64c7c8f885
Make some changes to the NEED_RESCHED and POLLING_NRFLAG to reduce confusion, and make their semantics rigid. Improves efficiency of resched_task and some cpu_idle routines. * In resched_task: - TIF_NEED_RESCHED is only cleared with the task's runqueue lock held, and as we hold it during resched_task, then there is no need for an atomic test and set there. The only other time this should be set is when the task's quantum expires, in the timer interrupt - this is protected against because the rq lock is irq-safe. - If TIF_NEED_RESCHED is set, then we don't need to do anything. It won't get unset until the task get's schedule()d off. - If we are running on the same CPU as the task we resched, then set TIF_NEED_RESCHED and no further action is required. - If we are running on another CPU, and TIF_POLLING_NRFLAG is *not* set after TIF_NEED_RESCHED has been set, then we need to send an IPI. Using these rules, we are able to remove the test and set operation in resched_task, and make clear the previously vague semantics of POLLING_NRFLAG. * In idle routines: - Enter cpu_idle with preempt disabled. When the need_resched() condition becomes true, explicitly call schedule(). This makes things a bit clearer (IMO), but haven't updated all architectures yet. - Many do a test and clear of TIF_NEED_RESCHED for some reason. According to the resched_task rules, this isn't needed (and actually breaks the assumption that TIF_NEED_RESCHED is only cleared with the runqueue lock held). So remove that. Generally one less locked memory op when switching to the idle thread. - Many idle routines clear TIF_POLLING_NRFLAG, and only set it in the inner most polling idle loops. The above resched_task semantics allow it to be set until before the last time need_resched() is checked before going into a halt requiring interrupt wakeup. Many idle routines simply never enter such a halt, and so POLLING_NRFLAG can be always left set, completely eliminating resched IPIs when rescheduling the idle task. POLLING_NRFLAG width can be increased, to reduce the chance of resched IPIs. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Con Kolivas <kernel@kolivas.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
1219 lines
29 KiB
C
1219 lines
29 KiB
C
/* smp.c: Sparc64 SMP support.
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*
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* Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/pagemap.h>
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#include <linux/threads.h>
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#include <linux/smp.h>
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#include <linux/smp_lock.h>
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#include <linux/interrupt.h>
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#include <linux/kernel_stat.h>
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <linux/spinlock.h>
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#include <linux/fs.h>
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#include <linux/seq_file.h>
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#include <linux/cache.h>
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#include <linux/jiffies.h>
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#include <linux/profile.h>
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#include <linux/bootmem.h>
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#include <asm/head.h>
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#include <asm/ptrace.h>
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#include <asm/atomic.h>
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#include <asm/tlbflush.h>
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#include <asm/mmu_context.h>
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#include <asm/cpudata.h>
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#include <asm/irq.h>
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#include <asm/oplib.h>
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#include <asm/uaccess.h>
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#include <asm/timer.h>
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#include <asm/starfire.h>
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#include <asm/tlb.h>
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extern int linux_num_cpus;
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extern void calibrate_delay(void);
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/* Please don't make this stuff initdata!!! --DaveM */
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static unsigned char boot_cpu_id;
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cpumask_t cpu_online_map __read_mostly = CPU_MASK_NONE;
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cpumask_t phys_cpu_present_map __read_mostly = CPU_MASK_NONE;
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static cpumask_t smp_commenced_mask;
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static cpumask_t cpu_callout_map;
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void smp_info(struct seq_file *m)
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{
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int i;
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seq_printf(m, "State:\n");
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for (i = 0; i < NR_CPUS; i++) {
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if (cpu_online(i))
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seq_printf(m,
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"CPU%d:\t\tonline\n", i);
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}
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}
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void smp_bogo(struct seq_file *m)
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{
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int i;
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for (i = 0; i < NR_CPUS; i++)
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if (cpu_online(i))
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seq_printf(m,
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"Cpu%dBogo\t: %lu.%02lu\n"
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"Cpu%dClkTck\t: %016lx\n",
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i, cpu_data(i).udelay_val / (500000/HZ),
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(cpu_data(i).udelay_val / (5000/HZ)) % 100,
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i, cpu_data(i).clock_tick);
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}
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void __init smp_store_cpu_info(int id)
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{
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int cpu_node;
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/* multiplier and counter set by
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smp_setup_percpu_timer() */
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cpu_data(id).udelay_val = loops_per_jiffy;
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cpu_find_by_mid(id, &cpu_node);
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cpu_data(id).clock_tick = prom_getintdefault(cpu_node,
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"clock-frequency", 0);
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cpu_data(id).pgcache_size = 0;
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cpu_data(id).pte_cache[0] = NULL;
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cpu_data(id).pte_cache[1] = NULL;
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cpu_data(id).pgd_cache = NULL;
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cpu_data(id).idle_volume = 1;
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cpu_data(id).dcache_size = prom_getintdefault(cpu_node, "dcache-size",
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16 * 1024);
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cpu_data(id).dcache_line_size =
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prom_getintdefault(cpu_node, "dcache-line-size", 32);
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cpu_data(id).icache_size = prom_getintdefault(cpu_node, "icache-size",
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16 * 1024);
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cpu_data(id).icache_line_size =
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prom_getintdefault(cpu_node, "icache-line-size", 32);
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cpu_data(id).ecache_size = prom_getintdefault(cpu_node, "ecache-size",
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4 * 1024 * 1024);
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cpu_data(id).ecache_line_size =
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prom_getintdefault(cpu_node, "ecache-line-size", 64);
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printk("CPU[%d]: Caches "
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"D[sz(%d):line_sz(%d)] "
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"I[sz(%d):line_sz(%d)] "
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"E[sz(%d):line_sz(%d)]\n",
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id,
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cpu_data(id).dcache_size, cpu_data(id).dcache_line_size,
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cpu_data(id).icache_size, cpu_data(id).icache_line_size,
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cpu_data(id).ecache_size, cpu_data(id).ecache_line_size);
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}
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static void smp_setup_percpu_timer(void);
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static volatile unsigned long callin_flag = 0;
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extern void inherit_locked_prom_mappings(int save_p);
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static inline void cpu_setup_percpu_base(unsigned long cpu_id)
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{
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__asm__ __volatile__("mov %0, %%g5\n\t"
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"stxa %0, [%1] %2\n\t"
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"membar #Sync"
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: /* no outputs */
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: "r" (__per_cpu_offset(cpu_id)),
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"r" (TSB_REG), "i" (ASI_IMMU));
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}
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void __init smp_callin(void)
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{
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int cpuid = hard_smp_processor_id();
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inherit_locked_prom_mappings(0);
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__flush_tlb_all();
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cpu_setup_percpu_base(cpuid);
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smp_setup_percpu_timer();
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if (cheetah_pcache_forced_on)
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cheetah_enable_pcache();
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local_irq_enable();
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calibrate_delay();
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smp_store_cpu_info(cpuid);
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callin_flag = 1;
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__asm__ __volatile__("membar #Sync\n\t"
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"flush %%g6" : : : "memory");
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/* Clear this or we will die instantly when we
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* schedule back to this idler...
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*/
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current_thread_info()->new_child = 0;
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/* Attach to the address space of init_task. */
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atomic_inc(&init_mm.mm_count);
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current->active_mm = &init_mm;
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while (!cpu_isset(cpuid, smp_commenced_mask))
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rmb();
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cpu_set(cpuid, cpu_online_map);
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/* idle thread is expected to have preempt disabled */
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preempt_disable();
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}
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void cpu_panic(void)
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{
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printk("CPU[%d]: Returns from cpu_idle!\n", smp_processor_id());
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panic("SMP bolixed\n");
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}
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static unsigned long current_tick_offset __read_mostly;
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/* This tick register synchronization scheme is taken entirely from
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* the ia64 port, see arch/ia64/kernel/smpboot.c for details and credit.
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*
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* The only change I've made is to rework it so that the master
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* initiates the synchonization instead of the slave. -DaveM
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*/
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#define MASTER 0
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#define SLAVE (SMP_CACHE_BYTES/sizeof(unsigned long))
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#define NUM_ROUNDS 64 /* magic value */
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#define NUM_ITERS 5 /* likewise */
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static DEFINE_SPINLOCK(itc_sync_lock);
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static unsigned long go[SLAVE + 1];
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#define DEBUG_TICK_SYNC 0
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static inline long get_delta (long *rt, long *master)
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{
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unsigned long best_t0 = 0, best_t1 = ~0UL, best_tm = 0;
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unsigned long tcenter, t0, t1, tm;
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unsigned long i;
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for (i = 0; i < NUM_ITERS; i++) {
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t0 = tick_ops->get_tick();
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go[MASTER] = 1;
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membar_storeload();
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while (!(tm = go[SLAVE]))
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rmb();
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go[SLAVE] = 0;
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wmb();
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t1 = tick_ops->get_tick();
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if (t1 - t0 < best_t1 - best_t0)
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best_t0 = t0, best_t1 = t1, best_tm = tm;
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}
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*rt = best_t1 - best_t0;
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*master = best_tm - best_t0;
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/* average best_t0 and best_t1 without overflow: */
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tcenter = (best_t0/2 + best_t1/2);
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if (best_t0 % 2 + best_t1 % 2 == 2)
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tcenter++;
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return tcenter - best_tm;
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}
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void smp_synchronize_tick_client(void)
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{
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long i, delta, adj, adjust_latency = 0, done = 0;
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unsigned long flags, rt, master_time_stamp, bound;
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#if DEBUG_TICK_SYNC
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struct {
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long rt; /* roundtrip time */
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long master; /* master's timestamp */
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long diff; /* difference between midpoint and master's timestamp */
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long lat; /* estimate of itc adjustment latency */
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} t[NUM_ROUNDS];
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#endif
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go[MASTER] = 1;
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while (go[MASTER])
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rmb();
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local_irq_save(flags);
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{
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for (i = 0; i < NUM_ROUNDS; i++) {
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delta = get_delta(&rt, &master_time_stamp);
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if (delta == 0) {
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done = 1; /* let's lock on to this... */
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bound = rt;
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}
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if (!done) {
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if (i > 0) {
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adjust_latency += -delta;
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adj = -delta + adjust_latency/4;
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} else
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adj = -delta;
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tick_ops->add_tick(adj, current_tick_offset);
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}
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#if DEBUG_TICK_SYNC
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t[i].rt = rt;
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t[i].master = master_time_stamp;
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t[i].diff = delta;
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t[i].lat = adjust_latency/4;
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#endif
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}
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}
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local_irq_restore(flags);
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#if DEBUG_TICK_SYNC
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for (i = 0; i < NUM_ROUNDS; i++)
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printk("rt=%5ld master=%5ld diff=%5ld adjlat=%5ld\n",
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t[i].rt, t[i].master, t[i].diff, t[i].lat);
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#endif
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printk(KERN_INFO "CPU %d: synchronized TICK with master CPU (last diff %ld cycles,"
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"maxerr %lu cycles)\n", smp_processor_id(), delta, rt);
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}
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static void smp_start_sync_tick_client(int cpu);
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static void smp_synchronize_one_tick(int cpu)
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{
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unsigned long flags, i;
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go[MASTER] = 0;
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smp_start_sync_tick_client(cpu);
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/* wait for client to be ready */
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while (!go[MASTER])
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rmb();
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/* now let the client proceed into his loop */
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go[MASTER] = 0;
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membar_storeload();
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spin_lock_irqsave(&itc_sync_lock, flags);
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{
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for (i = 0; i < NUM_ROUNDS*NUM_ITERS; i++) {
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while (!go[MASTER])
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rmb();
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go[MASTER] = 0;
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wmb();
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go[SLAVE] = tick_ops->get_tick();
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membar_storeload();
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}
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}
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spin_unlock_irqrestore(&itc_sync_lock, flags);
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}
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extern unsigned long sparc64_cpu_startup;
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/* The OBP cpu startup callback truncates the 3rd arg cookie to
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* 32-bits (I think) so to be safe we have it read the pointer
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* contained here so we work on >4GB machines. -DaveM
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*/
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static struct thread_info *cpu_new_thread = NULL;
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static int __devinit smp_boot_one_cpu(unsigned int cpu)
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{
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unsigned long entry =
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(unsigned long)(&sparc64_cpu_startup);
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unsigned long cookie =
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(unsigned long)(&cpu_new_thread);
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struct task_struct *p;
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int timeout, ret, cpu_node;
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p = fork_idle(cpu);
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callin_flag = 0;
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cpu_new_thread = p->thread_info;
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cpu_set(cpu, cpu_callout_map);
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cpu_find_by_mid(cpu, &cpu_node);
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prom_startcpu(cpu_node, entry, cookie);
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for (timeout = 0; timeout < 5000000; timeout++) {
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if (callin_flag)
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break;
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udelay(100);
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}
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if (callin_flag) {
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ret = 0;
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} else {
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printk("Processor %d is stuck.\n", cpu);
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cpu_clear(cpu, cpu_callout_map);
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ret = -ENODEV;
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}
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cpu_new_thread = NULL;
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return ret;
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}
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static void spitfire_xcall_helper(u64 data0, u64 data1, u64 data2, u64 pstate, unsigned long cpu)
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{
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u64 result, target;
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int stuck, tmp;
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if (this_is_starfire) {
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/* map to real upaid */
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cpu = (((cpu & 0x3c) << 1) |
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((cpu & 0x40) >> 4) |
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(cpu & 0x3));
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}
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target = (cpu << 14) | 0x70;
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again:
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/* Ok, this is the real Spitfire Errata #54.
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* One must read back from a UDB internal register
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* after writes to the UDB interrupt dispatch, but
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* before the membar Sync for that write.
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* So we use the high UDB control register (ASI 0x7f,
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* ADDR 0x20) for the dummy read. -DaveM
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*/
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tmp = 0x40;
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__asm__ __volatile__(
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"wrpr %1, %2, %%pstate\n\t"
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"stxa %4, [%0] %3\n\t"
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"stxa %5, [%0+%8] %3\n\t"
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"add %0, %8, %0\n\t"
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"stxa %6, [%0+%8] %3\n\t"
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"membar #Sync\n\t"
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"stxa %%g0, [%7] %3\n\t"
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"membar #Sync\n\t"
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"mov 0x20, %%g1\n\t"
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"ldxa [%%g1] 0x7f, %%g0\n\t"
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"membar #Sync"
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: "=r" (tmp)
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: "r" (pstate), "i" (PSTATE_IE), "i" (ASI_INTR_W),
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"r" (data0), "r" (data1), "r" (data2), "r" (target),
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"r" (0x10), "0" (tmp)
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: "g1");
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/* NOTE: PSTATE_IE is still clear. */
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stuck = 100000;
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do {
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__asm__ __volatile__("ldxa [%%g0] %1, %0"
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: "=r" (result)
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: "i" (ASI_INTR_DISPATCH_STAT));
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if (result == 0) {
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__asm__ __volatile__("wrpr %0, 0x0, %%pstate"
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: : "r" (pstate));
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return;
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}
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stuck -= 1;
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if (stuck == 0)
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break;
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} while (result & 0x1);
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__asm__ __volatile__("wrpr %0, 0x0, %%pstate"
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: : "r" (pstate));
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if (stuck == 0) {
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printk("CPU[%d]: mondo stuckage result[%016lx]\n",
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smp_processor_id(), result);
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} else {
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udelay(2);
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goto again;
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}
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}
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static __inline__ void spitfire_xcall_deliver(u64 data0, u64 data1, u64 data2, cpumask_t mask)
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{
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u64 pstate;
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int i;
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__asm__ __volatile__("rdpr %%pstate, %0" : "=r" (pstate));
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for_each_cpu_mask(i, mask)
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spitfire_xcall_helper(data0, data1, data2, pstate, i);
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}
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|
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/* Cheetah now allows to send the whole 64-bytes of data in the interrupt
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* packet, but we have no use for that. However we do take advantage of
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* the new pipelining feature (ie. dispatch to multiple cpus simultaneously).
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*/
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static void cheetah_xcall_deliver(u64 data0, u64 data1, u64 data2, cpumask_t mask)
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{
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u64 pstate, ver;
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int nack_busy_id, is_jalapeno;
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|
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if (cpus_empty(mask))
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return;
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|
|
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/* Unfortunately, someone at Sun had the brilliant idea to make the
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* busy/nack fields hard-coded by ITID number for this Ultra-III
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* derivative processor.
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*/
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__asm__ ("rdpr %%ver, %0" : "=r" (ver));
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is_jalapeno = ((ver >> 32) == 0x003e0016);
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|
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__asm__ __volatile__("rdpr %%pstate, %0" : "=r" (pstate));
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|
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retry:
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__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;
|
|
|
|
for_each_cpu_mask(i, mask) {
|
|
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++;
|
|
}
|
|
}
|
|
|
|
/* 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_each_cpu_mask(i, mask) {
|
|
u64 check_mask;
|
|
|
|
if (is_jalapeno)
|
|
check_mask = (0x2UL << (2*i));
|
|
else
|
|
check_mask = (0x2UL <<
|
|
this_busy_nack);
|
|
if ((dispatch_stat & check_mask) == 0)
|
|
cpu_clear(i, mask);
|
|
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, cpumask_t mask)
|
|
{
|
|
u64 data0 = (((u64)ctx)<<32 | (((u64)func) & 0xffffffff));
|
|
int this_cpu = get_cpu();
|
|
|
|
cpus_and(mask, mask, cpu_online_map);
|
|
cpu_clear(this_cpu, mask);
|
|
|
|
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. */
|
|
|
|
put_cpu();
|
|
}
|
|
|
|
extern unsigned long xcall_sync_tick;
|
|
|
|
static void smp_start_sync_tick_client(int cpu)
|
|
{
|
|
cpumask_t mask = cpumask_of_cpu(cpu);
|
|
|
|
smp_cross_call_masked(&xcall_sync_tick,
|
|
0, 0, 0, mask);
|
|
}
|
|
|
|
/* 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_online_map)
|
|
|
|
struct call_data_struct {
|
|
void (*func) (void *info);
|
|
void *info;
|
|
atomic_t finished;
|
|
int wait;
|
|
};
|
|
|
|
static DEFINE_SPINLOCK(call_lock);
|
|
static struct call_data_struct *call_data;
|
|
|
|
extern unsigned long xcall_call_function;
|
|
|
|
/*
|
|
* You must not call this function with disabled interrupts or from a
|
|
* hardware interrupt handler or from a bottom half handler.
|
|
*/
|
|
int smp_call_function(void (*func)(void *info), void *info,
|
|
int nonatomic, int wait)
|
|
{
|
|
struct call_data_struct data;
|
|
int cpus = num_online_cpus() - 1;
|
|
long timeout;
|
|
|
|
if (!cpus)
|
|
return 0;
|
|
|
|
/* Can deadlock when called with interrupts disabled */
|
|
WARN_ON(irqs_disabled());
|
|
|
|
data.func = func;
|
|
data.info = info;
|
|
atomic_set(&data.finished, 0);
|
|
data.wait = wait;
|
|
|
|
spin_lock(&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(&call_lock);
|
|
|
|
return 0;
|
|
|
|
out_timeout:
|
|
spin_unlock(&call_lock);
|
|
printk("XCALL: Remote cpus not responding, ncpus=%ld finished=%ld\n",
|
|
(long) num_online_cpus() - 1L,
|
|
(long) 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_mm;
|
|
extern unsigned long xcall_flush_tlb_pending;
|
|
extern unsigned long xcall_flush_tlb_kernel_range;
|
|
extern unsigned long xcall_flush_tlb_all_spitfire;
|
|
extern unsigned long xcall_flush_tlb_all_cheetah;
|
|
extern unsigned long xcall_report_regs;
|
|
extern unsigned long xcall_receive_signal;
|
|
|
|
#ifdef DCACHE_ALIASING_POSSIBLE
|
|
extern unsigned long xcall_flush_dcache_page_cheetah;
|
|
#endif
|
|
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)
|
|
{
|
|
#ifdef DCACHE_ALIASING_POSSIBLE
|
|
__flush_dcache_page(page_address(page),
|
|
((tlb_type == spitfire) &&
|
|
page_mapping(page) != NULL));
|
|
#else
|
|
if (page_mapping(page) != NULL &&
|
|
tlb_type == spitfire)
|
|
__flush_icache_page(__pa(page_address(page)));
|
|
#endif
|
|
}
|
|
|
|
void smp_flush_dcache_page_impl(struct page *page, int cpu)
|
|
{
|
|
cpumask_t mask = cpumask_of_cpu(cpu);
|
|
int this_cpu = get_cpu();
|
|
|
|
#ifdef CONFIG_DEBUG_DCFLUSH
|
|
atomic_inc(&dcpage_flushes);
|
|
#endif
|
|
if (cpu == this_cpu) {
|
|
__local_flush_dcache_page(page);
|
|
} else if (cpu_online(cpu)) {
|
|
void *pg_addr = page_address(page);
|
|
u64 data0;
|
|
|
|
if (tlb_type == spitfire) {
|
|
data0 =
|
|
((u64)&xcall_flush_dcache_page_spitfire);
|
|
if (page_mapping(page) != NULL)
|
|
data0 |= ((u64)1 << 32);
|
|
spitfire_xcall_deliver(data0,
|
|
__pa(pg_addr),
|
|
(u64) pg_addr,
|
|
mask);
|
|
} else {
|
|
#ifdef DCACHE_ALIASING_POSSIBLE
|
|
data0 =
|
|
((u64)&xcall_flush_dcache_page_cheetah);
|
|
cheetah_xcall_deliver(data0,
|
|
__pa(pg_addr),
|
|
0, mask);
|
|
#endif
|
|
}
|
|
#ifdef CONFIG_DEBUG_DCFLUSH
|
|
atomic_inc(&dcpage_flushes_xcall);
|
|
#endif
|
|
}
|
|
|
|
put_cpu();
|
|
}
|
|
|
|
void flush_dcache_page_all(struct mm_struct *mm, struct page *page)
|
|
{
|
|
void *pg_addr = page_address(page);
|
|
cpumask_t mask = cpu_online_map;
|
|
u64 data0;
|
|
int this_cpu = get_cpu();
|
|
|
|
cpu_clear(this_cpu, mask);
|
|
|
|
#ifdef CONFIG_DEBUG_DCFLUSH
|
|
atomic_inc(&dcpage_flushes);
|
|
#endif
|
|
if (cpus_empty(mask))
|
|
goto flush_self;
|
|
if (tlb_type == spitfire) {
|
|
data0 = ((u64)&xcall_flush_dcache_page_spitfire);
|
|
if (page_mapping(page) != NULL)
|
|
data0 |= ((u64)1 << 32);
|
|
spitfire_xcall_deliver(data0,
|
|
__pa(pg_addr),
|
|
(u64) pg_addr,
|
|
mask);
|
|
} else {
|
|
#ifdef DCACHE_ALIASING_POSSIBLE
|
|
data0 = ((u64)&xcall_flush_dcache_page_cheetah);
|
|
cheetah_xcall_deliver(data0,
|
|
__pa(pg_addr),
|
|
0, mask);
|
|
#endif
|
|
}
|
|
#ifdef CONFIG_DEBUG_DCFLUSH
|
|
atomic_inc(&dcpage_flushes_xcall);
|
|
#endif
|
|
flush_self:
|
|
__local_flush_dcache_page(page);
|
|
|
|
put_cpu();
|
|
}
|
|
|
|
void smp_receive_signal(int cpu)
|
|
{
|
|
cpumask_t mask = cpumask_of_cpu(cpu);
|
|
|
|
if (cpu_online(cpu)) {
|
|
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_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).
|
|
*/
|
|
|
|
/* This currently is only used by the hugetlb arch pre-fault
|
|
* hook on UltraSPARC-III+ and later when changing the pagesize
|
|
* bits of the context register for an address space.
|
|
*/
|
|
void smp_flush_tlb_mm(struct mm_struct *mm)
|
|
{
|
|
u32 ctx = CTX_HWBITS(mm->context);
|
|
int cpu = get_cpu();
|
|
|
|
if (atomic_read(&mm->mm_users) == 1) {
|
|
mm->cpu_vm_mask = cpumask_of_cpu(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);
|
|
|
|
put_cpu();
|
|
}
|
|
|
|
void smp_flush_tlb_pending(struct mm_struct *mm, unsigned long nr, unsigned long *vaddrs)
|
|
{
|
|
u32 ctx = CTX_HWBITS(mm->context);
|
|
int cpu = get_cpu();
|
|
|
|
if (mm == current->active_mm && atomic_read(&mm->mm_users) == 1)
|
|
mm->cpu_vm_mask = cpumask_of_cpu(cpu);
|
|
else
|
|
smp_cross_call_masked(&xcall_flush_tlb_pending,
|
|
ctx, nr, (unsigned long) vaddrs,
|
|
mm->cpu_vm_mask);
|
|
|
|
__flush_tlb_pending(ctx, nr, vaddrs);
|
|
|
|
put_cpu();
|
|
}
|
|
|
|
void smp_flush_tlb_kernel_range(unsigned long start, unsigned long end)
|
|
{
|
|
start &= PAGE_MASK;
|
|
end = PAGE_ALIGN(end);
|
|
if (start != end) {
|
|
smp_cross_call(&xcall_flush_tlb_kernel_range,
|
|
0, start, end);
|
|
|
|
__flush_tlb_kernel_range(start, end);
|
|
}
|
|
}
|
|
|
|
/* 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)
|
|
{
|
|
int result = atomic_add_ret(1, &smp_capture_depth);
|
|
|
|
if (result == 1) {
|
|
int ncpus = num_online_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)
|
|
rmb();
|
|
#ifdef CAPTURE_DEBUG
|
|
printk("done\n");
|
|
#endif
|
|
}
|
|
}
|
|
|
|
void smp_release(void)
|
|
{
|
|
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_storeload_storestore();
|
|
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);
|
|
|
|
preempt_disable();
|
|
|
|
__asm__ __volatile__("flushw");
|
|
save_alternate_globals(global_save);
|
|
prom_world(1);
|
|
atomic_inc(&smp_capture_registry);
|
|
membar_storeload_storestore();
|
|
while (penguins_are_doing_time)
|
|
rmb();
|
|
restore_alternate_globals(global_save);
|
|
atomic_dec(&smp_capture_registry);
|
|
prom_world(0);
|
|
|
|
preempt_enable();
|
|
}
|
|
|
|
#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 {
|
|
profile_tick(CPU_PROFILING, regs);
|
|
if (!--prof_counter(cpu)) {
|
|
irq_enter();
|
|
|
|
if (cpu == boot_cpu_id) {
|
|
kstat_this_cpu.irqs[0]++;
|
|
timer_tick_interrupt(regs);
|
|
}
|
|
|
|
update_process_times(user);
|
|
|
|
irq_exit();
|
|
|
|
prof_counter(cpu) = prof_multiplier(cpu);
|
|
}
|
|
|
|
/* Guarantee 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;
|
|
|
|
/* Guarantee 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)
|
|
{
|
|
boot_cpu_id = hard_smp_processor_id();
|
|
current_tick_offset = timer_tick_offset;
|
|
|
|
cpu_set(boot_cpu_id, cpu_online_map);
|
|
prof_counter(boot_cpu_id) = prof_multiplier(boot_cpu_id) = 1;
|
|
}
|
|
|
|
/* /proc/profile writes can call this, don't __init it please. */
|
|
static DEFINE_SPINLOCK(prof_setup_lock);
|
|
|
|
int setup_profiling_timer(unsigned int multiplier)
|
|
{
|
|
unsigned long flags;
|
|
int i;
|
|
|
|
if ((!multiplier) || (timer_tick_offset / multiplier) < 1000)
|
|
return -EINVAL;
|
|
|
|
spin_lock_irqsave(&prof_setup_lock, flags);
|
|
for (i = 0; i < NR_CPUS; i++)
|
|
prof_multiplier(i) = multiplier;
|
|
current_tick_offset = (timer_tick_offset / multiplier);
|
|
spin_unlock_irqrestore(&prof_setup_lock, flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
void __init smp_prepare_cpus(unsigned int max_cpus)
|
|
{
|
|
int instance, mid;
|
|
|
|
instance = 0;
|
|
while (!cpu_find_by_instance(instance, NULL, &mid)) {
|
|
if (mid < max_cpus)
|
|
cpu_set(mid, phys_cpu_present_map);
|
|
instance++;
|
|
}
|
|
|
|
if (num_possible_cpus() > max_cpus) {
|
|
instance = 0;
|
|
while (!cpu_find_by_instance(instance, NULL, &mid)) {
|
|
if (mid != boot_cpu_id) {
|
|
cpu_clear(mid, phys_cpu_present_map);
|
|
if (num_possible_cpus() <= max_cpus)
|
|
break;
|
|
}
|
|
instance++;
|
|
}
|
|
}
|
|
|
|
smp_store_cpu_info(boot_cpu_id);
|
|
}
|
|
|
|
void __devinit smp_prepare_boot_cpu(void)
|
|
{
|
|
if (hard_smp_processor_id() >= NR_CPUS) {
|
|
prom_printf("Serious problem, boot cpu id >= NR_CPUS\n");
|
|
prom_halt();
|
|
}
|
|
|
|
current_thread_info()->cpu = hard_smp_processor_id();
|
|
|
|
cpu_set(smp_processor_id(), cpu_online_map);
|
|
cpu_set(smp_processor_id(), phys_cpu_present_map);
|
|
}
|
|
|
|
int __devinit __cpu_up(unsigned int cpu)
|
|
{
|
|
int ret = smp_boot_one_cpu(cpu);
|
|
|
|
if (!ret) {
|
|
cpu_set(cpu, smp_commenced_mask);
|
|
while (!cpu_isset(cpu, cpu_online_map))
|
|
mb();
|
|
if (!cpu_isset(cpu, cpu_online_map)) {
|
|
ret = -ENODEV;
|
|
} else {
|
|
smp_synchronize_one_tick(cpu);
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
void __init smp_cpus_done(unsigned int max_cpus)
|
|
{
|
|
unsigned long bogosum = 0;
|
|
int i;
|
|
|
|
for (i = 0; i < NR_CPUS; i++) {
|
|
if (cpu_online(i))
|
|
bogosum += cpu_data(i).udelay_val;
|
|
}
|
|
printk("Total of %ld processors activated "
|
|
"(%lu.%02lu BogoMIPS).\n",
|
|
(long) num_online_cpus(),
|
|
bogosum/(500000/HZ),
|
|
(bogosum/(5000/HZ))%100);
|
|
}
|
|
|
|
void smp_send_reschedule(int cpu)
|
|
{
|
|
smp_receive_signal(cpu);
|
|
}
|
|
|
|
/* This is a nop because we capture all other cpus
|
|
* anyways when making the PROM active.
|
|
*/
|
|
void smp_send_stop(void)
|
|
{
|
|
}
|
|
|
|
unsigned long __per_cpu_base __read_mostly;
|
|
unsigned long __per_cpu_shift __read_mostly;
|
|
|
|
EXPORT_SYMBOL(__per_cpu_base);
|
|
EXPORT_SYMBOL(__per_cpu_shift);
|
|
|
|
void __init setup_per_cpu_areas(void)
|
|
{
|
|
unsigned long goal, size, i;
|
|
char *ptr;
|
|
/* Created by linker magic */
|
|
extern char __per_cpu_start[], __per_cpu_end[];
|
|
|
|
/* Copy section for each CPU (we discard the original) */
|
|
goal = ALIGN(__per_cpu_end - __per_cpu_start, PAGE_SIZE);
|
|
|
|
#ifdef CONFIG_MODULES
|
|
if (goal < PERCPU_ENOUGH_ROOM)
|
|
goal = PERCPU_ENOUGH_ROOM;
|
|
#endif
|
|
__per_cpu_shift = 0;
|
|
for (size = 1UL; size < goal; size <<= 1UL)
|
|
__per_cpu_shift++;
|
|
|
|
/* Make sure the resulting __per_cpu_base value
|
|
* will fit in the 43-bit sign extended IMMU
|
|
* TSB register.
|
|
*/
|
|
ptr = __alloc_bootmem(size * NR_CPUS, PAGE_SIZE,
|
|
(unsigned long) __per_cpu_start);
|
|
|
|
__per_cpu_base = ptr - __per_cpu_start;
|
|
|
|
if ((__per_cpu_shift < PAGE_SHIFT) ||
|
|
(__per_cpu_base & ~PAGE_MASK) ||
|
|
(__per_cpu_base != (((long) __per_cpu_base << 20) >> 20))) {
|
|
prom_printf("PER_CPU: Invalid layout, "
|
|
"ptr[%p] shift[%lx] base[%lx]\n",
|
|
ptr, __per_cpu_shift, __per_cpu_base);
|
|
prom_halt();
|
|
}
|
|
|
|
for (i = 0; i < NR_CPUS; i++, ptr += size)
|
|
memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
|
|
|
|
/* Finally, load in the boot cpu's base value.
|
|
* We abuse the IMMU TSB register for trap handler
|
|
* entry and exit loading of %g5. That is why it
|
|
* has to be page aligned.
|
|
*/
|
|
cpu_setup_percpu_base(hard_smp_processor_id());
|
|
}
|