> -----Original Message----- > From: iommu-bounces@xxxxxxxxxxxxxxxxxxxxxxxxxx [mailto:iommu- > bounces@xxxxxxxxxxxxxxxxxxxxxxxxxx] On Behalf Of Olav Haugan > Sent: Monday, June 30, 2014 10:22 PM > To: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; iommu@lists.linux- > foundation.org > Cc: linux-arm-msm@xxxxxxxxxxxxxxx; will.deacon@xxxxxxx; > thierry.reding@xxxxxxxxx; vgandhi@xxxxxxxxxxxxxx > Subject: [RFC/PATCH 7/7] iommu-api: Add domain attribute to enable > coherent HTW > > Add a new iommu domain attribute that can be used to enable cache > coherent hardware table walks (HTW) by the SMMU. HTW might be supported > by the SMMU HW but depending on the use case and the usage of the SMMU in > the SoC it might not be always beneficial to always turn on coherent HTW > for all domains/iommu's. > [Sethi Varun-B16395] Why won't you want to use the coherent table walk feature? > Signed-off-by: Olav Haugan <ohaugan@xxxxxxxxxxxxxx> > --- > drivers/iommu/msm_iommu-v1.c | 16 ++++++++++++++++ > include/linux/iommu.h | 1 + > 2 files changed, 17 insertions(+) > > diff --git a/drivers/iommu/msm_iommu-v1.c b/drivers/iommu/msm_iommu-v1.c > index 2c574ef..e163ffc 100644 > --- a/drivers/iommu/msm_iommu-v1.c > +++ b/drivers/iommu/msm_iommu-v1.c > @@ -1456,8 +1456,16 @@ static int msm_domain_get_attr(struct iommu_domain > *domain, > enum iommu_attr attr, void *data) { > s32 ret = 0; > + struct msm_iommu_priv *priv = domain->priv; > > switch (attr) { > + case DOMAIN_ATTR_COHERENT_HTW: > + { > + s32 *int_ptr = (s32 *) data; > + > + *int_ptr = priv->pt.redirect; > + break; > + } > default: > pr_err("Unsupported attribute type\n"); > ret = -EINVAL; > @@ -1471,8 +1479,16 @@ static int msm_domain_set_attr(struct iommu_domain > *domain, > enum iommu_attr attr, void *data) { > s32 ret = 0; > + struct msm_iommu_priv *priv = domain->priv; > > switch (attr) { > + case DOMAIN_ATTR_COHERENT_HTW: > + { > + s32 *int_ptr = (s32 *) data; > + > + priv->pt.redirect = *int_ptr; > + break; > + } > default: > pr_err("Unsupported attribute type\n"); > ret = -EINVAL; > diff --git a/include/linux/iommu.h b/include/linux/iommu.h index > 63dca6d..6d9596d 100644 > --- a/include/linux/iommu.h > +++ b/include/linux/iommu.h > @@ -81,6 +81,7 @@ enum iommu_attr { > DOMAIN_ATTR_FSL_PAMU_STASH, > DOMAIN_ATTR_FSL_PAMU_ENABLE, > DOMAIN_ATTR_FSL_PAMUV1, > + DOMAIN_ATTR_COHERENT_HTW, [Sethi Varun-B16395] Would it make sense to represent this as DOMAIN_ATTR_SMMU_COHERENT_HTW? I believe this is specific to SMMU. -Varun -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
