB internal register
383 * after writes to the UDB interrupt dispatch, but
384 * before the membar Sync for that write.
385 * So we use the high UDB control register (ASI 0x7f,
386 * ADDR 0x20) for the dummy read. -DaveM
389 __asm__ __volatile__(
390 "wrpr %1, %2, %%pstate\n\t"
391 "stxa %4, [%0] %3\n\t"
392 "stxa %5, [%0+%8] %3\n\t"
394 "stxa %6, [%0+%8] %3\n\t"
396 "stxa %%g0, [%7] %3\n\t"
399 "ldxa [%%g1] 0x7f, %%g0\n\t"
402 : "r" (pstate), "i" (PSTATE_IE), "i" (ASI_INTR_W),
403 "r" (data0), "r" (data1), "r" (data2), "r" (target),
404 "r" (0x10), "0" (tmp)
407 /* NOTE: PSTATE_IE is still clear. */
410 __asm__ __volatile__("ldxa [%%g0] %1, %0"
412 : "i" (ASI_INTR_DISPATCH_STAT));
414 __asm__ __volatile__("wrpr %0, 0x0, %%pstate"
421 } while (result & 0x1);
422 __asm__ __volatile__("wrpr %0, 0x0, %%pstate"
425 printk("CPU[%d]: mondo stuckage result[%016lx]\n",
426 smp_processor_id(), result);
433 static __inline__ void spitfire_xcall_deliver(u64 data0, u64 data1, u64 data2, cpumask_t mask)
438 __asm__ __volatile__("rdpr %%pstate, %0" : "=r" (pstate));
439 for_each_cpu_mask(i, mask)
440 spitfire_xcall_helper(data0, data1, data2, pstate, i);
443 /* Cheetah now allows to send the whole 64-bytes of data in the interrupt
444 * packet, but we have no use for that. However we do take advantage of
445 * the new pipelining feature (ie. dispatch to multiple cpus simultaneously).
447 static void cheetah_xcall_deliver(u64 data0, u64 data1, u64 data2, cpumask_t mask)
450 int nack_busy_id, is_jbus;
452 if (cpus_empty(mask))
455 /* Unfortunately, someone at Sun had the brilliant idea to make the
456 * busy/nack fields hard-coded by ITID number for this Ultra-III
457 * derivative processor.
459 __asm__ ("rdpr %%ver, %0" : "=r" (ver));
460 is_jbus = ((ver >> 32) == __JALAPENO_ID ||
461 (ver >> 32) == __SERRANO_ID);
463 __asm__ __volatile__("rdpr %%pstate, %0" : "=r" (pstate));
466 __asm__ __volatile__("wrpr %0, %1, %%pstate\n\t"
467 : : "r" (pstate), "i" (PSTATE_IE));
469 /* Setup the dispatch data registers. */
470 __asm__ __volatile__("stxa %0, [%3] %6\n\t"
471 "stxa %1, [%4] %6\n\t"
472 "stxa %2, [%5] %6\n\t"
475 : "r" (data0), "r" (data1), "r" (data2),
476 "r" (0x40), "r" (0x50), "r" (0x60),
483 for_each_cpu_mask(i, mask) {
484 u64 target = (i << 14) | 0x70;
487 target |= (nack_busy_id << 24);
488 __asm__ __volatile__(
489 "stxa %%g0, [%0] %1\n\t"
492 : "r" (target), "i" (ASI_INTR_W));
497 /* Now, poll for completion. */
502 stuck = 100000 * nack_busy_id;
504 __asm__ __volatile__("ldxa [%%g0] %1, %0"
505 : "=r" (dispatch_stat)
506 : "i" (ASI_INTR_DISPATCH_STAT));
507 if (dispatch_stat == 0UL) {
508 __asm__ __volatile__("wrpr %0, 0x0, %%pstate"
514 } while (dispatch_stat & 0x5555555555555555UL);
516 __asm__ __volatile__("wrpr %0, 0x0, %%pstate"
519 if ((dispatch_stat & ~(0x5555555555555555UL)) == 0) {
520 /* Busy bits will not clear, continue instead
521 * of freezing up on this cpu.
523 printk("CPU[%d]: mondo stuckage result[%016lx]\n",
524 smp_processor_id(), dispatch_stat);
526 int i, this_busy_nack = 0;
528 /* Delay some random time with interrupts enabled
529 * to prevent deadlock.
531 udelay(2 * nack_busy_id);
533 /* Clear out the mask bits for cpus which did not
536 for_each_cpu_mask(i, mask) {
540 check_mask = (0x2UL << (2*i));
542 check_mask = (0x2UL <<
544 if ((dispatch_stat & check_mask) == 0)
555 /* Multi-cpu list version. */
556 static int init_cpu_list(u16 *list, cpumask_t mask)
561 for_each_cpu_mask(i, mask)
567 static int update_cpu_list(u16 *list, int orig_cnt, cpumask_t mask)
571 for (i = 0; i < orig_cnt; i++) {
572 if (list[i] == 0xffff)
576 return init_cpu_list(list, mask);
579 static void hypervisor_xcall_deliver(u64 data0, u64 data1, u64 data2, cpumask_t mask)
581 int this_cpu = get_cpu();
582 struct trap_per_cpu *tb = &trap_block[this_cpu];
583 u64 *mondo = __va(tb->cpu_mondo_block_pa);
584 u16 *cpu_list = __va(tb->cpu_list_pa);
593 cnt = init_cpu_list(cpu_list, mask);
595 register unsigned long func __asm__("%o5");
596 register unsigned long arg0 __asm__("%o0");
597 register unsigned long arg1 __asm__("%o1");
598 register unsigned long arg2 __asm__("%o2");
600 func = HV_FAST_CPU_MONDO_SEND;
602 arg1 = tb->cpu_list_pa;
603 arg2 = tb->cpu_mondo_block_pa;
605 __asm__ __volatile__("ta %8"
606 : "=&r" (func), "=&r" (arg0),
607 "=&r" (arg1), "=&r" (arg2)
608 : "0" (func), "1" (arg0),
609 "2" (arg1), "3" (arg2),
612 if (likely(arg0 == HV_EOK))
615 if (unlikely(++retries > 100)) {
616 printk("CPU[%d]: sun4v mondo error %lu\n",
621 cnt = update_cpu_list(cpu_list, cnt, mask);
629 /* Single-cpu list version. */
630 static void hypervisor_xcall_deliver(u64 data0, u64 data1, u64 data2, cpumask_t mask)
632 int this_cpu = get_cpu();
633 struct trap_per_cpu *tb = &trap_block[this_cpu];
634 u64 *mondo = __va(tb->cpu_mondo_block_pa);
635 u16 *cpu_list = __va(tb->cpu_list_pa);
643 for_each_cpu_mask(i, mask) {
647 register unsigned long func __asm__("%o5");
648 register unsigned long arg0 __asm__("%o0");
649 register unsigned long arg1 __asm__("%o1");
650 register unsigned long arg2 __asm__("%o2");
653 func = HV_FAST_CPU_MONDO_SEND;
655 arg1 = tb->cpu_list_pa;
656 arg2 = tb->cpu_mondo_block_pa;
658 __asm__ __volatile__("ta %8"
659 : "=&r" (func), "=&r" (arg0),
660 "=&r" (arg1), "=&r" (arg2)
661 : "0" (func), "1" (arg0),
662 "2" (arg1), "3" (arg2),
665 if (likely(arg0 == HV_EOK))
668 if (unlikely(++retries > 100)) {
669 printk("CPU[%d]: sun4v mondo error %lu\n",
682 /* Send cross call to all processors mentioned in MASK
685 static void smp_cross_call_masked(unsigned long *func, u32 ctx, u64 data1, u64 data2, cpumask_t mask)
687 u64 data0 = (((u64)ctx)<<32 | (((u64)func) & 0xffffffff));
688 int this_cpu = get_cpu();
690 cpus_and(mask, mask, cpu_online_map);
691 cpu_clear(this_cpu, mask);
693 if (tlb_type == spitfire)
694 spitfire_xcall_deliver(data0, data1, data2, mask);
695 else if (tlb_type == cheetah || tlb_type == cheetah_plus)
696 cheetah_xcall_deliver(data0, data1, data2, mask);
698 hypervisor_xcall_deliver(data0, data1, data2, mask);
699 /* NOTE: Caller runs local copy on master. */
704 extern unsigned long xcall_sync_tick;
706 static void smp_start_sync_tick_client(int cpu)
708 cpumask_t mask = cpumask_of_cpu(cpu);
710 smp_cross_call_masked(&xcall_sync_tick,
714 /* Send cross call to all processors except self. */
715 #define smp_cross_call(func, ctx, data1, data2) \
716 smp_cross_call_masked(func, ctx, data1, data2, cpu_online_map)
718 struct call_data_struct {
719 void (*func) (void *info);
725 static DEFINE_SPINLOCK(call_lock);
726 static struct call_data_struct *call_data;
728 extern unsigned long xcall_call_function;
731 * You must not call this function with disabled interrupts or from a
732 * hardware interrupt handler or from a bottom half handler.
734 static int smp_call_function_mask(void (*func)(void *info), void *info,
735 int nonatomic, int wait, cpumask_t mask)
737 struct call_data_struct data;
738 int cpus = cpus_weight(mask) - 1;
744 /* Can deadlock when called with interrupts disabled */
745 WARN_ON(irqs_disabled());
749 atomic_set(&data.finished, 0);
752 spin_lock(&call_lock);
756 smp_cross_call_masked(&xcall_call_function, 0, 0, 0, mask);
759 * Wait for other cpus to complete function or at
760 * least snap the call data.
763 while (atomic_read(&data.finished) != cpus) {
770 spin_unlock(&call_lock);
775 spin_unlock(&call_lock);
776 printk("XCALL: Remote cpus not responding, ncpus=%ld finished=%ld\n",
777 (long) num_online_cpus() - 1L,
778 (long) atomic_read(&data.finished));
782 int smp_call_function(void (*func)(void *info), void *info,
783 int nonatomic, int wait)
785 return smp_call_function_mask(func, info, nonatomic, wait,
789 void smp_call_function_client(int irq, struct pt_regs *regs)
791 void (*func) (void *info) = call_data->func;
792 void *info = call_data->info;
794 clear_softint(1 << irq);
795 if (call_data->wait) {
796 /* let initiator proceed only after completion */
798 atomic_inc(&call_data->finished);
800 /* let initiator proceed after getting data */
801 atomic_inc(&call_data->finished);
806 static void tsb_sync(void *info)
808 struct mm_struct *mm = info;
810 if (current->active_mm == mm)
811 tsb_context_switch(mm);
814 void smp_tsb_sync(struct mm_struct *mm)
816 smp_call_function_mask(tsb_sync, mm, 0, 1, mm->cpu_vm_mask);
819 extern unsigned long xcall_flush_tlb_mm;
820 extern unsigned long xcall_flush_tlb_pending;
821 extern unsigned long xcall_flush_tlb_kernel_range;
822 extern unsigned long xcall_report_regs;
823 extern unsigned long xcall_receive_signal;
825 #ifdef DCACHE_ALIASING_POSSIBLE
826 extern unsigned long xcall_flush_dcache_page_cheetah;
828 extern unsigned long xcall_flush_dcache_page_spitfire;
830 #ifdef CONFIG_DEBUG_DCFLUSH
831 extern atomic_t dcpage_flushes;
832 extern atomic_t dcpage_flushes_xcall;
835 static __inline__ void __local_flush_dcache_page(struct page *page)
837 #ifdef DCACHE_ALIASING_POSSIBLE
838 __flush_dcache_page(page_address(page),
839 ((tlb_type == spitfire) &&
840 page_mapping(page) != NULL));
842 if (page_mapping(page) != NULL &&
843 tlb_type == spitfire)
844 __flush_icache_page(__pa(page_address(page)));
848 void smp_flush_dcache_page_impl(struct page *page, int cpu)
850 cpumask_t mask = cpumask_of_cpu(cpu);
853 if (tlb_type == hypervisor)
856 #ifdef CONFIG_DEBUG_DCFLUSH
857 atomic_inc(&dcpage_flushes);
860 this_cpu = get_cpu();
862 if (cpu == this_cpu) {
863 __local_flush_dcache_page(page);
864 } else if (cpu_online(cpu)) {
865 void *pg_addr = page_address(page);
868 if (tlb_type == spitfire) {
870 ((u64)&xcall_flush_dcache_page_spitfire);
871 if (page_mapping(page) != NULL)
872 data0 |= ((u64)1 << 32);
873 spitfire_xcall_deliver(data0,
877 } else if (tlb_type == cheetah || tlb_type == cheetah_plus) {
878 #ifdef DCACHE_ALIASING_POSSIBLE
880 ((u64)&xcall_flush_dcache_page_cheetah);
881 cheetah_xcall_deliver(data0,
886 #ifdef CONFIG_DEBUG_DCFLUSH
887 atomic_inc(&dcpage_flushes_xcall);
894 void flush_dcache_page_all(struct mm_struct *mm, struct page *page)
896 void *pg_addr = page_address(page);
897 cpumask_t mask = cpu_online_map;
901 if (tlb_type == hypervisor)
904 this_cpu = get_cpu();
906 cpu_clear(this_cpu, mask);
908 #ifdef CONFIG_DEBUG_DCFLUSH
909 atomic_inc(&dcpage_flushes);
911 if (cpus_empty(mask))
913 if (tlb_type == spitfire) {
914 data0 = ((u64)&xcall_flush_dcache_page_spitfire);
915 if (page_mapping(page) != NULL)
916 data0 |= ((u64)1 << 32);
917 spitfire_xcall_deliver(data0,
921 } else if (tlb_type == cheetah || tlb_type == cheetah_plus) {
922 #ifdef DCACHE_ALIASING_POSSIBLE
923 data0 = ((u64)&xcall_flush_dcache_page_cheetah);
924 cheetah_xcall_deliver(data0,
929 #ifdef CONFIG_DEBUG_DCFLUSH
930 atomic_inc(&dcpage_flushes_xcall);
933 __local_flush_dcache_page(page);
938 void smp_receive_signal(int cpu)
940 cpumask_t mask = cpumask_of_cpu(cpu);
942 if (cpu_online(cpu)) {
943 u64 data0 = (((u64)&xcall_receive_signal) & 0xffffffff);
945 if (tlb_type == spitfire)
946 spitfire_xcall_deliver(data0, 0, 0, mask);
947 else if (tlb_type == cheetah || tlb_type == cheetah_plus)
948 cheetah_xcall_deliver(data0, 0, 0, mask);
949 else if (tlb_type == hypervisor)
950 hypervisor_xcall_deliver(data0, 0, 0, mask);
954 void smp_receive_signal_client(int irq, struct pt_regs *regs)
956 /* Just return, rtrap takes care of the rest. */
957 clear_softint(1 << irq);
960 void smp_report_regs(void)
962 smp_cross_call(&xcall_report_regs, 0, 0, 0);
965 /* We know that the window frames of the user have been flushed
966 * to the stack before we get here because all callers of us
967 * are flush_tlb_*() routines, and these run after flush_cache_*()
968 * which performs the flushw.
970 * The SMP TLB coherency scheme we use works as follows:
972 * 1) mm->cpu_vm_mask is a bit mask of which cpus an address
973 * space has (potentially) executed on, this is the heuristic
974 * we use to avoid doing cross calls.
976 * Also, for flushing from kswapd and also for clones, we
977 * use cpu_vm_mask as the list of cpus to make run the TLB.
979 * 2) TLB context numbers are shared globally across all processors
980 * in the system, this allows us to play several games to avoid
983 * One invariant is that when a cpu switches to a process, and
984 * that processes tsk->active_mm->cpu_vm_mask does not have the
985 * current cpu's bit set, that tlb context is flushed locally.
987 * If the address space is non-shared (ie. mm->count == 1) we avoid
988 * cross calls when we want to flush the currently running process's
989 * tlb state. This is done by clearing all cpu bits except the current
990 * processor's in current->active_mm->cpu_vm_mask and performing the
991 * flush locally only. This will force any subsequent cpus which run
992 * this task to flush the context from the local tlb if the process
993 * migrates to another cpu (again).
995 * 3) For shared address spaces (threads) and swapping we bite the
996 * bullet for most cases and perform the cross call (but only to
997 * the cpus listed in cpu_vm_mask).
999 * The performance gain from "optimizing" away the cross call for threads is
1000 * questionable (in theory the big win for threads is the massive sharing of
1001 * address space state across processors).
1004 /* This currently is only used by the hugetlb arch pre-fault
1005 * hook on UltraSPARC-III+ and later when changing the pagesize
1006 * bits of the context register for an address space.
1008 void smp_flush_tlb_mm(struct mm_struct *mm)
1010 u32 ctx = CTX_HWBITS(mm->context);
1011 int cpu = get_cpu();
1013 if (atomic_read(&mm->mm_users) == 1) {
1014 mm->cpu_vm_mask = cpumask_of_cpu(cpu);
1015 goto local_flush_and_out;
1018 smp_cross_call_masked(&xcall_flush_tlb_mm,
1022 local_flush_and_out:
1023 __flush_tlb_mm(ctx, SECONDARY_CONTEXT);
1028 void smp_flush_tlb_pending(struct mm_struct *mm, unsigned long nr, unsigned long *vaddrs)
1030 u32 ctx = CTX_HWBITS(mm->context);
1031 int cpu = get_cpu();
1033 if (mm == current->active_mm && atomic_read(&mm->mm_users) == 1)
1034 mm->cpu_vm_mask = cpumask_of_cpu(cpu);
1036 smp_cross_call_masked(&xcall_flush_tlb_pending,
1037 ctx, nr, (unsigned long) vaddrs,
1040 __flush_tlb_pending(ctx, nr, vaddrs);
1045 void smp_flush_tlb_kernel_range(unsigned long start, unsigned long end)
1048 end = PAGE_ALIGN(end);
1050 smp_cross_call(&xcall_flush_tlb_kernel_range,
1053 __flush_tlb_kernel_range(start, end);
1058 /* #define CAPTURE_DEBUG */
1059 extern unsigned long xcall_capture;
1061 static atomic_t smp_capture_depth = ATOMIC_INIT(0);
1062 static atomic_t smp_capture_registry = ATOMIC_INIT(0);
1063 static unsigned long penguins_are_doing_time;
1065 void smp_capture(void)
1067 int result = atomic_add_ret(1, &smp_capture_depth);
1070 int ncpus = num_online_cpus();
1072 #ifdef CAPTURE_DEBUG
1073 printk("CPU[%d]: Sending penguins to jail...",
1074 smp_processor_id());
1076 penguins_are_doing_time = 1;
1077 membar_storestore_loadstore();
1078 atomic_inc(&smp_capture_registry);
1079 smp_cross_call(&xcall_capture, 0, 0, 0);
1080 while (atomic_read(&smp_capture_registry) != ncpus)
1082 #ifdef CAPTURE_DEBUG
1088 void smp_release(void)
1090 if (atomic_dec_and_test(&smp_capture_depth)) {
1091 #ifdef CAPTURE_DEBUG
1092 printk("CPU[%d]: Giving pardon to "
1093 "imprisoned penguins\n",
1094 smp_processor_id());
1096 penguins_are_doing_time = 0;
1097 membar_storeload_storestore();
1098 atomic_dec(&smp_capture_registry);
1102 /* Imprisoned penguins run with %pil == 15, but PSTATE_IE set, so they
1103 * can service tlb flush xcalls...
1105 extern void prom_world(int);
1107 void smp_penguin_jailcell(int irq, struct pt_regs *regs)
1109 clear_softint(1 << irq);
1113 __asm__ __volatile__("flushw");
1115 atomic_inc(&smp_capture_registry);
1116 membar_storeload_storestore();
1117 while (penguins_are_doing_time)
1119 atomic_dec(&smp_capture_registry);
1125 #define prof_multiplier(__cpu) cpu_data(__cpu).multiplier
1126 #define prof_counter(__cpu) cpu_data(__cpu).counter
1128 void smp_percpu_timer_interrupt(struct pt_regs *regs)
1130 unsigned long compare, tick, pstate;
1131 int cpu = smp_processor_id();
1132 int user = user_mode(regs);
1135 * Check for level 14 softint.
1138 unsigned long tick_mask = tick_ops->softint_mask;
1140 if (!(get_softint() & tick_mask)) {
1141 extern void handler_irq(int, struct pt_regs *);
1143 handler_irq(14, regs);
1146 clear_softint(tick_mask);
1150 profile_tick(CPU_PROFILING, regs);
1151 if (!--prof_counter(cpu)) {
1154 if (cpu == boot_cpu_id) {
1155 kstat_this_cpu.irqs[0]++;
1156 timer_tick_interrupt(regs);
1159 update_process_times(user);
1163 prof_counter(cpu) = prof_multiplier(cpu);
1166 /* Guarantee that the following sequences execute
1169 __asm__ __volatile__("rdpr %%pstate, %0\n\t"
1170 "wrpr %0, %1, %%pstate"
1174 compare = tick_ops->add_compare(current_tick_offset);
1175 tick = tick_ops->get_tick();
1177 /* Restore PSTATE_IE. */
1178 __asm__ __volatile__("wrpr %0, 0x0, %%pstate"
1181 } while (time_after_eq(tick, compare));
1184 static void __init smp_setup_percpu_timer(void)
1186 int cpu = smp_processor_id();
1187 unsigned long pstate;
1189 prof_counter(cpu) = prof_multiplier(cpu) = 1;
1191 /* Guarantee that the following sequences execute
1194 __asm__ __volatile__("rdpr %%pstate, %0\n\t"
1195 "wrpr %0, %1, %%pstate"
1199 tick_ops->init_tick(current_tick_offset);
1201 /* Restore PSTATE_IE. */
1202 __asm__ __volatile__("wrpr %0, 0x0, %%pstate"
1207 void __init smp_tick_init(void)
1209 boot_cpu_id = hard_smp_processor_id();
1210 current_tick_offset = timer_tick_offset;
1212 cpu_set(boot_cpu_id, cpu_online_map);
1213 prof_counter(boot_cpu_id) = prof_multiplier(boot_cpu_id) = 1;
1216 /* /proc/profile writes can call this, don't __init it please. */
1217 static DEFINE_SPINLOCK(prof_setup_lock);
1219 int setup_profiling_timer(unsigned int multiplier)
1221 unsigned long flags;
1224 if ((!multiplier) || (timer_tick_offset / multiplier) < 1000)
1227 spin_lock_irqsave(&prof_setup_lock, flags);
1228 for (i = 0; i < NR_CPUS; i++)
1229 prof_multiplier(i) = multiplier;
1230 current_tick_offset = (timer_tick_offset / multiplier);
1231 spin_unlock_irqrestore(&prof_setup_lock, flags);
1236 /* Constrain the number of cpus to max_cpus. */
1237 void __init smp_prepare_cpus(unsigned int max_cpus)
1239 if (num_possible_cpus() > max_cpus) {
1243 while (!cpu_find_by_instance(instance, NULL, &mid)) {
1244 if (mid != boot_cpu_id) {
1245 cpu_clear(mid, phys_cpu_present_map);
1246 if (num_possible_cpus() <= max_cpus)
1253 smp_store_cpu_info(boot_cpu_id);
1256 /* Set this up early so that things like the scheduler can init
1257 * properly. We use the same cpu mask for both the present and
1260 void __init smp_setup_cpu_possible_map(void)
1265 while (!cpu_find_by_instance(instance, NULL, &mid)) {
1267 cpu_set(mid, phys_cpu_present_map);
1272 void __devinit smp_prepare_boot_cpu(void)
1274 int cpu = hard_smp_processor_id();
1276 if (cpu >= NR_CPUS) {
1277 prom_printf("Serious problem, boot cpu id >= NR_CPUS\n");
1281 current_thread_info()->cpu = cpu;
1282 __local_per_cpu_offset = __per_cpu_offset(cpu);
1284 cpu_set(smp_processor_id(), cpu_online_map);
1285 cpu_set(smp_processor_id(), phys_cpu_present_map);
1288 int __devinit __cpu_up(unsigned int cpu)
1290 int ret = smp_boot_one_cpu(cpu);
1293 cpu_set(cpu, smp_commenced_mask);
1294 while (!cpu_isset(cpu, cpu_online_map))
1296 if (!cpu_isset(cpu, cpu_online_map)) {
1299 /* On SUN4V, writes to %tick and %stick are
1302 if (tlb_type != hypervisor)
1303 smp_synchronize_one_tick(cpu);
1309 void __init smp_cpus_done(unsigned int max_cpus)
1311 unsigned long bogosum = 0;
1314 for (i = 0; i < NR_CPUS; i++) {
1316 bogosum += cpu_data(i).udelay_val;
1318 printk("Total of %ld processors activated "
1319 "(%lu.%02lu BogoMIPS).\n",
1320 (long) num_online_cpus(),
1321 bogosum/(500000/HZ),
1322 (bogosum/(5000/HZ))%100);
1325 void smp_send_reschedule(int cpu)
1327 smp_receive_signal(cpu);
1330 /* This is a nop because we capture all other cpus
1331 * anyways when making the PROM active.
1333 void smp_send_stop(void)
1337 unsigned long __per_cpu_base __read_mostly;
1338 unsigned long __per_cpu_shift __read_mostly;
1340 EXPORT_SYMBOL(__per_cpu_base);
1341 EXPORT_SYMBOL(__per_cpu_shift);
1343 void __init setup_per_cpu_areas(void)
1345 unsigned long goal, size, i;
1348 /* Copy section for each CPU (we discard the original) */
1349 goal = ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES);
1350 #ifdef CONFIG_MODULES
1351 if (goal < PERCPU_ENOUGH_ROOM)
1352 goal = PERCPU_ENOUGH_ROOM;
1354 __per_cpu_shift = 0;
1355 for (size = 1UL; size < goal; size <<= 1UL)
1358 ptr = alloc_bootmem(size * NR_CPUS);
1360 __per_cpu_base = ptr - __per_cpu_start;
1362 for (i = 0; i < NR_CPUS; i++, ptr += size)
1363 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);