URL
https://opencores.org/ocsvn/or1k/or1k/trunk
Subversion Repositories or1k
[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [arch/] [sparc64/] [kernel/] [smp.c] - Rev 1275
Go to most recent revision | Compare with Previous | Blame | View Log
/* smp.c: Sparc64 SMP support. * * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu) */ #include <linux/kernel.h> #include <linux/sched.h> #include <linux/mm.h> #include <linux/pagemap.h> #include <linux/threads.h> #include <linux/smp.h> #include <linux/smp_lock.h> #include <linux/interrupt.h> #include <linux/kernel_stat.h> #include <linux/delay.h> #include <linux/init.h> #include <linux/spinlock.h> #include <linux/fs.h> #include <linux/seq_file.h> #include <linux/cache.h> #include <linux/timer.h> #include <asm/head.h> #include <asm/ptrace.h> #include <asm/atomic.h> #include <asm/irq.h> #include <asm/page.h> #include <asm/pgtable.h> #include <asm/oplib.h> #include <asm/hardirq.h> #include <asm/softirq.h> #include <asm/uaccess.h> #include <asm/timer.h> #include <asm/starfire.h> #define __KERNEL_SYSCALLS__ #include <linux/unistd.h> extern int linux_num_cpus; extern void calibrate_delay(void); extern unsigned prom_cpu_nodes[]; cpuinfo_sparc cpu_data[NR_CPUS]; volatile int __cpu_number_map[NR_CPUS] __attribute__ ((aligned (SMP_CACHE_BYTES))); volatile int __cpu_logical_map[NR_CPUS] __attribute__ ((aligned (SMP_CACHE_BYTES))); /* Please don't make this stuff initdata!!! --DaveM */ static unsigned char boot_cpu_id; static int smp_activated; /* Kernel spinlock */ spinlock_t kernel_flag __cacheline_aligned_in_smp = SPIN_LOCK_UNLOCKED; volatile int smp_processors_ready = 0; unsigned long cpu_present_map = 0; int smp_num_cpus = 1; int smp_threads_ready = 0; void __init smp_setup(char *str, int *ints) { /* XXX implement me XXX */ } static int max_cpus = NR_CPUS; static int __init maxcpus(char *str) { get_option(&str, &max_cpus); return 1; } __setup("maxcpus=", maxcpus); void smp_info(struct seq_file *m) { int i; seq_printf(m, "State:\n"); for (i = 0; i < NR_CPUS; i++) { if (cpu_present_map & (1UL << i)) seq_printf(m, "CPU%d:\t\tonline\n", i); } } void smp_bogo(struct seq_file *m) { int i; for (i = 0; i < NR_CPUS; i++) if (cpu_present_map & (1UL << i)) seq_printf(m, "Cpu%dBogo\t: %lu.%02lu\n" "Cpu%dClkTck\t: %016lx\n", i, cpu_data[i].udelay_val / (500000/HZ), (cpu_data[i].udelay_val / (5000/HZ)) % 100, i, cpu_data[i].clock_tick); } void __init smp_store_cpu_info(int id) { int i, no; /* multiplier and counter set by smp_setup_percpu_timer() */ cpu_data[id].udelay_val = loops_per_jiffy; for (no = 0; no < linux_num_cpus; no++) if (linux_cpus[no].mid == id) break; cpu_data[id].clock_tick = prom_getintdefault(linux_cpus[no].prom_node, "clock-frequency", 0); cpu_data[id].pgcache_size = 0; cpu_data[id].pte_cache[0] = NULL; cpu_data[id].pte_cache[1] = NULL; cpu_data[id].pgdcache_size = 0; cpu_data[id].pgd_cache = NULL; cpu_data[id].idle_volume = 1; for (i = 0; i < 16; i++) cpu_data[id].irq_worklists[i] = 0; } void __init smp_commence(void) { } static void smp_setup_percpu_timer(void); static volatile unsigned long callin_flag = 0; extern void inherit_locked_prom_mappings(int save_p); void __init smp_callin(void) { int cpuid = hard_smp_processor_id(); extern int bigkernel; extern unsigned long kern_locked_tte_data; if (bigkernel) { prom_dtlb_load(sparc64_highest_locked_tlbent()-1, kern_locked_tte_data + 0x400000, KERNBASE + 0x400000); prom_itlb_load(sparc64_highest_locked_tlbent()-1, kern_locked_tte_data + 0x400000, KERNBASE + 0x400000); } inherit_locked_prom_mappings(0); __flush_cache_all(); __flush_tlb_all(); smp_setup_percpu_timer(); __sti(); calibrate_delay(); smp_store_cpu_info(cpuid); callin_flag = 1; __asm__ __volatile__("membar #Sync\n\t" "flush %%g6" : : : "memory"); /* Clear this or we will die instantly when we * schedule back to this idler... */ current->thread.flags &= ~(SPARC_FLAG_NEWCHILD); /* Attach to the address space of init_task. */ atomic_inc(&init_mm.mm_count); current->active_mm = &init_mm; while (!smp_threads_ready) membar("#LoadLoad"); } extern int cpu_idle(void); extern void init_IRQ(void); int start_secondary(void *unused) { trap_init(); init_IRQ(); return cpu_idle(); } void cpu_panic(void) { printk("CPU[%d]: Returns from cpu_idle!\n", smp_processor_id()); panic("SMP bolixed\n"); } static unsigned long current_tick_offset; /* This tick register synchronization scheme is taken entirely from * the ia64 port, see arch/ia64/kernel/smpboot.c for details and credit. * * The only change I've made is to rework it so that the master * initiates the synchonization instead of the slave. -DaveM */ #define MASTER 0 #define SLAVE (SMP_CACHE_BYTES/sizeof(unsigned long)) #define NUM_ROUNDS 64 /* magic value */ #define NUM_ITERS 5 /* likewise */ static spinlock_t itc_sync_lock = SPIN_LOCK_UNLOCKED; static unsigned long go[SLAVE + 1]; #define DEBUG_TICK_SYNC 0 static inline long get_delta (long *rt, long *master) { unsigned long best_t0 = 0, best_t1 = ~0UL, best_tm = 0; unsigned long tcenter, t0, t1, tm; unsigned long i; for (i = 0; i < NUM_ITERS; i++) { t0 = tick_ops->get_tick(); go[MASTER] = 1; membar("#StoreLoad"); while (!(tm = go[SLAVE])) membar("#LoadLoad"); go[SLAVE] = 0; membar("#StoreStore"); t1 = tick_ops->get_tick(); if (t1 - t0 < best_t1 - best_t0) best_t0 = t0, best_t1 = t1, best_tm = tm; } *rt = best_t1 - best_t0; *master = best_tm - best_t0; /* average best_t0 and best_t1 without overflow: */ tcenter = (best_t0/2 + best_t1/2); if (best_t0 % 2 + best_t1 % 2 == 2) tcenter++; return tcenter - best_tm; } void smp_synchronize_tick_client(void) { long i, delta, adj, adjust_latency = 0, done = 0; unsigned long flags, rt, master_time_stamp, bound; #if DEBUG_TICK_SYNC struct { long rt; /* roundtrip time */ long master; /* master's timestamp */ long diff; /* difference between midpoint and master's timestamp */ long lat; /* estimate of itc adjustment latency */ } t[NUM_ROUNDS]; #endif go[MASTER] = 1; while (go[MASTER]) membar("#LoadLoad"); local_irq_save(flags); { for (i = 0; i < NUM_ROUNDS; i++) { delta = get_delta(&rt, &master_time_stamp); if (delta == 0) { done = 1; /* let's lock on to this... */ bound = rt; } if (!done) { if (i > 0) { adjust_latency += -delta; adj = -delta + adjust_latency/4; } else adj = -delta; tick_ops->add_tick(adj, current_tick_offset); } #if DEBUG_TICK_SYNC t[i].rt = rt; t[i].master = master_time_stamp; t[i].diff = delta; t[i].lat = adjust_latency/4; #endif } } local_irq_restore(flags); #if DEBUG_TICK_SYNC for (i = 0; i < NUM_ROUNDS; i++) printk("rt=%5ld master=%5ld diff=%5ld adjlat=%5ld\n", t[i].rt, t[i].master, t[i].diff, t[i].lat); #endif printk(KERN_INFO "CPU %d: synchronized TICK with master CPU (last diff %ld cycles," "maxerr %lu cycles)\n", smp_processor_id(), delta, rt); } static void smp_start_sync_tick_client(int cpu); static void smp_synchronize_one_tick(int cpu) { unsigned long flags, i; go[MASTER] = 0; smp_start_sync_tick_client(cpu); /* wait for client to be ready */ while (!go[MASTER]) membar("#LoadLoad"); /* now let the client proceed into his loop */ go[MASTER] = 0; membar("#StoreLoad"); spin_lock_irqsave(&itc_sync_lock, flags); { for (i = 0; i < NUM_ROUNDS*NUM_ITERS; i++) { while (!go[MASTER]) membar("#LoadLoad"); go[MASTER] = 0; membar("#StoreStore"); go[SLAVE] = tick_ops->get_tick(); membar("#StoreLoad"); } } spin_unlock_irqrestore(&itc_sync_lock, flags); } static void smp_synchronize_tick(void) { int cpu = smp_processor_id(); int i; for (i = 0; i < NR_CPUS; i++) { if (cpu_present_map & (1UL << i)) { if (i == cpu) continue; smp_synchronize_one_tick(i); } } } extern struct prom_cpuinfo linux_cpus[64]; extern unsigned long sparc64_cpu_startup; /* The OBP cpu startup callback truncates the 3rd arg cookie to * 32-bits (I think) so to be safe we have it read the pointer * contained here so we work on >4GB machines. -DaveM */ static struct task_struct *cpu_new_task = NULL; void __init smp_boot_cpus(void) { int cpucount = 0, i; printk("Entering UltraSMPenguin Mode...\n"); __sti(); smp_store_cpu_info(boot_cpu_id); init_idle(); if (linux_num_cpus == 1) return; for (i = 0; i < NR_CPUS; i++) { if (i == boot_cpu_id) continue; if ((cpucount + 1) == max_cpus) goto ignorecpu; if (cpu_present_map & (1UL << i)) { unsigned long entry = (unsigned long)(&sparc64_cpu_startup); unsigned long cookie = (unsigned long)(&cpu_new_task); struct task_struct *p; int timeout; int no; prom_printf("Starting CPU %d... ", i); kernel_thread(start_secondary, NULL, CLONE_PID); cpucount++; p = init_task.prev_task; init_tasks[cpucount] = p; p->processor = i; p->cpus_runnable = 1UL << i; /* we schedule the first task manually */ del_from_runqueue(p); unhash_process(p); callin_flag = 0; for (no = 0; no < linux_num_cpus; no++) if (linux_cpus[no].mid == i) break; cpu_new_task = p; prom_startcpu(linux_cpus[no].prom_node, entry, cookie); for (timeout = 0; timeout < 5000000; timeout++) { if (callin_flag) break; udelay(100); } if (callin_flag) { __cpu_number_map[i] = cpucount; __cpu_logical_map[cpucount] = i; prom_cpu_nodes[i] = linux_cpus[no].prom_node; prom_printf("OK\n"); } else { cpucount--; printk("Processor %d is stuck.\n", i); prom_printf("FAILED\n"); } } if (!callin_flag) { ignorecpu: cpu_present_map &= ~(1UL << i); __cpu_number_map[i] = -1; } } cpu_new_task = NULL; if (cpucount == 0) { if (max_cpus != 1) printk("Error: only one processor found.\n"); cpu_present_map = (1UL << smp_processor_id()); } else { unsigned long bogosum = 0; for (i = 0; i < NR_CPUS; i++) { if (cpu_present_map & (1UL << i)) bogosum += cpu_data[i].udelay_val; } printk("Total of %d processors activated (%lu.%02lu BogoMIPS).\n", cpucount + 1, bogosum/(500000/HZ), (bogosum/(5000/HZ))%100); smp_activated = 1; smp_num_cpus = cpucount + 1; } smp_processors_ready = 1; membar("#StoreStore | #StoreLoad"); smp_synchronize_tick(); } static void spitfire_xcall_helper(u64 data0, u64 data1, u64 data2, u64 pstate, unsigned long cpu) { u64 result, target; int stuck, tmp; if (this_is_starfire) { /* map to real upaid */ cpu = (((cpu & 0x3c) << 1) | ((cpu & 0x40) >> 4) | (cpu & 0x3)); } target = (cpu << 14) | 0x70; again: /* Ok, this is the real Spitfire Errata #54. * One must read back from a UDB internal register * after writes to the UDB interrupt dispatch, but * before the membar Sync for that write. * So we use the high UDB control register (ASI 0x7f, * ADDR 0x20) for the dummy read. -DaveM */ tmp = 0x40; __asm__ __volatile__( "wrpr %1, %2, %%pstate\n\t" "stxa %4, [%0] %3\n\t" "stxa %5, [%0+%8] %3\n\t" "add %0, %8, %0\n\t" "stxa %6, [%0+%8] %3\n\t" "membar #Sync\n\t" "stxa %%g0, [%7] %3\n\t" "membar #Sync\n\t" "mov 0x20, %%g1\n\t" "ldxa [%%g1] 0x7f, %%g0\n\t" "membar #Sync" : "=r" (tmp) : "r" (pstate), "i" (PSTATE_IE), "i" (ASI_INTR_W), "r" (data0), "r" (data1), "r" (data2), "r" (target), "r" (0x10), "0" (tmp) : "g1"); /* NOTE: PSTATE_IE is still clear. */ stuck = 100000; do { __asm__ __volatile__("ldxa [%%g0] %1, %0" : "=r" (result) : "i" (ASI_INTR_DISPATCH_STAT)); if (result == 0) { __asm__ __volatile__("wrpr %0, 0x0, %%pstate" : : "r" (pstate)); return; } stuck -= 1; if (stuck == 0) break; } while (result & 0x1); __asm__ __volatile__("wrpr %0, 0x0, %%pstate" : : "r" (pstate)); if (stuck == 0) { printk("CPU[%d]: mondo stuckage result[%016lx]\n", smp_processor_id(), result); } else { udelay(2); goto again; } } static __inline__ void spitfire_xcall_deliver(u64 data0, u64 data1, u64 data2, unsigned long mask) { int ncpus = smp_num_cpus - 1; int i; u64 pstate; __asm__ __volatile__("rdpr %%pstate, %0" : "=r" (pstate)); for (i = 0; (i < NR_CPUS) && ncpus; i++) { if (mask & (1UL << i)) { spitfire_xcall_helper(data0, data1, data2, pstate, i); ncpus--; } } } /* Cheetah now allows to send the whole 64-bytes of data in the interrupt * packet, but we have no use for that. However we do take advantage of * the new pipelining feature (ie. dispatch to multiple cpus simultaneously). */ #if NR_CPUS > 32 #error Fixup cheetah_xcall_deliver Dave... #endif static void cheetah_xcall_deliver(u64 data0, u64 data1, u64 data2, unsigned long mask) { u64 pstate, ver; int nack_busy_id, is_jalapeno; if (!mask) return; /* Unfortunately, someone at Sun had the brilliant idea to make the * busy/nack fields hard-coded by ITID number for this Ultra-III * derivative processor. */ __asm__ ("rdpr %%ver, %0" : "=r" (ver)); is_jalapeno = ((ver >> 32) == 0x003e0016); __asm__ __volatile__("rdpr %%pstate, %0" : "=r" (pstate)); retry: __asm__ __volatile__("wrpr %0, %1, %%pstate\n\t" : : "r" (pstate), "i" (PSTATE_IE)); /* Setup the dispatch data registers. */ __asm__ __volatile__("stxa %0, [%3] %6\n\t" "stxa %1, [%4] %6\n\t" "stxa %2, [%5] %6\n\t" "membar #Sync\n\t" : /* no outputs */ : "r" (data0), "r" (data1), "r" (data2), "r" (0x40), "r" (0x50), "r" (0x60), "i" (ASI_INTR_W)); nack_busy_id = 0; { int i, ncpus = smp_num_cpus - 1; for (i = 0; (i < NR_CPUS) && ncpus; i++) { if (mask & (1UL << i)) { u64 target = (i << 14) | 0x70; if (!is_jalapeno) target |= (nack_busy_id << 24); __asm__ __volatile__("stxa %%g0, [%0] %1\n\t" "membar #Sync\n\t" : /* no outputs */ : "r" (target), "i" (ASI_INTR_W)); nack_busy_id++; ncpus--; } } } /* Now, poll for completion. */ { u64 dispatch_stat; long stuck; stuck = 100000 * nack_busy_id; do { __asm__ __volatile__("ldxa [%%g0] %1, %0" : "=r" (dispatch_stat) : "i" (ASI_INTR_DISPATCH_STAT)); if (dispatch_stat == 0UL) { __asm__ __volatile__("wrpr %0, 0x0, %%pstate" : : "r" (pstate)); return; } if (!--stuck) break; } while (dispatch_stat & 0x5555555555555555UL); __asm__ __volatile__("wrpr %0, 0x0, %%pstate" : : "r" (pstate)); if ((dispatch_stat & ~(0x5555555555555555UL)) == 0) { /* Busy bits will not clear, continue instead * of freezing up on this cpu. */ printk("CPU[%d]: mondo stuckage result[%016lx]\n", smp_processor_id(), dispatch_stat); } else { int i, this_busy_nack = 0; /* Delay some random time with interrupts enabled * to prevent deadlock. */ udelay(2 * nack_busy_id); /* Clear out the mask bits for cpus which did not * NACK us. */ for (i = 0; i < NR_CPUS; i++) { if (mask & (1UL << i)) { u64 check_mask; if (is_jalapeno) check_mask = (0x2UL << (2*i)); else check_mask = (0x2UL << this_busy_nack); if ((dispatch_stat & check_mask) == 0) mask &= ~(1UL << i); this_busy_nack += 2; } } goto retry; } } } /* Send cross call to all processors mentioned in MASK * except self. */ static void smp_cross_call_masked(unsigned long *func, u32 ctx, u64 data1, u64 data2, unsigned long mask) { if (smp_processors_ready) { u64 data0 = (((u64)ctx)<<32 | (((u64)func) & 0xffffffff)); mask &= ~(1UL<<smp_processor_id()); if (tlb_type == spitfire) spitfire_xcall_deliver(data0, data1, data2, mask); else cheetah_xcall_deliver(data0, data1, data2, mask); /* NOTE: Caller runs local copy on master. */ } } extern unsigned long xcall_sync_tick; static void smp_start_sync_tick_client(int cpu) { smp_cross_call_masked(&xcall_sync_tick, 0, 0, 0, (1UL << cpu)); } /* Send cross call to all processors except self. */ #define smp_cross_call(func, ctx, data1, data2) \ smp_cross_call_masked(func, ctx, data1, data2, cpu_present_map) struct call_data_struct { void (*func) (void *info); void *info; atomic_t finished; int wait; }; static spinlock_t call_lock = SPIN_LOCK_UNLOCKED; static struct call_data_struct *call_data; extern unsigned long xcall_call_function; int smp_call_function(void (*func)(void *info), void *info, int nonatomic, int wait) { struct call_data_struct data; int cpus = smp_num_cpus - 1; long timeout; if (!cpus) return 0; data.func = func; data.info = info; atomic_set(&data.finished, 0); data.wait = wait; spin_lock_bh(&call_lock); call_data = &data; smp_cross_call(&xcall_call_function, 0, 0, 0); /* * Wait for other cpus to complete function or at * least snap the call data. */ timeout = 1000000; while (atomic_read(&data.finished) != cpus) { if (--timeout <= 0) goto out_timeout; barrier(); udelay(1); } spin_unlock_bh(&call_lock); return 0; out_timeout: spin_unlock_bh(&call_lock); printk("XCALL: Remote cpus not responding, ncpus=%d finished=%d\n", smp_num_cpus - 1, atomic_read(&data.finished)); return 0; } void smp_call_function_client(int irq, struct pt_regs *regs) { void (*func) (void *info) = call_data->func; void *info = call_data->info; clear_softint(1 << irq); if (call_data->wait) { /* let initiator proceed only after completion */ func(info); atomic_inc(&call_data->finished); } else { /* let initiator proceed after getting data */ atomic_inc(&call_data->finished); func(info); } } extern unsigned long xcall_flush_tlb_page; extern unsigned long xcall_flush_tlb_mm; extern unsigned long xcall_flush_tlb_range; extern unsigned long xcall_flush_tlb_all_spitfire; extern unsigned long xcall_flush_tlb_all_cheetah; extern unsigned long xcall_flush_cache_all_spitfire; extern unsigned long xcall_report_regs; extern unsigned long xcall_receive_signal; extern unsigned long xcall_flush_dcache_page_cheetah; extern unsigned long xcall_flush_dcache_page_spitfire; #ifdef CONFIG_DEBUG_DCFLUSH extern atomic_t dcpage_flushes; extern atomic_t dcpage_flushes_xcall; #endif static __inline__ void __local_flush_dcache_page(struct page *page) { #if (L1DCACHE_SIZE > PAGE_SIZE) __flush_dcache_page(page->virtual, ((tlb_type == spitfire) && page->mapping != NULL)); #else if (page->mapping != NULL && tlb_type == spitfire) __flush_icache_page(__pa(page->virtual)); #endif } void smp_flush_dcache_page_impl(struct page *page, int cpu) { if (smp_processors_ready) { unsigned long mask = 1UL << cpu; #ifdef CONFIG_DEBUG_DCFLUSH atomic_inc(&dcpage_flushes); #endif if (cpu == smp_processor_id()) { __local_flush_dcache_page(page); } else if ((cpu_present_map & mask) != 0) { u64 data0; if (tlb_type == spitfire) { data0 = ((u64)&xcall_flush_dcache_page_spitfire); if (page->mapping != NULL) data0 |= ((u64)1 << 32); spitfire_xcall_deliver(data0, __pa(page->virtual), (u64) page->virtual, mask); } else { data0 = ((u64)&xcall_flush_dcache_page_cheetah); cheetah_xcall_deliver(data0, __pa(page->virtual), 0, mask); } #ifdef CONFIG_DEBUG_DCFLUSH atomic_inc(&dcpage_flushes_xcall); #endif } } } void flush_dcache_page_all(struct mm_struct *mm, struct page *page) { if (smp_processors_ready) { unsigned long mask = cpu_present_map & ~(1UL << smp_processor_id()); u64 data0; #ifdef CONFIG_DEBUG_DCFLUSH atomic_inc(&dcpage_flushes); #endif if (mask == 0UL) goto flush_self; if (tlb_type == spitfire) { data0 = ((u64)&xcall_flush_dcache_page_spitfire); if (page->mapping != NULL) data0 |= ((u64)1 << 32); spitfire_xcall_deliver(data0, __pa(page->virtual), (u64) page->virtual, mask); } else { data0 = ((u64)&xcall_flush_dcache_page_cheetah); cheetah_xcall_deliver(data0, __pa(page->virtual), 0, mask); } #ifdef CONFIG_DEBUG_DCFLUSH atomic_inc(&dcpage_flushes_xcall); #endif flush_self: __local_flush_dcache_page(page); } } void smp_receive_signal(int cpu) { if (smp_processors_ready) { unsigned long mask = 1UL << cpu; if ((cpu_present_map & mask) != 0) { u64 data0 = (((u64)&xcall_receive_signal) & 0xffffffff); if (tlb_type == spitfire) spitfire_xcall_deliver(data0, 0, 0, mask); else cheetah_xcall_deliver(data0, 0, 0, mask); } } } void smp_receive_signal_client(int irq, struct pt_regs *regs) { /* Just return, rtrap takes care of the rest. */ clear_softint(1 << irq); } void smp_report_regs(void) { smp_cross_call(&xcall_report_regs, 0, 0, 0); } void smp_flush_cache_all(void) { /* Cheetah need do nothing. */ if (tlb_type == spitfire) { smp_cross_call(&xcall_flush_cache_all_spitfire, 0, 0, 0); __flush_cache_all(); } } void smp_flush_tlb_all(void) { if (tlb_type == spitfire) smp_cross_call(&xcall_flush_tlb_all_spitfire, 0, 0, 0); else smp_cross_call(&xcall_flush_tlb_all_cheetah, 0, 0, 0); __flush_tlb_all(); } /* We know that the window frames of the user have been flushed * to the stack before we get here because all callers of us * are flush_tlb_*() routines, and these run after flush_cache_*() * which performs the flushw. * * The SMP TLB coherency scheme we use works as follows: * * 1) mm->cpu_vm_mask is a bit mask of which cpus an address * space has (potentially) executed on, this is the heuristic * we use to avoid doing cross calls. * * Also, for flushing from kswapd and also for clones, we * use cpu_vm_mask as the list of cpus to make run the TLB. * * 2) TLB context numbers are shared globally across all processors * in the system, this allows us to play several games to avoid * cross calls. * * One invariant is that when a cpu switches to a process, and * that processes tsk->active_mm->cpu_vm_mask does not have the * current cpu's bit set, that tlb context is flushed locally. * * If the address space is non-shared (ie. mm->count == 1) we avoid * cross calls when we want to flush the currently running process's * tlb state. This is done by clearing all cpu bits except the current * processor's in current->active_mm->cpu_vm_mask and performing the * flush locally only. This will force any subsequent cpus which run * this task to flush the context from the local tlb if the process * migrates to another cpu (again). * * 3) For shared address spaces (threads) and swapping we bite the * bullet for most cases and perform the cross call (but only to * the cpus listed in cpu_vm_mask). * * The performance gain from "optimizing" away the cross call for threads is * questionable (in theory the big win for threads is the massive sharing of * address space state across processors). */ void smp_flush_tlb_mm(struct mm_struct *mm) { /* * This code is called from two places, dup_mmap and exit_mmap. In the * former case, we really need a flush. In the later case, the callers * are single threaded exec_mmap (really need a flush), multithreaded * exec_mmap case (do not need to flush, since the caller gets a new * context via activate_mm), and all other callers of mmput() whence * the flush can be optimized since the associated threads are dead and * the mm is being torn down (__exit_mm and other mmput callers) or the * owning thread is dissociating itself from the mm. The * (atomic_read(&mm->mm_users) == 0) check ensures real work is done * for single thread exec and dup_mmap cases. An alternate check might * have been (current->mm != mm). * Kanoj Sarcar */ if (atomic_read(&mm->mm_users) == 0) return; { u32 ctx = CTX_HWBITS(mm->context); int cpu = smp_processor_id(); if (atomic_read(&mm->mm_users) == 1) { /* See smp_flush_tlb_page for info about this. */ mm->cpu_vm_mask = (1UL << cpu); goto local_flush_and_out; } smp_cross_call_masked(&xcall_flush_tlb_mm, ctx, 0, 0, mm->cpu_vm_mask); local_flush_and_out: __flush_tlb_mm(ctx, SECONDARY_CONTEXT); } } void smp_flush_tlb_range(struct mm_struct *mm, unsigned long start, unsigned long end) { { u32 ctx = CTX_HWBITS(mm->context); int cpu = smp_processor_id(); start &= PAGE_MASK; end = PAGE_ALIGN(end); if (mm == current->active_mm && atomic_read(&mm->mm_users) == 1) { mm->cpu_vm_mask = (1UL << cpu); goto local_flush_and_out; } smp_cross_call_masked(&xcall_flush_tlb_range, ctx, start, end, mm->cpu_vm_mask); local_flush_and_out: __flush_tlb_range(ctx, start, SECONDARY_CONTEXT, end, PAGE_SIZE, (end-start)); } } void smp_flush_tlb_page(struct mm_struct *mm, unsigned long page) { { u32 ctx = CTX_HWBITS(mm->context); int cpu = smp_processor_id(); page &= PAGE_MASK; if (mm == current->active_mm && atomic_read(&mm->mm_users) == 1) { /* By virtue of being the current address space, and * having the only reference to it, the following operation * is safe. * * It would not be a win to perform the xcall tlb flush in * this case, because even if we switch back to one of the * other processors in cpu_vm_mask it is almost certain that * all TLB entries for this context will be replaced by the * time that happens. */ mm->cpu_vm_mask = (1UL << cpu); goto local_flush_and_out; } else { /* By virtue of running under the mm->page_table_lock, * and mmu_context.h:switch_mm doing the same, the following * operation is safe. */ if (mm->cpu_vm_mask == (1UL << cpu)) goto local_flush_and_out; } /* OK, we have to actually perform the cross call. Most likely * this is a cloned mm or kswapd is kicking out pages for a task * which has run recently on another cpu. */ smp_cross_call_masked(&xcall_flush_tlb_page, ctx, page, 0, mm->cpu_vm_mask); if (!(mm->cpu_vm_mask & (1UL << cpu))) return; local_flush_and_out: __flush_tlb_page(ctx, page, SECONDARY_CONTEXT); } } /* CPU capture. */ /* #define CAPTURE_DEBUG */ extern unsigned long xcall_capture; static atomic_t smp_capture_depth = ATOMIC_INIT(0); static atomic_t smp_capture_registry = ATOMIC_INIT(0); static unsigned long penguins_are_doing_time; void smp_capture(void) { if (smp_processors_ready) { int result = __atomic_add(1, &smp_capture_depth); membar("#StoreStore | #LoadStore"); if (result == 1) { int ncpus = smp_num_cpus; #ifdef CAPTURE_DEBUG printk("CPU[%d]: Sending penguins to jail...", smp_processor_id()); #endif penguins_are_doing_time = 1; membar("#StoreStore | #LoadStore"); atomic_inc(&smp_capture_registry); smp_cross_call(&xcall_capture, 0, 0, 0); while (atomic_read(&smp_capture_registry) != ncpus) membar("#LoadLoad"); #ifdef CAPTURE_DEBUG printk("done\n"); #endif } } } void smp_release(void) { if (smp_processors_ready) { if (atomic_dec_and_test(&smp_capture_depth)) { #ifdef CAPTURE_DEBUG printk("CPU[%d]: Giving pardon to imprisoned penguins\n", smp_processor_id()); #endif penguins_are_doing_time = 0; membar("#StoreStore | #StoreLoad"); atomic_dec(&smp_capture_registry); } } } /* Imprisoned penguins run with %pil == 15, but PSTATE_IE set, so they * can service tlb flush xcalls... */ extern void prom_world(int); extern void save_alternate_globals(unsigned long *); extern void restore_alternate_globals(unsigned long *); void smp_penguin_jailcell(int irq, struct pt_regs *regs) { unsigned long global_save[24]; clear_softint(1 << irq); __asm__ __volatile__("flushw"); save_alternate_globals(global_save); prom_world(1); atomic_inc(&smp_capture_registry); membar("#StoreLoad | #StoreStore"); while (penguins_are_doing_time) membar("#LoadLoad"); restore_alternate_globals(global_save); atomic_dec(&smp_capture_registry); prom_world(0); } extern unsigned long xcall_promstop; void smp_promstop_others(void) { if (smp_processors_ready) smp_cross_call(&xcall_promstop, 0, 0, 0); } extern void sparc64_do_profile(unsigned long pc, unsigned long o7); #define prof_multiplier(__cpu) cpu_data[(__cpu)].multiplier #define prof_counter(__cpu) cpu_data[(__cpu)].counter void smp_percpu_timer_interrupt(struct pt_regs *regs) { unsigned long compare, tick, pstate; int cpu = smp_processor_id(); int user = user_mode(regs); /* * Check for level 14 softint. */ { unsigned long tick_mask = tick_ops->softint_mask; if (!(get_softint() & tick_mask)) { extern void handler_irq(int, struct pt_regs *); handler_irq(14, regs); return; } clear_softint(tick_mask); } do { if (!user) sparc64_do_profile(regs->tpc, regs->u_regs[UREG_RETPC]); if (!--prof_counter(cpu)) { irq_enter(cpu, 0); if (cpu == boot_cpu_id) { kstat.irqs[cpu][0]++; timer_tick_interrupt(regs); } update_process_times(user); irq_exit(cpu, 0); prof_counter(cpu) = prof_multiplier(cpu); } /* Guarentee that the following sequences execute * uninterrupted. */ __asm__ __volatile__("rdpr %%pstate, %0\n\t" "wrpr %0, %1, %%pstate" : "=r" (pstate) : "i" (PSTATE_IE)); compare = tick_ops->add_compare(current_tick_offset); tick = tick_ops->get_tick(); /* Restore PSTATE_IE. */ __asm__ __volatile__("wrpr %0, 0x0, %%pstate" : /* no outputs */ : "r" (pstate)); } while (time_after_eq(tick, compare)); } static void __init smp_setup_percpu_timer(void) { int cpu = smp_processor_id(); unsigned long pstate; prof_counter(cpu) = prof_multiplier(cpu) = 1; /* Guarentee that the following sequences execute * uninterrupted. */ __asm__ __volatile__("rdpr %%pstate, %0\n\t" "wrpr %0, %1, %%pstate" : "=r" (pstate) : "i" (PSTATE_IE)); tick_ops->init_tick(current_tick_offset); /* Restore PSTATE_IE. */ __asm__ __volatile__("wrpr %0, 0x0, %%pstate" : /* no outputs */ : "r" (pstate)); } void __init smp_tick_init(void) { int i; boot_cpu_id = hard_smp_processor_id(); current_tick_offset = timer_tick_offset; cpu_present_map = 0; for (i = 0; i < linux_num_cpus; i++) cpu_present_map |= (1UL << linux_cpus[i].mid); for (i = 0; i < NR_CPUS; i++) { __cpu_number_map[i] = -1; __cpu_logical_map[i] = -1; } __cpu_number_map[boot_cpu_id] = 0; prom_cpu_nodes[boot_cpu_id] = linux_cpus[0].prom_node; __cpu_logical_map[0] = boot_cpu_id; current->processor = boot_cpu_id; prof_counter(boot_cpu_id) = prof_multiplier(boot_cpu_id) = 1; } static inline unsigned long find_flush_base(unsigned long size) { struct page *p = mem_map; unsigned long found, base; size = PAGE_ALIGN(size); found = size; base = (unsigned long) page_address(p); while (found != 0) { /* Failure. */ if (p >= (mem_map + max_mapnr)) return 0UL; if (PageReserved(p)) { found = size; base = (unsigned long) page_address(p); } else { found -= PAGE_SIZE; } p++; } return base; } /* /proc/profile writes can call this, don't __init it please. */ int setup_profiling_timer(unsigned int multiplier) { unsigned long flags; int i; if ((!multiplier) || (timer_tick_offset / multiplier) < 1000) return -EINVAL; save_and_cli(flags); for (i = 0; i < NR_CPUS; i++) { if (cpu_present_map & (1UL << i)) prof_multiplier(i) = multiplier; } current_tick_offset = (timer_tick_offset / multiplier); restore_flags(flags); return 0; }
Go to most recent revision | Compare with Previous | Blame | View Log