hdat: handle ISDIMM SPD blobs

Previously the HDAT format was only ever used with IBM hardware so it
would store vital product data (VPD) blobs in the IBM ASCII Keyword VPD
format. With P9 HDAT is used on OpenPower machines which use Industry
Standard DIMMs that provide their product data through a "Serial Present
Detect" EEPROM mounted on the DIMM.

The SPD blob has a different format and is exported in the device-tree
under the "spd" property rather than the "ibm,vpd" property. This patch
adds support for recognising these blobs and placing them in the
appropriate DT property.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

hdata/memory.c

@@ -269,6 +269,7 @@ static void vpd_add_ram_area(const struct HDIF_common_hdr *msarea)
 	const struct HDIF_ram_area_id *ram_id;
 	struct dt_node *ram_node;
 	u32 chip_id;
+	const void *vpd_blob;
 
 	ramptr = HDIF_child_arr(msarea, 0);
 	if (!CHECK_SPPTR(ramptr)) {
@@ -285,15 +286,33 @@ static void vpd_add_ram_area(const struct HDIF_common_hdr *msarea)
 		if (!CHECK_SPPTR(ram_id))
 			continue;
 
-		if ((be16_to_cpu(ram_id->flags) & RAM_AREA_INSTALLED) &&
-		    (be16_to_cpu(ram_id->flags) & RAM_AREA_FUNCTIONAL)) {
-			ram_node = dt_add_vpd_node(ramarea, 0, 1);
-			if (ram_node) {
-				chip_id = add_chip_id_to_ram_area(msarea,
-								  ram_node);
-				add_bus_freq_to_ram_area(ram_node, chip_id);
-				add_size_to_ram_area(ram_node, ramarea, 1);
-			}
+		/* Don't add VPD for non-existent RAM */
+		if (!(be16_to_cpu(ram_id->flags) & RAM_AREA_INSTALLED))
+			continue;
+
+		ram_node = dt_add_vpd_node(ramarea, 0, 1);
+		if (!ram_node)
+			continue;
+
+		chip_id = add_chip_id_to_ram_area(msarea, ram_node);
+		add_bus_freq_to_ram_area(ram_node, chip_id);
+
+		vpd_blob = HDIF_get_idata(ramarea, 1, &ram_sz);
+
+		/*
+		 * For direct-attached memory we have a DDR "Serial
+		 * Presence Detection" blob rather than an IBM keyword
+		 * blob.
+		 */
+		if (vpd_valid(vpd_blob, ram_sz)) {
+			/* the ibm,vpd blob was added in dt_add_vpd_node() */
+			add_size_to_ram_area(ram_node, ramarea, 1);
+		} else {
+			/*
+			 * FIXME: There's probably a way to calculate the
+			 * size of the DIMM from the SPD info.
+			 */
+			dt_add_property(ram_node, "spd", vpd_blob, ram_sz);
 		}
 	}
 }

hdata/vpd.c

@@ -590,7 +590,8 @@ struct dt_node *dt_add_vpd_node(const struct HDIF_common_hdr *hdr,
 	}
 
 	/* Parse VPD fields, ensure that it has not been added already */
-	if (!dt_find_property(node, "ibm,vpd")) {
+	if (vpd_valid(fruvpd, fruvpd_sz)
+	    && !dt_find_property(node, "ibm,vpd")) {
 		dt_add_property(node, "ibm,vpd", fruvpd, fruvpd_sz);
 		vpd_vini_parse(node, fruvpd, fruvpd_sz);
 	}