From 0a8d8b47c79e53a6042404467d61af44424ad6cd Mon Sep 17 00:00:00 2001
From: Jon Hunter <jonathanh@nvidia.com>
Date: Wed, 4 Dec 2024 10:40:41 +0000
Subject: [PATCH] drivers: gpu: Fix IOMMU support for Linux v6.13

In Linux v6.13, commit f6440fcc9c7b ("iommu: Remove
iommu_domain_alloc()") removed iommu_domain_alloc() and was replaced by
iommu_paging_domain_alloc(). Use conftest to detect if the function
iommu_paging_domain_alloc() is supported by the kernel and update the
Tegra DRM and Host1x drivers accordingly.

Bug 4991705

Change-Id: I86221d96232396fdb6bdccf40c412e029881c513
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/3261695
(cherry picked from commit e374ac996dceee884296c9f1e53fdd0f281b3e0c)
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/3499750
Reviewed-by: Brad Griffis <bgriffis@nvidia.com>
Tested-by: Brad Griffis <bgriffis@nvidia.com>
GVS: buildbot_gerritrpt <buildbot_gerritrpt@nvidia.com>
---
 drivers/gpu/drm/tegra/drm.c  |  8 ++++++++
 drivers/gpu/host1x/dev.c     |  7 +++++++
 scripts/conftest/Makefile    |  1 +
 scripts/conftest/conftest.sh | 17 +++++++++++++++++
 4 files changed, 33 insertions(+)

diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
index df7e33d3..605bbe68 100644
--- a/drivers/gpu/drm/tegra/drm.c
+++ b/drivers/gpu/drm/tegra/drm.c
@@ -1182,6 +1182,9 @@ static bool host1x_drm_wants_iommu(struct host1x_device *dev)
 
 static int host1x_drm_probe(struct host1x_device *dev)
 {
+#if defined(NV_IOMMU_PAGING_DOMAIN_ALLOC_PRESENT) /* Linux v6.11 */
+	struct device *dma_dev = dev->dev.parent;
+#endif
 	struct tegra_drm *tegra;
 	struct drm_device *drm;
 	int err;
@@ -1196,8 +1199,13 @@ static int host1x_drm_probe(struct host1x_device *dev)
 		goto put;
 	}
 
+#if defined(NV_IOMMU_PAGING_DOMAIN_ALLOC_PRESENT) /* Linux v6.11 */
+	if (host1x_drm_wants_iommu(dev) && device_iommu_mapped(dma_dev)) {
+		tegra->domain = iommu_paging_domain_alloc(dma_dev);
+#else
 	if (host1x_drm_wants_iommu(dev) && iommu_present(&platform_bus_type)) {
 		tegra->domain = iommu_domain_alloc(&platform_bus_type);
+#endif
 		if (!tegra->domain) {
 			err = -ENOMEM;
 			goto free;
diff --git a/drivers/gpu/host1x/dev.c b/drivers/gpu/host1x/dev.c
index 452dd79d..40338da6 100644
--- a/drivers/gpu/host1x/dev.c
+++ b/drivers/gpu/host1x/dev.c
@@ -620,9 +620,16 @@ static struct iommu_domain *host1x_iommu_attach(struct host1x *host)
 		if (err < 0)
 			goto put_group;
 
+#if defined(NV_IOMMU_PAGING_DOMAIN_ALLOC_PRESENT) /* Linux v6.11 */
+		host->domain = iommu_paging_domain_alloc(host->dev);
+		if (IS_ERR(host->domain)) {
+			err = PTR_ERR(host->domain);
+			host->domain = NULL;
+#else
 		host->domain = iommu_domain_alloc(&platform_bus_type);
 		if (!host->domain) {
 			err = -ENOMEM;
+#endif
 			goto put_cache;
 		}
 
diff --git a/scripts/conftest/Makefile b/scripts/conftest/Makefile
index 66ddd78a..49c4475a 100644
--- a/scripts/conftest/Makefile
+++ b/scripts/conftest/Makefile
@@ -140,6 +140,7 @@ NV_CONFTEST_FUNCTION_COMPILE_TESTS += i2c_driver_struct_remove_return_type_int
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += i2c_mux_add_adapter_has_no_class_argument
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += iio_dev_opaque_has_mlock
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += iommu_map_has_gfp_arg
+NV_CONFTEST_FUNCTION_COMPILE_TESTS += iommu_paging_domain_alloc
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += irq_get_nr_irqs
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += kthread_complete_and_exit
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += media_entity_remote_pad
diff --git a/scripts/conftest/conftest.sh b/scripts/conftest/conftest.sh
index bd13fb02..4b22822e 100755
--- a/scripts/conftest/conftest.sh
+++ b/scripts/conftest/conftest.sh
@@ -7437,6 +7437,23 @@ compile_test() {
             compile_check_conftest "$CODE" "NV_NETIF_NAPI_ADD_WEIGHT_PRESENT" "" "functions"
         ;;
 
+        iommu_paging_domain_alloc)
+            #
+            # Determine if iommu_paging_domain_alloc() function is present
+            #
+            # Added by commit a27bf2743cb8 ("iommu: Add iommu_paging_domain_alloc()
+            # interface") in Linux v6.11.
+            #
+            CODE="
+            #include <linux/iommu.h>
+            void conftest_iommu_paging_domain_alloc(void)
+            {
+                    iommu_paging_domain_alloc();
+            }
+            "
+            compile_check_conftest "$CODE" "NV_IOMMU_PAGING_DOMAIN_ALLOC_PRESENT" "" "functions"
+        ;;
+
         iommu_map_has_gfp_arg)
             #
             # Determine if iommu_map() has 'gfp' argument.