drm/xe: map MMIO BAR according to the num of tiles in device desc

When MMIO BAR is initially mapped, the driver assumes a single tile device.
However, former memory allocations take all tiles into account.
First, a common standard for resource usage is needed here.
Second, with the next (6th) patch in this series, the MMIO BAR remapping
will be done only if a reduced-tile device is attached.
Signed-off-by: Koby Elbaz <kelbaz@habana.ai>
Reviewed-by: Ofir Bitton <obitton@habana.ai>
Reviewed-by: Moti Haimovski <mhaimovski@habana.ai>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drivers/gpu/drm/xe/xe_mmio.c

@@ -383,14 +383,13 @@ int xe_mmio_init(struct xe_device *xe)
 	int err;
 
 	/*
-	 * Map the first 16MB of th BAR, which includes the registers (0-4MB),
-	 * reserved space (4MB-8MB), and GGTT (8MB-16MB) for a single tile.
-	 * This will get remapped later if we determine that we're running
-	 * on a multi-tile system.
+	 * Map the maximum expected BAR size, which will get remapped later
+	 * if we determine that we're running on a reduced-tile system.
+	 * The first 16MB of the BAR, belong to the root tile, and include:
+	 * registers (0-4MB), reserved space (4MB-8MB) and GGTT (8MB-16MB).
 	 */
-	xe->mmio.size = SZ_16M;
-	xe->mmio.regs = pci_iomap(to_pci_dev(xe->drm.dev), mmio_bar,
-				  xe->mmio.size);
+	xe->mmio.size = (SZ_16M + xe->info.tile_mmio_ext_size) * xe->info.tile_count;
+	xe->mmio.regs = pci_iomap(to_pci_dev(xe->drm.dev), mmio_bar, xe->mmio.size);
 	if (xe->mmio.regs == NULL) {
 		drm_err(&xe->drm, "failed to map registers\n");
 		return -EIO;