tests: introduce igt_require

Since igt_skip has funny control flow we can abuse it and make it work
like a special kind of assert which automatically skips tests if a
requirement fails.

Note that in places where we have a less strict test which should
always succeed (e.g. ioctl works or isn't available) the igt_assert
should be place before the igt_require with the more strict
requirements. Otherwise we'll skip a test instead of properly failing
it.

Convert a few users of igt_skip over to igt_require to showcase its
use.

v2: s/gem_check_/gem_require_/ so that we consistently use "require"
to indicate magic check that can call igt_skip. Imo hiding the
igt_require for feature checks is ok, but for more traditional assert
like use cases an explicit igt_require might be better.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

lib/drmtest.c

@@ -393,7 +393,7 @@ struct local_drm_i915_gem_caching {
 #define LOCAL_DRM_IOCTL_I915_GEM_GET_CACHEING \
 	DRM_IOWR(DRM_COMMAND_BASE + LOCAL_DRM_I915_GEM_GET_CACHEING, struct local_drm_i915_gem_caching)
 
-void gem_check_caching(int fd)
+void gem_require_caching(int fd)
 {
 	struct local_drm_i915_gem_caching arg;
 	int ret;
@@ -405,11 +405,7 @@ void gem_check_caching(int fd)
 	ret = ioctl(fd, LOCAL_DRM_IOCTL_I915_GEM_SET_CACHEING, &arg);
 	gem_close(fd, arg.handle);
 
-	if (ret != 0) {
-		if (!igt_only_list_subtests())
-			printf("no set_caching support detected\n");
-		igt_skip();
-	}
+	igt_require(ret == 0);
 }
 
 void gem_set_caching(int fd, uint32_t handle, int caching)
@@ -421,10 +417,8 @@ void gem_set_caching(int fd, uint32_t handle, int caching)
 	arg.caching = caching;
 	ret = ioctl(fd, LOCAL_DRM_IOCTL_I915_GEM_SET_CACHEING, &arg);
 
-	if (ret != 0 && (errno == ENOTTY || errno == EINVAL))
-		igt_skip();
-	else
-		igt_assert(ret == 0);
+	igt_assert(ret == 0 || (errno == ENOTTY || errno == EINVAL));
+	igt_require(ret == 0);
 }
 
 uint32_t gem_get_caching(int fd, uint32_t handle)
@@ -770,6 +764,15 @@ void igt_skip(void)
 		exit(77);
 }
 
+void __igt_skip_check(const char *file, const int line,
+		      const char *func, const char *check)
+{
+	printf("Test requirement not met in function %s, file %s:%i:\n"
+	       "Test requirement: (%s)\n",
+	       func, file, line, check);
+	igt_skip();
+}
+
 void igt_success(void)
 {
 	succeeded_one = true;
@@ -847,8 +850,7 @@ void igt_skip_on_simulation(void)
 	if (igt_only_list_subtests())
 		return;
 
-	if (igt_run_in_simulation())
-		igt_skip();
+	igt_require(!igt_run_in_simulation());
 }
 
 /* other helpers */

lib/drmtest.h

@@ -36,6 +36,7 @@
 
 #include "xf86drm.h"
 #include "xf86drmMode.h"
+#include "i915_drm.h"
 #include "intel_batchbuffer.h"
 #include "intel_chipset.h"
 #include "intel_gpu_tools.h"
@@ -104,41 +105,48 @@ bool __igt_run_subtest(const char *subtest_name);
 				   igt_success())
 bool igt_only_list_subtests(void);
 void igt_skip(void);
+void __igt_skip_check(const char *file, const int line,
+		      const char *func, const char *check);
 void igt_success(void);
 void igt_fail(int exitcode) __attribute__((noreturn));
 void __igt_fail_assert(int exitcode, const char *file,
 		       const int line, const char *func, const char *assertion)
 	__attribute__((noreturn));
 void igt_exit(void);
+/**
+ * igt_assert - fails (sub-)test if a condition is not met
+ *
+ * Should be used everywhere where a test checks results.
+ */
 #define igt_assert(expr) do { if (!(expr)) __igt_fail_assert(99, __FILE__, __LINE__, __func__, #expr ); } while (0)
+/**
+ * igt_require - skip a (sub-)test if a condition is not met
+ *
+ * This is useful to streamline the skip logic since it allows for a more flat
+ * code control flow.
+ */
+#define igt_require(expr) do { if (!(expr)) __igt_skip_check(__FILE__, __LINE__, __func__, #expr ); } while (0)
 
 /* check functions which auto-skip tests by calling igt_skip() */
-void gem_check_caching(int fd);
-static inline bool gem_check_vebox(int fd)
+void gem_require_caching(int fd);
+static inline void gem_require_ring(int fd, int ring_id)
 {
-	if (gem_has_vebox(fd))
-		return true;
-
-	igt_skip();
-	return false;
-}
-
-static inline bool gem_check_bsd(int fd)
-{
-	if (HAS_BSD_RING(intel_get_drm_devid(fd)))
-		return true;
-
-	igt_skip();
-	return false;
-}
-
-static inline bool gem_check_blt(int fd)
-{
-	if (HAS_BLT_RING(intel_get_drm_devid(fd)))
-		return true;
-
-	igt_skip();
-	return false;
+	switch (ring_id) {
+	case I915_EXEC_RENDER:
+		return;
+	case I915_EXEC_BLT:
+		igt_require(HAS_BLT_RING(intel_get_drm_devid(fd)));
+		return;
+	case I915_EXEC_BSD:
+		igt_require(HAS_BSD_RING(intel_get_drm_devid(fd)));
+		return;
+	case I915_EXEC_VEBOX:
+		igt_require(gem_has_vebox(fd));
+		return;
+	default:
+		assert(0);
+		return;
+	}
 }
 
 /* helpers to automatically reduce test runtime in simulation */

tests/gem_caching.c

@@ -117,7 +117,7 @@ int main(int argc, char **argv)
 
 	fd = drm_open_any();
 
-	gem_check_caching(fd);
+	gem_require_caching(fd);
 
 	devid = intel_get_drm_devid(fd);
 	if (IS_GEN2(devid)) /* chipset only handles cached -> uncached */

tests/gem_cs_tlb.c

@@ -101,6 +101,8 @@ static void run_on_ring(int fd, unsigned ring_id, const char *ring_name)
 	char buf[100];
 	int i;
 
+	gem_require_ring(fd, ring_id);
+
 	sprintf(buf, "testing %s cs tlb coherency: ", ring_name);
 
 	/* Shut up gcc, too stupid. */
@@ -163,16 +165,13 @@ int main(int argc, char **argv)
 		run_on_ring(fd, I915_EXEC_RENDER, "render");
 
 	igt_subtest("bsd")
-		if (gem_check_bsd(fd))
-			run_on_ring(fd, I915_EXEC_BSD, "bsd");
+		run_on_ring(fd, I915_EXEC_BSD, "bsd");
 
 	igt_subtest("blt")
-		if (gem_check_blt(fd))
-			run_on_ring(fd, I915_EXEC_BLT, "blt");
+		run_on_ring(fd, I915_EXEC_BLT, "blt");
 
 	igt_subtest("vebox")
-		if (gem_check_vebox(fd))
-			run_on_ring(fd, LOCAL_I915_EXEC_VEBOX, "vebox");
+		run_on_ring(fd, LOCAL_I915_EXEC_VEBOX, "vebox");
 
 	close(fd);
 

tests/gem_dummy_reloc_loop.c

@@ -166,30 +166,27 @@ int main(int argc, char **argv)
 	}
 
 	igt_subtest("bsd") {
-		if (gem_check_bsd(fd)) {
-			sleep(2);
-			printf("running dummy loop on bsd\n");
-			dummy_reloc_loop(I915_EXEC_BSD);
-			printf("dummy loop run on bsd completed\n");
-		}
+		gem_require_ring(fd, I915_EXEC_BSD);
+		sleep(2);
+		printf("running dummy loop on bsd\n");
+		dummy_reloc_loop(I915_EXEC_BSD);
+		printf("dummy loop run on bsd completed\n");
 	}
 
 	igt_subtest("blt") {
-		if (gem_check_blt(fd)) {
-			sleep(2);
-			printf("running dummy loop on blt\n");
-			dummy_reloc_loop(I915_EXEC_BLT);
-			printf("dummy loop run on blt completed\n");
-		}
+		gem_require_ring(fd, I915_EXEC_BLT);
+		sleep(2);
+		printf("running dummy loop on blt\n");
+		dummy_reloc_loop(I915_EXEC_BLT);
+		printf("dummy loop run on blt completed\n");
 	}
 
 	igt_subtest("vebox") {
-		if (gem_check_vebox(fd)) {
-			sleep(2);
-			printf("running dummy loop on vebox\n");
-			dummy_reloc_loop(LOCAL_I915_EXEC_VEBOX);
-			printf("dummy loop run on vebox completed\n");
-		}
+		gem_require_ring(fd, I915_EXEC_VEBOX);
+		sleep(2);
+		printf("running dummy loop on vebox\n");
+		dummy_reloc_loop(LOCAL_I915_EXEC_VEBOX);
+		printf("dummy loop run on vebox completed\n");
 	}
 
 	igt_subtest("mixed") {

tests/gem_exec_nop.c

@@ -92,6 +92,8 @@ static void loop(int fd, uint32_t handle, unsigned ring_id, const char *ring_nam
 {
 	int count;
 
+	gem_require_ring(fd, ring_id);
+
 	for (count = 1; count <= SLOW_QUICK(1<<17, 1<<4); count <<= 1) {
 		struct timeval start, end;
 
@@ -103,8 +105,8 @@ static void loop(int fd, uint32_t handle, unsigned ring_id, const char *ring_nam
 		       count, elapsed(&start, &end, count), ring_name);
 		fflush(stdout);
 	}
-
 }
+
 int main(int argc, char **argv)
 {
 	uint32_t batch[2] = {MI_BATCH_BUFFER_END};
@@ -122,16 +124,13 @@ int main(int argc, char **argv)
 		loop(fd, handle, I915_EXEC_RENDER, "render");
 
 	igt_subtest("bsd")
-		if (gem_check_blt(fd))
-			loop(fd, handle, I915_EXEC_BSD, "bsd");
+		loop(fd, handle, I915_EXEC_BSD, "bsd");
 
 	igt_subtest("blt")
-		if (gem_check_blt(fd))
-			loop(fd, handle, I915_EXEC_BLT, "blt");
+		loop(fd, handle, I915_EXEC_BLT, "blt");
 
 	igt_subtest("vebox")
-		if (gem_check_vebox(fd))
-			loop(fd, handle, LOCAL_I915_EXEC_VEBOX, "vebox");
+		loop(fd, handle, LOCAL_I915_EXEC_VEBOX, "vebox");
 
 	gem_close(fd, handle);
 

tests/gem_reg_read.c

@@ -66,16 +66,14 @@ static uint64_t timer_query(int fd)
 int main(int argc, char *argv[])
 {
 	struct local_drm_i915_reg_read reg_read;
-	int fd;
+	int fd, ret;
 
 	fd = drm_open_any();
 
 	reg_read.offset = 0x2358;
-	if (drmIoctl(fd, REG_READ_IOCTL, &reg_read)) {
-		if (errno == EINVAL)
-			igt_skip();
-		igt_fail(1);
-	}
+	ret = drmIoctl(fd, REG_READ_IOCTL, &reg_read);
+	igt_assert(ret == 0 || errno == EINVAL);
+	igt_require(ret == 0);
 
 	reg_read.val = timer_query(fd);
 	sleep(1);

tests/gem_write_read_ring_switch.c

@@ -146,20 +146,6 @@ static void run_test(int ring, const char *testname)
 	drm_intel_bo_unreference(target_bo);
 }
 
-static int has_ring(int ring)
-{
-	switch (ring) {
-	case I915_EXEC_RENDER: /* test only makes sense with separate blitter */
-		return gem_check_blt(fd);
-	case I915_EXEC_BSD:
-		return gem_check_bsd(fd);
-	case LOCAL_I915_EXEC_VEBOX:
-		return gem_check_vebox(fd);
-	default:
-		return 0;
-	}
-}
-
 int main(int argc, char **argv)
 {
 	static const struct {
@@ -206,8 +192,11 @@ int main(int argc, char **argv)
 
 	for (i = 0; i < ARRAY_SIZE(tests); i++) {
 		igt_subtest(tests[i].name) {
-			if (has_ring(tests[i].ring))
-				run_test(tests[i].ring, tests[i].name);
+			gem_require_ring(fd, tests[i].ring);
+			/* Testing render only makes sense with separate blt. */
+			if (tests[i].ring == I915_EXEC_RENDER)
+				gem_require_ring(fd, I915_EXEC_BLT);
+			run_test(tests[i].ring, tests[i].name);
 		}
 	}