powerpc/ioda: Use ibm, supported-tce-sizes for IOMMU page size mask

At the moment we assume that IODA2 and newer PHBs can always do 4K/64K/16M
IOMMU pages, however this is not the case for POWER9 and now skiboot
advertises the supported sizes via the device so we use that instead
of hard coding the mask.

Signed-off-by: Alexey Kardashevskiy <[e-mail]>
Signed-off-by: Michael Ellerman <[e-mail]>

arch/powerpc/platforms/powernv/pci-ioda.c

···
 			tbl->it_indirect_levels);
 }
 
+static unsigned long pnv_ioda_parse_tce_sizes(struct pnv_phb *phb)
+{
+	struct pci_controller *hose = phb->hose;
+	struct device_node *dn = hose->dn;
+	unsigned long mask = 0;
+	int i, rc, count;
+	u32 val;
+
+	count = of_property_count_u32_elems(dn, "ibm,supported-tce-sizes");
+	if (count <= 0) {
+		mask = SZ_4K | SZ_64K;
+		/* Add 16M for POWER8 by default */
+		if (cpu_has_feature(CPU_FTR_ARCH_207S) &&
+				!cpu_has_feature(CPU_FTR_ARCH_300))
+			mask |= SZ_16M;
+		return mask;
+	}
+
+	for (i = 0; i < count; i++) {
+		rc = of_property_read_u32_index(dn, "ibm,supported-tce-sizes",
+						i, &val);
+		if (rc == 0)
+			mask |= 1ULL << val;
+	}
+
+	return mask;
+}
+
 static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
 				       struct pnv_ioda_pe *pe)
 {
···
 	pe->table_group.max_dynamic_windows_supported =
 			IOMMU_TABLE_GROUP_MAX_TABLES;
 	pe->table_group.max_levels = POWERNV_IOMMU_MAX_LEVELS;
-	pe->table_group.pgsizes = SZ_4K | SZ_64K | SZ_16M;
+	pe->table_group.pgsizes = pnv_ioda_parse_tce_sizes(phb);
 #ifdef CONFIG_IOMMU_API
 	pe->table_group.ops = &pnv_pci_ioda2_ops;
 #endif