From mboxrd@z Thu Jan 1 00:00:00 1970 From: magnus.damm@gmail.com (Magnus Damm) Date: Fri, 27 Jan 2017 15:14:36 +0900 Subject: [PATCH/RFC v2 3/4] iommu/ipmmu-vmsa: Check devices in xlate() In-Reply-To: <148549764733.22203.16459470412085471955.sendpatchset@little-apple> References: <148549764733.22203.16459470412085471955.sendpatchset@little-apple> Message-ID: <148549767671.22203.10735883809069203556.sendpatchset@little-apple> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Magnus Damm Rework the IPMMU code to validate devices in ->xlate() instead of accepting all devices in xlate() and instead validating devices in ->add_device(). This makes it possible for the IPMMU device driver to reject slave devices based on software policy. Once a slave device is rejected by the ->xlate() callback the shared function of_iommu_configure() will fail as well which in turn disables per-device IOMMU handing in the arch-specific mapping code by not passing any IOMMU callbacks to arch_setup_dma_ops(). Signed-off-by: Magnus Damm --- TODO: Make sure this does not break R-Car Gen2 support drivers/iommu/ipmmu-vmsa.c | 27 +++++++-------------------- 1 file changed, 7 insertions(+), 20 deletions(-) --- 0007/drivers/iommu/ipmmu-vmsa.c +++ work/drivers/iommu/ipmmu-vmsa.c 2017-01-27 13:11:35.970607110 +0900 @@ -1007,16 +1007,14 @@ static int ipmmu_add_device_dma(struct d struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu; struct iommu_group *group; - /* only accept devices with iommus property */ - if (of_count_phandle_with_args(dev->of_node, "iommus", - "#iommu-cells") < 0) + /* The device needs to be verified in xlate() */ + if (!archdata) return -ENODEV; group = iommu_group_get_for_dev(dev); if (IS_ERR(group)) return PTR_ERR(group); - archdata = dev->archdata.iommu; spin_lock(&ipmmu_slave_devices_lock); list_add(&archdata->list, &ipmmu_slave_devices); spin_unlock(&ipmmu_slave_devices_lock); @@ -1034,24 +1032,13 @@ static void ipmmu_remove_device_dma(stru iommu_group_remove_device(dev); } -static struct iommu_group *ipmmu_device_group_dma(struct device *dev) -{ - struct iommu_group *group; - int ret; - - ret = ipmmu_init_platform_device(dev); - if (!ret) - group = ipmmu_find_group(dev); - else - group = ERR_PTR(ret); - - return group; -} - static int ipmmu_of_xlate_dma(struct device *dev, struct of_phandle_args *spec) { - return 0; + /* For now only tested on R-Car Gen3 with ARM64 arch init order + * TODO: Test R-Car Gen2 with ARM32 arch init order + */ + return ipmmu_init_platform_device(dev); } static const struct iommu_ops ipmmu_ops = { @@ -1065,7 +1052,7 @@ static const struct iommu_ops ipmmu_ops .iova_to_phys = ipmmu_iova_to_phys, .add_device = ipmmu_add_device_dma, .remove_device = ipmmu_remove_device_dma, - .device_group = ipmmu_device_group_dma, + .device_group = ipmmu_find_group, .pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K, .of_xlate = ipmmu_of_xlate_dma, };