[S390] config option for z9-109 code generation.

Add a kernel config option for the IBM System z9. This will produce
faster code on newer compilers using the -march=z9-109 option.

Signed-off-by: Christian Borntraeger <cborntra@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 9 insertions, 0 deletions

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index b6b42f9f0d52..f900a516f099 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -153,6 +153,14 @@ config MARCH_Z990
           This will be slightly faster but does not work on
           older machines such as the z900.
 
+config MARCH_Z9_109
+        bool "IBM System z9"
+        help
+          Select this to enable optimizations for IBM System z9-109, IBM
+          System z9 Enterprise Class (z9 EC), and IBM System z9 Business
+          Class (z9 BC). The kernel will be slightly faster but will not
+          work on older machines such as the z990, z890, z900, and z800.
+
 endchoice
 
 config PACK_STACK
diff --git a/arch/s390/Makefile b/arch/s390/Makefile
index 74ef57dcfa60..5deb9f7544a1 100644
--- a/arch/s390/Makefile
+++ b/arch/s390/Makefile
@@ -33,6 +33,7 @@ endif
 cflags-$(CONFIG_MARCH_G5)   += $(call cc-option,-march=g5)
 cflags-$(CONFIG_MARCH_Z900) += $(call cc-option,-march=z900)
 cflags-$(CONFIG_MARCH_Z990) += $(call cc-option,-march=z990)
+cflags-$(CONFIG_MARCH_Z9_109) += $(call cc-option,-march=z9-109)
 
 #
 # Prevent tail-call optimizations, to get clearer backtraces: