Re: [PATCH v6 07/25] iommu/mtk_iommu_v1: Implement an IDENTITY domain
From: Baolu Lu <baolu.lu@linux.intel.com>
Date: 2023-08-14 03:07:12
Also in:
linux-arm-kernel, linux-arm-msm, linux-iommu, linux-mediatek, linux-rockchip, linux-s390, linux-samsung-soc, linux-sunxi, linux-tegra
On 2023/8/3 8:07, Jason Gunthorpe wrote:
What mtk does during mtk_iommu_v1_set_platform_dma() is actually putting
the iommu into identity mode. Make this available as a proper IDENTITY
domain.
The mtk_iommu_v1_def_domain_type() from
commit 8bbe13f52cb7 ("iommu/mediatek-v1: Add def_domain_type") explains
this was needed to allow probe_finalize() to be called, but now the
IDENTITY domain will do the same job so change the returned
def_domain_type.
mkt_v1 is the only driver that returns IOMMU_DOMAIN_UNMANAGED from
def_domain_type(). This allows the next patch to enforce an IDENTITY
domain policy for this driver.This code seems to be not working properly. * @def_domain_type: device default domain type, return value: * - IOMMU_DOMAIN_IDENTITY: must use an identity domain * - IOMMU_DOMAIN_DMA: must use a dma domain * - 0: use the default setting The core code is not ready to accept any other return value.
quoted hunk ↗ jump to hunk
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> --- drivers/iommu/mtk_iommu_v1.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-)diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c index 8a0a5e5d049f4a..cc3e7d53d33ad9 100644 --- a/drivers/iommu/mtk_iommu_v1.c +++ b/drivers/iommu/mtk_iommu_v1.c@@ -319,11 +319,27 @@ static int mtk_iommu_v1_attach_device(struct iommu_domain *domain, struct device return 0; } -static void mtk_iommu_v1_set_platform_dma(struct device *dev) +static int mtk_iommu_v1_identity_attach(struct iommu_domain *identity_domain, + struct device *dev) { struct mtk_iommu_v1_data *data = dev_iommu_priv_get(dev); mtk_iommu_v1_config(data, dev, false); + return 0; +} + +static struct iommu_domain_ops mtk_iommu_v1_identity_ops = { + .attach_dev = mtk_iommu_v1_identity_attach, +}; + +static struct iommu_domain mtk_iommu_v1_identity_domain = { + .type = IOMMU_DOMAIN_IDENTITY, + .ops = &mtk_iommu_v1_identity_ops, +}; + +static void mtk_iommu_v1_set_platform_dma(struct device *dev) +{ + mtk_iommu_v1_identity_attach(&mtk_iommu_v1_identity_domain, dev);
This callback seems to be a dead code now.
quoted hunk ↗ jump to hunk
} static int mtk_iommu_v1_map(struct iommu_domain *domain, unsigned long iova,@@ -443,7 +459,7 @@ static int mtk_iommu_v1_create_mapping(struct device *dev, struct of_phandle_arg static int mtk_iommu_v1_def_domain_type(struct device *dev) { - return IOMMU_DOMAIN_UNMANAGED; + return IOMMU_DOMAIN_IDENTITY;
def_domain_type can't be used for this purpose. But this seems to be a temporary code, as it will be removed in patch 09/25.
quoted hunk ↗ jump to hunk
} static struct iommu_device *mtk_iommu_v1_probe_device(struct device *dev)@@ -578,6 +594,7 @@ static int mtk_iommu_v1_hw_init(const struct mtk_iommu_v1_data *data) } static const struct iommu_ops mtk_iommu_v1_ops = { + .identity_domain = &mtk_iommu_v1_identity_domain, .domain_alloc = mtk_iommu_v1_domain_alloc, .probe_device = mtk_iommu_v1_probe_device, .probe_finalize = mtk_iommu_v1_probe_finalize,
Best regards, baolu