[PATCH] Consolidate Linux readahead implementation

[Adhemerval Zanella <adhemerval dot zanella at linaro dot org>]

This patch consolidate Linux readahead implementation on generic
sysdeps/unix/sysv/linux/readahead.c one.  The changes are:

  - Assume __NR_readahead existence with current minimum kernel of 3.2
    for all architectures.

  - Use INLINE_SYSCALL_CALL, __ALIGNMENT_ARG, and SYSCALL_LL64 to pass
    the 64 bit offset.  This allows architectures with different abis
    to use the same implementation.

  - Remove arch-specific supreflous code.

Checked on x86_64-linux-gnu and i686-linux-gnu.

	* sysdeps/unix/sysv/linux/arm/readahead.c: Remove file.
	* sysdeps/unix/sysv/linux/mips/mips32/readahead.c: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n32/syscalls.list (readahead):
	Remove.
	* sysdeps/unix/sysv/linux/mips/mips64/n64/syscalls.list: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/syscalls.list: Likewise.
	* sysdeps/unix/sysv/linux/wordsize-64/syscalls.list: Likewise.
	* sysdeps/unix/sysv/linux/readahead.c (__readahead): Assume
	__NR_readahead existence, and use INLINE_SYSCALL_CALL, __ALIGNMENT_ARG,
	and SYSCALL_LL64.
---
 ChangeLog                                          | 13 ++++++++
 sysdeps/unix/sysv/linux/arm/readahead.c            | 37 ----------------------
 sysdeps/unix/sysv/linux/mips/mips32/readahead.c    |  1 -
 .../unix/sysv/linux/mips/mips64/n32/syscalls.list  |  2 --
 .../unix/sysv/linux/mips/mips64/n64/syscalls.list  |  2 --
 .../sysv/linux/powerpc/powerpc32/syscalls.list     |  3 --
 sysdeps/unix/sysv/linux/readahead.c                | 24 +++-----------
 sysdeps/unix/sysv/linux/wordsize-64/syscalls.list  |  1 -
 8 files changed, 17 insertions(+), 66 deletions(-)
 delete mode 100644 sysdeps/unix/sysv/linux/arm/readahead.c
 delete mode 100644 sysdeps/unix/sysv/linux/mips/mips32/readahead.c

diff --git a/sysdeps/unix/sysv/linux/arm/readahead.c b/sysdeps/unix/sysv/linux/arm/readahead.c
deleted file mode 100644
index 4a3c87f..0000000
--- a/sysdeps/unix/sysv/linux/arm/readahead.c
+++ /dev/null
@@ -1,37 +0,0 @@
-/* Provide kernel hint to read ahead.
-   Copyright (C) 2002-2018 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library.  If not, see
-   <http://www.gnu.org/licenses/>.  */
-
-#include <errno.h>
-#include <fcntl.h>
-#include <sys/types.h>
-#include <endian.h>
-
-#include <sysdep.h>
-#include <sys/syscall.h>
-
-
-ssize_t
-__readahead (int fd, off64_t offset, size_t count)
-{
-  return INLINE_SYSCALL (readahead, 5, fd, 0,
-			 __LONG_LONG_PAIR ((off_t) (offset >> 32),
-					   (off_t) (offset & 0xffffffff)),
-			 count);
-}
-
-weak_alias (__readahead, readahead)
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/readahead.c b/sysdeps/unix/sysv/linux/mips/mips32/readahead.c
deleted file mode 100644
index 80170c3..0000000
--- a/sysdeps/unix/sysv/linux/mips/mips32/readahead.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <sysdeps/unix/sysv/linux/arm/readahead.c>
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/syscalls.list b/sysdeps/unix/sysv/linux/mips/mips64/n32/syscalls.list
index 5f3d047..33d968f 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/syscalls.list
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/syscalls.list
@@ -4,8 +4,6 @@
 # return value.
 lseek64		-	lseek		i:iii	__lseek64	__libc_lseek64 lseek64 llseek
 
-readahead	-	readahead	i:iii	__readahead	readahead
-
 prlimit64	EXTRA	prlimit64	i:iipp	prlimit64
 
 fanotify_mark	EXTRA	fanotify_mark	i:iiiis	fanotify_mark
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/syscalls.list b/sysdeps/unix/sysv/linux/mips/mips64/n64/syscalls.list
index 2866420..8e7d516 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n64/syscalls.list
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/syscalls.list
@@ -1,7 +1,5 @@
 # File name	Caller	Syscall name	# args	Strong name	Weak names
 
-readahead	-	readahead	i:iii	__readahead	readahead
-
 prlimit		EXTRA	prlimit64	i:iipp	prlimit		prlimit64
 
 fanotify_mark	EXTRA	fanotify_mark	i:iiiis	fanotify_mark
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/syscalls.list b/sysdeps/unix/sysv/linux/powerpc/powerpc32/syscalls.list
index 9313747..966856e 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/syscalls.list
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/syscalls.list
@@ -3,8 +3,5 @@
 chown		-	chown		i:sii	__chown		chown@@GLIBC_2.1
 lchown		-	lchown		i:sii	__lchown	lchown@@GLIBC_2.0 chown@GLIBC_2.0
 
-# Due to 64bit alignment there is a dummy second parameter
-readahead	-	readahead	i:iiiii	__readahead	readahead
-
 prlimit64	EXTRA	prlimit64	i:iipp	prlimit64
 fanotify_mark	EXTRA	fanotify_mark	i:iiiiis	fanotify_mark
diff --git a/sysdeps/unix/sysv/linux/readahead.c b/sysdeps/unix/sysv/linux/readahead.c
index 49f5eb4..f84d210 100644
--- a/sysdeps/unix/sysv/linux/readahead.c
+++ b/sysdeps/unix/sysv/linux/readahead.c
@@ -16,31 +16,15 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <errno.h>
 #include <fcntl.h>
-#include <sys/types.h>
-
+#include <errno.h>
 #include <sysdep.h>
-#include <sys/syscall.h>
-
-
-#ifdef __NR_readahead
 
 ssize_t
 __readahead (int fd, off64_t offset, size_t count)
 {
-  return INLINE_SYSCALL (readahead, 4, fd,
-			 __LONG_LONG_PAIR ((off_t) (offset >> 32),
-					   (off_t) (offset & 0xffffffff)),
-			 count);
+  return INLINE_SYSCALL_CALL (readahead, fd,
+			      __ALIGNMENT_ARG SYSCALL_LL64 (offset),
+			      count);
 }
-#else
-ssize_t
-__readahead (int fd, off64_t offset, size_t count)
-{
-  return INLINE_SYSCALL_ERROR_RETURN_VALUE (ENOSYS);
-}
-stub_warning (readahead)
-#endif
-
 weak_alias (__readahead, readahead)
diff --git a/sysdeps/unix/sysv/linux/wordsize-64/syscalls.list b/sysdeps/unix/sysv/linux/wordsize-64/syscalls.list
index 4bb7ebf..5de6ec8 100644
--- a/sysdeps/unix/sysv/linux/wordsize-64/syscalls.list
+++ b/sysdeps/unix/sysv/linux/wordsize-64/syscalls.list
@@ -2,7 +2,6 @@
 
 fstatfs		-	fstatfs		i:ip	__fstatfs	fstatfs fstatfs64 __fstatfs64
 statfs		-	statfs		i:sp	__statfs	statfs statfs64
-readahead	-	readahead	i:iii	__readahead	readahead
 sendfile	-	sendfile	i:iipi	sendfile	sendfile64
 prlimit		EXTRA	prlimit64	i:iipp	prlimit		prlimit64
 
-- 
2.7.4