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 <ch...@chris-wilson.co.uk>
---
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;
+ } 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
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