queue-4.9/arc-fix-__ffs-return-value-to-avoid-build-warnings.patch

   1 From 1ff144d5cd786241b06cf18fb3c4216003277bdc Mon Sep 17 00:00:00 2001
   2 From: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
   3 Date: Thu, 13 Dec 2018 18:42:57 +0300
   4 Subject: ARC: fix __ffs return value to avoid build warnings
   5
   6 [ Upstream commit 4e868f8419cb4cb558c5d428e7ab5629cef864c7 ]
   7
   8 |  CC      mm/nobootmem.o
   9 |In file included from ./include/asm-generic/bug.h:18:0,
  10 |                 from ./arch/arc/include/asm/bug.h:32,
  11 |                 from ./include/linux/bug.h:5,
  12 |                 from ./include/linux/mmdebug.h:5,
  13 |                 from ./include/linux/gfp.h:5,
  14 |                 from ./include/linux/slab.h:15,
  15 |                 from mm/nobootmem.c:14:
  16 |mm/nobootmem.c: In function '__free_pages_memory':
  17 |./include/linux/kernel.h:845:29: warning: comparison of distinct pointer types lacks a cast
  18 |   (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
  19 |                             ^
  20 |./include/linux/kernel.h:859:4: note: in expansion of macro '__typecheck'
  21 |   (__typecheck(x, y) && __no_side_effects(x, y))
  22 |    ^~~~~~~~~~~
  23 |./include/linux/kernel.h:869:24: note: in expansion of macro '__safe_cmp'
  24 |  __builtin_choose_expr(__safe_cmp(x, y), \
  25 |                        ^~~~~~~~~~
  26 |./include/linux/kernel.h:878:19: note: in expansion of macro '__careful_cmp'
  27 | #define min(x, y) __careful_cmp(x, y, <)
  28 |                   ^~~~~~~~~~~~~
  29 |mm/nobootmem.c:104:11: note: in expansion of macro 'min'
  30 |   order = min(MAX_ORDER - 1UL, __ffs(start));
  31
  32 Change __ffs return value from 'int' to 'unsigned long' as it
  33 is done in other implementations (like asm-generic, x86, etc...)
  34 to avoid build-time warnings in places where type is strictly
  35 checked.
  36
  37 As __ffs may return values in [0-31] interval changing return
  38 type to unsigned is valid.
  39
  40 Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
  41 Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
  42 Signed-off-by: Sasha Levin <sashal@kernel.org>
  43 ---
  44  arch/arc/include/asm/bitops.h | 6 +++---
  45  1 file changed, 3 insertions(+), 3 deletions(-)
  46
  47 diff --git a/arch/arc/include/asm/bitops.h b/arch/arc/include/asm/bitops.h
  48 index 8da87feec59aa..99e6d8948f4ac 100644
  49 --- a/arch/arc/include/asm/bitops.h
  50 +++ b/arch/arc/include/asm/bitops.h
  51 @@ -340,7 +340,7 @@ static inline __attribute__ ((const)) int __fls(unsigned long x)
  52  /*
  53   * __ffs: Similar to ffs, but zero based (0-31)
  54   */
  55 -static inline __attribute__ ((const)) int __ffs(unsigned long word)
  56 +static inline __attribute__ ((const)) unsigned long __ffs(unsigned long word)
  57  {
  58         if (!word)
  59                 return word;
  60 @@ -400,9 +400,9 @@ static inline __attribute__ ((const)) int ffs(unsigned long x)
  61  /*
  62   * __ffs: Similar to ffs, but zero based (0-31)
  63   */
  64 -static inline __attribute__ ((const)) int __ffs(unsigned long x)
  65 +static inline __attribute__ ((const)) unsigned long __ffs(unsigned long x)
  66  {
  67 -       int n;
  68 +       unsigned long n;
  69
  70         asm volatile(
  71         "       ffs.f   %0, %1          \n"  /* 0:31; 31(Z) if src 0 */
  72 --
  73 2.19.1
  74