From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x227Kw47JGB3/RyRlgj7yPoHkQRTAihxdN1lRBtRi6H469dO1zY7ZXtZnFQ9rtffLXG3auQkD ARC-Seal: i=1; a=rsa-sha256; t=1517855020; cv=none; d=google.com; s=arc-20160816; b=S+7HbdF9SYC01Dd3cfpDQ+6omBSLE7Fdoai/nMURnBTA7voFuM4i3BwHwiuEIuiGTV tZkTEks2W5q+M8ZoX1UelWZveg7f80912i6fe7dAVBep83PnLUAJr/uf0uGKXfZhothx iNFfVqe1nnHSfhJ6MRLM8CpntJA20lrn9B1xoLzqvGWbwi05yj94rjbUa4+z56op1TTH s1atn8BWnbi3P6gQjdYfGCwuRjBChWm/rwzavY07ByzyMD3CQ0+FaNGX9+wNzkDc4opA 7BuCVxRiTFGoa+JUxFVsBAywLAbOBQxd/+/rE1IYTRYX3pRTc80wv0zbFTHL3ucO7lvs /SWQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=1Sc0lw0t+rh67154D/TBQd0+lE1/BBSwMqfoZIORYiw=; b=Y53HFmLocw7SSnWT6oVwWuPAH/5MxbgKHvzDhirPTgix/OjmZU4qlhPauho2gODpFn XNWFljtPv6LppW6HQfle+kQ3kS4pV6AllFkPcv8loS1210C59fTt1D6Rvc0l/TbbJK7b Vhz2xnkRAGvB7drN+dR1ZpC37B14z46ifqmZsRwCT4SC2dmhIas5a9IQMg6WD+gHJDeA DGZgbJw3hTmbriiJ1WAMwJicwqQ2Y0mhhNyBojmuBz1PgecXarJLFDq0/s3Y5Oh6iXag Yry6beAGrQnitwyXWGSuciVU5WPA5EfKFbsy1qHyHO1LGTBXCCxeBPh7dmT56vtahLDG Qa9Q== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 104.132.1.108 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 104.132.1.108 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Ellerman , Nicholas Piggin Subject: [PATCH 4.14 03/64] powerpc/64s: Allow control of RFI flush via debugfs Date: Mon, 5 Feb 2018 10:22:22 -0800 Message-Id: <20180205182138.714615532@linuxfoundation.org> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180205182138.571333346@linuxfoundation.org> References: <20180205182138.571333346@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1591586346194152818?= X-GMAIL-MSGID: =?utf-8?q?1591586346194152818?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michael Ellerman commit 236003e6b5443c45c18e613d2b0d776a9f87540e upstream. Expose the state of the RFI flush (enabled/disabled) via debugfs, and allow it to be enabled/disabled at runtime. eg: $ cat /sys/kernel/debug/powerpc/rfi_flush 1 $ echo 0 > /sys/kernel/debug/powerpc/rfi_flush $ cat /sys/kernel/debug/powerpc/rfi_flush 0 Signed-off-by: Michael Ellerman Reviewed-by: Nicholas Piggin Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/setup_64.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -38,6 +38,7 @@ #include #include +#include #include #include #include @@ -885,6 +886,35 @@ void __init setup_rfi_flush(enum l1d_flu rfi_flush_enable(enable); } +#ifdef CONFIG_DEBUG_FS +static int rfi_flush_set(void *data, u64 val) +{ + if (val == 1) + rfi_flush_enable(true); + else if (val == 0) + rfi_flush_enable(false); + else + return -EINVAL; + + return 0; +} + +static int rfi_flush_get(void *data, u64 *val) +{ + *val = rfi_flush ? 1 : 0; + return 0; +} + +DEFINE_SIMPLE_ATTRIBUTE(fops_rfi_flush, rfi_flush_get, rfi_flush_set, "%llu\n"); + +static __init int rfi_flush_debugfs_init(void) +{ + debugfs_create_file("rfi_flush", 0600, powerpc_debugfs_root, NULL, &fops_rfi_flush); + return 0; +} +device_initcall(rfi_flush_debugfs_init); +#endif + ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf) { if (rfi_flush)