iommu/tegra-gart: Remove tegra-gart

Thierry says this is not used anymore, and doesn't think it makes sense as
an iommu driver. The HW it supports is about 10 years old now and newer HW
uses different IOMMU drivers.

As this is the only driver with a GART approach, and it doesn't really
meet the driver expectations from the IOMMU core, let's just remove it
so we don't have to think about how to make it fit in.

It has a number of identified problems:
 - The assignment of iommu_groups doesn't match the HW behavior

 - It claims to have an UNMANAGED domain but it is really an IDENTITY
   domain with a translation aperture. This is inconsistent with the core
   expectation for security sensitive operations

 - It doesn't implement a SW page table under struct iommu_domain so
   * It can't accept a map until the domain is attached
   * It forgets about all maps after the domain is detached
   * It doesn't clear the HW of maps once the domain is detached
     (made worse by having the wrong groups)

Cc: Thierry Reding <treding@nvidia.com>
Cc: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/6-v8-81230027b2fa+9d-iommu_all_defdom_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 0 insertions, 26 deletions

diff --git a/include/soc/tegra/mc.h b/include/soc/tegra/mc.h
index a5ef84944a06..71ae37d3bedd 100644
--- a/include/soc/tegra/mc.h
+++ b/include/soc/tegra/mc.h
@@ -96,7 +96,6 @@ struct tegra_smmu_soc {
 
 struct tegra_mc;
 struct tegra_smmu;
-struct gart_device;
 
 #ifdef CONFIG_TEGRA_IOMMU_SMMU
 struct tegra_smmu *tegra_smmu_probe(struct device *dev,
@@ -116,28 +115,6 @@ static inline void tegra_smmu_remove(struct tegra_smmu *smmu)
 }
 #endif
 
-#ifdef CONFIG_TEGRA_IOMMU_GART
-struct gart_device *tegra_gart_probe(struct device *dev, struct tegra_mc *mc);
-int tegra_gart_suspend(struct gart_device *gart);
-int tegra_gart_resume(struct gart_device *gart);
-#else
-static inline struct gart_device *
-tegra_gart_probe(struct device *dev, struct tegra_mc *mc)
-{
-	return ERR_PTR(-ENODEV);
-}
-
-static inline int tegra_gart_suspend(struct gart_device *gart)
-{
-	return -ENODEV;
-}
-
-static inline int tegra_gart_resume(struct gart_device *gart)
-{
-	return -ENODEV;
-}
-#endif
-
 struct tegra_mc_reset {
 	const char *name;
 	unsigned long id;
@@ -185,8 +162,6 @@ struct tegra_mc_ops {
 	 */
 	int (*probe)(struct tegra_mc *mc);
 	void (*remove)(struct tegra_mc *mc);
-	int (*suspend)(struct tegra_mc *mc);
-	int (*resume)(struct tegra_mc *mc);
 	irqreturn_t (*handle_irq)(int irq, void *data);
 	int (*probe_device)(struct tegra_mc *mc, struct device *dev);
 };
@@ -225,7 +200,6 @@ struct tegra_mc {
 	struct tegra_bpmp *bpmp;
 	struct device *dev;
 	struct tegra_smmu *smmu;
-	struct gart_device *gart;
 	void __iomem *regs;
 	void __iomem *bcast_ch_regs;
 	void __iomem **ch_regs;