nvmap: Use conftest to find get_rcu_file() argument type

The argument of get_rcu_file() get changed to pointer
type of file handle form Linux 6.7 with
commit 0ede61d8589cc ("file: convert to SLAB_TYPESAFE_BY_RCU").

Use conftest to findout this new argument type.

Bug 4346767

Change-Id: I18943421dd4c2ed4f409ce071b182e68d3d393e6
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/3028575
(cherry picked from commit ed5ae591c9)
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/3036792
Reviewed-by: Jonathan Hunter <jonathanh@nvidia.com>
Tested-by: Jonathan Hunter <jonathanh@nvidia.com>
GVS: Gerrit_Virtual_Submit <buildbot_gerritrpt@nvidia.com>

Makefile

@@ -53,12 +53,6 @@ subdir-ccflags-y += -DNV_V4L2_ASYNC_NF_SUBDEVICE_INIT_RENAME
 export CONFIG_SKIP_CRYPTO=y
 endif
 
-# Changes done in Linux 6.7 onwards
-ifeq ($(shell test $(LINUX_VERSION) -ge $(LINUX_VERSION_6_7); echo $$?),0)
-# get_file_rcu() have change the argument
-subdir-ccflags-y += -DNV_GET_FILE_RCU_HAS_PTR_FILE_ARGS
-endif
-
 ifeq ($(CONFIG_TEGRA_VIRTUALIZATION),y)
 subdir-ccflags-y += -DCONFIG_TEGRA_VIRTUALIZATION
 endif

drivers/video/tegra/nvmap/nvmap_handle.c

@@ -5,6 +5,8 @@
  * Handle allocation and freeing routines for nvmap
  */
 
+#include <nvidia/conftest.h>
+
 #define pr_fmt(fmt)	"%s: " fmt, __func__
 
 #include <linux/err.h>
@@ -515,7 +517,7 @@ struct nvmap_handle_ref *nvmap_dup_handle_ro(struct nvmap_client *client,
 			return ERR_CAST(h->dmabuf_ro);
 		}
 	} else {
-#if defined(NV_GET_FILE_RCU_HAS_PTR_FILE_ARGS)
+#if defined(NV_GET_FILE_RCU_HAS_DOUBLE_PTR_FILE_ARG) /* Linux 6.7 */
 		if (!get_file_rcu(&h->dmabuf_ro->file)) {
 #else
 		if (!get_file_rcu(h->dmabuf_ro->file)) {

drivers/video/tegra/nvmap/nvmap_sci_ipc.c

@@ -5,6 +5,8 @@
  * mapping between nvmap_hnadle and sci_ipc entery
  */
 
+#include <nvidia/conftest.h>
+
 #define pr_fmt(fmt)	"%s: " fmt, __func__
 
 #include <linux/slab.h>
@@ -249,7 +251,7 @@ int nvmap_get_handle_from_sci_ipc_id(struct nvmap_client *client, u32 flags,
 				goto unlock;
 			}
 		} else {
-#if defined(NV_GET_FILE_RCU_HAS_PTR_FILE_ARGS)
+#if defined(NV_GET_FILE_RCU_HAS_DOUBLE_PTR_FILE_ARG) /* Linux 6.7 */
 			if (!get_file_rcu(&h->dmabuf_ro->file)) {
 #else
 			if (!get_file_rcu(h->dmabuf_ro->file)) {

scripts/conftest/Makefile

@@ -115,6 +115,7 @@ NV_CONFTEST_FUNCTION_COMPILE_TESTS += drm_mode_config_struct_has_fb_base_arg
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += drm_scdc_get_set_has_struct_drm_connector_arg
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += ethtool_ops_get_set_coalesce_has_coal_and_extack_args
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += ethtool_ops_get_set_ringparam_has_ringparam_and_extack_args
+NV_CONFTEST_FUNCTION_COMPILE_TESTS += get_file_rcu_has_double_ptr_file_arg
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += get_user_pages
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += iio_dev_opaque_has_mlock
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += iommu_map_has_gfp_arg

scripts/conftest/conftest.sh

@@ -2448,6 +2448,23 @@ compile_test() {
             compile_check_conftest "$CODE" "NV_PCI_DEV_HAS_ATS_ENABLED" "" "types"
         ;;
 
+        get_file_rcu_has_double_ptr_file_arg)
+            #
+            # Determine if the function 'get_file_rcu()' has pointer to pointer of file
+            # type argument or not.
+            #
+            # In Linux v6.7, commit 0ede61d8589cc2 ("file: convert to SLAB_TYPESAFE_BY_RCU")
+            # changed the argument of file handle to pointer type.
+            #
+            CODE="
+            #include <linux/fs.h>
+            struct file *conftest_get_file_rcu_has_double_ptr_file_arg(struct file __rcu *f) {
+                    return get_file_rcu(&f);
+            }"
+
+            compile_check_conftest "$CODE" "NV_GET_FILE_RCU_HAS_DOUBLE_PTR_FILE_ARG" "" "types"
+        ;;
+
         get_user_pages)
             #
             # Conftest for get_user_pages()