From nobody Sat Oct 4 04:59:42 2025 Received: from cstnet.cn (smtp21.cstnet.cn [159.226.251.21]) (using TLSv1.2 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 02750321F59 for ; Wed, 20 Aug 2025 13:45:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.226.251.21 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755697513; cv=none; b=ow2dI345D61gcsB6OKm8jhi9craVMZcnXjoKp3yDD4sX4CSFmgWamxeBI6tg/dWP3x8I3sFNBLYOfo4ujI2cxR5dH944PouYXmA1ZaRmKZD3Etc2uKrLHbC91Ug8i4ntg+127UMlMXUGxgDkDa5JWtSil9RvtFLZ8L9bfCZ7VYs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755697513; c=relaxed/simple; bh=UaCKawQeo4rcaFjHfUPRvD0w2sJMwd20/syfhFSKKaA=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=TvE0ixoq1q+5xmNDGHRItusThIy88JrTBs+RMhCEKQFbxpsdi8C9bfxLm3l77ZitQPcjOzeYza3tKOhvZ2eBTQ7CVeKE+k0Ai3f94ar84KHaFFb8RK1yv8P9VTs6LB4Vvdlhc+Wc7SRKYzhgFOCqe7YRFmMcxLFwRbh5HSbgcUs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn; spf=pass smtp.mailfrom=iscas.ac.cn; arc=none smtp.client-ip=159.226.251.21 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=iscas.ac.cn Received: from [127.0.0.2] (unknown [114.241.87.235]) by APP-01 (Coremail) with SMTP id qwCowABHN6tT0aVogOTBDQ--.24665S4; Wed, 20 Aug 2025 21:44:52 +0800 (CST) From: Vivian Wang Date: Wed, 20 Aug 2025 21:44:46 +0800 Subject: [PATCH 2/6] riscv: pgtable: Convert to use_alternative_unlikely Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250820-riscv-altn-helper-wip-v1-2-c3c626c1f7e6@iscas.ac.cn> References: <20250820-riscv-altn-helper-wip-v1-0-c3c626c1f7e6@iscas.ac.cn> In-Reply-To: <20250820-riscv-altn-helper-wip-v1-0-c3c626c1f7e6@iscas.ac.cn> To: Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Yury Norov , Rasmus Villemoes Cc: Vivian Wang , Vivian Wang , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org X-Mailer: b4 0.14.2 X-CM-TRANSID: qwCowABHN6tT0aVogOTBDQ--.24665S4 X-Coremail-Antispam: 1UD129KBjvJXoWxJFWUKFWUWrWxtFyftF1xGrg_yoW5CFy5pr Z3CasxXFWrGw1I9rZayr4Uur45Z39ag3Z8tr1S93ZYyr4akrWavFnxJ3WSvry8Ja97X34x KF4Ykr45Gw1ayr7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUmj14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_Jryl82xGYIkIc2 x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_Gr0_Xr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1l84 ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_GcCE3s1le2I2 62IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcV AFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG 0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lFIxGxcIEc7CjxVA2Y2ka0xkIwI 1lc7CjxVAaw2AFwI0_Jw0_GFyl42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_ Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17 CE14v26r1q6r43MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0 I7IYx2IY6xkF7I0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I 8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4UJVWxJrUvcSsGvfC2Kfnx nUUI43ZEXa7VUbH5lUUUUUU== X-CM-SenderInfo: pzdqw2pxlnt03j6l2u1dvotugofq/ Use use_alternative_unlikely() to check for RISCV_ISA_EXT_SVVPTC, replacing the use of asm goto with ALTERNATIVE. The "unlikely" variant is used to match the behavior of the original implementation using ALTERNATIVE("nop", "j %l[svvptc]", ...). Signed-off-by: Vivian Wang --- arch/riscv/include/asm/pgtable.h | 15 +++++++-------- arch/riscv/mm/pgtable.c | 22 ++++++++++------------ 2 files changed, 17 insertions(+), 20 deletions(-) diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgta= ble.h index 91697fbf1f9013005800f713797e4b6b1fc8d312..81eb386da837f064c7372530e2f= 2227575a703d3 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -495,8 +495,13 @@ static inline void update_mmu_cache_range(struct vm_fa= ult *vmf, struct vm_area_struct *vma, unsigned long address, pte_t *ptep, unsigned int nr) { - asm goto(ALTERNATIVE("nop", "j %l[svvptc]", 0, RISCV_ISA_EXT_SVVPTC, 1) - : : : : svvptc); + /* + * Svvptc guarantees that the new valid pte will be visible within + * a bounded timeframe, so when the uarch does not cache invalid + * entries, we don't have to do anything. + */ + if (use_alternative_unlikely(0, RISCV_ISA_EXT_SVVPTC)) + return; =20 /* * The kernel assumes that TLBs don't cache invalid entries, but @@ -508,12 +513,6 @@ static inline void update_mmu_cache_range(struct vm_fa= ult *vmf, while (nr--) local_flush_tlb_page(address + nr * PAGE_SIZE); =20 -svvptc:; - /* - * Svvptc guarantees that the new valid pte will be visible within - * a bounded timeframe, so when the uarch does not cache invalid - * entries, we don't have to do anything. - */ } #define update_mmu_cache(vma, addr, ptep) \ update_mmu_cache_range(NULL, vma, addr, ptep, 1) diff --git a/arch/riscv/mm/pgtable.c b/arch/riscv/mm/pgtable.c index 8b6c0a112a8db4e91de54c3bd3bd527a605a6197..e0c414fa0d433fdc39c80ec390c= 467ca59a9a334 100644 --- a/arch/riscv/mm/pgtable.c +++ b/arch/riscv/mm/pgtable.c @@ -9,8 +9,16 @@ int ptep_set_access_flags(struct vm_area_struct *vma, unsigned long address, pte_t *ptep, pte_t entry, int dirty) { - asm goto(ALTERNATIVE("nop", "j %l[svvptc]", 0, RISCV_ISA_EXT_SVVPTC, 1) - : : : : svvptc); + if (use_alternative_unlikely(0, RISCV_ISA_EXT_SVVPTC)) { + if (!pte_same(ptep_get(ptep), entry)) { + __set_pte_at(vma->vm_mm, ptep, entry); + /* Here only not svadu is impacted */ + flush_tlb_page(vma, address); + return true; + } + + return false; + } =20 if (!pte_same(ptep_get(ptep), entry)) __set_pte_at(vma->vm_mm, ptep, entry); @@ -19,16 +27,6 @@ int ptep_set_access_flags(struct vm_area_struct *vma, * the case that the PTE changed and the spurious fault case. */ return true; - -svvptc: - if (!pte_same(ptep_get(ptep), entry)) { - __set_pte_at(vma->vm_mm, ptep, entry); - /* Here only not svadu is impacted */ - flush_tlb_page(vma, address); - return true; - } - - return false; } =20 int ptep_test_and_clear_young(struct vm_area_struct *vma, --=20 2.50.1