Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
References: <20190816070754.15653-1-hch@lst.de> <20190816070754.15653-5-hch@lst.de>
In-Reply-To: <20190816070754.15653-5-hch@lst.de>
From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Fri, 16 Aug 2019 09:43:40 +0200
Message-ID: <CAMuHMdVk3LZk3Ro3PYn9aOZ6NRUr5AOp+NwSNiaq2hBTS0-BtQ@mail.gmail.com>
Subject: Re: [PATCH 4/6] dma-mapping: remove arch_dma_mmap_pgprot
To:     Christoph Hellwig <hch@lst.de>
Cc:     Linux IOMMU <iommu@lists.linux-foundation.org>,
        Shawn Anastasio <shawn@anastas.io>,
        Will Deacon <will@kernel.org>,
        linux-m68k <linux-m68k@lists.linux-m68k.org>,
        Guan Xuetao <gxt@pku.edu.cn>,
        linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Russell King <linux@armlinux.org.uk>,
        linux-mips@vger.kernel.org, Paul Burton <paul.burton@mips.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        James Hogan <jhogan@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Fri, Aug 16, 2019 at 9:19 AM Christoph Hellwig <hch@lst.de> wrote:
> arch_dma_mmap_pgprot is used for two things:
>
>  1) to override the "normal" uncached page attributes for mapping
>     memory coherent to devices that can't snoop the CPU caches
>  2) to provide the special DMA_ATTR_WRITE_COMBINE semantics on older
>     arm systems
>
> Replace one with the pgprot_dmacoherent macro that is already provided
> by arm and much simpler to use, and lift the DMA_ATTR_WRITE_COMBINE
> handling to common code with an explicit arch opt-in.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

>  arch/m68k/Kconfig                  |  1 -
>  arch/m68k/include/asm/pgtable_mm.h |  3 +++
>  arch/m68k/kernel/dma.c             |  3 +--

Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds