On Thu, May 26, 2016 at 05:19:35PM +0100, Chris Wilson wrote:
> igt_sysfs_set() for setting an attribute via sysfs, igt_sysfs_get() for
> reading.
>
> v2: Lots of little bugs in igt_sysfs_get()
> v3: Pass device to open, stop assuming Intel rules.
> v4: Test opening and reading!
>
> Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
> ---
> lib/Makefile.sources | 2 +
> lib/igt_sysfs.c | 205 +++++++++++++++++++++++++++++++++++++++++++++++++++
> lib/igt_sysfs.h | 34 +++++++++
> 3 files changed, 241 insertions(+)
> create mode 100644 lib/igt_sysfs.c
> create mode 100644 lib/igt_sysfs.h
>
> diff --git a/lib/Makefile.sources b/lib/Makefile.sources
> index 1316fd2..f50ff4d 100644
> --- a/lib/Makefile.sources
> +++ b/lib/Makefile.sources
> @@ -16,6 +16,8 @@ libintel_tools_la_SOURCES = \
> igt_gt.h \
> igt_stats.c \
> igt_stats.h \
> + igt_sysfs.c \
> + igt_sysfs.h \
> instdone.c \
> instdone.h \
> intel_batchbuffer.c \
> diff --git a/lib/igt_sysfs.c b/lib/igt_sysfs.c
> new file mode 100644
> index 0000000..e9dba0a
> --- /dev/null
> +++ b/lib/igt_sysfs.c
> @@ -0,0 +1,205 @@
> +/*
> + * Copyright © 2016 Intel Corporation
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> + * IN THE SOFTWARE.
> + *
> + */
> +
> +#include <inttypes.h>
> +#include <sys/stat.h>
> +#include <sys/mount.h>
> +#include <errno.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <limits.h>
> +#include <string.h>
> +#include <fcntl.h>
> +#include <unistd.h>
> +#include <i915_drm.h>
> +
> +#include "igt_sysfs.h"
> +
> +static int readN(int fd, char *buf, int len)
> +{
> + int total = 0;
> + do {
> + int ret = read(fd, buf + total, len - total);
> + if (ret < 0 && (errno == EINTR || errno == EAGAIN))
> + continue;
> +
> + if (ret <= 0)
> + return total ?: ret;
> +
> + total += ret;
> + } while (1);
> +}
> +
> +static int writeN(int fd, const char *buf, int len)
> +{
> + int total = 0;
> + do {
> + int ret = write(fd, buf + total, len - total);
> + if (ret < 0 && (errno == EINTR || errno == EAGAIN))
> + continue;
> +
> + if (ret <= 0)
> + return total ?: ret;
> +
> + total += ret;
> + } while (1);
> +}
> +
> +/**
> + * igt_sysfs_open:
> + * @device: fd of the device (or -1 to default to Intel)
> + *
> + * This opens the sysfs directory corresponding to device for use
> + * with igt_sysfs_set() and igt_sysfs_get().
> + *
> + * Returns:
> + * The directory fd, or -1 on failure.
> + */
> +int igt_sysfs_open(int fd, int *idx)
> +{
> + char device[80];
> + char path[80];
> + struct stat st;
> +
> + device[0] = '\0';
> + if (fd != -1) {
> + if (fstat(fd, &st) || !S_ISCHR(st.st_mode))
> + return -1;
> +
> + sprintf(device, "%d:%d", major(st.st_rdev), minor(st.st_rdev));
> + }
> +
> + for (int n = 0; n < 16; n++) {
> + int len = sprintf(path, "/sys/class/drm/card%d", n);
> + if (device[0]) {
> + char tmp[80];
> + int ret;
> +
> + sprintf(path + len, "/dev");
> + fd = open(path, O_RDONLY);
> + if (fd == -1)
> + continue;
> +
> + ret = read(fd, tmp, sizeof(tmp-1));
> + if (ret < 0)
> + ret = 0;
> + tmp[ret] = '\0';
> + while (ret > 0 && tmp[ret-1] == '\n')
> + tmp[--ret] = '\0';
> + close(fd);
> +
> + if (strcmp(tmp, device))
> + continue;
fscanf?
> + } else {
> + /* Bleh. Search for intel */
> + sprintf(path + len, "/error");
> + if (stat(path, &st))
> + continue;
> + }
> +
> + path[len] = '\0';
> + if (idx)
> + *idx = n;
> + return open(path, O_RDONLY);
> + }
> +
> + return -1;
> +}
> +
> +/**
> + * igt_sysfs_set:
> + * @dir: directory for the device from igt_sysfs_open()
> + * @attr: name of the sysfs node to open
> + * @value: the string to write
> + *
> + * This writes the value to the sysfs file.
> + *
> + * Returns:
> + * True on success, false on failure.
> + */
> +bool igt_sysfs_set(int dir, const char *attr, const char *value)
> +{
> + int fd, len, ret;
> +
> + fd = openat(dir, attr, O_WRONLY);
> + if (fd < 0)
> + return false;
> +
> + len = strlen(value);
> + ret = writeN(fd, value, len);
> + close(fd);
> +
> + return len == ret;
> +}
> +
> +/**
> + * igt_sysfs_get:
> + * @dir: directory for the device from igt_sysfs_open()
> + * @attr: name of the sysfs node to open
> + *
> + * This reads the value from the sysfs file.
> + *
> + * Returns:
> + * A nul-terminated string, must be freed by caller after use, or NULL
> + * on failure.
> + */
> +char *igt_sysfs_get(int dir, const char *attr)
> +{
> + char *buf;
> + int len, offset, rem;
> + int ret, fd;
> +
> + fd = openat(dir, attr, O_RDONLY);
> + if (fd < 0)
> + return NULL;
> +
> + offset = 0;
> + len = 64;
> + rem = len - offset - 1;
> + buf = malloc(len);
> + if (!buf)
> + goto out;
> +
> + while ((ret = readN(fd, buf + offset, rem)) == rem) {
> + char *newbuf;
> +
> + newbuf = realloc(buf, 2*len);
> + if (!newbuf)
> + break;
> +
> + len *= 2;
> + offset += ret;
> + rem = len - offset - 1;
> + }
> +
> + if (ret != -1)
> + offset += ret;
> + buf[offset] = '\0';
> + while (offset > 0 && buf[offset-1] == '\n')
> + buf[--offset] = '\0';
> +
> +out:
> + close(fd);
> + return buf;
> +}
> diff --git a/lib/igt_sysfs.h b/lib/igt_sysfs.h
> new file mode 100644
> index 0000000..5c49f64
> --- /dev/null
> +++ b/lib/igt_sysfs.h
> @@ -0,0 +1,34 @@
> +/*
> + * Copyright © 2016 Intel Corporation
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> + * IN THE SOFTWARE.
> + *
> + */
> +
> +#ifndef __IGT_SYSFS_H__
> +#define __IGT_SYSFS_H__
> +
> +#include <stdbool.h>
> +
> +int igt_sysfs_open(int device, int *idx);
> +bool igt_sysfs_set(int dir, const char *attr, const char *value);
> +char *igt_sysfs_get(int dir, const char *attr);
> +
> +#endif /* __IGT_SYSFS_H__ */
> --
> 2.8.1
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
--
Ville Syrjälä
Intel OTC
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
