From: Qian Cai <cai@lca.pw>
Date: Mon, 29 Apr 2019 17:37:01 +0000 (-0400)
Subject: arm64: Fix compiler warning from pte_unmap() with -Wunused-but-set-variable
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=74dd022f9e6260c3b5b8d15901d27ebcc5f21eda;p=openwrt%2Fstaging%2Fblogic.git

arm64: Fix compiler warning from pte_unmap() with -Wunused-but-set-variable

When building with -Wunused-but-set-variable, the compiler shouts about
a number of pte_unmap() users, since this expands to an empty macro on
arm64:

  | mm/gup.c: In function 'gup_pte_range':
  | mm/gup.c:1727:16: warning: variable 'ptem' set but not used
  | [-Wunused-but-set-variable]
  | mm/gup.c: At top level:
  | mm/memory.c: In function 'copy_pte_range':
  | mm/memory.c:821:24: warning: variable 'orig_dst_pte' set but not used
  | [-Wunused-but-set-variable]
  | mm/memory.c:821:9: warning: variable 'orig_src_pte' set but not used
  | [-Wunused-but-set-variable]
  | mm/swap_state.c: In function 'swap_ra_info':
  | mm/swap_state.c:641:15: warning: variable 'orig_pte' set but not used
  | [-Wunused-but-set-variable]
  | mm/madvise.c: In function 'madvise_free_pte_range':
  | mm/madvise.c:318:9: warning: variable 'orig_pte' set but not used
  | [-Wunused-but-set-variable]

Rewrite pte_unmap() as a static inline function, which silences the
warnings.

Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Will Deacon <will.deacon@arm.com>
---

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index de70c1eabf33..74ebe9693714 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -478,6 +478,8 @@ static inline phys_addr_t pmd_page_paddr(pmd_t pmd)
 	return __pmd_to_phys(pmd);
 }
 
+static inline void pte_unmap(pte_t *pte) { }
+
 /* Find an entry in the third-level page table. */
 #define pte_index(addr)		(((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 
@@ -486,7 +488,6 @@ static inline phys_addr_t pmd_page_paddr(pmd_t pmd)
 
 #define pte_offset_map(dir,addr)	pte_offset_kernel((dir), (addr))
 #define pte_offset_map_nested(dir,addr)	pte_offset_kernel((dir), (addr))
-#define pte_unmap(pte)			do { } while (0)
 #define pte_unmap_nested(pte)		do { } while (0)
 
 #define pte_set_fixmap(addr)		((pte_t *)set_fixmap_offset(FIX_PTE, addr))