drm/nouveau/gr/gf117-: assume no PPC if NV_PGRAPH_GPC_GPM_PD_PES_TPC_ID_MASK is zero

fdo#92761
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nvkm/engine/gr/ctxgf117.c

@@ -207,6 +207,8 @@ gf117_grctx_generate_attrib(struct gf100_grctx *info)
 			const u32 b =  beta * gr->ppc_tpc_nr[gpc][ppc];
 			const u32 t = timeslice_mode;
 			const u32 o = PPC_UNIT(gpc, ppc, 0);
+			if (!(gr->ppc_mask[gpc] & (1 << ppc)))
+				continue;
 			mmio_skip(info, o + 0xc0, (t << 28) | (b << 16) | ++bo);
 			mmio_wr32(info, o + 0xc0, (t << 28) | (b << 16) | --bo);
 			bo += grctx->attrib_nr_max * gr->ppc_tpc_nr[gpc][ppc];

drivers/gpu/drm/nouveau/nvkm/engine/gr/gf100.c

@@ -1530,6 +1530,8 @@ gf100_gr_oneinit(struct nvkm_gr *base)
 		gr->ppc_nr[i]  = gr->func->ppc_nr;
 		for (j = 0; j < gr->ppc_nr[i]; j++) {
 			u8 mask = nvkm_rd32(device, GPC_UNIT(i, 0x0c30 + (j * 4)));
+			if (mask)
+				gr->ppc_mask[i] |= (1 << j);
 			gr->ppc_tpc_nr[i][j] = hweight8(mask);
 		}
 	}

drivers/gpu/drm/nouveau/nvkm/engine/gr/gf100.h

@@ -97,6 +97,7 @@ struct gf100_gr {
 	u8 tpc_nr[GPC_MAX];
 	u8 tpc_total;
 	u8 ppc_nr[GPC_MAX];
+	u8 ppc_mask[GPC_MAX];
 	u8 ppc_tpc_nr[GPC_MAX][4];
 
 	struct nvkm_memory *unk4188b4;