From nobody Sat Sep 6 17:15:44 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 17568893358691015.0023391424218; Wed, 3 Sep 2025 01:48:55 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1utjAY-0003LK-NU; Wed, 03 Sep 2025 04:48:42 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1utjAX-0003Jk-8B for qemu-devel@nongnu.org; Wed, 03 Sep 2025 04:48:41 -0400 Received: from mail.loongson.cn ([114.242.206.163]) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1utjAU-0007NB-3S for qemu-devel@nongnu.org; Wed, 03 Sep 2025 04:48:40 -0400 Received: from loongson.cn (unknown [10.2.5.213]) by gateway (Coremail) with SMTP id _____8CxaNHjALhoJycGAA--.12926S3; Wed, 03 Sep 2025 16:48:35 +0800 (CST) Received: from localhost.localdomain (unknown [10.2.5.213]) by front1 (Coremail) with SMTP id qMiowJDxbMHcALhoc916AA--.5293S6; Wed, 03 Sep 2025 16:48:35 +0800 (CST) From: Bibo Mao To: Song Gao , Richard Henderson , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Cc: Jiaxun Yang , qemu-devel@nongnu.org Subject: [PATCH v3 04/12] target/loongarch: Update TLB index selection method Date: Wed, 3 Sep 2025 16:48:19 +0800 Message-Id: <20250903084827.3085911-5-maobibo@loongson.cn> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20250903084827.3085911-1-maobibo@loongson.cn> References: <20250903084827.3085911-1-maobibo@loongson.cn> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: qMiowJDxbMHcALhoc916AA--.5293S6 X-CM-SenderInfo: xpdruxter6z05rqj20fqof0/ X-Coremail-Antispam: 1Uk129KBjDUn29KB7ZKAUJUUUUU529EdanIXcx71UUUUU7KY7 ZEXasCq-sGcSsGvfJ3UbIjqfuFe4nvWSU5nxnvy29KBjDU0xBIdaVrnUUvcSsGvfC2Kfnx nUUI43ZEXa7xR_UUUUUUUUU== Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=114.242.206.163; envelope-from=maobibo@loongson.cn; helo=mail.loongson.cn X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1756889338684116600 Content-Type: text/plain; charset="utf-8" With function helper_tlbfill(), since there is no suitable TLB entry, new TLB will be added and invalidate one old TLB entry. The old TLB entry index is selected randomly, instead it can be optimized as following: 1. invalid TLB entry can be selected at first. 2. TLB entry with other ASID can be selected secondly 3. random method is used by last. Signed-off-by: Bibo Mao Reviewed-by: Richard Henderson --- target/loongarch/tcg/tlb_helper.c | 49 ++++++++++++++++++++++++++----- 1 file changed, 42 insertions(+), 7 deletions(-) diff --git a/target/loongarch/tcg/tlb_helper.c b/target/loongarch/tcg/tlb_h= elper.c index 331b485b1a..00422f259d 100644 --- a/target/loongarch/tcg/tlb_helper.c +++ b/target/loongarch/tcg/tlb_helper.c @@ -340,8 +340,11 @@ void helper_tlbwr(CPULoongArchState *env) void helper_tlbfill(CPULoongArchState *env) { uint64_t address, entryhi; - int index, set, stlb_idx; + int index, set, i, stlb_idx; uint16_t pagesize, stlb_ps; + uint16_t asid, tlb_asid; + LoongArchTLB *tlb; + uint8_t tlb_e; =20 if (FIELD_EX64(env->CSR_TLBRERA, CSR_TLBRERA, ISTLBR)) { entryhi =3D env->CSR_TLBREHI; @@ -355,20 +358,52 @@ void helper_tlbfill(CPULoongArchState *env) =20 /* Validity of stlb_ps is checked in helper_csrwr_stlbps() */ stlb_ps =3D FIELD_EX64(env->CSR_STLBPS, CSR_STLBPS, PS); + asid =3D FIELD_EX64(env->CSR_ASID, CSR_ASID, ASID); if (pagesize =3D=3D stlb_ps) { /* Only write into STLB bits [47:13] */ address =3D entryhi & ~MAKE_64BIT_MASK(0, R_CSR_TLBEHI_64_VPPN_SHI= FT); - - /* Choose one set ramdomly */ - set =3D get_random_tlb(0, 7); - - /* Index in one set */ + set =3D -1; stlb_idx =3D (address >> (stlb_ps + 1)) & 0xff; /* [0,255] */ + for (i =3D 0; i < 8; ++i) { + tlb =3D &env->tlb[i * 256 + stlb_idx]; + tlb_e =3D FIELD_EX64(tlb->tlb_misc, TLB_MISC, E); + if (!tlb_e) { + set =3D i; + break; + } + + tlb_asid =3D FIELD_EX64(tlb->tlb_misc, TLB_MISC, ASID); + if (asid !=3D tlb_asid) { + set =3D i; + } + } =20 + /* Choose one set randomly */ + if (set < 0) { + set =3D get_random_tlb(0, 7); + } index =3D set * 256 + stlb_idx; } else { /* Only write into MTLB */ - index =3D get_random_tlb(LOONGARCH_STLB, LOONGARCH_TLB_MAX - 1); + index =3D -1; + for (i =3D LOONGARCH_STLB; i < LOONGARCH_TLB_MAX; i++) { + tlb =3D &env->tlb[i]; + tlb_e =3D FIELD_EX64(tlb->tlb_misc, TLB_MISC, E); + + if (!tlb_e) { + index =3D i; + break; + } + + tlb_asid =3D FIELD_EX64(tlb->tlb_misc, TLB_MISC, ASID); + if (asid !=3D tlb_asid) { + index =3D i; + } + } + + if (index < 0) { + index =3D get_random_tlb(LOONGARCH_STLB, LOONGARCH_TLB_MAX - 1= ); + } } =20 invalidate_tlb(env, index); --=20 2.39.3