From: Michael Ellerman <mpe@ellerman.id.au>
Date: Wed, 23 Jul 2014 07:20:04 +0000 (+1000)
Subject: powerpc/perf: Fix MMCR2 handling for EBB
X-Git-Tag: omap-for-v3.17/fixes-against-rc2~220^2~2
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8903461c9bc56fcb041fb92d054e2529951770b6;p=pandora-kernel.git

powerpc/perf: Fix MMCR2 handling for EBB

In the recent commit b50a6c584bb4 "Clear MMCR2 when enabling PMU", I
screwed up the handling of MMCR2 for tasks using EBB.

We must make sure we set MMCR2 *before* ebb_switch_in(), otherwise we
overwrite the value of MMCR2 that userspace may have written. That
potentially breaks a task that uses EBB and manually uses MMCR2 for
event freezing.

Fixes: b50a6c584bb4 ("powerpc/perf: Clear MMCR2 when enabling PMU")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---

Reading git-diff-tree failed