From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH v2 21/22] iommu/tegra: smmu: Support Multiple ASID Date: Thu, 18 Jul 2013 14:43:06 -0600 Message-ID: <51E8535A.30605@wwwdotorg.org> References: <1373021097-32420-1-git-send-email-hdoyu@nvidia.com> <1373021097-32420-22-git-send-email-hdoyu@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1373021097-32420-22-git-send-email-hdoyu-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Hiroshi Doyu Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org List-Id: linux-tegra@vger.kernel.org On 07/05/2013 04:44 AM, Hiroshi Doyu wrote: > Support Multiple Address Space(AS). Tegra SMMU can have multiple > ASes. We reserve 2 of them for static assignment, AS[0] for system > default, AS[1] for AHB clusters as protected domain from others, where > there are many traditional pheripheral devices like USB, SD/MMC. They > should be isolated from some smart devices like host1x for system > robustness. Even if smart devices behaves wrongly, the traditional > devices(SD/MMC, USB) wouldn't be affected, and the system could > continue most likely. > diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c > static int smmu_iommu_add_device(struct device *dev) > { > int err; > - struct dma_iommu_mapping *map = smmu_handle->map[SYSTEM_DEFAULT]; > + u64 swgroup; > + struct dma_iommu_mapping *map = NULL; > + > + swgroup = smmu_of_get_memory_client(dev); > + switch (swgroup) { > + case TEGRA_SWGROUP_BIT(PPCS): > + map = smmu_handle->map[SYSTEM_PROTECTED]; > + break; > + default: > + map = smmu_handle->map[SYSTEM_DEFAULT]; I already mentioned this, but just for completeness: What is smmu->num_as <= SYSTEM_DEFAULT?