[PATCH 1/5] PCI/VPD: Refactor pci_vpd_size

[Heiner Kallweit <hkallweit1@xxxxxxxxx>]

The only Short Resource Data Type tag is the end tag. This allows to
remove the generic SRDT tag handling and the code be significantly
simplified.

Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
---
 drivers/pci/vpd.c | 46 ++++++++++++----------------------------------
 1 file changed, 12 insertions(+), 34 deletions(-)

diff --git a/drivers/pci/vpd.c b/drivers/pci/vpd.c
index 26bf7c877..ecdce170f 100644
--- a/drivers/pci/vpd.c
+++ b/drivers/pci/vpd.c
@@ -73,50 +73,28 @@ EXPORT_SYMBOL(pci_write_vpd);
 static size_t pci_vpd_size(struct pci_dev *dev, size_t old_size)
 {
 	size_t off = 0;
-	unsigned char header[1+2];	/* 1 byte tag, 2 bytes length */
+	u8 header[3];	/* 1 byte tag, 2 bytes length */
 
 	while (off < old_size && pci_read_vpd(dev, off, 1, header) == 1) {
-		unsigned char tag;
-
 		if (!header[0] && !off) {
 			pci_info(dev, "Invalid VPD tag 00, assume missing optional VPD EPROM\n");
 			return 0;
 		}
 
-		if (header[0] & PCI_VPD_LRDT) {
-			/* Large Resource Data Type Tag */
-			tag = pci_vpd_lrdt_tag(header);
-			/* Only read length from known tag items */
-			if ((tag == PCI_VPD_LTIN_ID_STRING) ||
-			    (tag == PCI_VPD_LTIN_RO_DATA) ||
-			    (tag == PCI_VPD_LTIN_RW_DATA)) {
-				if (pci_read_vpd(dev, off+1, 2,
-						 &header[1]) != 2) {
-					pci_warn(dev, "invalid large VPD tag %02x size at offset %zu",
-						 tag, off + 1);
-					return 0;
-				}
-				off += PCI_VPD_LRDT_TAG_SIZE +
-					pci_vpd_lrdt_size(header);
-			}
-		} else {
-			/* Short Resource Data Type Tag */
-			off += PCI_VPD_SRDT_TAG_SIZE +
-				pci_vpd_srdt_size(header);
-			tag = pci_vpd_srdt_tag(header);
-		}
-
-		if (tag == PCI_VPD_STIN_END)	/* End tag descriptor */
-			return off;
+		if (header[0] == PCI_VPD_SRDT_END)
+			return off + PCI_VPD_SRDT_TAG_SIZE;
 
-		if ((tag != PCI_VPD_LTIN_ID_STRING) &&
-		    (tag != PCI_VPD_LTIN_RO_DATA) &&
-		    (tag != PCI_VPD_LTIN_RW_DATA)) {
-			pci_warn(dev, "invalid %s VPD tag %02x at offset %zu",
-				 (header[0] & PCI_VPD_LRDT) ? "large" : "short",
-				 tag, off);
+		if (header[0] != PCI_VPD_LRDT_ID_STRING &&
+		    header[0] != PCI_VPD_LRDT_RO_DATA &&
+		    header[0] != PCI_VPD_LRDT_RW_DATA) {
+			pci_warn(dev, "invalid VPD tag %02x at offset %zu", header[0], off);
 			return 0;
 		}
+
+		if (pci_read_vpd(dev, off + 1, 2, header + 1) != 2)
+			return 0;
+
+		off += PCI_VPD_LRDT_TAG_SIZE + pci_vpd_lrdt_size(header);
 	}
 	return 0;
 }
-- 
2.31.1