Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1374310 > unrolled thread

[PATCH] lib: lz4: fixed zram with lz4 on big endian machines

Back to article view | Back to linux.kernel

Contents

  [PATCH] lib: lz4: fixed zram with lz4 on big endian machines Rui Salvaterra <rsalvaterra@gmail.com> - 2016-04-08 17:30 +0200
    Re: [PATCH] lib: lz4: fixed zram with lz4 on big endian machines Greg KH <gregkh@linuxfoundation.org> - 2016-04-08 19:00 +0200
      Re: [PATCH] lib: lz4: fixed zram with lz4 on big endian machines Greg KH <gregkh@linuxfoundation.org> - 2016-04-08 22:10 +0200

#1374310 — [PATCH] lib: lz4: fixed zram with lz4 on big endian machines

Based on Sergey's test patch [1], this fixes zram with lz4 compression on big endian cpus. Tested on ppc64 with no regression on x86_64.

[1] http://marc.info/?l=linux-kernel&m=145994470805853&w=4

Cc: stable@vger.kernel.org
Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>
---
 lib/lz4/lz4defs.h | 29 +++++++++++++++--------------
 1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/lib/lz4/lz4defs.h b/lib/lz4/lz4defs.h
index abcecdc..a98c08c 100644
--- a/lib/lz4/lz4defs.h
+++ b/lib/lz4/lz4defs.h
@@ -11,8 +11,7 @@
 /*
  * Detects 64 bits mode
  */
-#if (defined(__x86_64__) || defined(__x86_64) || defined(__amd64__) \
-	|| defined(__ppc64__) || defined(__LP64__))
+#if defined(CONFIG_64BIT)
 #define LZ4_ARCH64 1
 #else
 #define LZ4_ARCH64 0
@@ -25,9 +24,7 @@
 typedef struct _U16_S { u16 v; } U16_S;
 typedef struct _U32_S { u32 v; } U32_S;
 typedef struct _U64_S { u64 v; } U64_S;
-#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)		\
-	|| defined(CONFIG_ARM) && __LINUX_ARM_ARCH__ >= 6	\
-	&& defined(ARM_EFFICIENT_UNALIGNED_ACCESS)
+#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
 
 #define A16(x) (((U16_S *)(x))->v)
 #define A32(x) (((U32_S *)(x))->v)
@@ -35,6 +32,10 @@ typedef struct _U64_S { u64 v; } U64_S;
 
 #define PUT4(s, d) (A32(d) = A32(s))
 #define PUT8(s, d) (A64(d) = A64(s))
+
+#define LZ4_READ_LITTLEENDIAN_16(d, s, p)	\
+	(d = s - A16(p))
+
 #define LZ4_WRITE_LITTLEENDIAN_16(p, v)	\
 	do {	\
 		A16(p) = v; \
@@ -51,12 +52,15 @@ typedef struct _U64_S { u64 v; } U64_S;
 #define PUT8(s, d) \
 	put_unaligned(get_unaligned((const u64 *) s), (u64 *) d)
 
-#define LZ4_WRITE_LITTLEENDIAN_16(p, v)	\
-	do {	\
-		put_unaligned(v, (u16 *)(p)); \
-		p += 2; \
+#define LZ4_READ_LITTLEENDIAN_16(d, s, p)	\
+	(d = s - get_unaligned_le16(p))
+
+#define LZ4_WRITE_LITTLEENDIAN_16(p, v)			\
+	do {						\
+		put_unaligned_le16(v, (u16 *)(p));	\
+		p += 2;					\
 	} while (0)
-#endif
+#endif /* CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS */
 
 #define COPYLENGTH 8
 #define ML_BITS  4
@@ -138,10 +142,7 @@ typedef struct _U64_S { u64 v; } U64_S;
 #define LZ4_NBCOMMONBYTES(val) (__builtin_ctz(val) >> 3)
 #endif
 
-#endif
-
-#define LZ4_READ_LITTLEENDIAN_16(d, s, p) \
-	(d = s - get_unaligned_le16(p))
+#endif /* LZ4_ARCH64 */
 
 #define LZ4_WILDCOPY(s, d, e)		\
 	do {				\
-- 
2.7.4

[toc] | [next] | [standalone]

#1374368

On Fri, Apr 08, 2016 at 04:23:24PM +0100, Rui Salvaterra wrote:
> Based on Sergey's test patch [1], this fixes zram with lz4 compression on big endian cpus. Tested on ppc64 with no regression on x86_64.

Please wrap your text at 72 columns in a changelog comment.

> 
> [1] http://marc.info/?l=linux-kernel&m=145994470805853&w=4
> 
> Cc: stable@vger.kernel.org
> Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>

Please attribute Sergey here in the signed-off-by area with a
"Suggested-by:" type mark

> ---
>  lib/lz4/lz4defs.h | 29 +++++++++++++++--------------
>  1 file changed, 15 insertions(+), 14 deletions(-)
> 
> diff --git a/lib/lz4/lz4defs.h b/lib/lz4/lz4defs.h
> index abcecdc..a98c08c 100644
> --- a/lib/lz4/lz4defs.h
> +++ b/lib/lz4/lz4defs.h
> @@ -11,8 +11,7 @@
>  /*
>   * Detects 64 bits mode
>   */
> -#if (defined(__x86_64__) || defined(__x86_64) || defined(__amd64__) \
> -	|| defined(__ppc64__) || defined(__LP64__))
> +#if defined(CONFIG_64BIT)

This patch seems to do two different things, clean up the #if tests, and
change the endian of some calls.  Can you break this up into 2 different
patches?

thanks,

greg k-h

[toc] | [prev] | [next] | [standalone]

#1374447

On Fri, Apr 08, 2016 at 08:51:17PM +0100, Rui Salvaterra wrote:
> 
> On 8 Apr 2016 17:50, "Greg KH" <gregkh@linuxfoundation.org> wrote:
> >
> > On Fri, Apr 08, 2016 at 04:23:24PM +0100, Rui Salvaterra wrote:
> > > Based on Sergey's test patch [1], this fixes zram with lz4 compression on
> big endian cpus. Tested on ppc64 with no regression on x86_64.
> >
> > Please wrap your text at 72 columns in a changelog comment.
> >
> > >
> > > [1] http://marc.info/?l=linux-kernel&m=145994470805853&w=4
> > >
> > > Cc: stable@vger.kernel.org
> > > Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>
> >
> > Please attribute Sergey here in the signed-off-by area with a
> > "Suggested-by:" type mark
> >
> > > ---
> > >  lib/lz4/lz4defs.h | 29 +++++++++++++++--------------
> > >  1 file changed, 15 insertions(+), 14 deletions(-)
> > >
> > > diff --git a/lib/lz4/lz4defs.h b/lib/lz4/lz4defs.h
> > > index abcecdc..a98c08c 100644
> > > --- a/lib/lz4/lz4defs.h
> > > +++ b/lib/lz4/lz4defs.h
> > > @@ -11,8 +11,7 @@
> > >  /*
> > >   * Detects 64 bits mode
> > >   */
> > > -#if (defined(__x86_64__) || defined(__x86_64) || defined(__amd64__) \
> > > -     || defined(__ppc64__) || defined(__LP64__))
> > > +#if defined(CONFIG_64BIT)
> >
> > This patch seems to do two different things, clean up the #if tests, and
> > change the endian of some calls.  Can you break this up into 2 different
> > patches?
> >
> > thanks,
> >
> > greg k-h
> 
> Hi Greg,
> 
> Thanks for the review (and patience). The 64-bit #if test is actually part of
> the fix, since __ppc64__ isn't defined anywhere and we'd fall into the 32-bit
> definitions for ppc64. I can send the other one separately, for sure. I'll do a
> v2 tomorrow.

Ah, well document that please, it was not obvious at all that this was
required.

thanks,

greg k-h-

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web