Merge: redhat: automotive: remove tech preview message

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-10/-/merge_requests/314

JIRA: https://issues.redhat.com/browse/RHEL-77268
Upstream Status: RHEL only

This introduces a Red Hat only config used to define code that differs
from RHEL when building the automotive kernel. This new config is then
used to remove the tech preview warning message for real-time kernels
in the automotive kernel.

Depends: !287

Signed-off-by: Scott Weaver <scweaver@redhat.com>

Approved-by: Eder Zulian <ezulian@redhat.com>
Approved-by: Eric Chanudet <echanude@redhat.com>
Approved-by: Derek Barbosa <debarbos@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: CKI GitLab Kmaint Pipeline Bot <26919896-cki-kmaint-pipeline-bot@users.noreply.gitlab.com>

Author: CKI KWF Bot

Kconfig.redhat

@@ -20,4 +20,12 @@ config RH_KABI_SIZE_ALIGN_CHECKS
 	  be disabled in case of a debug build, because debug builds
 	  allow to change struct sizes.
 
+config RH_AUTOMOTIVE
+	bool "Enable automotive only code"
+	depends on RHEL_DIFFERENCES
+	default n
+	help
+	  This option controls whether code is included in the automotive
+	  kernel build. If you are building an automotive kernel, say Y.
+
 endmenu

arch/arm64/kernel/setup.c

@@ -336,7 +336,7 @@ void __init __no_sanitize_address setup_arch(char **cmdline_p)
 
 	paging_init();
 
-	if (IS_ENABLED(CONFIG_PREEMPT_RT))
+	if (IS_ENABLED(CONFIG_PREEMPT_RT) && !IS_ENABLED(CONFIG_RH_AUTOMOTIVE))
 		mark_tech_preview("RHEL-RT on ARM64", NULL);
 
 	acpi_table_upgrade();

redhat/configs/rhel/automotive/generic/CONFIG_RH_AUTOMOTIVE

@@ -0,0 +1 @@
+CONFIG_RH_AUTOMOTIVE=y

redhat/configs/rhel/generic/CONFIG_RH_AUTOMOTIVE

@@ -0,0 +1 @@
+# CONFIG_RH_AUTOMOTIVE is not set