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1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright © 2020 Intel Corporation4 */5 6static struct intel_ring *mock_ring(unsigned long sz)7{8 struct intel_ring *ring;9 10 ring = kzalloc(sizeof(*ring) + sz, GFP_KERNEL);11 if (!ring)12 return NULL;13 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);20 21 intel_ring_update_space(ring);22 23 return ring;24}25 26static void mock_ring_free(struct intel_ring *ring)27{28 kfree(ring);29}30 31static int check_ring_direction(struct intel_ring *ring,32 u32 next, u32 prev,33 int expected)34{35 int result;36 37 result = intel_ring_direction(ring, next, prev);38 if (result < 0)39 result = -1;40 else if (result > 0)41 result = 1;42 43 if (result != expected) {44 pr_err("intel_ring_direction(%u, %u):%d != %d\n",45 next, prev, result, expected);46 return -EINVAL;47 }48 49 return 0;50}51 52static int check_ring_step(struct intel_ring *ring, u32 x, u32 step)53{54 u32 prev = x, next = intel_ring_wrap(ring, x + step);55 int err = 0;56 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);61 62 return err;63}64 65static int check_ring_offset(struct intel_ring *ring, u32 x, u32 step)66{67 int err = 0;68 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);72 73 return err;74}75 76static int igt_ring_direction(void *dummy)77{78 struct intel_ring *ring;79 unsigned int half = 2048;80 int step, err = 0;81 82 ring = mock_ring(2 * half);83 if (!ring)84 return -ENOMEM;85 86 GEM_BUG_ON(ring->size != 2 * half);87 88 /* Precision of wrap detection is limited to ring->size / 2 */89 for (step = 1; step < half; step <<= 1) {90 err |= check_ring_offset(ring, 0, step);91 err |= check_ring_offset(ring, half, step);92 }93 err |= check_ring_step(ring, 0, half - 64);94 95 /* And check unwrapped handling for good measure */96 err |= check_ring_offset(ring, 0, 2 * half + 64);97 err |= check_ring_offset(ring, 3 * half, 1);98 99 mock_ring_free(ring);100 return err;101}102 103int intel_ring_mock_selftests(void)104{105 static const struct i915_subtest tests[] = {106 SUBTEST(igt_ring_direction),107 };108 109 return i915_subtests(tests, NULL);110}111