[Intel-gfx] [PATCH v2] drm/i915/selftests: Ensure we don't clamp a random offset to 32b

[Chris Wilson]

Specify that we do want a 64b value for sizeof(u32) as we want to
compute the mask of the upper 62bits.

v2: Use round_down() for automatic type promotion

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala at linux.intel.com>
---
 drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c | 2 +-
 drivers/gpu/drm/i915/gt/intel_gpu_commands.h          | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
index 3abe15a08b6d..695bfb18b0d4 100644
--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
@@ -1539,7 +1539,7 @@ static int igt_vm_isolation(void *arg)
 
 			div64_u64_rem(i915_prandom_u64_state(&prng),
 				      vm_total, &offset);
-			offset &= -sizeof(u32);
+			offset = round_down(offset, alignof_dword);
 			offset += I915_GTT_PAGE_SIZE;
 
 			err = write_to_scratch(ctx_a, engine,
diff --git a/drivers/gpu/drm/i915/gt/intel_gpu_commands.h b/drivers/gpu/drm/i915/gt/intel_gpu_commands.h
index eec31e36aca7..69f34737325f 100644
--- a/drivers/gpu/drm/i915/gt/intel_gpu_commands.h
+++ b/drivers/gpu/drm/i915/gt/intel_gpu_commands.h
@@ -7,6 +7,13 @@
 #ifndef _INTEL_GPU_COMMANDS_H_
 #define _INTEL_GPU_COMMANDS_H_
 
+/*
+ * Target address alignments required for GPU access e.g.
+ * MI_STORE_DWORD_IMM.
+ */
+#define alignof_dword 4
+#define alignof_qword 8
+
 /*
  * Instruction field definitions used by the command parser
  */
-- 
2.22.0