[PATCH 2/2] powerpc/64: Use -mtune=pwr10/9/8 for clang

[Michael Ellerman <mpe@ellerman.id.au>]

For the -mtune option clang doesn't accept power10/9/8, instead it
accepts pwr10/9/8. That will be fixed in future versions of clang, but
the kernel must support the clang versions in the wild.

So add support for the "pwr" spelling if clang is in use.

Reported-by: Nathan Chancellor <nathan@kernel.org>
BugLink: https://github.com/ClangBuiltLinux/linux/issues/1799
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/platforms/Kconfig.cputype | 4 ++++
 1 file changed, 4 insertions(+)

Need to confirm the clang <= 16 statement is correct.

diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 7d7477b73951..e4e0e81be7de 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -278,6 +278,10 @@ config TUNE_CPU
 	default "-mtune=power10" if POWERPC64_CPU && CC_IS_GCC   && $(cc-option,-mtune=power10)
 	default "-mtune=power9"  if POWERPC64_CPU && CC_IS_GCC   && $(cc-option,-mtune=power9)
 	default "-mtune=power8"  if POWERPC64_CPU && CC_IS_GCC   && $(cc-option,-mtune=power8)
+	# clang <= 16 only supports the "pwr" names
+	default "-mtune=pwr10"   if POWERPC64_CPU && CC_IS_CLANG && $(cc-option,-mtune=pwr10)
+	default "-mtune=pwr9"    if POWERPC64_CPU && CC_IS_CLANG && $(cc-option,-mtune=pwr9)
+	default "-mtune=pwr8"    if POWERPC64_CPU && CC_IS_CLANG && $(cc-option,-mtune=pwr8)
 
 config PPC_BOOK3S
 	def_bool y
-- 
2.39.2