From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZoFMSpHC8+Yj2w2DerF5SAKP6EhI2BZTVGTbd81we4oyaaLdGrVTOB70T+XDGQRiXTkqY0n ARC-Seal: i=1; a=rsa-sha256; t=1525116366; cv=none; d=google.com; s=arc-20160816; b=zPW5znB6vMzl/sE0bdqWL+LlGARflHwuMA8VfmxrVXlHxJxbtSMttcPIepbjpTz6qm AhqIZhRUvhhfrocLPw0ql6IDIqIm8sS3/4+jkgjF6EdeYxfUJ1j/Xb3j57WnJ6/vw0oo 68g6yKFlgqiUQFhMy6ruU8UbvajkYZ2UB2z5fQqCaxWKqfM20HU8Oo4Uu66l9Cb1Vt8v 6T80bGa3Hk68sZWcWxOI8S3qCEhH6GtNR5Sk/WOd6oSVWwNNayBR5Ry+mS9vEGgF/icF OQTZlHeGWRUdIWJTpa7qKl1pY1xCWijiKTgwWrQa6hq4q0lgZMFELRs/Hg2yrozV0cZQ lBtA== 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=+cqqRqnAmt42Yo7pJWUROHFnvb53JS3WNP+2HV2Wwpo=; b=w4n06o23QGlJrPqzL796rBpIYpYraRXGlq0Bc4MMXe3f2HoRU2vG/HgMHyqunc5Aol 4B9YLKje2IrJ9IANT98zf/YcflVdeXu9LkojSJ/G40Fae8NK0L84kV3SuDRRmO/3Uecf shcZLcZWExPmmfiw18ipJknUHCSVLWvexsRnV5ChJeBPwrvU/42x+YWN+11xZh1WIsR3 jWw61WTBYo9o2yk3leJAav+wBrI4iRdZH2/syT6ek+dfCcmxwHoQC9ve6dDiyulJwckH wqPrEQVitJkwezWfKShg6RU0tyGYB5+8PnAzuX1sjCW0pjmhTXY1cNhOpQ+emNN4rJJn zR5Q== 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 AC03622DAC 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 4.4 41/44] x86/smpboot: Dont use mwait_play_dead() on AMD systems Date: Mon, 30 Apr 2018 12:24:52 -0700 Message-Id: <20180430190947.967684398@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180430190946.093694747@linuxfoundation.org> References: <20180430190946.093694747@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?1599200418723747238?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.4-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 @@ -1442,6 +1442,8 @@ 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))