i915/gt/selftest_ring.c

8 	struct intel_ring *ring;
10 	ring = kzalloc(sizeof(*ring) + sz, GFP_KERNEL);
11 	if (!ring)
14 	kref_init(&ring->ref);
15 	ring->size = sz;
16 	ring->wrap = BITS_PER_TYPE(ring->size) - ilog2(sz);
17 	ring->effective_size = sz;
18 	ring->vaddr = (void *)(ring + 1);
19 	atomic_set(&ring->pin_count, 1);
21 	intel_ring_update_space(ring);
23 	return ring;
26 static void mock_ring_free(struct intel_ring *ring)
28 	kfree(ring);
31 static int check_ring_direction(struct intel_ring *ring,
37 	result = intel_ring_direction(ring, next, prev);
52 static int check_ring_step(struct intel_ring *ring, u32 x, u32 step)
54 	u32 prev = x, next = intel_ring_wrap(ring, x + step);
57 	err |= check_ring_direction(ring, next, next,  0);
58 	err |= check_ring_direction(ring, prev, prev,  0);
59 	err |= check_ring_direction(ring, next, prev,  1);
60 	err |= check_ring_direction(ring, prev, next, -1);
65 static int check_ring_offset(struct intel_ring *ring, u32 x, u32 step)
69 	err |= check_ring_step(ring, x, step);
70 	err |= check_ring_step(ring, intel_ring_wrap(ring, x + 1), step);
71 	err |= check_ring_step(ring, intel_ring_wrap(ring, x - 1), step);
78 	struct intel_ring *ring;
82 	ring = mock_ring(2 * half);
83 	if (!ring)
86 	GEM_BUG_ON(ring->size != 2 * half);
88 	/* Precision of wrap detection is limited to ring->size / 2 */
90 		err |= check_ring_offset(ring, 0, step);
91 		err |= check_ring_offset(ring, half, step);
93 	err |= check_ring_step(ring, 0, half - 64);
96 	err |= check_ring_offset(ring, 0, 2 * half + 64);
97 	err |= check_ring_offset(ring, 3 * half, 1);
99 	mock_ring_free(ring);