From e98befd010bd56b8b3f2afea2d600e30df023e6b Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Wed, 13 Sep 2023 10:43:42 -0300 Subject: iommu: Allow an IDENTITY domain as the default_domain in ARM32 Even though dma-iommu.c and CONFIG_ARM_DMA_USE_IOMMU do approximately the same stuff, the way they relate to the IOMMU core is quiet different. dma-iommu.c expects the core code to setup an UNMANAGED domain (of type IOMMU_DOMAIN_DMA) and then configures itself to use that domain. This becomes the default_domain for the group. ARM_DMA_USE_IOMMU does not use the default_domain, instead it directly allocates an UNMANAGED domain and operates it just like an external driver. In this case group->default_domain is NULL. If the driver provides a global static identity_domain then automatically use it as the default_domain when in ARM_DMA_USE_IOMMU mode. This allows drivers that implemented default_domain == NULL as an IDENTITY translation to trivially get a properly labeled non-NULL default_domain on ARM32 configs. With this arrangment when ARM_DMA_USE_IOMMU wants to disconnect from the device the normal detach_domain flow will restore the IDENTITY domain as the default domain. Overall this makes attach_dev() of the IDENTITY domain called in the same places as detach_dev(). This effectively migrates these drivers to default_domain mode. For drivers that support ARM64 they will gain support for the IDENTITY translation mode for the dma_api and behave in a uniform way. Drivers use this by setting ops->identity_domain to a static singleton iommu_domain that implements the identity attach. If the core detects ARM_DMA_USE_IOMMU mode then it automatically attaches the IDENTITY domain during probe. Drivers can continue to prevent the use of DMA translation by returning IOMMU_DOMAIN_IDENTITY from def_domain_type, this will completely prevent IOMMU_DMA from running but will not impact ARM_DMA_USE_IOMMU. This allows removing the set_platform_dma_ops() from every remaining driver. Remove the set_platform_dma_ops from rockchip and mkt_v1 as all it does is set an existing global static identity domain. mkt_v1 does not support IOMMU_DOMAIN_DMA and it does not compile on ARM64 so this transformation is safe. Tested-by: Steven Price Tested-by: Marek Szyprowski Tested-by: Nicolin Chen Reviewed-by: Lu Baolu Reviewed-by: Jerry Snitselaar Signed-off-by: Jason Gunthorpe Link: https://lore.kernel.org/r/9-v8-81230027b2fa+9d-iommu_all_defdom_jgg@nvidia.com Signed-off-by: Joerg Roedel --- drivers/iommu/rockchip-iommu.c | 10 ---------- 1 file changed, 10 deletions(-) (limited to 'drivers/iommu/rockchip-iommu.c') diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c index 033678f2f8b3..a582525d36f8 100644 --- a/drivers/iommu/rockchip-iommu.c +++ b/drivers/iommu/rockchip-iommu.c @@ -998,13 +998,6 @@ static struct iommu_domain rk_identity_domain = { .ops = &rk_identity_ops, }; -#ifdef CONFIG_ARM -static void rk_iommu_set_platform_dma(struct device *dev) -{ - WARN_ON(rk_iommu_identity_attach(&rk_identity_domain, dev)); -} -#endif - static int rk_iommu_attach_device(struct iommu_domain *domain, struct device *dev) { @@ -1183,9 +1176,6 @@ static const struct iommu_ops rk_iommu_ops = { .probe_device = rk_iommu_probe_device, .release_device = rk_iommu_release_device, .device_group = rk_iommu_device_group, -#ifdef CONFIG_ARM - .set_platform_dma_ops = rk_iommu_set_platform_dma, -#endif .pgsize_bitmap = RK_IOMMU_PGSIZE_BITMAP, .of_xlate = rk_iommu_of_xlate, .default_domain_ops = &(const struct iommu_domain_ops) { -- cgit