powerpc: Force inlining of arch_vmap_p{u/m}d_supported()

arch_vmap_pud_supported() and arch_vmap_pmd_supported() are
expected to constant-fold to false when RADIX is not enabled.

Force inlining in order to avoid following failure which
leads to unexpected call of non-existing pud_set_huge() and
pmd_set_huge() on powerpc 8xx.

In function 'pud_huge_tests',
    inlined from 'debug_vm_pgtable' at mm/debug_vm_pgtable.c:1399:2:
./arch/powerpc/include/asm/vmalloc.h:9:33: warning: inlining failed in call to 'arch_vmap_pud_supported.isra': call is unlikely and code size would grow [-Winline]
    9 | #define arch_vmap_pud_supported arch_vmap_pud_supported
      |                                 ^~~~~~~~~~~~~~~~~~~~~~~
./arch/powerpc/include/asm/vmalloc.h:10:20: note: in expansion of macro 'arch_vmap_pud_supported'
   10 | static inline bool arch_vmap_pud_supported(pgprot_t prot)
      |                    ^~~~~~~~~~~~~~~~~~~~~~~
./arch/powerpc/include/asm/vmalloc.h:9:33: note: called from here
    9 | #define arch_vmap_pud_supported arch_vmap_pud_supported
mm/debug_vm_pgtable.c:458:14: note: in expansion of macro 'arch_vmap_pud_supported'
  458 |         if (!arch_vmap_pud_supported(args->page_prot) ||
      |              ^~~~~~~~~~~~~~~~~~~~~~~
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202402131836.OU1TDuoi-lkp@intel.com/
Fixes: 8309c9d7 ("powerpc: inline huge vmap supported functions")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/bbd84ad52bf377e8d3b5865a906f2dc5d99964ba.1707832677.git.christophe.leroy@csgroup.eu

arch/powerpc/include/asm/vmalloc.h

@@ -7,14 +7,14 @@
 #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
 
 #define arch_vmap_pud_supported arch_vmap_pud_supported
-static inline bool arch_vmap_pud_supported(pgprot_t prot)
+static __always_inline bool arch_vmap_pud_supported(pgprot_t prot)
 {
 	/* HPT does not cope with large pages in the vmalloc area */
 	return radix_enabled();
 }
 
 #define arch_vmap_pmd_supported arch_vmap_pmd_supported
-static inline bool arch_vmap_pmd_supported(pgprot_t prot)
+static __always_inline bool arch_vmap_pmd_supported(pgprot_t prot)
 {
 	return radix_enabled();
 }