From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZrsrm7xXq+ZWwtZcOJ+v4zP2MACZWbtgA/EnT1YDgXLdSD1DBzA7ZFgoXo5m/UspJtNAlGY ARC-Seal: i=1; a=rsa-sha256; t=1525116463; cv=none; d=google.com; s=arc-20160816; b=jkYeS5RIWmiKLxVXsSH33qfKsSZ6QbhPW7WBxdJfAg7yvY7TB2Iy7cYzLOI607sLk1 16AlVw37Z/2hTNF7VOtHZa3uinRnYeMqjf62td+TSQyHT6hHFcCsNN9zGEOuCuMQfrC7 b7GJA1rVcR8z2fpxnvUhVXkybJCS4OGZjOloezyQHV94ZufnrQal2oiLASrTK0Wcomdc Gka5eJdM15HFkVvhB/3+rLzozIzwSlQ+yRCbDBb9178Po1t6NWitPdPLWwLxMd2/YmQe pzn7oFwzVurmtvoqo/pHot5+NqZ68ZtAZsbh1qpaI+NYSod0BFFCoSm0maEBwZ4MSJLK gkxw== 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=4BCaLsfBnHLfGsC2Jwjf55gMHCvqdKzPdCgnZ2HOCRg=; b=pO6JtCJeBBGzSZcTOI13iyj0YKMppi0z3O/9DJBRQ096EOnFUeNM0FdyS5vYXTYgE/ qThZaQdSA+HdVRb30jr5k6PQ3jguScHvOzf3cHAx2mGNJUAaOhhiejHPER0aGmNHiT/T L3F/qrhKoaS588yxXyTfzEcX/PFcwkjIMKED5XuGtEGlBn/jT3enI2ldGoiFx3HlDa5n 8X6IrNDsc1wx5dHhU38kJAasITrRHYG4+k1uTnLqyBw/ZAiYYe1+NP8RC82+WSVIWAmH WqFDBI3jPjY2EzvKVQWST8raeyegZ54FBcLQFIMELMT5imnm+z06PH4seuWAR94RDjvb knfw== 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 D86A222DCC 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 4.14 85/91] x86/smpboot: Dont use mwait_play_dead() on AMD systems Date: Mon, 30 Apr 2018 12:25:07 -0700 Message-Id: <20180430184008.726821539@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180430184004.216234025@linuxfoundation.org> References: <20180430184004.216234025@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?1599200520500193185?= 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: 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 @@ -1613,6 +1613,8 @@ 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))