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Subject: [PATCH] powerpc/64: Fix an out of date comment about MMIO ordering
Date:   Thu, 16 Jul 2020 12:38:20 -0700
Message-Id: <20200716193820.1141936-1-palmer@dabbelt.com>
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Cc:     mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org,
        npiggin@gmail.com, msuchanek@suse.de, tglx@linutronix.de,
        bigeasy@linutronix.de, jniethe5@gmail.com,
        linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
        kernel-team@android.com, Palmer Dabbelt <palmerdabbelt@google.com>
From:   Palmer Dabbelt <palmer@dabbelt.com>
To:     Will Deacon <willdeacon@google.com>
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From: Palmer Dabbelt <palmerdabbelt@google.com>

This primitive has been renamed, but because it was spelled incorrectly in the
first place it must have escaped the fixup patch.  As far as I can tell this
logic is still correct: smp_mb__after_spinlock() uses the default smp_mb()
implementation, which is "sync" rather than "hwsync" but those are the same
(though I'm not that familiar with PowerPC).

Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 arch/powerpc/kernel/entry_64.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index b3c9f15089b6..7b38b4daca93 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -357,7 +357,7 @@ _GLOBAL(_switch)
 	 * kernel/sched/core.c).
 	 *
 	 * Uncacheable stores in the case of involuntary preemption must
-	 * be taken care of. The smp_mb__before_spin_lock() in __schedule()
+	 * be taken care of. The smp_mb__after_spinlock() in __schedule()
 	 * is implemented as hwsync on powerpc, which orders MMIO too. So
 	 * long as there is an hwsync in the context switch path, it will
 	 * be executed on the source CPU after the task has performed
-- 
2.28.0.rc0.105.gf9edc3c819-goog