On Wed, 30 Sep 2020 at 10:48, Nicolin Chen <nicoleotsuka@xxxxxxxxx> wrote: > > Previously the driver relies on bus_set_iommu() in .probe() to call > in .probe_device() function so each client can poll iommus property > in DTB to configure fwspec via tegra_smmu_configure(). According to > the comments in .probe(), this is a bit of a hack. And this doesn't > work for a client that doesn't exist in DTB, PCI device for example. > > Actually when a device/client gets probed, the of_iommu_configure() > will call in .probe_device() function again, with a prepared fwspec > from of_iommu_configure() that reads the SWGROUP id in DTB as we do > in tegra-smmu driver. > > Additionally, as a new helper devm_tegra_get_memory_controller() is > introduced, there's no need to poll the iommus property in order to > get mc->smmu pointers or SWGROUP id. > > This patch reworks .probe_device() and .attach_dev() by doing: > 1) Using fwspec to get swgroup id in .attach_dev/.dettach_dev() > 2) Removing DT polling code, tegra_smmu_find/tegra_smmu_configure() > 3) Calling devm_tegra_get_memory_controller() in .probe_device() > 4) Also dropping the hack in .probe() that's no longer needed. > > Signed-off-by: Nicolin Chen <nicoleotsuka@xxxxxxxxx> > --- > > Changelog > v2->v3 > * Used devm_tegra_get_memory_controller() to get mc pointer > * Replaced IS_ERR_OR_NULL with IS_ERR in .probe_device() > v1->v2 > * Replaced in .probe_device() tegra_smmu_find/tegra_smmu_configure() > with tegra_get_memory_controller call. > * Dropped the hack in tegra_smmu_probe(). > > drivers/iommu/tegra-smmu.c | 144 ++++++++++--------------------------- > 1 file changed, 36 insertions(+), 108 deletions(-) > > diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c > index 6a3ecc334481..636dc3b89545 100644 > --- a/drivers/iommu/tegra-smmu.c > +++ b/drivers/iommu/tegra-smmu.c > @@ -61,6 +61,8 @@ struct tegra_smmu_as { > u32 attr; > }; > > +static const struct iommu_ops tegra_smmu_ops; I cannot find in this patch where this is assigned. Best regards, Krzysztof