From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> To: Robin Murphy <robin.murphy@arm.com> Cc: "axboe@kernel.dk" <axboe@kernel.dk>, "linux-renesas-soc@vger.kernel.org" <linux-renesas-soc@vger.kernel.org>, "ulf.hansson@linaro.org" <ulf.hansson@linaro.org>, "linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>, "linux-block@vger.kernel.org" <linux-block@vger.kernel.org>, "wsa+renesas@sang-engineering.com" <wsa+renesas@sang-engineering.com>, "iommu@lists.linux-foundation.org" <iommu@lists.linux-foundation.org>, "hch@lst.de" <hch@lst.de> Subject: RE: [PATCH v9 2/5] iommu/dma: Add a new dma_map_ops of get_merge_boundary() Date: Tue, 20 Aug 2019 01:42:18 +0000 Message-ID: <TYAPR01MB4544A7A255738624E2A405C9D8AB0@TYAPR01MB4544.jpnprd01.prod.outlook.com> (raw) In-Reply-To: <312d6e38-5143-fb07-1efb-01e60cafa2c9@arm.com> Hi Robin, > From: Robin Murphy, Sent: Monday, August 19, 2019 9:55 PM > > On 26/07/2019 09:31, Yoshihiro Shimoda wrote: > > This patch adds a new dma_map_ops of get_merge_boundary() to > > expose the DMA merge boundary if the domain type is IOMMU_DOMAIN_DMA. > > > > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> > > Reviewed-by: Simon Horman <horms+renesas@verge.net.au> > > --- > > drivers/iommu/dma-iommu.c | 11 +++++++++++ > > 1 file changed, 11 insertions(+) > > > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > > index a7f9c3e..2992ce4 100644 > > --- a/drivers/iommu/dma-iommu.c > > +++ b/drivers/iommu/dma-iommu.c > > @@ -1085,6 +1085,16 @@ static int iommu_dma_get_sgtable(struct device *dev, struct sg_table *sgt, > > return ret; > > } > > > > +static unsigned long iommu_dma_get_merge_boundary(struct device *dev) > > +{ > > + struct iommu_domain *domain = iommu_get_dma_domain(dev); > > + > > + if (domain->type != IOMMU_DOMAIN_DMA) > > Did you actually need this check? In principle, if the default domain is > not of type IOMMU_DOMAIN_DMA then the device should be assigned > dma_direct_ops rather than iommu_dma_ops, thus it shouldn't be possible > to get here. If you did manage to hit a case where the domain type > didn't match the ops it would be interesting to figure out how. Thank you for your review! You're correct. The current dma-iommu.c sets the iommu_dma_ops to the device dma_ops only when the type is IOMMU_DOMAIN_DMA like below: --- if (domain->type == IOMMU_DOMAIN_DMA) { if (iommu_dma_init_domain(domain, dma_base, size, dev)) goto out_err; dev->dma_ops = &iommu_dma_ops; } https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/iommu/dma-iommu.c#n1118 --- So, I'll remove this check. Best regards, Yoshihiro Shimoda > Robin. > > > + return 0; /* can't merge */ > > + > > + return (1UL << __ffs(domain->pgsize_bitmap)) - 1; > > +} > > + > > static const struct dma_map_ops iommu_dma_ops = { > > .alloc = iommu_dma_alloc, > > .free = iommu_dma_free, > > @@ -1100,6 +1110,7 @@ static const struct dma_map_ops iommu_dma_ops = { > > .sync_sg_for_device = iommu_dma_sync_sg_for_device, > > .map_resource = iommu_dma_map_resource, > > .unmap_resource = iommu_dma_unmap_resource, > > + .get_merge_boundary = iommu_dma_get_merge_boundary, > > }; > > > > /* > > _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply index Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-07-26 8:31 [PATCH v9 0/5] treewide: improve R-Car SDHI performance Yoshihiro Shimoda 2019-07-26 8:31 ` [PATCH v9 1/5] dma: Introduce dma_get_merge_boundary() Yoshihiro Shimoda 2019-07-26 8:31 ` [PATCH v9 2/5] iommu/dma: Add a new dma_map_ops of get_merge_boundary() Yoshihiro Shimoda 2019-08-16 19:48 ` Wolfram Sang 2019-08-19 12:45 ` Joerg Roedel 2019-08-19 12:54 ` Robin Murphy 2019-08-20 1:42 ` Yoshihiro Shimoda [this message] 2019-07-26 8:31 ` [PATCH v9 3/5] block: sort headers on blk-setting.c Yoshihiro Shimoda 2019-08-16 19:50 ` Wolfram Sang 2019-08-19 14:53 ` Jens Axboe 2019-08-20 1:50 ` Yoshihiro Shimoda 2019-08-22 9:35 ` Wolfram Sang 2019-07-26 8:31 ` [PATCH v9 4/5] block: add a helper function to merge the segments Yoshihiro Shimoda 2019-07-26 8:31 ` [PATCH v9 5/5] mmc: queue: Use bigger segments if DMA MAP layer can " Yoshihiro Shimoda 2019-08-15 7:30 ` [PATCH v9 0/5] treewide: improve R-Car SDHI performance Christoph Hellwig
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