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Commit 4f07118f authored by David S. Miller's avatar David S. Miller
Browse files

[SPARC64]: More fully work around Spitfire Errata 51. 



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: default avatarDavid S. Miller <davem@davemloft.net>
parent 442464a5

arch/sparc64/kernel/pci_iommu.c

+1 −1
Original line number Diff line number Diff line
@@ -466,7 +466,7 @@ do_flush_sync: 
		if (!limit)

			break;

		udelay(1);

		membar("#LoadLoad");

		rmb();

	}

	if (!limit)

		printk(KERN_WARNING "pci_strbuf_flush: flushflag timeout "

arch/sparc64/kernel/process.c

+1 −1
Original line number Diff line number Diff line
@@ -103,7 +103,7 @@ void cpu_idle(void) 
		 * other cpus see our increasing idleness for the buddy

		 * redistribution algorithm.  -DaveM

		 */

		membar("#StoreStore | #StoreLoad");

		membar_storeload_storestore();

	}

}

arch/sparc64/kernel/sbus.c

+1 −1
Original line number Diff line number Diff line
@@ -147,7 +147,7 @@ static void sbus_strbuf_flush(struct sbus_iommu *iommu, u32 base, unsigned long 
		if (!limit)

			break;

		udelay(1);

		membar("#LoadLoad");

		rmb();

	}

	if (!limit)

		printk(KERN_WARNING "sbus_strbuf_flush: flushflag timeout "

arch/sparc64/kernel/signal32.c

+12 −10
Original line number Diff line number Diff line
@@ -877,10 +877,11 @@ static void new_setup_frame32(struct k_sigaction *ka, struct pt_regs *regs, 
			unsigned long page = (unsigned long)

				page_address(pte_page(*ptep));



			__asm__ __volatile__(

			"	membar	#StoreStore\n"

			"	flush	%0 + %1"

			: : "r" (page), "r" (address & (PAGE_SIZE - 1))

			wmb();

			__asm__ __volatile__("flush	%0 + %1"

					     : /* no outputs */

					     : "r" (page),

					       "r" (address & (PAGE_SIZE - 1))

					     : "memory");

		}

		pte_unmap(ptep);
@@ -1292,10 +1293,11 @@ static void setup_rt_frame32(struct k_sigaction *ka, struct pt_regs *regs, 
			unsigned long page = (unsigned long)

				page_address(pte_page(*ptep));



			__asm__ __volatile__(

			"	membar	#StoreStore\n"

			"	flush	%0 + %1"

			: : "r" (page), "r" (address & (PAGE_SIZE - 1))

			wmb();

			__asm__ __volatile__("flush	%0 + %1"

					     : /* no outputs */

					     : "r" (page),

					       "r" (address & (PAGE_SIZE - 1))

					     : "memory");

		}

		pte_unmap(ptep);

arch/sparc64/kernel/smp.c

+15 −15
Original line number Diff line number Diff line
@@ -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);