From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: [PATCH v5 1/1] iommu-api: Add map_sg/unmap_sg functions Date: Thu, 25 Sep 2014 19:01:08 +0200 Message-ID: <20140925170108.GE8306@8bytes.org> References: <1407797150-515-1-git-send-email-ohaugan@codeaurora.org> <1407797150-515-2-git-send-email-ohaugan@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1407797150-515-2-git-send-email-ohaugan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Olav Haugan Cc: laurent.pinchart+renesas-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org, linux-arm-msm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, will.deacon-5wv7dgnIgG8@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, Varun.Sethi-KZfg59tc24xl57MIdRCFDg@public.gmane.org, kgene.kim-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org, dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: linux-arm-msm@vger.kernel.org On Mon, Aug 11, 2014 at 03:45:50PM -0700, Olav Haugan wrote: > +static inline int iommu_map_sg(struct iommu_domain *domain, unsigned long iova, > + struct scatterlist *sg, unsigned int nents, > + int prot, unsigned long flags) > +{ > + return domain->ops->map_sg(domain, iova, sg, nents, prot, flags); > +} > + > +static inline int iommu_unmap_sg(struct iommu_domain *domain, > + unsigned long iova, size_t size, > + unsigned long flags) > +{ > + return domain->ops->unmap_sg(domain, iova, size, flags); > +} I have thought a little bit more about this interface and think that it would be better to just return a size_t from iommu_map_sg(). The function returns the amount of address space mapped by it, 0 in the worst case. This makes it easy to unmap the region just with iommu_unmap(domain, iova, size) in the end and removing the need for a new iommu_unmap_sg() function. Also the error-path of the map_sg call-backs becomes easier as the function then just returns the amount of address-space already mapped before the error happened. So the prototype would be: size_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova, struct scatterlist *sg, unsigned int nents, int prot); (as I said before, the flags parameter should not be added by this patch-set). Joerg From mboxrd@z Thu Jan 1 00:00:00 1970 From: joro@8bytes.org (Joerg Roedel) Date: Thu, 25 Sep 2014 19:01:08 +0200 Subject: [PATCH v5 1/1] iommu-api: Add map_sg/unmap_sg functions In-Reply-To: <1407797150-515-2-git-send-email-ohaugan@codeaurora.org> References: <1407797150-515-1-git-send-email-ohaugan@codeaurora.org> <1407797150-515-2-git-send-email-ohaugan@codeaurora.org> Message-ID: <20140925170108.GE8306@8bytes.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Aug 11, 2014 at 03:45:50PM -0700, Olav Haugan wrote: > +static inline int iommu_map_sg(struct iommu_domain *domain, unsigned long iova, > + struct scatterlist *sg, unsigned int nents, > + int prot, unsigned long flags) > +{ > + return domain->ops->map_sg(domain, iova, sg, nents, prot, flags); > +} > + > +static inline int iommu_unmap_sg(struct iommu_domain *domain, > + unsigned long iova, size_t size, > + unsigned long flags) > +{ > + return domain->ops->unmap_sg(domain, iova, size, flags); > +} I have thought a little bit more about this interface and think that it would be better to just return a size_t from iommu_map_sg(). The function returns the amount of address space mapped by it, 0 in the worst case. This makes it easy to unmap the region just with iommu_unmap(domain, iova, size) in the end and removing the need for a new iommu_unmap_sg() function. Also the error-path of the map_sg call-backs becomes easier as the function then just returns the amount of address-space already mapped before the error happened. So the prototype would be: size_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova, struct scatterlist *sg, unsigned int nents, int prot); (as I said before, the flags parameter should not be added by this patch-set). Joerg