[PATCH 2/2] drm/xe/vf: Perform early GT MMIO initialization to read GMDID

[Michal Wajdeczko]

VFs need to communicate with the GuC to obtain the GMDID value
and existing GuC functions used for that assume that the GT has
it's MMIO members already setup. However, due to recent refactoring
the gt->mmio is initialized later, and any attempt by the VF to use
xe_mmio_read|write() from GuC functions will lead to NPD crash due
to unset MMIO register address:

[] xe 0000:00:02.1: [drm] Running in SR-IOV VF mode
[] xe 0000:00:02.1: [drm] GT0: sending H2G MMIO 0x5507
[] BUG: unable to handle page fault for address: 0000000000190240

Since we are already tweaking the id and type of the primary GT to
mimic it's a Media GT before initializing the GuC communication,
we can also call xe_gt_mmio_init() to perform early setup of the
gt->mmio which will make those GuC functions work again.

Fixes: 58548b91101f ("drm/xe: Defer gt->mmio initialization until after multi-tile setup")
Fixes: 0afda5d7bba4 ("drm/xe/pci: Convert register access to use xe_mmio")
Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Matt Roper <matthew.d.roper at intel.com>
Cc: Piotr Piórkowski <piotr.piorkowski at intel.com>
---
 drivers/gpu/drm/xe/xe_pci.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/xe/xe_pci.c b/drivers/gpu/drm/xe/xe_pci.c
index 9b81e7d00a86..8388a92c8fc2 100644
--- a/drivers/gpu/drm/xe/xe_pci.c
+++ b/drivers/gpu/drm/xe/xe_pci.c
@@ -507,6 +507,7 @@ static void read_gmdid(struct xe_device *xe, enum xe_gmdid_type type, u32 *ver,
 			gt->info.type = XE_GT_TYPE_MAIN;
 		}
 
+		xe_gt_mmio_init(gt);
 		xe_guc_comm_init_early(&gt->uc.guc);
 
 		/* Don't bother with GMDID if failed to negotiate the GuC ABI */
-- 
2.43.0