[Intel-gfx] [PATCH i-g-t v10 17/21] lib/sw_sync: Add igt_require_sw_sync to enable skipping on no sw_sync support

[Robert Foss]

Add igt_require_sw_sync to provide tests to skip if sw_sync support isn't
available on the host machine.

Signed-off-by: Robert Foss <robert.foss at collabora.com>
Reviewed-by: Tomeu Vizoso <tomeu.vizoso at collabora.com>
---
 lib/sw_sync.c | 22 ++++++++++++++++++++++
 lib/sw_sync.h |  1 +
 2 files changed, 23 insertions(+)

diff --git a/lib/sw_sync.c b/lib/sw_sync.c
index a2168f78..d4ecc898 100644
--- a/lib/sw_sync.c
+++ b/lib/sw_sync.c
@@ -194,3 +194,25 @@ int sync_fence_count_status(int fd, int status)
 	igt_assert_f(count >= 0, "No fences with supplied status found");
 	return count;
 }
+
+static bool kernel_has_sw_sync(void)
+{
+	bool err;
+
+	igt_ignore_warn(system("/sbin/modprobe -s r sw_sync"));
+
+	err = false;
+	if (access(DEVFS_SW_SYNC, R_OK | W_OK) < 0) {
+		char buf[128];
+
+		snprintf(buf, sizeof(buf), "%s/sw_sync", igt_debugfs_mount());
+		err = access(DEBUGFS_SW_SYNC, R_OK | W_OK) < 0;
+	}
+
+	return !err;
+}
+
+void igt_require_sw_sync(void)
+{
+	igt_require(kernel_has_sw_sync());
+}
diff --git a/lib/sw_sync.h b/lib/sw_sync.h
index cea5a603..82af3378 100644
--- a/lib/sw_sync.h
+++ b/lib/sw_sync.h
@@ -39,6 +39,7 @@ int sync_merge(int fd1, int fd2);
 int sync_wait(int fence, int timeout);
 int sync_fence_count(int fd);
 int sync_fence_count_status(int fd, int status);
+void igt_require_sw_sync(void);
 
 #endif
 
-- 
2.11.0