From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZrxWlAQR+LdjlQm4QNdJhNrOfRDrzGxaJCYqrz51iSJY4wZfhiehk77RkddIojxl6+2IKhg ARC-Seal: i=1; a=rsa-sha256; t=1525116407; cv=none; d=google.com; s=arc-20160816; b=HZnWkciXyq5DdUfYALBeCyu1RQWpNwjXrPMyz/Vxw/41maCS4bZGV6efdLrQYjo6xz tZRLCBj7fKH50XtYr6Q26yKt4ATxJbY1r0mCx0Ns3hjIuEKeJ7KHi9lYi4xJQyvz/1Vu h1YKTiKPU7nnFst6fnW5WCz8Y8WTYfJndDZVb1DOKuRXKeiL4jjBE662XT/vhTkUjhho fvuMHA3fB89AtYqHzHkzqW9Sq3Xxr9o+ry7aaV1X575FlemmBbOioD41LZqvPjiAX6C+ RvD2U2CD2ZrDz69Lcyexpm6TyRNTU5Nujuliv/MTLg1q00GoHGPvnPMKqnRVKs/mFqUI FOLw== 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:dmarc-filter:arc-authentication-results; bh=H/EgJzDNcUZ4cPK6rZIEwQOeDwn/Roqh2oEw5A1wWVs=; b=FLcu4hK+FW8x37GeVcr+JVtidYQKph6k5/54gAgb0+331+FhiAOFYY+2qrrveQSl54 3XfSn4N73KTwj01H5DAXgYtTHmUIMPl7W2nNiu35jhhDCOGeP3QN0HX6mit+IHKACYKH GkLtiT/uOXTommewrBLrLU6tci7oPyLp/GTw/m284AdOp2gGOJOkSGl1dDH+sddpCzjG +DjWJzuewbifYYdYakrZmdKHfwlrpJRF5Rc1sKB1GTcl/bh5QyCLYdnCxecR/LhesKVf ecxJOD1PUxUFwT7XSQRx3sVWeSutTE9FvfAAEvlQoh4EWjJiPxnfnKAuwfZSYuifd32u hAqA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of srs0=k66p=ht=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=K66P=HT=linuxfoundation.org=gregkh@kernel.org Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of srs0=k66p=ht=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=K66P=HT=linuxfoundation.org=gregkh@kernel.org DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4D78A22DCB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=fail smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yazen Ghannam , Thomas Gleixner , Borislav Petkov , Yazen Ghannam Subject: [PATCH 4.9 59/61] x86/smpboot: Dont use mwait_play_dead() on AMD systems Date: Mon, 30 Apr 2018 12:25:02 -0700 Message-Id: <20180430183956.262525567@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180430183951.312721450@linuxfoundation.org> References: <20180430183951.312721450@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review 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?1599200418723747238?= X-GMAIL-MSGID: =?utf-8?q?1599200462866947465?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yazen Ghannam commit da6fa7ef67f07108a1b0cb9fd9e7fcaabd39c051 upstream. Recent AMD systems support using MWAIT for C1 state. However, MWAIT will not allow deeper cstates than C1 on current systems. play_dead() expects to use the deepest state available. The deepest state available on AMD systems is reached through SystemIO or HALT. If MWAIT is available, it is preferred over the other methods, so the CPU never reaches the deepest possible state. Don't try to use MWAIT to play_dead() on AMD systems. Instead, use CPUIDLE to enter the deepest state advertised by firmware. If CPUIDLE is not available then fallback to HALT. Signed-off-by: Yazen Ghannam Signed-off-by: Thomas Gleixner Reviewed-by: Borislav Petkov Cc: stable@vger.kernel.org Cc: Yazen Ghannam Link: https://lkml.kernel.org/r/20180403140228.58540-1-Yazen.Ghannam@amd.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/smpboot.c | 2 ++ 1 file changed, 2 insertions(+) --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1591,6 +1591,8 @@ static inline void mwait_play_dead(void) void *mwait_ptr; int i; + if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) + return; if (!this_cpu_has(X86_FEATURE_MWAIT)) return; if (!this_cpu_has(X86_FEATURE_CLFLUSH))