igt/gem_ctx_switch: Add basic test for context switching

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

tests/Makefile.sources

@@ -135,6 +135,7 @@ TESTS_progs = \
 	gem_ctx_bad_destroy \
 	gem_ctx_basic \
 	gem_ctx_create \
+	gem_ctx_switch \
 	gem_ctx_thrash \
 	gem_double_irq_loop \
 	gem_exec_big \

tests/gem_ctx_switch.c

@@ -0,0 +1,166 @@
+/*
+ * Copyright © 2011 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.
+ *
+ * Authors:
+ *    Chris Wilson <chris@chris-wilson.co.uk>
+ *
+ */
+
+#include "igt.h"
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/time.h>
+#include <time.h>
+#include "drm.h"
+
+#define LOCAL_I915_EXEC_NO_RELOC (1<<11)
+#define LOCAL_I915_EXEC_HANDLE_LUT (1<<12)
+
+#define INTERRUPTIBLE 1
+
+static int __gem_context_create(int fd, uint32_t *ctx_id)
+{
+	struct drm_i915_gem_context_create arg;
+	int ret = 0;
+
+	memset(&arg, 0, sizeof(arg));
+	if (drmIoctl(fd, DRM_IOCTL_I915_GEM_CONTEXT_CREATE, &arg))
+		ret = -errno;
+
+	*ctx_id = arg.ctx_id;
+	return ret;
+}
+
+static double elapsed(const struct timespec *start, const struct timespec *end)
+{
+	return ((end->tv_sec - start->tv_sec) +
+		(end->tv_nsec - start->tv_nsec)*1e-9);
+}
+
+static void single(int fd, uint32_t handle,
+		   const struct intel_execution_engine *e,
+		   unsigned flags)
+{
+	struct drm_i915_gem_execbuffer2 execbuf;
+	struct drm_i915_gem_exec_object2 obj;
+	struct drm_i915_gem_relocation_entry reloc;
+	struct timespec start, now;
+	uint32_t contexts[64];
+	unsigned int count = 0;
+	int n;
+
+	gem_require_ring(fd, e->exec_id | e->flags);
+
+	igt_require(__gem_context_create(fd, &contexts[0]) == 0);
+	for (n = 1; n < 64; n++)
+		contexts[n] = gem_context_create(fd);
+
+	memset(&obj, 0, sizeof(obj));
+	obj.handle = handle;
+
+	if (flags & INTERRUPTIBLE) {
+		/* Be tricksy and force a relocation every batch so that
+		 * we don't emit the batch but just do MI_SET_CONTEXT
+		 */
+		memset(&reloc, 0, sizeof(reloc));
+		reloc.offset = 1024;
+		reloc.read_domains = I915_GEM_DOMAIN_INSTRUCTION;
+		obj.relocs_ptr = (uintptr_t)&reloc;
+		obj.relocation_count = 1;
+	}
+
+	memset(&execbuf, 0, sizeof(execbuf));
+	execbuf.buffers_ptr = (uintptr_t)&obj;
+	execbuf.buffer_count = 1;
+	execbuf.rsvd1 = contexts[0];
+	execbuf.flags = e->exec_id | e->flags;
+	execbuf.flags |= LOCAL_I915_EXEC_HANDLE_LUT;
+	execbuf.flags |= LOCAL_I915_EXEC_NO_RELOC;
+	igt_require(__gem_execbuf(fd, &execbuf) == 0);
+	if (__gem_execbuf(fd, &execbuf)) {
+		execbuf.flags = e->exec_id | e->flags;
+		reloc.target_handle = obj.handle;
+		gem_execbuf(fd, &execbuf);
+	}
+	gem_sync(fd, handle);
+
+	clock_gettime(CLOCK_MONOTONIC, &start);
+	do {
+		igt_interruptible(flags & INTERRUPTIBLE) {
+			for (int loop = 0; loop < 1024; loop++) {
+				execbuf.rsvd1 = contexts[loop % 64];
+				reloc.presumed_offset = 0;
+				gem_execbuf(fd, &execbuf);
+			}
+			count += 1024;
+		}
+		clock_gettime(CLOCK_MONOTONIC, &now);
+	} while (elapsed(&start, &now) < 20.);
+	gem_sync(fd, handle);
+	clock_gettime(CLOCK_MONOTONIC, &now);
+
+	igt_info("%s: %'u cycles: %.3fus%s\n",
+		 e->name, count, elapsed(&start, &now)*1e6 / count,
+		 flags & INTERRUPTIBLE ? " (interruptible)" : "");
+
+	for (n = 0; n < 64; n++)
+		gem_context_destroy(fd, contexts[n]);
+}
+
+igt_main
+{
+	const struct intel_execution_engine *e;
+	uint32_t handle = 0;
+	int fd = -1;
+
+	igt_fixture {
+		const uint32_t bbe = MI_BATCH_BUFFER_END;
+
+		fd = drm_open_driver(DRIVER_INTEL);
+		handle = gem_create(fd, 4096);
+		gem_write(fd, handle, 0, &bbe, sizeof(bbe));
+	}
+
+	igt_fork_hang_detector(fd);
+
+	for (e = intel_execution_engines; e->name; e++) {
+		igt_subtest_f("%s%s", e->exec_id == 0 ? "basic-" : "", e->name)
+			single(fd, handle, e, 0);
+		igt_subtest_f("%s-interruptible", e->name)
+			single(fd, handle, e, INTERRUPTIBLE);
+	}
+
+	igt_stop_hang_detector();
+
+	igt_fixture {
+		gem_close(fd, handle);
+		close(fd);
+	}
+}