xiaomi-sm8450/android_kernel_xiaomi_sm8450
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[SPARC64]: More fully work around Spitfire Errata 51.

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It appears that a memory barrier soon after a mispredicted
branch, not just in the delay slot, can cause the hang
condition of this cpu errata.

So move them out-of-line, and explicitly put them into
a "branch always, predict taken" delay slot which should
fully kill this problem.

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller
2005-08-29 12:46:22 -07:00
parent 442464a500
commit 4f07118f65
14 changed files with 143 additions and 54 deletions
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30
arch/sparc64/kernel/smp.c
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@@ -144,7 +144,7 @@ void __init smp_callin(void)
current->active_mm = &init_mm;
while (!cpu_isset(cpuid, smp_commenced_mask))
membar("#LoadLoad");
rmb();
cpu_set(cpuid, cpu_online_map);
}
@@ -184,11 +184,11 @@ static inline long get_delta (long *rt, long *master)
for (i = 0; i < NUM_ITERS; i++) {
t0 = tick_ops->get_tick();
go[MASTER] = 1;
membar("#StoreLoad");
membar_storeload();
while (!(tm = go[SLAVE]))
membar("#LoadLoad");
rmb();
go[SLAVE] = 0;
membar("#StoreStore");
wmb();
t1 = tick_ops->get_tick();
if (t1 - t0 < best_t1 - best_t0)
@@ -221,7 +221,7 @@ void smp_synchronize_tick_client(void)
go[MASTER] = 1;
while (go[MASTER])
membar("#LoadLoad");
rmb();
local_irq_save(flags);
{
@@ -273,21 +273,21 @@ static void smp_synchronize_one_tick(int cpu)
/* wait for client to be ready */
while (!go[MASTER])
membar("#LoadLoad");
rmb();
/* now let the client proceed into his loop */
go[MASTER] = 0;
membar("#StoreLoad");
membar_storeload();
spin_lock_irqsave(&itc_sync_lock, flags);
{
for (i = 0; i < NUM_ROUNDS*NUM_ITERS; i++) {
while (!go[MASTER])
membar("#LoadLoad");
rmb();
go[MASTER] = 0;
membar("#StoreStore");
wmb();
go[SLAVE] = tick_ops->get_tick();
membar("#StoreLoad");
membar_storeload();
}
}
spin_unlock_irqrestore(&itc_sync_lock, flags);
@@ -927,11 +927,11 @@ void smp_capture(void)
smp_processor_id());
#endif
penguins_are_doing_time = 1;
membar("#StoreStore | #LoadStore");
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");
rmb();
#ifdef CAPTURE_DEBUG
printk("done\n");
#endif
@@ -947,7 +947,7 @@ void smp_release(void)
smp_processor_id());
#endif
penguins_are_doing_time = 0;
membar("#StoreStore | #StoreLoad");
membar_storeload_storestore();
atomic_dec(&smp_capture_registry);
}
}
@@ -970,9 +970,9 @@ void smp_penguin_jailcell(int irq, struct pt_regs *regs)
save_alternate_globals(global_save);
prom_world(1);
atomic_inc(&smp_capture_registry);
membar("#StoreLoad | #StoreStore");
membar_storeload_storestore();
while (penguins_are_doing_time)
membar("#LoadLoad");
rmb();
restore_alternate_globals(global_save);
atomic_dec(&smp_capture_registry);
prom_world(0);