releases/4.4.9/lib-lz4-fixed-zram-with-lz4-on-big-endian-machines.patch

   1 From 3e26a691fe3fe1e02a76e5bab0c143ace4b137b4 Mon Sep 17 00:00:00 2001
   2 From: Rui Salvaterra <rsalvaterra@gmail.com>
   3 Date: Sat, 9 Apr 2016 22:05:34 +0100
   4 Subject: lib: lz4: fixed zram with lz4 on big endian machines
   5
   6 From: Rui Salvaterra <rsalvaterra@gmail.com>
   7
   8 commit 3e26a691fe3fe1e02a76e5bab0c143ace4b137b4 upstream.
   9
  10 Based on Sergey's test patch [1], this fixes zram with lz4 compression
  11 on big endian cpus.
  12
  13 Note that the 64-bit preprocessor test is not a cleanup, it's part of
  14 the fix, since those identifiers are bogus (for example, __ppc64__
  15 isn't defined anywhere else in the kernel, which means we'd fall into
  16 the 32-bit definitions on ppc64).
  17
  18 Tested on ppc64 with no regression on x86_64.
  19
  20 [1] http://marc.info/?l=linux-kernel&m=145994470805853&w=4
  21
  22 Suggested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
  23 Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>
  24 Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
  25 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  26
  27 ---
  28  lib/lz4/lz4defs.h |   21 ++++++++++++---------
  29  1 file changed, 12 insertions(+), 9 deletions(-)
  30
  31 --- a/lib/lz4/lz4defs.h
  32 +++ b/lib/lz4/lz4defs.h
  33 @@ -11,8 +11,7 @@
  34  /*
  35   * Detects 64 bits mode
  36   */
  37 -#if (defined(__x86_64__) || defined(__x86_64) || defined(__amd64__) \
  38 -       || defined(__ppc64__) || defined(__LP64__))
  39 +#if defined(CONFIG_64BIT)
  40  #define LZ4_ARCH64 1
  41  #else
  42  #define LZ4_ARCH64 0
  43 @@ -35,6 +34,10 @@ typedef struct _U64_S { u64 v; } U64_S;
  44
  45  #define PUT4(s, d) (A32(d) = A32(s))
  46  #define PUT8(s, d) (A64(d) = A64(s))
  47 +
  48 +#define LZ4_READ_LITTLEENDIAN_16(d, s, p)      \
  49 +       (d = s - A16(p))
  50 +
  51  #define LZ4_WRITE_LITTLEENDIAN_16(p, v)        \
  52         do {    \
  53                 A16(p) = v; \
  54 @@ -51,10 +54,13 @@ typedef struct _U64_S { u64 v; } U64_S;
  55  #define PUT8(s, d) \
  56         put_unaligned(get_unaligned((const u64 *) s), (u64 *) d)
  57
  58 -#define LZ4_WRITE_LITTLEENDIAN_16(p, v)        \
  59 -       do {    \
  60 -               put_unaligned(v, (u16 *)(p)); \
  61 -               p += 2; \
  62 +#define LZ4_READ_LITTLEENDIAN_16(d, s, p)      \
  63 +       (d = s - get_unaligned_le16(p))
  64 +
  65 +#define LZ4_WRITE_LITTLEENDIAN_16(p, v)                        \
  66 +       do {                                            \
  67 +               put_unaligned_le16(v, (u16 *)(p));      \
  68 +               p += 2;                                 \
  69         } while (0)
  70  #endif
  71
  72 @@ -140,9 +146,6 @@ typedef struct _U64_S { u64 v; } U64_S;
  73
  74  #endif
  75
  76 -#define LZ4_READ_LITTLEENDIAN_16(d, s, p) \
  77 -       (d = s - get_unaligned_le16(p))
  78 -
  79  #define LZ4_WILDCOPY(s, d, e)          \
  80         do {                            \
  81                 LZ4_COPYPACKET(s, d);   \