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path: root/drivers/gpu/drm/i915/selftests/i915_random.c
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Diffstat (limited to 'drivers/gpu/drm/i915/selftests/i915_random.c')
-rw-r--r--drivers/gpu/drm/i915/selftests/i915_random.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/selftests/i915_random.c b/drivers/gpu/drm/i915/selftests/i915_random.c
index 716a3f19f030..abdfadcf626b 100644
--- a/drivers/gpu/drm/i915/selftests/i915_random.c
+++ b/drivers/gpu/drm/i915/selftests/i915_random.c
@@ -29,6 +29,7 @@
#include <linux/types.h>
#include "i915_random.h"
+#include "i915_utils.h"
u64 i915_prandom_u64_state(struct rnd_state *rnd)
{
@@ -87,3 +88,22 @@ unsigned int *i915_random_order(unsigned int count, struct rnd_state *state)
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);
+}