From 176a1bff8d9a1e36f08a73e0883730088a6eab4d Mon Sep 17 00:00:00 2001
From: Laxman Dewangan <ldewangan@nvidia.com>
Date: Fri, 8 Dec 2023 06:37:09 +0000
Subject: [PATCH] tegra_hv: Use conftest to find if class_attribute function
 has const type arg

Determine if struct class_attribute function has const type
"struct class_attribute" argument or not.

Modified the argument by change
commit 75a2d4226b5371 ("driver core: class: mark the struct class
for sysfs callbacks as constant") for Linux 6.3

Bug 4346767

Change-Id: I2a36025b23af80761faf1da406481731289eedd2
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/3030734
(cherry picked from commit de4295cfa6b8973c4bfd946eef3f564cd9bbaffa)
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/3059278
Tested-by: Jonathan Hunter <jonathanh@nvidia.com>
Reviewed-by: Jonathan Hunter <jonathanh@nvidia.com>
GVS: Gerrit_Virtual_Submit <buildbot_gerritrpt@nvidia.com>
---
 Makefile                      |  9 ---------
 drivers/virt/tegra/tegra_hv.c |  2 +-
 scripts/conftest/Makefile     |  1 +
 scripts/conftest/conftest.sh  | 20 ++++++++++++++++++++
 4 files changed, 22 insertions(+), 10 deletions(-)

diff --git a/Makefile b/Makefile
index ea06bf2c..de4f6b10 100644
--- a/Makefile
+++ b/Makefile
@@ -7,15 +7,6 @@ LINUXINCLUDE += -I$(srctree.nvidia-oot)/include
 subdir-ccflags-y += -Werror
 subdir-ccflags-y += -Wmissing-prototypes
 
-LINUX_VERSION := $(shell expr $(VERSION) \* 256 + $(PATCHLEVEL))
-LINUX_VERSION_6_4 := $(shell expr 6 \* 256 + 4)
-
-# Changes done in Linux 6.4 onwards
-ifeq ($(shell test $(LINUX_VERSION) -ge $(LINUX_VERSION_6_4); echo $$?),0)
-# Argument on class attribute callback changed to constant type
-subdir-ccflags-y += -DNV_CLASS_ATTRIBUTE_STRUCT_HAS_CONST_STRUCT_CLASS_ARG
-endif
-
 ifeq ($(CONFIG_TEGRA_VIRTUALIZATION),y)
 subdir-ccflags-y += -DCONFIG_TEGRA_VIRTUALIZATION
 endif
diff --git a/drivers/virt/tegra/tegra_hv.c b/drivers/virt/tegra/tegra_hv.c
index 134f5e78..37eeb6af 100644
--- a/drivers/virt/tegra/tegra_hv.c
+++ b/drivers/virt/tegra/tegra_hv.c
@@ -416,7 +416,7 @@ static void tegra_hv_cleanup(struct tegra_hv_data *hvd)
 	}
 }
 
-#if defined(NV_CLASS_ATTRIBUTE_STRUCT_HAS_CONST_STRUCT_CLASS_ARG)
+#if defined(NV_CLASS_ATTRIBUTE_STRUCT_HAS_CONST_STRUCT_CLASS_ATTRIBUTE_ARG)
 static ssize_t vmid_show(const struct class *class,
 	const struct class_attribute *attr, char *buf)
 #else
diff --git a/scripts/conftest/Makefile b/scripts/conftest/Makefile
index 00ebb3ec..e4e68320 100644
--- a/scripts/conftest/Makefile
+++ b/scripts/conftest/Makefile
@@ -96,6 +96,7 @@ NV_CONFTEST_FUNCTION_COMPILE_TESTS += block_device_operations_open_has_gendisk_a
 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_attribute_struct_has_const_struct_class_attribute
 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 fbead866..a7fb0197 100755
--- a/scripts/conftest/conftest.sh
+++ b/scripts/conftest/conftest.sh
@@ -6604,6 +6604,26 @@ compile_test() {
             compile_check_conftest "$CODE" "NV_BUS_TYPE_STRUCT_UEVENT_HAS_CONST_DEV_ARG" "" "types"
         ;;
 
+        class_attribute_struct_has_const_struct_class_attribute)
+            #
+            # Determine if struct class_attribute function has const type "struct class_attribute"
+            # argument or not.
+            #
+            # Modified the argument by change commit 75a2d4226b5371 ("driver core: class: mark
+            # the struct class for sysfs callbacks as constant") for Linux 6.3
+            #
+            CODE="
+            #include <linux/device/class.h>
+            static ssize_t show_cb(struct class *class, struct class_attribute *attr, char *buf) {
+                 return 0;
+            }
+            static struct class_attribute ca = {
+                 .show = show_cb,
+            };"
+
+            compile_check_conftest "$CODE" "NV_CLASS_ATTRIBUTE_STRUCT_HAS_CONST_STRUCT_CLASS_ATTRIBUTE_ARG" "" "functions"
+        ;;
+
         class_create_has_no_owner_arg)
             #
             # Determine if the class_create() function has the 'owner' argument.