5 files changed, 217 insertions, 0 deletions
diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig
index b6a9c2f1bc41..a23b6752d11a 100644
--- a/drivers/dma-buf/Kconfig
+++ b/drivers/dma-buf/Kconfig
@@ -39,4 +39,9 @@ config UDMABUF
 	  A driver to let userspace turn memfd regions into dma-bufs.
 	  Qemu can use this to create host dmabufs for guest framebuffers.
 
+config DMABUF_SELFTESTS
+	tristate "Selftests for the dma-buf interfaces"
+	default n
+	depends on DMA_SHARED_BUFFER
+
 endmenu
diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile
index dcfb01e7c6f4..b5ae122a9349 100644
--- a/drivers/dma-buf/Makefile
+++ b/drivers/dma-buf/Makefile
@@ -4,3 +4,6 @@ obj-y := dma-buf.o dma-fence.o dma-fence-array.o dma-fence-chain.o \
 obj-$(CONFIG_SYNC_FILE)		+= sync_file.o
 obj-$(CONFIG_SW_SYNC)		+= sw_sync.o sync_debug.o
 obj-$(CONFIG_UDMABUF)		+= udmabuf.o
+
+dmabuf_selftests-y := selftest.o
+obj-$(CONFIG_DMABUF_SELFTESTS)	+= dmabuf_selftests.o
diff --git a/drivers/dma-buf/selftest.c b/drivers/dma-buf/selftest.c
new file mode 100644
index 000000000000..c60b6944b4bd
--- /dev/null
+++ b/drivers/dma-buf/selftest.c
@@ -0,0 +1,167 @@
+/* SPDX-License-Identifier: MIT */
+
+/*
+ * Copyright © 2019 Intel Corporation
+ */
+
+#include <linux/compiler.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sched/signal.h>
+#include <linux/slab.h>
+
+#include "selftest.h"
+
+enum {
+#define selftest(n, func) __idx_##n,
+#include "selftests.h"
+#undef selftest
+};
+
+#define selftest(n, f) [__idx_##n] = { .name = #n, .func = f },
+static struct selftest {
+	bool enabled;
+	const char *name;
+	int (*func)(void);
+} selftests[] = {
+#include "selftests.h"
+};
+#undef selftest
+
+/* Embed the line number into the parameter name so that we can order tests */
+#define param(n) __PASTE(igt__, __PASTE(__PASTE(__LINE__, __), n))
+#define selftest_0(n, func, id) \
+module_param_named(id, selftests[__idx_##n].enabled, bool, 0400);
+#define selftest(n, func) selftest_0(n, func, param(n))
+#include "selftests.h"
+#undef selftest
+
+int __sanitycheck__(void)
+{
+	pr_debug("Hello World!\n");
+	return 0;
+}
+
+static char *__st_filter;
+
+static bool apply_subtest_filter(const char *caller, const char *name)
+{
+	char *filter, *sep, *tok;
+	bool result = true;
+
+	filter = kstrdup(__st_filter, GFP_KERNEL);
+	for (sep = filter; (tok = strsep(&sep, ","));) {
+		bool allow = true;
+		char *sl;
+
+		if (*tok == '!') {
+			allow = false;
+			tok++;
+		}
+
+		if (*tok == '\0')
+			continue;
+
+		sl = strchr(tok, '/');
+		if (sl) {
+			*sl++ = '\0';
+			if (strcmp(tok, caller)) {
+				if (allow)
+					result = false;
+				continue;
+			}
+			tok = sl;
+		}
+
+		if (strcmp(tok, name)) {
+			if (allow)
+				result = false;
+			continue;
+		}
+
+		result = allow;
+		break;
+	}
+	kfree(filter);
+
+	return result;
+}
+
+int
+__subtests(const char *caller, const struct subtest *st, int count, void *data)
+{
+	int err;
+
+	for (; count--; st++) {
+		cond_resched();
+		if (signal_pending(current))
+			return -EINTR;
+
+		if (!apply_subtest_filter(caller, st->name))
+			continue;
+
+		pr_info("dma-buf: Running %s/%s\n", caller, st->name);
+
+		err = st->func(data);
+		if (err && err != -EINTR) {
+			pr_err("dma-buf/%s: %s failed with error %d\n",
+			       caller, st->name, err);
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+static void set_default_test_all(struct selftest *st, unsigned long count)
+{
+	unsigned long i;
+
+	for (i = 0; i < count; i++)
+		if (st[i].enabled)
+			return;
+
+	for (i = 0; i < count; i++)
+		st[i].enabled = true;
+}
+
+static int run_selftests(struct selftest *st, unsigned long count)
+{
+	int err = 0;
+
+	set_default_test_all(st, count);
+
+	/* Tests are listed in natural order in selftests.h */
+	for (; count--; st++) {
+		if (!st->enabled)
+			continue;
+
+		pr_info("dma-buf: Running %s\n", st->name);
+		err = st->func();
+		if (err)
+			break;
+	}
+
+	if (WARN(err > 0 || err == -ENOTTY,
+		 "%s returned %d, conflicting with selftest's magic values!\n",
+		 st->name, err))
+		err = -1;
+
+	return err;
+}
+
+static int __init st_init(void)
+{
+	return run_selftests(selftests, ARRAY_SIZE(selftests));
+}
+
+static void __exit st_exit(void)
+{
+}
+
+module_param_named(st_filter, __st_filter, charp, 0400);
+module_init(st_init);
+module_exit(st_exit);
+
+MODULE_DESCRIPTION("Self-test harness for dma-buf");
+MODULE_LICENSE("GPL and additional rights");
diff --git a/drivers/dma-buf/selftest.h b/drivers/dma-buf/selftest.h
new file mode 100644
index 000000000000..45793aff6142
--- /dev/null
+++ b/drivers/dma-buf/selftest.h
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: MIT
+
+/*
+ * Copyright © 2019 Intel Corporation
+ */
+
+#ifndef __SELFTEST_H__
+#define __SELFTEST_H__
+
+#include <linux/compiler.h>
+
+#define selftest(name, func) int func(void);
+#include "selftests.h"
+#undef selftest
+
+struct subtest {
+	int (*func)(void *data);
+	const char *name;
+};
+
+int __subtests(const char *caller,
+	       const struct subtest *st,
+	       int count,
+	       void *data);
+#define subtests(T, data) \
+	__subtests(__func__, T, ARRAY_SIZE(T), data)
+
+#define SUBTEST(x) { x, #x }
+
+#endif /* __SELFTEST_H__ */
diff --git a/drivers/dma-buf/selftests.h b/drivers/dma-buf/selftests.h
new file mode 100644
index 000000000000..44b44390d23a
--- /dev/null
+++ b/drivers/dma-buf/selftests.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: MIT */
+/* List each unit test as selftest(name, function)
+ *
+ * The name is used as both an enum and expanded as subtest__name to create
+ * a module parameter. It must be unique and legal for a C identifier.
+ *
+ * The function should be of type int function(void). It may be conditionally
+ * compiled using #if IS_ENABLED(DRM_I915_SELFTEST).
+ *
+ * Tests are executed in order by igt/dmabuf_selftest
+ */
+selftest(sanitycheck, __sanitycheck__) /* keep first (igt selfcheck) */