drm/i915: Skip applying copy engine fuses

Support for reading the fuses to check what are the Link Copy engines
was added in commit ad5f74f34201 ("drm/i915/pvc: read fuses for link
copy engines"). However they were added unconditionally because the
FUSE3 register is present since graphics version 10.

However the bitfield with meml3 fuses only exists since graphics version
12. Moreover, Link Copy engines are currently only available in PVC.
Tying additional copy engines to the meml3 fuses is not correct for
other platforms.

Make sure there is a check for  `12.60 <= ver < 12.70`. Later platforms
may extend this function later if it's needed to fuse off copy engines.

Currently it's harmless as the Link Copy engines are still not exported:
info->engine_mask only has BCS0 set and the register is only read for
platforms that do have it.

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220912-copy-engine-v1-1-ef92fd81758d@intel.com

diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
index 814f83b5fe59258e60e7bf76d6bb4cc33b973957..1f7188129cd1f6a1f15a91f15121d42a333f43ce 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
@@ -764,6 +764,10 @@ static void engine_mask_apply_copy_fuses(struct intel_gt *gt)
        unsigned long meml3_mask;
        unsigned long quad;
 
+       if (!(GRAPHICS_VER_FULL(i915) >= IP_VER(12, 60) &&
+             GRAPHICS_VER_FULL(i915) < IP_VER(12, 70)))
+               return;
+
        meml3_mask = intel_uncore_read(gt->uncore, GEN10_MIRROR_FUSE3);
        meml3_mask = REG_FIELD_GET(GEN12_MEML3_EN_MASK, meml3_mask);