pci: Add VPD information field helper functions

This patch adds a preprocessor constant to describe the PCI VPD
information field header size and an inline function to extract the
size of the information field itself.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 13 insertions, 0 deletions

diff --git a/include/linux/pci.h b/include/linux/pci.h
index e30ceea7345b..cfff32fc6e35 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1373,6 +1373,8 @@ void pci_request_acs(void);
 #define PCI_VPD_LRDT_TAG_SIZE           3
 #define PCI_VPD_SRDT_TAG_SIZE           1
 
+#define PCI_VPD_INFO_FLD_HDR_SIZE       3
+
 /**
  * pci_vpd_lrdt_size - Extracts the Large Resource Data Type length
  * @lrdt: Pointer to the beginning of the Large Resource Data Type tag
@@ -1396,6 +1398,17 @@ static inline u8 pci_vpd_srdt_size(const u8 *srdt)
 }
 
 /**
+ * pci_vpd_info_field_size - Extracts the information field length
+ * @lrdt: Pointer to the beginning of an information field header
+ *
+ * Returns the extracted information field length.
+ */
+static inline u8 pci_vpd_info_field_size(const u8 *info_field)
+{
+        return info_field[2];
+}
+
+/**
  * pci_vpd_find_tag - Locates the Resource Data Type tag provided
  * @buf: Pointer to buffered vpd data
  * @off: The offset into the buffer at which to begin the search