powerpc/vdso: Fix build of VDSO32 with pcrel

Building vdso32 on power10 with pcrel leads to following errors:

	  VDSO32A arch/powerpc/kernel/vdso/gettimeofday-32.o
	arch/powerpc/kernel/vdso/gettimeofday.S: Assembler messages:
	arch/powerpc/kernel/vdso/gettimeofday.S:40: Error: syntax error; found `@', expected `,'
	arch/powerpc/kernel/vdso/gettimeofday.S:71:  Info: macro invoked from here
	arch/powerpc/kernel/vdso/gettimeofday.S:40: Error: junk at end of line: `@notoc'
	arch/powerpc/kernel/vdso/gettimeofday.S:71:  Info: macro invoked from here
	 ...
	make[2]: *** [arch/powerpc/kernel/vdso/Makefile:85: arch/powerpc/kernel/vdso/gettimeofday-32.o] Error 1
	make[1]: *** [arch/powerpc/Makefile:388: vdso_prepare] Error 2

Once the above is fixed, the following happens:

	  VDSO32C arch/powerpc/kernel/vdso/vgettimeofday-32.o
	cc1: error: '-mpcrel' requires '-mcmodel=medium'
	make[2]: *** [arch/powerpc/kernel/vdso/Makefile:89: arch/powerpc/kernel/vdso/vgettimeofday-32.o] Error 1
	make[1]: *** [arch/powerpc/Makefile:388: vdso_prepare] Error 2
	make: *** [Makefile:251: __sub-make] Error 2

Make sure pcrel version of CFUNC() macro is used only for powerpc64
builds and remove -mpcrel for powerpc32 builds.

Fixes: 7e3a68b ("powerpc/64: vmlinux support building with PCREL addresing")
Signed-off-by: Christophe Leroy <[email protected]>
Signed-off-by: Madhavan Srinivasan <[email protected]>
Link: https://patch.msgid.link/1fa3453f07d42a50a70114da9905bf7b73304fca.1747073669.git.christophe.leroy@csgroup.eu

Author: chleroy

arch/powerpc/include/asm/ppc_asm.h

@@ -183,7 +183,7 @@
 /*
  * Used to name C functions called from asm
  */
-#ifdef CONFIG_PPC_KERNEL_PCREL
+#if defined(__powerpc64__) && defined(CONFIG_PPC_KERNEL_PCREL)
 #define CFUNC(name) name@notoc
 #else
 #define CFUNC(name) name

arch/powerpc/kernel/vdso/Makefile

@@ -53,7 +53,7 @@ ldflags-$(CONFIG_LD_ORPHAN_WARN) += -Wl,--orphan-handling=$(CONFIG_LD_ORPHAN_WAR
 ldflags-y += $(filter-out $(CC_AUTO_VAR_INIT_ZERO_ENABLER) $(CC_FLAGS_FTRACE) -Wa$(comma)%, $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS))
 
 CC32FLAGS := -m32
-CC32FLAGSREMOVE := -mcmodel=medium -mabi=elfv1 -mabi=elfv2 -mcall-aixdesc
+CC32FLAGSREMOVE := -mcmodel=medium -mabi=elfv1 -mabi=elfv2 -mcall-aixdesc -mpcrel
 ifdef CONFIG_CC_IS_CLANG
 # This flag is supported by clang for 64-bit but not 32-bit so it will cause
 # an unused command line flag warning for this file.