[PATCH] powerpc: wire up preadv and pwritev

From: Stephen Rothwell
Date: Mon Apr 06 2009 - 23:20:35 EST



Signed-off-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
---
arch/powerpc/include/asm/systbl.h | 2 ++
arch/powerpc/include/asm/unistd.h | 4 +++-
2 files changed, 5 insertions(+), 1 deletions(-)

Tested on pseries_defconfig (verified using strace{,64} and inspecting
the files). Test program (modified from the original because the API and
ABI changed and I added a test with larger offsets):

#if 0
set -x
gcc -Wall -O2 -m32 -o preadv $0
gcc -Wall -O2 -m32 -D_FILE_OFFSET_BITS=64 -DLARGE_TEST -o preadv32 $0
gcc -Wall -O2 -m64 -DLARGE_TEST -o preadv64 $0
./preadv
./preadv32
./preadv64
exit 0
#endif
/*
* preadv demo / test
*
* (c) 2008 Gerd Hoffmann <kraxel@xxxxxxxxxx>
* Modified for new ABI and large offset test by Stephen Rothwell
*
* build with "sh $thisfile"
*/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <inttypes.h>
#include <sys/uio.h>

/* ----------------------------------------------------------------- */
/* syscall windup */

#include <sys/syscall.h>
#if 1
/* WARNING: Be sure you know what you are doing if you enable this.
* linux syscall code isn't upstream yet, syscall numbers are subject
* to change */
# ifndef __NR_preadv
# ifdef __i386__
# define __NR_preadv 333
# define __NR_pwritev 334
# endif
# ifdef __x86_64__
# define __NR_preadv 295
# define __NR_pwritev 296
# endif
# ifdef __powerpc__
# define __NR_preadv 319
# define __NR_pwritev 320
# endif
# endif
#endif
#ifndef __NR_preadv
# error preadv/pwritev syscall numbers are unknown
#endif

#define HALF_BITS (sizeof(unsigned long)*4)

static ssize_t preadv(int fd, const struct iovec *iov, int iovcnt,
off_t offset)
{
return syscall(__NR_preadv, fd, iov, iovcnt,
(unsigned long)offset,
(unsigned long)((offset >> HALF_BITS) >> HALF_BITS));
}

static ssize_t pwritev(int fd, const struct iovec *iov, int iovcnt,
off_t offset)
{
return syscall(__NR_pwritev, fd, iov, iovcnt,
(unsigned long)offset,
(unsigned long)((offset >> HALF_BITS) >> HALF_BITS));
}

/* ----------------------------------------------------------------- */
/* demo/test app */

static char filename[] = "/tmp/preadv-XXXXXX";
static char outbuf[11] = "0123456789";
static char inbuf[11] = "----------";

static struct iovec ovec[2] = {{
.iov_base = outbuf + 5,
.iov_len = 5,
},{
.iov_base = outbuf + 0,
.iov_len = 5,
}};

static struct iovec ivec[3] = {{
.iov_base = inbuf + 6,
.iov_len = 2,
},{
.iov_base = inbuf + 4,
.iov_len = 2,
},{
.iov_base = inbuf + 2,
.iov_len = 2,
}};

void cleanup(void)
{
unlink(filename);
}

int main(int argc, char **argv)
{
int fd, rc;

fd = mkstemp(filename);
if (-1 == fd) {
perror("mkstemp");
exit(1);
}
atexit(cleanup);

/* write to file: "56789-01234" */
rc = pwritev(fd, ovec, 2, 0);
if (rc < 0) {
perror("pwritev");
exit(1);
}

/* read from file: "78-90-12" */
rc = preadv(fd, ivec, 3, 2);
if (rc < 0) {
perror("preadv");
exit(1);
}

printf("result : %s\n", inbuf);
printf("expected: %s\n", "--129078--");

#ifdef LARGE_TEST

/* write to file: "56789-01234" */
rc = pwritev(fd, ovec, 2, 0x300000000ULL);
if (rc < 0) {
perror("pwritev");
exit(1);
}

/* read from file: "78-90-12" */
rc = preadv(fd, ivec, 3, 0x300000000ULL + 2);
if (rc < 0) {
perror("preadv");
exit(1);
}

printf("result : %s\n", inbuf);
printf("expected: %s\n", "--129078--");

#endif

exit(0);
}


diff --git a/arch/powerpc/include/asm/systbl.h b/arch/powerpc/include/asm/systbl.h
index fe16649..3fb6d9e 100644
--- a/arch/powerpc/include/asm/systbl.h
+++ b/arch/powerpc/include/asm/systbl.h
@@ -322,3 +322,5 @@ SYSCALL_SPU(epoll_create1)
SYSCALL_SPU(dup3)
SYSCALL_SPU(pipe2)
SYSCALL(inotify_init1)
+COMPAT_SYS_SPU(preadv)
+COMPAT_SYS_SPU(pwritev)
diff --git a/arch/powerpc/include/asm/unistd.h b/arch/powerpc/include/asm/unistd.h
index e07d0c7..7e03ebe 100644
--- a/arch/powerpc/include/asm/unistd.h
+++ b/arch/powerpc/include/asm/unistd.h
@@ -341,10 +341,12 @@
#define __NR_dup3 316
#define __NR_pipe2 317
#define __NR_inotify_init1 318
+#define __NR_preadv 319
+#define __NR_pwritev 320

#ifdef __KERNEL__

-#define __NR_syscalls 319
+#define __NR_syscalls 321

#define __NR__exit __NR_exit
#define NR_syscalls __NR_syscalls
--
1.6.2.1

--
Cheers,
Stephen Rothwell sfr@xxxxxxxxxxxxxxxx
http://www.canb.auug.org.au/~sfr/
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