Storing the EU mask internally in the same format the I915_QUERY
topology queries use makes the final copy_to_user() a bit simpler, but
makes the rest of the driver's SSEU more complicated and harder to
follow.  Let's switch to an internal representation that's more natural:
Xe_HP platforms will be a simple array of u16 masks, whereas pre-Xe_HP
platforms will be a two-dimensional array, indexed by [slice][subslice].
We'll convert to the uapi format only when the query uapi is called.

v2:
 - Drop has_common_ss_eumask.  We waste some space repeating identical
   EU masks for every single DSS, but the code is simpler without it.
   (Tvrtko)

Cc: Tvrtko Ursulin <tvrtko.ursu...@linux.intel.com>
Signed-off-by: Matt Roper <matthew.d.ro...@intel.com>
---
 drivers/gpu/drm/i915/gt/intel_sseu.c | 77 +++++++++++++++++++---------
 drivers/gpu/drm/i915/gt/intel_sseu.h |  9 +++-
 drivers/gpu/drm/i915/i915_query.c    |  8 +--
 3 files changed, 65 insertions(+), 29 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_sseu.c 
b/drivers/gpu/drm/i915/gt/intel_sseu.c
index ade3e1805782..d89e2e0f05e5 100644
--- a/drivers/gpu/drm/i915/gt/intel_sseu.c
+++ b/drivers/gpu/drm/i915/gt/intel_sseu.c
@@ -78,47 +78,76 @@ intel_sseu_subslices_per_slice(const struct sseu_dev_info 
*sseu, u8 slice)
        return hweight32(intel_sseu_get_subslices(sseu, slice));
 }
 
-static int sseu_eu_idx(const struct sseu_dev_info *sseu, int slice,
-                      int subslice)
-{
-       int slice_stride = sseu->max_subslices * sseu->eu_stride;
-
-       return slice * slice_stride + subslice * sseu->eu_stride;
-}
-
 static u16 sseu_get_eus(const struct sseu_dev_info *sseu, int slice,
                        int subslice)
 {
-       int i, offset = sseu_eu_idx(sseu, slice, subslice);
-       u16 eu_mask = 0;
-
-       for (i = 0; i < sseu->eu_stride; i++)
-               eu_mask |=
-                       ((u16)sseu->eu_mask[offset + i]) << (i * BITS_PER_BYTE);
-
-       return eu_mask;
+       if (sseu->has_xehp_dss) {
+               WARN_ON(slice > 0);
+               return sseu->eu_mask.xehp[subslice];
+       } else {
+               return sseu->eu_mask.hsw[slice][subslice];
+       }
 }
 
 static void sseu_set_eus(struct sseu_dev_info *sseu, int slice, int subslice,
                         u16 eu_mask)
 {
-       int i, offset = sseu_eu_idx(sseu, slice, subslice);
-
-       for (i = 0; i < sseu->eu_stride; i++)
-               sseu->eu_mask[offset + i] =
-                       (eu_mask >> (BITS_PER_BYTE * i)) & 0xff;
+       if (sseu->has_xehp_dss) {
+               WARN_ON(slice > 0);
+               sseu->eu_mask.xehp[subslice] = eu_mask;
+       } else {
+               eu_mask &= GENMASK(sseu->max_eus_per_subslice - 1, 0);
+               sseu->eu_mask.hsw[slice][subslice] = eu_mask;
+       }
 }
 
 static u16 compute_eu_total(const struct sseu_dev_info *sseu)
 {
-       u16 i, total = 0;
+       int s, ss, total = 0;
 
-       for (i = 0; i < ARRAY_SIZE(sseu->eu_mask); i++)
-               total += hweight8(sseu->eu_mask[i]);
+       for (s = 0; s < sseu->max_slices; s++)
+               for (ss = 0; ss < sseu->max_subslices; ss++)
+                       if (sseu->has_xehp_dss)
+                               total += hweight16(sseu->eu_mask.xehp[ss]);
+                       else
+                               total += hweight16(sseu->eu_mask.hsw[s][ss]);
 
        return total;
 }
 
+/**
+ * intel_sseu_copy_eumask_to_user - Copy EU mask into a userspace buffer
+ * @to: Pointer to userspace buffer to copy to
+ * @sseu: SSEU structure containing EU mask to copy
+ *
+ * Copies the EU mask to a userspace buffer in the format expected by
+ * the query ioctl's topology queries.
+ *
+ * Returns the result of the copy_to_user() operation.
+ */
+int intel_sseu_copy_eumask_to_user(void __user *to,
+                                  const struct sseu_dev_info *sseu)
+{
+       u8 eu_mask[GEN_SS_MASK_SIZE * GEN_MAX_EU_STRIDE] = {};
+       int len = sseu->max_slices * sseu->max_subslices * sseu->eu_stride;
+       int s, ss, i;
+
+       for (s = 0; s < sseu->max_slices; s++) {
+               for (ss = 0; ss < sseu->max_subslices; ss++) {
+                       int uapi_offset =
+                               s * sseu->max_subslices * sseu->eu_stride +
+                               ss * sseu->eu_stride;
+                       u16 mask = sseu_get_eus(sseu, s, ss);
+
+                       for (i = 0; i < sseu->eu_stride; i++)
+                               eu_mask[uapi_offset + i] =
+                                       (mask >> (BITS_PER_BYTE * i)) & 0xff;
+               }
+       }
+
+       return copy_to_user(to, eu_mask, len);
+}
+
 static void gen11_compute_sseu_info(struct sseu_dev_info *sseu,
                                    u32 g_ss_en, u32 c_ss_en, u16 eu_en)
 {
diff --git a/drivers/gpu/drm/i915/gt/intel_sseu.h 
b/drivers/gpu/drm/i915/gt/intel_sseu.h
index 4a041f9dc490..43a8f8f98687 100644
--- a/drivers/gpu/drm/i915/gt/intel_sseu.h
+++ b/drivers/gpu/drm/i915/gt/intel_sseu.h
@@ -57,7 +57,11 @@ struct sseu_dev_info {
        u8 subslice_mask[GEN_SS_MASK_SIZE];
        u8 geometry_subslice_mask[GEN_SS_MASK_SIZE];
        u8 compute_subslice_mask[GEN_SS_MASK_SIZE];
-       u8 eu_mask[GEN_SS_MASK_SIZE * GEN_MAX_EU_STRIDE];
+       union {
+               u16 hsw[GEN_MAX_HSW_SLICES][GEN_MAX_SS_PER_HSW_SLICE];
+               u16 xehp[GEN_MAX_DSS];
+       } eu_mask;
+
        u16 eu_total;
        u8 eu_per_subslice;
        u8 min_eu_in_pool;
@@ -150,4 +154,7 @@ void intel_sseu_print_topology(struct drm_i915_private 
*i915,
 
 u16 intel_slicemask_from_dssmask(u64 dss_mask, int dss_per_slice);
 
+int intel_sseu_copy_eumask_to_user(void __user *to,
+                                  const struct sseu_dev_info *sseu);
+
 #endif /* __INTEL_SSEU_H__ */
diff --git a/drivers/gpu/drm/i915/i915_query.c 
b/drivers/gpu/drm/i915/i915_query.c
index 7584cec53d5d..16f43bf32a05 100644
--- a/drivers/gpu/drm/i915/i915_query.c
+++ b/drivers/gpu/drm/i915/i915_query.c
@@ -76,10 +76,10 @@ static int fill_topology_info(const struct sseu_dev_info 
*sseu,
                         subslice_mask, subslice_length))
                return -EFAULT;
 
-       if (copy_to_user(u64_to_user_ptr(query_item->data_ptr +
-                                        sizeof(topo) +
-                                        slice_length + subslice_length),
-                        sseu->eu_mask, eu_length))
+       if (intel_sseu_copy_eumask_to_user(u64_to_user_ptr(query_item->data_ptr 
+
+                                                          sizeof(topo) +
+                                                          slice_length + 
subslice_length),
+                                          sseu))
                return -EFAULT;
 
        return total_length;
-- 
2.35.3

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