From nobody Sun Feb 8 17:42:10 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of groups.io designates 66.175.222.108 as permitted sender) client-ip=66.175.222.108; envelope-from=bounce+27952+109067+1787277+3901457@groups.io; helo=mail02.groups.io; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of groups.io designates 66.175.222.108 as permitted sender) smtp.mailfrom=bounce+27952+109067+1787277+3901457@groups.io; dmarc=fail(p=none dis=none) header.from=intel.com ARC-Seal: i=1; a=rsa-sha256; t=1695728380; cv=none; d=zohomail.com; s=zohoarc; b=YGisDI0kYs4yD1ZfCl/Iob+yb00u1VNINaFc2L3ogShnFUPMZ5jGSmxn9D7FKgCMWD474O33E7+pt/KBaitqw5GBbJ0hqtvZbG9CDIeXXWR7wzkzjQ9RUeN0fubnwZfmCdVEdCQISXrbrwkNNio6SiJEbrzngGbu5xxQVw+qx5s= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1695728380; h=Cc:Date:From:In-Reply-To:List-Subscribe:List-Id:List-Help:List-Unsubscribe:Message-ID:Reply-To:References:Sender:Subject:To; bh=YHcUFBSm5XVcVTPrUFNpxpIenhruE/23z8t6S/mk2ys=; b=CsvlsRIpgKtQY+mXfclT18Yciamg++ezDcFgyXMFdvlzhDFITbVUwnecIk1t6XyCg9SeVCG6AVxPR27kDm6gspUWMDpAMeCfm19h/LvDTsJEXqxUlHQCUx+Wbw7kN1IGIOWUjKSxWE1Q8losQGaDskPQ6KijGtD5l7PGikyLus4= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of groups.io designates 66.175.222.108 as permitted sender) smtp.mailfrom=bounce+27952+109067+1787277+3901457@groups.io; dmarc=fail header.from= (p=none dis=none) Received: from mail02.groups.io (mail02.groups.io [66.175.222.108]) by mx.zohomail.com with SMTPS id 1695728380556814.2804176355694; Tue, 26 Sep 2023 04:39:40 -0700 (PDT) Return-Path: DKIM-Signature: a=rsa-sha256; bh=S9g+/yazCOhMEqYd7QsE4geAwI1Cw9KZ2Vb7S9J/42M=; c=relaxed/simple; d=groups.io; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References:Precedence:List-Subscribe:List-Help:Sender:List-Id:Mailing-List:Delivered-To:Reply-To:List-Unsubscribe-Post:List-Unsubscribe; s=20140610; t=1695728380; v=1; b=ixCXEsvOdKc0sM0w0PidRvqRP3oVWD1jorrF08naRrYQwXywOO3C3q+r0fOjDASBKHWduTJy 0gPynFjj66YRF+5hj7yncTRCX/nSHnguLHuwxNZWt2G8CFC8EdnSLdSp6/wRvRTzGEDNoD/WBwg RwKsP5SHXY/8xL1Y6auJnv5Y= X-Received: by 127.0.0.2 with SMTP id FCdMYY1788612xQBfhNRVH5o; Tue, 26 Sep 2023 04:39:40 -0700 X-Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.126]) by mx.groups.io with SMTP id smtpd.web11.16623.1695728378396479540 for ; Tue, 26 Sep 2023 04:39:39 -0700 X-IronPort-AV: E=McAfee;i="6600,9927,10843"; a="366603648" X-IronPort-AV: E=Sophos;i="6.03,177,1694761200"; d="scan'208";a="366603648" X-Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Sep 2023 04:39:39 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10843"; a="995802135" X-IronPort-AV: E=Sophos;i="6.03,177,1694761200"; d="scan'208";a="995802135" X-Received: from sh1gapp1009.ccr.corp.intel.com ([10.239.189.219]) by fmsmga006.fm.intel.com with ESMTP; 26 Sep 2023 04:39:37 -0700 From: "Wu, Jiaxin" To: devel@edk2.groups.io Cc: Eric Dong , Ray Ni , Zeng Star , Rahul Kumar , Gerd Hoffmann Subject: [edk2-devel] [PATCH v1 1/2] UefiCpuPkg/PiSmmCpuDxeSmm: Optimize semaphore sync between BSP and AP Date: Tue, 26 Sep 2023 19:39:33 +0800 Message-Id: <20230926113934.8548-2-jiaxin.wu@intel.com> In-Reply-To: <20230926113934.8548-1-jiaxin.wu@intel.com> References: <20230926113934.8548-1-jiaxin.wu@intel.com> Precedence: Bulk List-Subscribe: List-Help: Sender: devel@edk2.groups.io List-Id: Mailing-List: list devel@edk2.groups.io; contact devel+owner@edk2.groups.io Reply-To: devel@edk2.groups.io,jiaxin.wu@intel.com List-Unsubscribe-Post: List-Unsubscribe=One-Click List-Unsubscribe: X-Gm-Message-State: sqoAsd8BRjHrR7tZYFAzTkXRx1787277AA= X-ZohoMail-DKIM: pass (identity @groups.io) X-ZM-MESSAGEID: 1695728381645100005 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" This patch is to: 1. Define 2 new functions (WaitForBsp & ReleaseBsp) used for the semaphore sync between BSP & AP. 2. Add ReleaseOneAp(), used for BSP to release one AP. With the change, BSP & AP Sync flow will be easy understand: BSP to Release All APs ---> AP to Wait BSP ReleaseAllAPs () WaitForBsp BSP to Wait All APs <--- AP to Release BSP WaitForAllAPs () ReleaseBsp BSP to Release One Ap ---> AP to Wait BSP ReleaseOneAp () ReleaseBsp Cc: Eric Dong Cc: Ray Ni Cc: Zeng Star Cc: Rahul Kumar Cc: Gerd Hoffmann Signed-off-by: Jiaxin Wu --- UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c | 72 ++++++++++++++++++++++++++++---= ---- 1 file changed, 58 insertions(+), 14 deletions(-) diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c b/UefiCpuPkg/PiSmmCpuDxe= Smm/MpService.c index 25d058c5b9..e96c7f51d6 100644 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c @@ -120,10 +120,11 @@ LockdownSemaphore ( =20 return Value; } =20 /** + Used for BSP to wait all APs. Wait all APs to performs an atomic compare exchange operation to release= semaphore. =20 @param NumberOfAPs AP number =20 **/ @@ -139,10 +140,11 @@ WaitForAllAPs ( WaitForSemaphore (mSmmMpSyncData->CpuData[BspIndex].Run); } } =20 /** + Used for BSP to release all APs. Performs an atomic compare exchange operation to release semaphore for each AP. =20 **/ VOID @@ -157,10 +159,52 @@ ReleaseAllAPs ( ReleaseSemaphore (mSmmMpSyncData->CpuData[Index].Run); } } } =20 +/** + Used for BSP to release one AP. + + @param ApSem IN: 32-bit unsigned integer + OUT: original integer + 1 +**/ +VOID +ReleaseOneAp ( + IN OUT volatile UINT32 *ApSem + ) +{ + ReleaseSemaphore (ApSem); +} + +/** + Used for AP to wait BSP. + + @param ApSem IN: 32-bit unsigned integer + OUT: original integer 0 +**/ +VOID +WaitForBsp ( + IN OUT volatile UINT32 *ApSem + ) +{ + WaitForSemaphore (ApSem); +} + +/** + Used for AP to release BSP. + + @param BspSem IN: 32-bit unsigned integer + OUT: original integer + 1 +**/ +VOID +ReleaseBsp ( + IN OUT volatile UINT32 *BspSem + ) +{ + ReleaseSemaphore (BspSem); +} + /** Check whether the index of CPU perform the package level register programming during System Management Mode initialization. =20 The index of Processor specified by mPackageFirstThreadIndex[PackageInde= x] @@ -632,11 +676,11 @@ BSPHandler ( // Signal all APs it's time for backup MTRRs // ReleaseAllAPs (); =20 // - // WaitForSemaphore() may wait for ever if an AP happens to enter SM= M at + // WaitForBsp() may wait for ever if an AP happens to enter SMM at // exactly this point. Please make sure PcdCpuSmmMaxSyncLoops has be= en set // to a large enough value to avoid this situation. // Note: For HT capable CPUs, threads within a core share the same s= et of MTRRs. // We do the backup first and then set MTRR to avoid race condition = for threads // in the same core. @@ -652,11 +696,11 @@ BSPHandler ( // Let all processors program SMM MTRRs together // ReleaseAllAPs (); =20 // - // WaitForSemaphore() may wait for ever if an AP happens to enter SM= M at + // WaitForBsp() may wait for ever if an AP happens to enter SMM at // exactly this point. Please make sure PcdCpuSmmMaxSyncLoops has be= en set // to a large enough value to avoid this situation. // ReplaceOSMtrrs (CpuIndex); =20 @@ -898,50 +942,50 @@ APHandler ( =20 if ((SyncMode =3D=3D SmmCpuSyncModeTradition) || SmmCpuFeaturesNeedConfi= gureMtrrs ()) { // // Notify BSP of arrival at this point // - ReleaseSemaphore (mSmmMpSyncData->CpuData[BspIndex].Run); + ReleaseBsp (mSmmMpSyncData->CpuData[BspIndex].Run); } =20 if (SmmCpuFeaturesNeedConfigureMtrrs ()) { // // Wait for the signal from BSP to backup MTRRs // - WaitForSemaphore (mSmmMpSyncData->CpuData[CpuIndex].Run); + WaitForBsp (mSmmMpSyncData->CpuData[CpuIndex].Run); =20 // // Backup OS MTRRs // MtrrGetAllMtrrs (&Mtrrs); =20 // // Signal BSP the completion of this AP // - ReleaseSemaphore (mSmmMpSyncData->CpuData[BspIndex].Run); + ReleaseBsp (mSmmMpSyncData->CpuData[BspIndex].Run); =20 // // Wait for BSP's signal to program MTRRs // - WaitForSemaphore (mSmmMpSyncData->CpuData[CpuIndex].Run); + WaitForBsp (mSmmMpSyncData->CpuData[CpuIndex].Run); =20 // // Replace OS MTRRs with SMI MTRRs // ReplaceOSMtrrs (CpuIndex); =20 // // Signal BSP the completion of this AP // - ReleaseSemaphore (mSmmMpSyncData->CpuData[BspIndex].Run); + ReleaseBsp (mSmmMpSyncData->CpuData[BspIndex].Run); } =20 while (TRUE) { // // Wait for something to happen // - WaitForSemaphore (mSmmMpSyncData->CpuData[CpuIndex].Run); + WaitForBsp (mSmmMpSyncData->CpuData[CpuIndex].Run); =20 // // Check if BSP wants to exit SMM // if (!(*mSmmMpSyncData->InsideSmm)) { @@ -977,16 +1021,16 @@ APHandler ( =20 if (SmmCpuFeaturesNeedConfigureMtrrs ()) { // // Notify BSP the readiness of this AP to program MTRRs // - ReleaseSemaphore (mSmmMpSyncData->CpuData[BspIndex].Run); + ReleaseBsp (mSmmMpSyncData->CpuData[BspIndex].Run); =20 // // Wait for the signal from BSP to program MTRRs // - WaitForSemaphore (mSmmMpSyncData->CpuData[CpuIndex].Run); + WaitForBsp (mSmmMpSyncData->CpuData[CpuIndex].Run); =20 // // Restore OS MTRRs // SmmCpuFeaturesReenableSmrr (); @@ -994,26 +1038,26 @@ APHandler ( } =20 // // Notify BSP the readiness of this AP to Reset states/semaphore for thi= s processor // - ReleaseSemaphore (mSmmMpSyncData->CpuData[BspIndex].Run); + ReleaseBsp (mSmmMpSyncData->CpuData[BspIndex].Run); =20 // // Wait for the signal from BSP to Reset states/semaphore for this proce= ssor // - WaitForSemaphore (mSmmMpSyncData->CpuData[CpuIndex].Run); + WaitForBsp (mSmmMpSyncData->CpuData[CpuIndex].Run); =20 // // Reset states/semaphore for this processor // *(mSmmMpSyncData->CpuData[CpuIndex].Present) =3D FALSE; =20 // // Notify BSP the readiness of this AP to exit SMM // - ReleaseSemaphore (mSmmMpSyncData->CpuData[BspIndex].Run); + ReleaseBsp (mSmmMpSyncData->CpuData[BspIndex].Run); } =20 /** Checks whether the input token is the current used token. =20 @@ -1277,11 +1321,11 @@ InternalSmmStartupThisAp ( mSmmMpSyncData->CpuData[CpuIndex].Status =3D CpuStatus; if (mSmmMpSyncData->CpuData[CpuIndex].Status !=3D NULL) { *mSmmMpSyncData->CpuData[CpuIndex].Status =3D EFI_NOT_READY; } =20 - ReleaseSemaphore (mSmmMpSyncData->CpuData[CpuIndex].Run); + ReleaseOneAp (mSmmMpSyncData->CpuData[CpuIndex].Run); =20 if (Token =3D=3D NULL) { AcquireSpinLock (mSmmMpSyncData->CpuData[CpuIndex].Busy); ReleaseSpinLock (mSmmMpSyncData->CpuData[CpuIndex].Busy); } --=20 2.16.2.windows.1 -=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D- Groups.io Links: You receive all messages sent to this group. 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