drm/i915: Provide a hook for selftests

Some pieces of code are independent of hardware but are very tricky to
exercise through the normal userspace ABI or via debugfs hooks. Being
able to create mock unit tests and execute them through CI is vital.
Start by adding a central point where we can execute unit tests and
a parameter to enable them. This is disabled by default as the
expectation is that these tests will occasionally explode.

To facilitate integration with igt, any parameter beginning with
i915.igt__ is interpreted as a subtest executable independently via
igt/drv_selftest.

Two classes of selftests are recognised: mock unit tests and integration
tests. Mock unit tests are run as soon as the module is loaded, before
the device is probed. At that point there is no driver instantiated and
all hw interactions must be "mocked". This is very useful for writing
universal tests to exercise code not typically run on a broad range of
architectures. Alternatively, you can hook into the live selftests and
run when the device has been instantiated - hw interactions are real.

v2: Add a macro for compiling conditional code for mock objects inside
real objects.
v3: Differentiate between mock unit tests and late integration test.
v4: List the tests in natural order, use igt to sort after modparam.
v5: s/late/live/
v6: s/unsigned long/unsigned int/
v7: Use igt_ prefixes for long helpers.
v8: Deobfuscate macros overriding functions, stop using -I$(src)

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170213171558.20942-1-chris@chris-wilson.co.uk

1 files changed, 250 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/selftests/i915_selftest.c b/drivers/gpu/drm/i915/selftests/i915_selftest.c
new file mode 100644
index 000000000000..6ba3abb10c6f
--- /dev/null
+++ b/drivers/gpu/drm/i915/selftests/i915_selftest.c
@@ -0,0 +1,250 @@
+/*
+ * 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 <linux/random.h>
+
+#include "../i915_drv.h"
+#include "../i915_selftest.h"
+
+struct i915_selftest i915_selftest __read_mostly = {
+	.timeout_ms = 1000,
+};
+
+int i915_mock_sanitycheck(void)
+{
+	pr_info(DRIVER_NAME ": %s() - ok!\n", __func__);
+	return 0;
+}
+
+int i915_live_sanitycheck(struct drm_i915_private *i915)
+{
+	pr_info("%s: %s() - ok!\n", i915->drm.driver->name, __func__);
+	return 0;
+}
+
+enum {
+#define selftest(name, func) mock_##name,
+#include "i915_mock_selftests.h"
+#undef selftest
+};
+
+enum {
+#define selftest(name, func) live_##name,
+#include "i915_live_selftests.h"
+#undef selftest
+};
+
+struct selftest {
+	bool enabled;
+	const char *name;
+	union {
+		int (*mock)(void);
+		int (*live)(struct drm_i915_private *);
+	};
+};
+
+#define selftest(n, f) [mock_##n] = { .name = #n, .mock = f },
+static struct selftest mock_selftests[] = {
+#include "i915_mock_selftests.h"
+};
+#undef selftest
+
+#define selftest(n, f) [live_##n] = { .name = #n, .live = f },
+static struct selftest live_selftests[] = {
+#include "i915_live_selftests.h"
+};
+#undef selftest
+
+/* Embed the line number into the parameter name so that we can order tests */
+#define selftest(n, func) selftest_0(n, func, param(n))
+#define param(n) __PASTE(igt__, __PASTE(__LINE__, __mock_##n))
+#define selftest_0(n, func, id) \
+module_param_named(id, mock_selftests[mock_##n].enabled, bool, 0400);
+#include "i915_mock_selftests.h"
+#undef selftest_0
+#undef param
+
+#define param(n) __PASTE(igt__, __PASTE(__LINE__, __live_##n))
+#define selftest_0(n, func, id) \
+module_param_named(id, live_selftests[live_##n].enabled, bool, 0400);
+#include "i915_live_selftests.h"
+#undef selftest_0
+#undef param
+#undef selftest
+
+static void set_default_test_all(struct selftest *st, unsigned int count)
+{
+	unsigned int 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(const char *name,
+			   struct selftest *st,
+			   unsigned int count,
+			   void *data)
+{
+	int err = 0;
+
+	while (!i915_selftest.random_seed)
+		i915_selftest.random_seed = get_random_int();
+
+	i915_selftest.timeout_jiffies =
+		i915_selftest.timeout_ms ?
+		msecs_to_jiffies_timeout(i915_selftest.timeout_ms) :
+		MAX_SCHEDULE_TIMEOUT;
+
+	set_default_test_all(st, count);
+
+	pr_info(DRIVER_NAME ": Performing %s selftests with st_random_seed=0x%x st_timeout=%u\n",
+		name, i915_selftest.random_seed, i915_selftest.timeout_ms);
+
+	/* Tests are listed in order in i915_*_selftests.h */
+	for (; count--; st++) {
+		if (!st->enabled)
+			continue;
+
+		cond_resched();
+		if (signal_pending(current))
+			return -EINTR;
+
+		pr_debug(DRIVER_NAME ": Running %s\n", st->name);
+		if (data)
+			err = st->live(data);
+		else
+			err = st->mock();
+		if (err == -EINTR && !signal_pending(current))
+			err = 0;
+		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;
+}
+
+#define run_selftests(x, data) \
+	__run_selftests(#x, x##_selftests, ARRAY_SIZE(x##_selftests), data)
+
+int i915_mock_selftests(void)
+{
+	int err;
+
+	if (!i915_selftest.mock)
+		return 0;
+
+	err = run_selftests(mock, NULL);
+	if (err) {
+		i915_selftest.mock = err;
+		return err;
+	}
+
+	if (i915_selftest.mock < 0) {
+		i915_selftest.mock = -ENOTTY;
+		return 1;
+	}
+
+	return 0;
+}
+
+int i915_live_selftests(struct pci_dev *pdev)
+{
+	int err;
+
+	if (!i915_selftest.live)
+		return 0;
+
+	err = run_selftests(live, to_i915(pci_get_drvdata(pdev)));
+	if (err) {
+		i915_selftest.live = err;
+		return err;
+	}
+
+	if (i915_selftest.live < 0) {
+		i915_selftest.live = -ENOTTY;
+		return 1;
+	}
+
+	return 0;
+}
+
+int __i915_subtests(const char *caller,
+		    const struct i915_subtest *st,
+		    unsigned int count,
+		    void *data)
+{
+	int err;
+
+	for (; count--; st++) {
+		cond_resched();
+		if (signal_pending(current))
+			return -EINTR;
+
+		pr_debug(DRIVER_NAME ": Running %s/%s\n", caller, st->name);
+		err = st->func(data);
+		if (err && err != -EINTR) {
+			pr_err(DRIVER_NAME "/%s: %s failed with error %d\n",
+			       caller, st->name, err);
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+bool __igt_timeout(unsigned long timeout, const char *fmt, ...)
+{
+	va_list va;
+
+	if (!signal_pending(current)) {
+		cond_resched();
+		if (time_before(jiffies, timeout))
+			return false;
+	}
+
+	if (fmt) {
+		va_start(va, fmt);
+		vprintk(fmt, va);
+		va_end(va);
+	}
+
+	return true;
+}
+
+module_param_named(st_random_seed, i915_selftest.random_seed, uint, 0400);
+module_param_named(st_timeout, i915_selftest.timeout_ms, uint, 0400);
+
+module_param_named_unsafe(mock_selftests, i915_selftest.mock, int, 0400);
+MODULE_PARM_DESC(mock_selftests, "Run selftests before loading, using mock hardware (0:disabled [default], 1:run tests then load driver, -1:run tests then exit module)");
+
+module_param_named_unsafe(live_selftests, i915_selftest.live, int, 0400);
+MODULE_PARM_DESC(live_selftests, "Run selftests after driver initialisation on the live system (0:disabled [default], 1:run tests then continue, -1:run tests then exit module)");