drm/xe/xe2: Use XE_CACHE_WB pat index

The pat table entry associated with XE_CACHE_WB is coherent whereas
XE_CACHE_NONE is non coherent. Migration expects the coherency
with cpu therefore use the coherent entry XE_CACHE_WB for
buffers not supporting compression. For read/write to flat ccs region
the issue is not related to coherency with cpu. The hardware expects
the pat index associated with GPUVA for indirect access to be
compression enabled hence use XE_CACHE_NONE_COMPRESSION.

v2
- Fix the argument to emit_pte, pass the bool directly. (Thomas)

v3
- Rebase
- Update commit message (Matt)

v4
- Add a Fixes: tag. (Thomas)

Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Fixes: 65ef8dba ("drm/xe/xe2: Update emit_pte to use compression enabled PAT index")
Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240119041826.1670496-1-himal.prasad.ghimiray@intel.com

drivers/gpu/drm/xe/xe_migrate.c

@@ -481,7 +481,7 @@ static void emit_pte(struct xe_migrate *m,
 	/* Indirect access needs compression enabled uncached PAT index */
 	if (GRAPHICS_VERx100(xe) >= 2000)
 		pat_index = is_comp_pte ? xe->pat.idx[XE_CACHE_NONE_COMPRESSION] :
-					  xe->pat.idx[XE_CACHE_NONE];
+					  xe->pat.idx[XE_CACHE_WB];
 	else
 		pat_index = xe->pat.idx[XE_CACHE_WB];
 
@@ -769,14 +769,14 @@ struct dma_fence *xe_migrate_copy(struct xe_migrate *m,
 		if (src_is_vram && xe_migrate_allow_identity(src_L0, &src_it))
 			xe_res_next(&src_it, src_L0);
 		else
-			emit_pte(m, bb, src_L0_pt, src_is_vram, true, &src_it, src_L0,
-				 src);
+			emit_pte(m, bb, src_L0_pt, src_is_vram, copy_system_ccs,
+				 &src_it, src_L0, src);
 
 		if (dst_is_vram && xe_migrate_allow_identity(src_L0, &dst_it))
 			xe_res_next(&dst_it, src_L0);
 		else
-			emit_pte(m, bb, dst_L0_pt, dst_is_vram, true, &dst_it, src_L0,
-				 dst);
+			emit_pte(m, bb, dst_L0_pt, dst_is_vram, copy_system_ccs,
+				 &dst_it, src_L0, dst);
 
 		if (copy_system_ccs)
 			emit_pte(m, bb, ccs_pt, false, false, &ccs_it, ccs_size, src);
@@ -1018,8 +1018,8 @@ struct dma_fence *xe_migrate_clear(struct xe_migrate *m,
 		if (clear_vram && xe_migrate_allow_identity(clear_L0, &src_it))
 			xe_res_next(&src_it, clear_L0);
 		else
-			emit_pte(m, bb, clear_L0_pt, clear_vram, true, &src_it, clear_L0,
-				 dst);
+			emit_pte(m, bb, clear_L0_pt, clear_vram, clear_system_ccs,
+				 &src_it, clear_L0, dst);
 
 		bb->cs[bb->len++] = MI_BATCH_BUFFER_END;
 		update_idx = bb->len;