From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: From: Laurent Pinchart To: Niklas =?ISO-8859-1?Q?S=F6derlund?= Cc: linux-renesas-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org, iommu@lists.linux-foundation.org, robin.murphy@arm.com, vinod.koul@intel.com, geert+renesas@glider.be, linus.walleij@linaro.org, dan.j.williams@intel.com, arnd@arndb.de, linux-arch@vger.kernel.org Subject: Re: [PATCH v3 1/8] iommu: Add MMIO mapping type Date: Thu, 11 Feb 2016 02:02:11 +0200 Message-ID: <13740597.5lZXKsEG19@avalon> In-Reply-To: <1455065878-11906-2-git-send-email-niklas.soderlund+renesas@ragnatech.se> References: <1455065878-11906-1-git-send-email-niklas.soderlund+renesas@ragnatech.se> <1455065878-11906-2-git-send-email-niklas.soderlund+renesas@ragnatech.se> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT Content-Type: text/plain; charset="iso-8859-1" Sender: linux-kernel-owner@vger.kernel.org List-ID: Hi Niklas, Thank you for the patch. On Wednesday 10 February 2016 01:57:51 Niklas S�derlund wrote: > From: Robin Murphy > > On some platforms, MMIO regions might need slightly different treatment > compared to mapping regular memory; add the notion of MMIO mappings to > the IOMMU API's memory type flags, so that callers can let the IOMMU > drivers know to do the right thing. > > Signed-off-by: Robin Murphy > Acked-by: Laurent Pinchart Answering the question from the cover letter, yes, it's totally fine to pick the ack, that's actually expected. > --- > drivers/iommu/io-pgtable-arm.c | 4 +++- > include/linux/iommu.h | 1 + You might be asked to split this patch in two. > 2 files changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c > index 381ca5a..3ff4f87 100644 > --- a/drivers/iommu/io-pgtable-arm.c > +++ b/drivers/iommu/io-pgtable-arm.c > @@ -364,7 +364,9 @@ static arm_lpae_iopte arm_lpae_prot_to_pte(struct > arm_lpae_io_pgtable *data, pte |= ARM_LPAE_PTE_HAP_READ; > if (prot & IOMMU_WRITE) > pte |= ARM_LPAE_PTE_HAP_WRITE; > - if (prot & IOMMU_CACHE) > + if (prot & IOMMU_MMIO) > + pte |= ARM_LPAE_PTE_MEMATTR_DEV; > + else if (prot & IOMMU_CACHE) > pte |= ARM_LPAE_PTE_MEMATTR_OIWB; > else > pte |= ARM_LPAE_PTE_MEMATTR_NC; > diff --git a/include/linux/iommu.h b/include/linux/iommu.h > index a5c539f..34b6432 100644 > --- a/include/linux/iommu.h > +++ b/include/linux/iommu.h > @@ -30,6 +30,7 @@ > #define IOMMU_WRITE (1 << 1) > #define IOMMU_CACHE (1 << 2) /* DMA cache coherency */ > #define IOMMU_NOEXEC (1 << 3) > +#define IOMMU_MMIO (1 << 4) /* e.g. things like MSI doorbells */ > > struct iommu_ops; > struct iommu_group; -- Regards, Laurent Pinchart