From nobody Fri Dec 19 07:19:02 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id E86D734DB5F for ; Tue, 16 Dec 2025 14:46:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765896397; cv=none; b=I0Zt1GOnT6Ziv/f3GcFRqwaGXHEXVngubEbRsLWVDndh1Vd0SGFi0nNpjR5MV9j224lzR2jIuSz0rmCvh/IsZZ6IJw6gM8ejQwbq8zNHAyOmfYHz1Ez86WAzWDqxyFOsFo8mfDndZqEPD+b+4L0ouj/MKNYxFUhw4BdFTiIG5Bg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765896397; c=relaxed/simple; bh=y8aTYMZA5YV99XSnf+mSwccANYKfRqrljoaBJ6X2zko=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=a4+wZFDYOGYff7iax19O0KRod+OAFFrc6O4bxqmUY0olRk6ckDyH+H8f0x0gFM5qoYGnl5OuLkdCpnB8mvFtkMw9Y1FSAW4ln1hAFsjIYpIbdNKB2FK1rnGiEwdXxfHmkhsfRNo0isJwTtf8WsKKSQwPQ7geiLWM+xi0tsG8PZE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id CC2741516; Tue, 16 Dec 2025 06:46:26 -0800 (PST) Received: from e125769.cambridge.arm.com (e125769.cambridge.arm.com [10.1.196.27]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7E1F53F73F; Tue, 16 Dec 2025 06:46:32 -0800 (PST) From: Ryan Roberts To: Will Deacon , Ard Biesheuvel , Catalin Marinas , Mark Rutland , Linus Torvalds , Oliver Upton , Marc Zyngier , Dev Jain , Linu Cherian Cc: Ryan Roberts , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v1 13/13] arm64: mm: Provide level hint for flush_tlb_page() Date: Tue, 16 Dec 2025 14:45:58 +0000 Message-ID: <20251216144601.2106412-14-ryan.roberts@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20251216144601.2106412-1-ryan.roberts@arm.com> References: <20251216144601.2106412-1-ryan.roberts@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Previously tlb invalidations issued by __flush_tlb_page() did not contain a level hint. But the function is clearly only ever targeting level 3 tlb entries and its documentation agrees: | this operation only invalidates a single, last-level page-table | entry and therefore does not affect any walk-caches However, it turns out that the function was actually being used to invalidate a level 2 mapping via flush_tlb_fix_spurious_fault_pmd(). The bug was benign because the level hint was not set so the HW would still invalidate the PMD mapping, and also because the TLBF_NONOTIFY flag was set, the bounds of the mapping were never used for anything else. Now that we have the new and improved range-invalidation API, it is trival to fix flush_tlb_fix_spurious_fault_pmd() to explicitly flush the whole range (locally, without notification and last level only). So let's do that, and then update __flush_tlb_page() to hint level 3. Signed-off-by: Ryan Roberts --- arch/arm64/include/asm/pgtable.h | 5 +++-- arch/arm64/include/asm/tlbflush.h | 2 +- 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgta= ble.h index b96a7ca465a1..61f57647361a 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -138,8 +138,9 @@ static inline void arch_leave_lazy_mmu_mode(void) #define flush_tlb_fix_spurious_fault(vma, address, ptep) \ __flush_tlb_page(vma, address, TLBF_NOBROADCAST | TLBF_NONOTIFY) =20 -#define flush_tlb_fix_spurious_fault_pmd(vma, address, pmdp) \ - __flush_tlb_page(vma, address, TLBF_NOBROADCAST | TLBF_NONOTIFY) +#define flush_tlb_fix_spurious_fault_pmd(vma, address, pmdp) \ + __flush_tlb_range(vma, address, address + PMD_SIZE, PMD_SIZE, 2, \ + TLBF_NOBROADCAST | TLBF_NONOTIFY | TLBF_NOWALKCACHE) =20 /* * ZERO_PAGE is a global shared page that is always zero: used diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlb= flush.h index fa5aee990742..f24211b51df3 100644 --- a/arch/arm64/include/asm/tlbflush.h +++ b/arch/arm64/include/asm/tlbflush.h @@ -577,7 +577,7 @@ static inline void __flush_tlb_page(struct vm_area_stru= ct *vma, unsigned long start =3D round_down(uaddr, PAGE_SIZE); unsigned long end =3D start + PAGE_SIZE; =20 - ___flush_tlb_range(vma, start, end, PAGE_SIZE, TLBI_TTL_UNKNOWN, + ___flush_tlb_range(vma, start, end, PAGE_SIZE, 3, TLBF_NOWALKCACHE | flags); } =20 --=20 2.43.0