[PATCH AUTOSEL 5.14 37/99] powerpc: Always inline radix_enabled() to fix build failure

[Sasha Levin]

From: Jordan Niethe <jniethe5@xxxxxxxxx>

[ Upstream commit 27fd1111051dc218e5b6cb2da5dbb3f342879ff1 ]

This is the same as commit acdad8fb4a15 ("powerpc: Force inlining of
mmu_has_feature to fix build failure") but for radix_enabled().  The
config in the linked bugzilla causes the following build failure:

  LD      .tmp_vmlinux.kallsyms1
  powerpc64-linux-ld: arch/powerpc/mm/pgtable.o: in function `.__ptep_set_access_flags':
  pgtable.c:(.text+0x17c): undefined reference to `.radix__ptep_set_access_flags'
  powerpc64-linux-ld: arch/powerpc/mm/pageattr.o: in function `.change_page_attr':
  pageattr.c:(.text+0xc0): undefined reference to `.radix__flush_tlb_kernel_range'
  etc.

This is due to radix_enabled() not being inlined. See extract from
building with -Winline:

  In file included from arch/powerpc/include/asm/lppaca.h:46,
                   from arch/powerpc/include/asm/paca.h:17,
                   from arch/powerpc/include/asm/current.h:13,
                   from include/linux/thread_info.h:23,
                   from include/asm-generic/preempt.h:5,
                   from ./arch/powerpc/include/generated/asm/preempt.h:1,
                   from include/linux/preempt.h:78,
                   from include/linux/spinlock.h:51,
                   from include/linux/mmzone.h:8,
                   from include/linux/gfp.h:6,
                   from arch/powerpc/mm/pgtable.c:21:
  arch/powerpc/include/asm/book3s/64/pgtable.h: In function '__ptep_set_access_flags':
  arch/powerpc/include/asm/mmu.h:327:20: error: inlining failed in call to 'radix_enabled': call is unlikely and code size would grow [-Werror=inline]

The code relies on constant folding of MMU_FTRS_POSSIBLE at buildtime
and elimination of non possible parts of code at compile time. For this
to work radix_enabled() must be inlined so make it __always_inline.

Reported-by: Erhard F. <erhard_f@xxxxxxxxxxx>
Suggested-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Tested-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Signed-off-by: Jordan Niethe <jniethe5@xxxxxxxxx>
[mpe: Trimmed error messages in change log]
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=213803
Link: https://lore.kernel.org/r/20210804013724.514468-1-jniethe5@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 arch/powerpc/include/asm/mmu.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
index 27016b98ecb2..8abe8e42e045 100644
--- a/arch/powerpc/include/asm/mmu.h
+++ b/arch/powerpc/include/asm/mmu.h
@@ -324,7 +324,7 @@ static inline void assert_pte_locked(struct mm_struct *mm, unsigned long addr)
 }
 #endif /* !CONFIG_DEBUG_VM */
 
-static inline bool radix_enabled(void)
+static __always_inline bool radix_enabled(void)
 {
 	return mmu_has_feature(MMU_FTR_TYPE_RADIX);
 }
-- 
2.30.2