linux_dsm_epyc7002/tools/perf/lib/lib.c
Jiri Olsa c03538b1f1 libperf: Adopt the readn()/writen() functions from tools/perf
Move the readn()/writen() functions into libperf.

Keep those non-namespaced names because they will be shared only between
perf and libperf.

Again, these are not exported functions.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190721112506.12306-61-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-07-29 18:34:46 -03:00

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C

// SPDX-License-Identifier: GPL-2.0
#include <unistd.h>
#include <stdbool.h>
#include <errno.h>
#include <linux/kernel.h>
#include <internal/lib.h>
static ssize_t ion(bool is_read, int fd, void *buf, size_t n)
{
void *buf_start = buf;
size_t left = n;
while (left) {
/* buf must be treated as const if !is_read. */
ssize_t ret = is_read ? read(fd, buf, left) :
write(fd, buf, left);
if (ret < 0 && errno == EINTR)
continue;
if (ret <= 0)
return ret;
left -= ret;
buf += ret;
}
BUG_ON((size_t)(buf - buf_start) != n);
return n;
}
/*
* Read exactly 'n' bytes or return an error.
*/
ssize_t readn(int fd, void *buf, size_t n)
{
return ion(true, fd, buf, n);
}
/*
* Write exactly 'n' bytes or return an error.
*/
ssize_t writen(int fd, const void *buf, size_t n)
{
/* ion does not modify buf. */
return ion(false, fd, (void *)buf, n);
}