From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailout2.w1.samsung.com (mailout2.w1.samsung.com [210.118.77.12]) (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 82AA4145348 for ; Wed, 18 Feb 2026 10:28:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=210.118.77.12 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771410502; cv=none; b=JCCa77dwjB9lFNeYwgqgnYBm2Zq1A+/OH3CXfSECedunleFFMtBm+0sRjTa8d0iPtsfIdrVJxXbBWlKY+6NZMKsOyUa7aBMcVZcyz/J59StxncTjQ/zGQltsTGZNDJgUfuEu/8zr2b+Int51o9JjOzV9sFijmoVRfXTSU8SVylo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771410502; c=relaxed/simple; bh=ja7QsXClnH5fC2d+6KAmqInMSQLj/cwZr9gxtWAKnDU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:From:In-Reply-To: Content-Type:References; b=dj1gdpN0N84QOAfclCu9P5xPJ41r8lScASD1VvnhsKG+w2xdqN6zMThC4IMPL9EZRLG3+W7v1hyx+NdeMJ/NXHak3PuAlcM1wUxArxUpBzKDKWG6C9Yca4neequMIVbCW+O6UiNN+iMo3LmVjmle2Eqk9g9wdkAQLhveXtcVxfk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=samsung.com; spf=pass smtp.mailfrom=samsung.com; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b=rrttDyty; arc=none smtp.client-ip=210.118.77.12 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=samsung.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=samsung.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b="rrttDyty" Received: from eucas1p1.samsung.com (unknown [182.198.249.206]) by mailout2.w1.samsung.com (KnoxPortal) with ESMTP id 20260218102813euoutp02d0f8a40391f1959d0da6eaed0903e18a~VUHVHgogz2380523805euoutp02Q for ; Wed, 18 Feb 2026 10:28:13 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout2.w1.samsung.com 20260218102813euoutp02d0f8a40391f1959d0da6eaed0903e18a~VUHVHgogz2380523805euoutp02Q DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1771410493; bh=WYbuAzkmAoYdFGQJF6gMDEDJjTsojA819vtdrhe+N7Y=; h=Date:Subject:To:Cc:From:In-Reply-To:References:From; b=rrttDyty2eH7ifkXZHvyt7ZQSGiuOh9l6xpLtdvSHfKGETnXXcsb4beJiUuySSF1y cQmvIYhmlLFhfQzf243ijfshNox2QcIuu53SZfduGTXcE/+UrQd47lTGB3v8nLWHQM Qs3W+Se2cqOV60xBliqrxQQyP99b0oQsofkE8scM= Received: from eusmtip1.samsung.com (unknown [203.254.199.221]) by eucas1p2.samsung.com (KnoxPortal) with ESMTPA id 20260218102812eucas1p2ad9d4f90fb5a37a5ffa38aa561ad89b5~VUHU5hHum0837908379eucas1p2I; Wed, 18 Feb 2026 10:28:12 +0000 (GMT) Received: from [106.210.134.192] (unknown [106.210.134.192]) by eusmtip1.samsung.com (KnoxPortal) with ESMTPA id 20260218102812eusmtip191a5a92c80ab503e46e9e714fbebd102~VUHUhydGR1468614686eusmtip1n; Wed, 18 Feb 2026 10:28:12 +0000 (GMT) Message-ID: <0bdd9ad5-e1b4-4dea-b936-e078b19d2996@samsung.com> Date: Wed, 18 Feb 2026 11:28:10 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Betterbird (Windows) Subject: Re: [PATCH v2] sparc: Fix page alignment in dma mapping To: stian@itx.no, John Paul Adrian Glaubitz Cc: "David S. Miller" , Andreas Larsson , Leon Romanovsky , sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org Content-Language: en-US From: Marek Szyprowski In-Reply-To: <20260217171104.5643-3-stian@itx.no> Content-Transfer-Encoding: 8bit X-CMS-MailID: 20260218102812eucas1p2ad9d4f90fb5a37a5ffa38aa561ad89b5 X-Msg-Generator: CA Content-Type: text/plain; charset="utf-8" X-RootMTR: 20260217171231eucas1p1f915cdb1081b194466431155fd8ec136 X-EPHeader: CA X-CMS-RootMailID: 20260217171231eucas1p1f915cdb1081b194466431155fd8ec136 References: <60c8265afe8be501a9eb5c811c5b564b0842b156.camel@physik.fu-berlin.de> <20260217171104.5643-3-stian@itx.no> On 17.02.2026 18:10, stian@itx.no wrote: > 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://protect2.fireeye.com/v1/url?k=4d8fbc00-1214850c-4d8e374f-000babff3563-ee1be24be576e072&q=1&e=0f8967ce-f558-4339-bddb-f324ec46c035&u=https%3A%2F%2Fgithub.com%2Fsparclinux%2Fissues%2Fissues%2F75 > Suggested-by: Marek Szyprowski > Signed-off-by: Stian Halseth > --- > arch/sparc/kernel/iommu.c | 2 ++ > arch/sparc/kernel/pci_sun4v.c | 2 +- > 2 files changed, 3 insertions(+), 1 deletion(-) > > diff --git a/arch/sparc/kernel/iommu.c b/arch/sparc/kernel/iommu.c > index 46ef88bc9c26..f3755a388ac7 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, phys_addr_t phys, > if (direction != DMA_TO_DEVICE) > iopte_protection |= IOPTE_WRITE; > > + phys -= offset_in_page(phys); > + I've just noticed that IO_PAGE_SIZE might not equal to PAGE_SIZE (not sure if this is true in case of SPARCs), so it would be better to rely on IO_PAGE_MASK or IO_PAGE_SIZE only. Just unify the fix for the both affected functions either by masking phys with IO_PAGE_SIZE where it is used or by subtracting (phys & ~IO_PAGE_MASK) from it. > for (i = 0; i < npages; i++, base++, phys += IO_PAGE_SIZE) > iopte_val(*base) = iopte_protection | phys; > > diff --git a/arch/sparc/kernel/pci_sun4v.c b/arch/sparc/kernel/pci_sun4v.c > index 791f0a76665f..2f30eeac4861 100644 > --- a/arch/sparc/kernel/pci_sun4v.c > +++ b/arch/sparc/kernel/pci_sun4v.c > @@ -411,7 +411,7 @@ static dma_addr_t dma_4v_map_phys(struct device *dev, phys_addr_t phys, > iommu_batch_start(dev, prot, entry); > > for (i = 0; i < npages; i++, phys += IO_PAGE_SIZE) { > - long err = iommu_batch_add(phys, mask); > + long err = iommu_batch_add(phys & IO_PAGE_MASK, mask); > if (unlikely(err < 0L)) > goto iommu_map_fail; > } Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland