From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 24C8A2367C3; Wed, 17 Sep 2025 10:36:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758105409; cv=none; b=ukYFl/s0d7JvR6a6fsHNHdMPW8yRtIum/5JnQh31wj64PiHES2Wa9UhaJU+6Bl+lQ5xLNEwwREeOmirLvB4qNQ4oINRgT1rh2qsEu6ytJCTBwyCSwQgP02pmoqPYnSOaNLiE8AGi7sWIfwu1SXqSpIUat0R3VlYchiCpKKZjpLg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758105409; c=relaxed/simple; bh=9+CfYEPcX9RBMZk8bYI4Kxv/QQTIj2Zq3577UGdLueI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=nZUVcjxOrV1mDGGX6g+3iSemVBIEzvaiPdaFhfgRG2rqa1KlcOnq9gGG+nz0Z1R1wB7iaWVVLQeGPRuAhXPWBLCu6lvzErUANf5XdrEpGgUwi8T0AEF3n2XFDmdnyiKXqYuRcrW35NOXzapwW7qAqcR3MGiwbjdr5HyHZQwI6ac= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QCefrIWD; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="QCefrIWD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2481FC4CEFC; Wed, 17 Sep 2025 10:36:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758105408; bh=9+CfYEPcX9RBMZk8bYI4Kxv/QQTIj2Zq3577UGdLueI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QCefrIWDpyeDN3tXCB94u2Q5MHcY4yejTjtLsnQVEmKCthEh6xZgfJLbg0LQHPSrA nSRFKqERWoVpqSJRGh2DasAyTzco1FZJiQ6RV8TxkrkGc6jukqP6yo3IsgptEsd7b9 ZPjqCne7q7h0dMm/687O7OdUOK4Sx3X1cX5N7PnoEz1D4z93ewUSVpM6AJLAoz+qLQ tB4jan9ZQqw8jp1Mp9F67+yZRi2ivSd+Xs5sHJOxM1s9jbSS2eGenOP4oD7vtFmg2P 7UnjEMEaBp8ZKfTszdcjLZOf2Ezycnw6joQfJW/BWvhcuIOSFMdO0eAw/bx6/+U2Of FAOvNCNFqe7QQ== Date: Wed, 17 Sep 2025 13:36:44 +0300 From: Leon Romanovsky To: Jason Gunthorpe Cc: Marek Szyprowski , iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Russell King Subject: Re: [PATCH v3 3/4] ARM: dma-mapping: Switch to physical address mapping callbacks Message-ID: <20250917103644.GB6464@unreal> References: <5f96e44b1fb5d92a6a5f25fc9148a733a1a53b9d.1758006942.git.leon@kernel.org> <20250916184617.GW1086830@nvidia.com> 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=us-ascii Content-Disposition: inline In-Reply-To: <20250916184617.GW1086830@nvidia.com> On Tue, Sep 16, 2025 at 03:46:17PM -0300, Jason Gunthorpe wrote: > On Tue, Sep 16, 2025 at 10:32:06AM +0300, Leon Romanovsky wrote: > > + if (!dev->dma_coherent && > > + !(attrs & (DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_MMIO))) > > + __dma_page_cpu_to_dev(phys_to_page(phys), offset, size, dir); > > I'd keep going and get rid of the page here too, maybe as a second > patch in this series: Thanks, it is always unclear how far to go with cleanups. > > diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c > index 88c2d68a69c9ee..a84d12cd0ba4a9 100644 > --- a/arch/arm/mm/dma-mapping.c > +++ b/arch/arm/mm/dma-mapping.c > @@ -624,16 +624,14 @@ static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr, > kfree(buf); > } > > -static void dma_cache_maint_page(struct page *page, unsigned long offset, > +static void dma_cache_maint_page(phys_addr_t paddr, > size_t size, enum dma_data_direction dir, > void (*op)(const void *, size_t, int)) > { > - unsigned long pfn; > + unsigned long pfn = paddr / PAGE_SIZE; > + unsigned int offset = paddr % PAGE_SIZE; > size_t left = size; > > - pfn = page_to_pfn(page) + offset / PAGE_SIZE; > - offset %= PAGE_SIZE; > - > /* > * A single sg entry may refer to multiple physically contiguous > * pages. But we still need to process highmem pages individually. > @@ -644,17 +642,17 @@ static void dma_cache_maint_page(struct page *page, unsigned long offset, > size_t len = left; > void *vaddr; > > - page = pfn_to_page(pfn); > - > - if (PageHighMem(page)) { > + if (PhysHighMem(pfn << PAGE_SHIFT)) { > if (len + offset > PAGE_SIZE) > len = PAGE_SIZE - offset; > > if (cache_is_vipt_nonaliasing()) { > - vaddr = kmap_atomic(page); > + vaddr = kmap_atomic_pfn(pfn); > op(vaddr + offset, len, dir); > kunmap_atomic(vaddr); > } else { > + struct page *page = pfn_to_page(pfn); > + > vaddr = kmap_high_get(page); > if (vaddr) { > op(vaddr + offset, len, dir); > @@ -662,7 +660,7 @@ static void dma_cache_maint_page(struct page *page, unsigned long offset, > } > } > } else { > - vaddr = page_address(page) + offset; > + vaddr = phys_to_virt(pfn) + offset; > op(vaddr, len, dir); > } > offset = 0; > @@ -676,14 +674,11 @@ static void dma_cache_maint_page(struct page *page, unsigned long offset, > * Note: Drivers should NOT use this function directly. > * Use the driver DMA support - see dma-mapping.h (dma_sync_*) > */ > -static void __dma_page_cpu_to_dev(struct page *page, unsigned long off, > +static void __dma_page_cpu_to_dev(phys_addr_t paddr, > size_t size, enum dma_data_direction dir) > { > - phys_addr_t paddr; > + dma_cache_maint_page(paddr, size, dir, dmac_map_area); > > - dma_cache_maint_page(page, off, size, dir, dmac_map_area); > - > - paddr = page_to_phys(page) + off; > if (dir == DMA_FROM_DEVICE) { > outer_inv_range(paddr, paddr + size); > } else { > > > + if (!dev->dma_coherent && > > + !(attrs & (DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_MMIO))) { > > page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova)); > > __dma_page_dev_to_cpu(page, offset, size, dir); > > Same treatment here.. > > Looks Ok though, I didn't notice any pitfalls > > Reviewed-by: Jason Gunthorpe > > Jason >