[Intel-gfx] [PATCH 07/11] drm/i915: Use subslice stride to set subslices for a given slice

[Stuart Summers]

Add a subslice stride calculation when setting subslices. This
aligns more closely with the userspace expectation of the subslice
mask structure.

v2: Use local variable for subslice_mask on HSW and
    clean up a few other subslice_mask local variable
    changes
v3: Add GEM_BUG_ON for ss_stride to prevent array overflow (Chris)
    Split main set function and refactors in intel_device_info.c
    into separate patches (Chris)

Signed-off-by: Stuart Summers <stuart.summers at intel.com>
---
 drivers/gpu/drm/i915/gt/intel_sseu.c | 12 ++++++++++--
 drivers/gpu/drm/i915/gt/intel_sseu.h |  2 +-
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_sseu.c b/drivers/gpu/drm/i915/gt/intel_sseu.c
index 79a9b5f186f9..5d537ec97fcc 100644
--- a/drivers/gpu/drm/i915/gt/intel_sseu.c
+++ b/drivers/gpu/drm/i915/gt/intel_sseu.c
@@ -31,9 +31,17 @@ intel_sseu_subslice_total(const struct sseu_dev_info *sseu)
 }
 
 void intel_sseu_set_subslices(struct sseu_dev_info *sseu, int slice,
-			      u8 ss_mask)
+			      u32 ss_mask)
 {
-	sseu->subslice_mask[i] = ss_mask & 0xff;
+	int i, offset;
+
+	GEM_BUG_ON(sseu->ss_stride > 32);
+
+	offset = slice * sseu->ss_stride;
+
+	for (i = 0; i < sseu->ss_stride; i++)
+		sseu->subslice_mask[offset + i] =
+			(ss_mask >> (BITS_PER_BYTE * i)) & 0xff;
 }
 
 unsigned int
diff --git a/drivers/gpu/drm/i915/gt/intel_sseu.h b/drivers/gpu/drm/i915/gt/intel_sseu.h
index 3099e04611ce..2261d4e7d98b 100644
--- a/drivers/gpu/drm/i915/gt/intel_sseu.h
+++ b/drivers/gpu/drm/i915/gt/intel_sseu.h
@@ -76,7 +76,7 @@ unsigned int
 intel_sseu_subslices_per_slice(const struct sseu_dev_info *sseu, u8 slice);
 
 void intel_sseu_set_subslices(struct sseu_dev_info *sseu, int slice,
-			      u8 ss_mask);
+			      u32 ss_mask);
 
 u32 intel_sseu_make_rpcs(struct drm_i915_private *i915,
 			 const struct intel_sseu *req_sseu);
-- 
2.22.0