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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/gpu/drm/i915/selftests/i915_random.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/gpu/drm/i915/selftests/i915_random.c')
-rw-r--r--drivers/gpu/drm/i915/selftests/i915_random.c109
1 files changed, 109 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/selftests/i915_random.c b/drivers/gpu/drm/i915/selftests/i915_random.c
new file mode 100644
index 000000000..abdfadcf6
--- /dev/null
+++ b/drivers/gpu/drm/i915/selftests/i915_random.c
@@ -0,0 +1,109 @@
+/*
+ * Copyright © 2016 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.
+ *
+ */
+
+#include <linux/bitops.h>
+#include <linux/kernel.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include "i915_random.h"
+#include "i915_utils.h"
+
+u64 i915_prandom_u64_state(struct rnd_state *rnd)
+{
+ u64 x;
+
+ x = prandom_u32_state(rnd);
+ x <<= 32;
+ x |= prandom_u32_state(rnd);
+
+ return x;
+}
+
+void i915_prandom_shuffle(void *arr, size_t elsz, size_t count,
+ struct rnd_state *state)
+{
+ char stack[128];
+
+ if (WARN_ON(elsz > sizeof(stack) || count > U32_MAX))
+ return;
+
+ if (!elsz || !count)
+ return;
+
+ /* Fisher-Yates shuffle courtesy of Knuth */
+ while (--count) {
+ size_t swp;
+
+ swp = i915_prandom_u32_max_state(count + 1, state);
+ if (swp == count)
+ continue;
+
+ memcpy(stack, arr + count * elsz, elsz);
+ memcpy(arr + count * elsz, arr + swp * elsz, elsz);
+ memcpy(arr + swp * elsz, stack, elsz);
+ }
+}
+
+void i915_random_reorder(unsigned int *order, unsigned int count,
+ struct rnd_state *state)
+{
+ i915_prandom_shuffle(order, sizeof(*order), count, state);
+}
+
+unsigned int *i915_random_order(unsigned int count, struct rnd_state *state)
+{
+ unsigned int *order, i;
+
+ order = kmalloc_array(count, sizeof(*order),
+ GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
+ if (!order)
+ return order;
+
+ for (i = 0; i < count; i++)
+ order[i] = i;
+
+ i915_random_reorder(order, count, state);
+ return order;
+}
+
+u64 igt_random_offset(struct rnd_state *state,
+ u64 start, u64 end,
+ u64 len, u64 align)
+{
+ u64 range, addr;
+
+ BUG_ON(range_overflows(start, len, end));
+ BUG_ON(round_up(start, align) > round_down(end - len, align));
+
+ range = round_down(end - len, align) - round_up(start, align);
+ if (range) {
+ addr = i915_prandom_u64_state(state);
+ div64_u64_rem(addr, range, &addr);
+ start += addr;
+ }
+
+ return round_up(start, align);
+}