From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4F85A381D5; Fri, 24 Nov 2023 18:14:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="LN/9dbAD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D15ABC433C8; Fri, 24 Nov 2023 18:14:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700849652; bh=34N0RO3lxd1+/vpVfA1FfyiEUDk4UyMBDWxKIBaj6Gs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LN/9dbADI5B7ExMiL8d6ZeY9cH4X/rg84a0LGFGMS4+8ygfIYAKmdmmM7Oj+oiliY xbuO5xnsgJtnaE3oVOfvQ5H0m7yy3eYzlRRHl96IFBNaebJaJzwpfWq+rS7xC1hph7 69JPIRZAh8jFKHN+nKjcGr+KoDHwY+BPDEIk8NLY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Nicholas Piggin , Michael Ellerman Subject: [PATCH 6.6 242/530] powerpc/perf: Fix disabling BHRB and instruction sampling Date: Fri, 24 Nov 2023 17:46:48 +0000 Message-ID: <20231124172035.423970877@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231124172028.107505484@linuxfoundation.org> References: <20231124172028.107505484@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nicholas Piggin commit ea142e590aec55ba40c5affb4d49e68c713c63dc upstream. When the PMU is disabled, MMCRA is not updated to disable BHRB and instruction sampling. This can lead to those features remaining enabled, which can slow down a real or emulated CPU. Fixes: 1cade527f6e9 ("powerpc/perf: BHRB control to disable BHRB logic when not used") Cc: stable@vger.kernel.org # v5.9+ Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://msgid.link/20231018153423.298373-1-npiggin@gmail.com Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/perf/core-book3s.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -1371,8 +1371,7 @@ static void power_pmu_disable(struct pmu /* * Disable instruction sampling if it was enabled */ - if (cpuhw->mmcr.mmcra & MMCRA_SAMPLE_ENABLE) - val &= ~MMCRA_SAMPLE_ENABLE; + val &= ~MMCRA_SAMPLE_ENABLE; /* Disable BHRB via mmcra (BHRBRD) for p10 */ if (ppmu->flags & PPMU_ARCH_31) @@ -1383,7 +1382,7 @@ static void power_pmu_disable(struct pmu * instruction sampling or BHRB. */ if (val != mmcra) { - mtspr(SPRN_MMCRA, mmcra); + mtspr(SPRN_MMCRA, val); mb(); isync(); }