From nobody Fri Apr 3 04:46:22 2026 Received: from mx.itxnorge.no (itx-kvm-14.itxnorge.no [91.189.121.228]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3E2C42F6591; Wed, 18 Feb 2026 12:02:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.189.121.228 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771416165; cv=none; b=A2hEuTAPv7wnUC4PPuQ2OZA0uX0K3V0mRLo7iKZNnhls9jus1apKN/stAICf346URbDb1qcxXuBwhy5AbMN1cRK8+QtRsOGGyO34hXlEPHhS6ihMDHhGarxXMC24OmJL8RhHkmw2sdaJxqgKGb+2zmQvlOnI3SU3JfvEw9gRZ8M= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771416165; c=relaxed/simple; bh=lFVcKWp7lydqdzf2fycmrgJTC3hAP/pyYAFfQTkreao=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=G+GlkUKNK4XMrDAOo/kQkvQhBHy99FbtBwmxGmTKixCaJFqq+BDDlnyJqRyG+3CxChi7SBF5jlvpOrAWD0/Ar0NkzMK0r2mMztfKAOi5RVikndqxxlh2HpX5vCdJ9z8vVStdwDMtFuJi9whYfMB3iml+WmsCgXYnyrvlYey1yGk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=itx.no; spf=pass smtp.mailfrom=itx.no; dkim=pass (1024-bit key) header.d=itx.no header.i=@itx.no header.b=TrhCyfh+; arc=none smtp.client-ip=91.189.121.228 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=itx.no Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=itx.no Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=itx.no header.i=@itx.no header.b="TrhCyfh+" From: stian@itx.no DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=itx.no; s=mx.itx.no; t=1771416162; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=YceTr2EILPmfYE2DJGVNspLLsigq/xxpHiCraazo8xc=; b=TrhCyfh+isMfpP8qmLUfteE5t2uwdHhpkyFQxMRJksu1eZie0FIpo+9p+jobvdDo1P/iCp mkMbErYuRQToE/cdyTVyswLJZJ7KeeKWNlyDdyIPvoGHyKFWlQMgcSpBJBIXbsudr50M7m 3EU/juLv2auFF9ft2vZ9V7ILp59oXEE= To: sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Stian Halseth , Marek Szyprowski , "David S. Miller" , Andreas Larsson , Leon Romanovsky Subject: [PATCH v3] sparc: Fix page alignment in dma mapping Date: Wed, 18 Feb 2026 13:00:24 +0100 Message-ID: <20260218120056.3366-2-stian@itx.no> 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" From: Stian Halseth 'phys' may include an offset within the page, while 'base_paddr' is already page-aligned. This caused incorrect DMA mapping in dma_4u_map_phys and dma_4v_map_phys. Fix both functions by masking phys with IO_PAGE_MASK or subtracting the page offset, covering both generic SPARC code and sun4v. Fixes: 38c0d0ebf520 ("sparc: Use physical address DMA mapping") Reported-by: Stian Halseth Closes: https://github.com/sparclinux/issues/issues/75 Suggested-by: Marek Szyprowski Signed-off-by: Stian Halseth Tested-by: Han Gao # on SPARC Enterprise T5220 Tested-by: Nathaniel Roach --- Changelog: v3: - Use IO_PAGE_MASK for alignment in both dma_4u_map_phys and dma_4v_map_phys - Align phys before the loop in pci_sun4v.c - Drop masking inside iommu_batch_add() v2: https://lore.kernel.org/all/20260217171104.5643-3-stian@itx.no/ - Add Fixes tag - Add Closes tag - Trim commit message to 80-column lines - Remove newlines - Subject: Remove the "iommu/pci_sun4v:" (generic sparc patch, not specific= to sun4v) v1: https://lore.kernel.org/all/20260217150350.3541-2-stian@itx.no/=20 --- arch/sparc/kernel/iommu.c | 2 ++ arch/sparc/kernel/pci_sun4v.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/arch/sparc/kernel/iommu.c b/arch/sparc/kernel/iommu.c index 46ef88bc9c26..7613ab0ffb89 100644 --- a/arch/sparc/kernel/iommu.c +++ b/arch/sparc/kernel/iommu.c @@ -312,6 +312,8 @@ static dma_addr_t dma_4u_map_phys(struct device *dev, p= hys_addr_t phys, if (direction !=3D DMA_TO_DEVICE) iopte_protection |=3D IOPTE_WRITE; =20 + phys &=3D IO_PAGE_MASK; + for (i =3D 0; i < npages; i++, base++, phys +=3D IO_PAGE_SIZE) iopte_val(*base) =3D iopte_protection | phys; =20 diff --git a/arch/sparc/kernel/pci_sun4v.c b/arch/sparc/kernel/pci_sun4v.c index 791f0a76665f..58ca4148f86b 100644 --- a/arch/sparc/kernel/pci_sun4v.c +++ b/arch/sparc/kernel/pci_sun4v.c @@ -410,6 +410,8 @@ static dma_addr_t dma_4v_map_phys(struct device *dev, p= hys_addr_t phys, =20 iommu_batch_start(dev, prot, entry); =20 + phys &=3D IO_PAGE_MASK; + for (i =3D 0; i < npages; i++, phys +=3D IO_PAGE_SIZE) { long err =3D iommu_batch_add(phys, mask); if (unlikely(err < 0L)) --=20 2.53.0