From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=134.134.136.100; helo=mga07.intel.com; envelope-from=ruiyu.ni@intel.com; receiver=edk2-devel@lists.01.org Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id DFEFF21FC7497 for ; Thu, 12 Oct 2017 01:44:44 -0700 (PDT) Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga105.jf.intel.com with ESMTP; 12 Oct 2017 01:48:15 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.43,365,1503385200"; d="scan'208";a="909212124" Received: from ray-dev.ccr.corp.intel.com ([10.239.9.7]) by FMSMGA003.fm.intel.com with ESMTP; 12 Oct 2017 01:48:14 -0700 From: Ruiyu Ni To: edk2-devel@lists.01.org Cc: Michael D Kinney , Eric Dong Date: Thu, 12 Oct 2017 16:48:08 +0800 Message-Id: <20171012084810.148196-3-ruiyu.ni@intel.com> X-Mailer: git-send-email 2.12.2.windows.2 In-Reply-To: <20171012084810.148196-1-ruiyu.ni@intel.com> References: <20171012084810.148196-1-ruiyu.ni@intel.com> Subject: [PATCH 2/4] UefiCpuPkg/MtrrLib: Optimize MtrrLibLeastAlignment() X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 12 Oct 2017 08:44:45 -0000 The patch changes MtrrLibLeastAlignment() to MtrrLibBiggestAlignment() and optimizes the implementation to be more efficient. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ruiyu Ni Cc: Michael D Kinney Cc: Eric Dong --- UefiCpuPkg/Library/MtrrLib/MtrrLib.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c index 5b21fe11f1..0fecc0122c 100644 --- a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c +++ b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c @@ -656,7 +656,8 @@ MtrrGetMemoryAttributeInVariableMtrr ( } /** - Return the least alignment of address. + Return the biggest alignment (lowest set bit) of address. + The function is equivalent to: 1 << LowBitSet64 (Address). @param Address The address to return the alignment. @param Alignment0 The alignment to return when Address is 0. @@ -664,7 +665,7 @@ MtrrGetMemoryAttributeInVariableMtrr ( @return The least alignment of the Address. **/ UINT64 -MtrrLibLeastAlignment ( +MtrrLibBiggestAlignment ( UINT64 Address, UINT64 Alignment0 ) @@ -673,7 +674,7 @@ MtrrLibLeastAlignment ( return Alignment0; } - return LShiftU64 (1, (UINTN) LowBitSet64 (Address)); + return Address & ((~Address) + 1); } /** @@ -705,12 +706,12 @@ MtrrLibGetPositiveMtrrNumber ( // for (MtrrNumber = 0; Length != 0; MtrrNumber++) { if (UseLeastAlignment) { - SubLength = MtrrLibLeastAlignment (BaseAddress, Alignment0); + SubLength = MtrrLibBiggestAlignment (BaseAddress, Alignment0); if (SubLength > Length) { // // Set a flag when remaining length is too small - // so that MtrrLibLeastAlignment() is not called in following loops. + // so that MtrrLibBiggestAlignment() is not called in following loops. // UseLeastAlignment = FALSE; } @@ -873,7 +874,7 @@ MtrrLibGetMtrrNumber ( // Left subtraction bit by bit, to find the optimal left subtraction solution. // for (SubtractiveMtrrNumber = 0, SubtractiveCount = 1; BaseAddress != 0; SubtractiveCount++) { - Alignment = MtrrLibLeastAlignment (BaseAddress, Alignment0); + Alignment = MtrrLibBiggestAlignment (BaseAddress, Alignment0); // // Check whether the memory type of [BaseAddress - Alignment, BaseAddress) can override Type. @@ -928,7 +929,7 @@ MtrrLibGetMtrrNumber ( // MiddleMtrrNumber = 0; while (Length != 0) { - BaseAlignment = MtrrLibLeastAlignment (BaseAddress, Alignment0); + BaseAlignment = MtrrLibBiggestAlignment (BaseAddress, Alignment0); if (BaseAlignment > Length) { break; } @@ -953,7 +954,7 @@ MtrrLibGetMtrrNumber ( LeastRightMtrrNumber = MtrrLibGetPositiveMtrrNumber (BaseAddress, Length, Alignment0); for (SubtractiveCount = 1; Length < BaseAlignment; SubtractiveCount++) { - Alignment = MtrrLibLeastAlignment (BaseAddress + Length, Alignment0); + Alignment = MtrrLibBiggestAlignment (BaseAddress + Length, Alignment0); if (!MtrrLibSubstractable (Ranges, RangeCount, Type, BaseAddress + Length, Alignment)) { break; } @@ -1644,7 +1645,7 @@ MtrrLibSetMemoryAttributeInVariableMtrr ( } while (SubtractiveLeft-- != 0) { - Alignment = MtrrLibLeastAlignment (BaseAddress, Alignment0); + Alignment = MtrrLibBiggestAlignment (BaseAddress, Alignment0); ASSERT (Alignment <= Length); MtrrLibAddVariableMtrr (Ranges, RangeCount, VariableMtrr, VariableMtrrCapacity, VariableMtrrCount, @@ -1654,7 +1655,7 @@ MtrrLibSetMemoryAttributeInVariableMtrr ( } while (Length != 0) { - Alignment = MtrrLibLeastAlignment (BaseAddress, Alignment0); + Alignment = MtrrLibBiggestAlignment (BaseAddress, Alignment0); if (Alignment > Length) { break; } @@ -1665,7 +1666,7 @@ MtrrLibSetMemoryAttributeInVariableMtrr ( } while (SubtractiveRight-- != 0) { - Alignment = MtrrLibLeastAlignment (BaseAddress + Length, Alignment0); + Alignment = MtrrLibBiggestAlignment (BaseAddress + Length, Alignment0); MtrrLibAddVariableMtrr (Ranges, RangeCount, VariableMtrr, VariableMtrrCapacity, VariableMtrrCount, BaseAddress + Length, Alignment, CacheInvalid, Alignment0); Length += Alignment; @@ -1674,7 +1675,7 @@ MtrrLibSetMemoryAttributeInVariableMtrr ( UseLeastAlignment = TRUE; while (Length != 0) { if (UseLeastAlignment) { - Alignment = MtrrLibLeastAlignment (BaseAddress, Alignment0); + Alignment = MtrrLibBiggestAlignment (BaseAddress, Alignment0); if (Alignment > Length) { UseLeastAlignment = FALSE; } -- 2.12.2.windows.2