From 45cee87fa724bb679575a01a5093f4aa4729a5e7 Mon Sep 17 00:00:00 2001
From: Jon Hunter <jonathanh@nvidia.com>
Date: Tue, 21 Nov 2023 16:04:16 +0000
Subject: [PATCH] gpu/host1x: Use conftest for Linux v6.3

Use conftest to determine if the uevent() function pointer in the
bus_type structure has a const dev argument. This fixes the build for
Linux kernels prior to Linux v6.3 that include the upstream change that
changed the arguments to this function.

Bug 4014315

Change-Id: I1553e08c951be9dd27141c273bf91be38dd954a6
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/3019964
(cherry picked from commit 5fe2e2aacc1e83be52fa4cf60a9cc409b7ecfbc5)
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/3020430
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
---
 drivers/gpu/host1x/bus.c     |  5 +++--
 scripts/conftest/Makefile    |  1 +
 scripts/conftest/conftest.sh | 20 ++++++++++++++++++++
 3 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/host1x/bus.c b/drivers/gpu/host1x/bus.c
index fe8e12e6..3777585e 100644
--- a/drivers/gpu/host1x/bus.c
+++ b/drivers/gpu/host1x/bus.c
@@ -4,6 +4,8 @@
  * Copyright (C) 2012-2013, NVIDIA Corporation
  */
 
+#include <nvidia/conftest.h>
+
 #include <linux/debugfs.h>
 #include <linux/dma-mapping.h>
 #include <linux/host1x-next.h>
@@ -11,7 +13,6 @@
 #include <linux/seq_file.h>
 #include <linux/slab.h>
 #include <linux/of_device.h>
-#include <linux/version.h>
 
 #include "bus.h"
 #include "dev.h"
@@ -339,7 +340,7 @@ static int host1x_device_match(struct device *dev, struct device_driver *drv)
 	return strcmp(dev_name(dev), drv->name) == 0;
 }
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 3, 0)
+#if defined(NV_BUS_TYPE_STRUCT_UEVENT_HAS_CONST_DEV_ARG) /* Linux v6.3 */
 static int host1x_device_uevent(const struct device *dev,
 #else
 static int host1x_device_uevent(struct device *dev,
diff --git a/scripts/conftest/Makefile b/scripts/conftest/Makefile
index 462c1a5a..fc5f942f 100644
--- a/scripts/conftest/Makefile
+++ b/scripts/conftest/Makefile
@@ -95,6 +95,7 @@ NV_CONFTEST_FUNCTION_COMPILE_TESTS += blk_mq_destroy_queue
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += block_device_operations_open_has_gendisk_arg
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += block_device_operations_release_has_no_mode_arg
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += bus_type_struct_remove_has_int_return_type
+NV_CONFTEST_FUNCTION_COMPILE_TESTS += bus_type_struct_uevent_has_const_dev_arg
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += class_create_has_no_owner_arg
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += class_struct_devnode_has_const_dev_arg
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += define_semaphore_has_number_arg
diff --git a/scripts/conftest/conftest.sh b/scripts/conftest/conftest.sh
index e686765c..133a9fee 100755
--- a/scripts/conftest/conftest.sh
+++ b/scripts/conftest/conftest.sh
@@ -6461,6 +6461,26 @@ compile_test() {
             compile_check_conftest "$CODE" "NV_BUS_TYPE_STRUCT_REMOVE_HAS_INT_RETURN_TYPE" "" "types"
         ;;
 
+        bus_type_struct_uevent_has_const_dev_arg)
+            #
+            # Determine if the 'uevent' callback from the 'bus_type' structure
+            # has a const 'struct dev' argument.
+            #
+            # Commit 2a81ada32f0e ("driver core: make struct bus_type.uevent()
+            # take a const *") updated the arguments to the uevent callback
+            # function in Linux v6.3.
+            #
+            CODE="
+            #include <linux/device/bus.h>
+            int conftest_bus_type_struct_remove_has_int_return_type(const struct device *dev,
+                                                                    struct kobj_uevent_env *env,
+                                                                    struct bus_type *bus) {
+                    return bus->uevent(dev, env);
+            }"
+
+            compile_check_conftest "$CODE" "NV_BUS_TYPE_STRUCT_UEVENT_HAS_CONST_DEV_ARG" "" "types"
+        ;;
+
         class_create_has_no_owner_arg)
             #
             # Determine if the class_create() function has the 'owner' argument.