From c8a83b569243c11720cd906296d6f153ab8d2cdb Mon Sep 17 00:00:00 2001
From: Laxman Dewangan <ldewangan@nvidia.com>
Date: Wed, 8 Nov 2023 14:15:29 +0000
Subject: [PATCH] tegra_hv: Use const in class attributes APIs for Linux 6.4
 and above

The callback APIs of class attribute are updated on
Linux6.4 and above to have the constant type pointer
argument.

Update the driver compatible with the updated APIs
for Linux 6.4 and above.

Bug 4370594

Change-Id: Ic06cb0d752797bb272f110aa0bb35bdd3afa1e6a
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/3013107
GVS: Gerrit_Virtual_Submit <buildbot_gerritrpt@nvidia.com>
---
 Makefile                      | 7 +++++++
 drivers/virt/tegra/tegra_hv.c | 5 +++++
 2 files changed, 12 insertions(+)

diff --git a/Makefile b/Makefile
index acfe092e..7a529bc6 100644
--- a/Makefile
+++ b/Makefile
@@ -9,6 +9,7 @@ subdir-ccflags-y += -Werror
 LINUX_VERSION := $(shell expr $(VERSION) \* 256 + $(PATCHLEVEL))
 LINUX_VERSION_6_2 := $(shell expr 6 \* 256 + 2)
 LINUX_VERSION_6_3 := $(shell expr 6 \* 256 + 3)
+LINUX_VERSION_6_4 := $(shell expr 6 \* 256 + 4)
 LINUX_VERSION_6_6 := $(shell expr 6 \* 256 + 6)
 
 # The Tegra IVC driver was updated to support iosys-map in Linux v6.2.
@@ -26,6 +27,12 @@ ifeq ($(shell test $(LINUX_VERSION) -ge $(LINUX_VERSION_6_3); echo $$?),0)
 export CONFIG_TEGRA_GPIO_LEGACY_DISABLE=y
 endif
 
+# Changes done in Linux 6.4 onwards
+ifeq ($(shell test $(LINUX_VERSION) -ge $(LINUX_VERSION_6_4); echo $$?),0)
+# Argument on class attribute callback changed to constant type
+subdir-ccflags-y += -DNV_CLASS_ATTRIBUTE_STRUCT_HAS_CONST_STRUCT_CLASS_ARG
+endif
+
 # Changes done in Linux 6.6 onwards
 ifeq ($(shell test $(LINUX_VERSION) -ge $(LINUX_VERSION_6_6); echo $$?),0)
 # Move probe to DAI Ops.
diff --git a/drivers/virt/tegra/tegra_hv.c b/drivers/virt/tegra/tegra_hv.c
index 3b85a97b..87f87a4e 100644
--- a/drivers/virt/tegra/tegra_hv.c
+++ b/drivers/virt/tegra/tegra_hv.c
@@ -393,8 +393,13 @@ static void tegra_hv_cleanup(struct tegra_hv_data *hvd)
 	}
 }
 
+#if defined(NV_CLASS_ATTRIBUTE_STRUCT_HAS_CONST_STRUCT_CLASS_ARG)
+static ssize_t vmid_show(const struct class *class,
+	const struct class_attribute *attr, char *buf)
+#else
 static ssize_t vmid_show(struct class *class,
 	struct class_attribute *attr, char *buf)
+#endif
 {
 	struct tegra_hv_data *hvd = get_hvd();