igt/gem_busy: Slow down the writer

Add a few more (128) loops to the page full of MI_STORE_DWORD in an
attempt to try and slow down the execution to the point where a
full-debug kernel can beat the GPU.

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

1 files changed, 93 insertions, 28 deletions

diff --git a/tests/gem_busy.c b/tests/gem_busy.c
index 372eb451..ddb19916 100644
--- a/tests/gem_busy.c
+++ b/tests/gem_busy.c
@@ -222,17 +222,68 @@ static void semaphore(int fd, unsigned ring, uint32_t flags)
 		gem_close(fd, handle[i]);
 }
 
+static void create_indirect(int fd,
+			    struct drm_i915_gem_exec_object2 *obj,
+			    struct drm_i915_gem_exec_object2 *target)
+{
+	const int gen = intel_gen(intel_get_drm_devid(fd));
+	const int nreloc = 128;
+	struct drm_i915_gem_relocation_entry *reloc;
+	uint32_t *batch;
+	int i, count;
+
+	reloc = calloc(nreloc, sizeof(*reloc));
+
+	obj->handle = gem_create(fd, 4096);
+	obj->relocs_ptr = (uintptr_t)reloc;
+	obj->relocation_count = nreloc;
+
+	batch = gem_mmap__cpu(fd, obj->handle, 0, 4096, PROT_WRITE);
+	gem_set_domain(fd, obj->handle,
+			I915_GEM_DOMAIN_CPU, I915_GEM_DOMAIN_CPU);
+
+	i = 0;
+	for (count = 0; count < nreloc; count++) {
+		reloc[count].target_handle = target->handle;
+		reloc[count].presumed_offset = target->offset;
+		reloc[count].offset = sizeof(uint32_t) * (i + 1);
+		reloc[count].delta = 0;
+		reloc[count].read_domains = I915_GEM_DOMAIN_COMMAND;
+		reloc[count].write_domain = 0;
+		batch[i] = MI_BATCH_BUFFER_START;
+		if (gen >= 8) {
+			batch[i] |= 1 << 8 | 1;
+			batch[++i] = target->offset;
+			batch[++i] = target->offset >> 32;
+		} else if (gen >= 6) {
+			batch[i] |= 1 << 8;
+			batch[++i] = target->offset;
+		} else {
+			batch[i] |= 2 << 6;
+			batch[++i] = target->offset;
+			if (gen < 4) {
+				batch[i] |= 1;
+				reloc[count].delta = 1;
+			}
+		}
+		i++;
+	}
+	batch[++i] = MI_BATCH_BUFFER_END;
+	igt_assert(i < 4096/sizeof(*batch));
+	munmap(batch, 4096);
+}
+
 static void store(int fd, unsigned ring, uint32_t flags)
 {
 	const int gen = intel_gen(intel_get_drm_devid(fd));
-	struct drm_i915_gem_exec_object2 obj[2];
-	struct drm_i915_gem_relocation_entry reloc[1024];
+	struct drm_i915_gem_exec_object2 obj[16];
+	struct drm_i915_gem_relocation_entry store[1024];
 	struct drm_i915_gem_execbuffer2 execbuf;
-	unsigned size = ALIGN(ARRAY_SIZE(reloc)*16 + 4, 4096);
+	unsigned size = ALIGN(ARRAY_SIZE(store)*16 + 4, 4096);
 	uint32_t read[2], write[2];
 	struct timespec tv;
 	uint32_t *batch;
-	int i, count;
+	int i, count, idx;
 
 	gem_require_ring(fd, ring | flags);
 	igt_skip_on_f(gen == 6 && (ring & ~(3<<13)) == I915_EXEC_BSD,
@@ -252,22 +303,22 @@ static void store(int fd, unsigned ring, uint32_t flags)
 	obj[0].flags = EXEC_OBJECT_WRITE;
 	obj[1].handle = gem_create(fd, size);
 
-	memset(reloc, 0, sizeof(reloc));
-	obj[1].relocs_ptr = (uintptr_t)reloc;
-	obj[1].relocation_count = ARRAY_SIZE(reloc);
+	memset(store, 0, sizeof(store));
+	obj[1].relocs_ptr = (uintptr_t)store;
+	obj[1].relocation_count = ARRAY_SIZE(store);
 
 	batch = gem_mmap__cpu(fd, obj[1].handle, 0, size, PROT_WRITE);
 	gem_set_domain(fd, obj[1].handle,
 			I915_GEM_DOMAIN_CPU, I915_GEM_DOMAIN_CPU);
 
 	i = 0;
-	for (count = 0; count < ARRAY_SIZE(reloc); count++) {
-		reloc[count].target_handle = obj[0].handle;
-		reloc[count].presumed_offset = 0;
-		reloc[count].offset = sizeof(uint32_t) * (i + 1);
-		reloc[count].delta = 0;
-		reloc[count].read_domains = I915_GEM_DOMAIN_INSTRUCTION;
-		reloc[count].write_domain = I915_GEM_DOMAIN_INSTRUCTION;
+	for (count = 0; count < ARRAY_SIZE(store); count++) {
+		store[count].target_handle = obj[0].handle;
+		store[count].presumed_offset = -1;
+		store[count].offset = sizeof(uint32_t) * (i + 1);
+		store[count].delta = sizeof(uint32_t) * count;
+		store[count].read_domains = I915_GEM_DOMAIN_INSTRUCTION;
+		store[count].write_domain = I915_GEM_DOMAIN_INSTRUCTION;
 		batch[i] = MI_STORE_DWORD_IMM | (gen < 6 ? 1 << 22 : 0);
 		if (gen >= 8) {
 			batch[++i] = 0;
@@ -275,44 +326,58 @@ static void store(int fd, unsigned ring, uint32_t flags)
 		} else if (gen >= 4) {
 			batch[++i] = 0;
 			batch[++i] = 0;
-			reloc[count].offset += sizeof(uint32_t);
+			store[count].offset += sizeof(uint32_t);
 		} else {
 			batch[i]--;
 			batch[++i] = 0;
 		}
-		batch[++i] = 0xc0ffee;
+		batch[++i] = count;
 		i++;
 	}
 	batch[++i] = MI_BATCH_BUFFER_END;
+	igt_assert(i < size/sizeof(*batch));
 	munmap(batch, size);
 	igt_require(__gem_execbuf(fd, &execbuf) == 0);
 
-	count = 16;
 	do {
-		for (i = 0; i < count; i++)
-			gem_execbuf(fd, &execbuf);
+		idx = execbuf.buffer_count++;
+		igt_require(idx < ARRAY_SIZE(obj));
+		create_indirect(fd, &obj[idx], &obj[idx-1]);
+		igt_require(__gem_execbuf(fd, &execbuf) == 0);
+
+		gem_execbuf(fd, &execbuf);
 		__gem_busy(fd, obj[0].handle, &read[0], &write[0]);
-		__gem_busy(fd, obj[1].handle, &read[1], &write[1]);
+		__gem_busy(fd, obj[idx].handle, &read[1], &write[1]);
 		igt_debug("After %d cycles: read[0]=%x read[1]=%x\n",
-			  count, read[0], read[1]);
-		igt_require(count <= 1 << 10);
-		count <<= 1;
+			  idx-1, read[0], read[1]);
 	} while (read[0] == 0 || read[1] == 0);
 
 	igt_assert_eq(write[0], ring);
-	igt_assert_eq(read[0], 1 << ring);
+	igt_assert_eq_u32(read[0], 1 << ring);
 
 	igt_assert_eq(write[1], 0);
-	igt_assert_eq(read[1], 1 << ring);
+	igt_assert_eq_u32(read[1], 1 << ring);
 
 	/* Calling busy in a loop should be enough to flush the rendering */
 	memset(&tv, 0, sizeof(tv));
-	while (gem_busy(fd, obj[1].handle))
+	while (gem_busy(fd, obj[idx].handle))
 		igt_assert(igt_seconds_elapsed(&tv) < 10);
 	igt_assert(!gem_busy(fd, obj[0].handle));
 
-	gem_close(fd, obj[1].handle);
-	gem_close(fd, obj[0].handle);
+	batch = gem_mmap__gtt(fd, obj[0].handle, 4096, PROT_READ);
+	for (i = 0; i < 1024; i++)
+		igt_assert_eq_u32(batch[i], i);
+	munmap(batch, 4096);
+
+	for (i = 0; i <= idx; i++) {
+		struct drm_i915_gem_relocation_entry *r;
+
+		r = (struct drm_i915_gem_relocation_entry *)
+			(uintptr_t)obj[i].relocs_ptr;
+		if (r != store)
+			free(r);
+		gem_close(fd, obj[i].handle);
+	}
 }
 
 static bool has_semaphores(int fd)