VPD checksum information and checksum calculation are specified by PCIe
r5.0, sec 6.28.2.2. Therefore checksum handling can and should be moved
into the PCI VPD core.
Add pci_vpd_check_csum() to validate the VPD checksum.
[bhelgaas: split to separate patch]
Link: https://lore.kernel.org/r/1643bd7a-088e-1028-c9b0-9d112cf48d63@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
}
EXPORT_SYMBOL_GPL(pci_vpd_find_ro_info_keyword);
+int pci_vpd_check_csum(const void *buf, unsigned int len)
+{
+ const u8 *vpd = buf;
+ unsigned int size;
+ u8 csum = 0;
+ int rv_start;
+
+ rv_start = pci_vpd_find_ro_info_keyword(buf, len, PCI_VPD_RO_KEYWORD_CHKSUM, &size);
+ if (rv_start == -ENOENT) /* no checksum in VPD */
+ return 1;
+ else if (rv_start < 0)
+ return rv_start;
+
+ if (!size)
+ return -EINVAL;
+
+ while (rv_start >= 0)
+ csum += vpd[rv_start--];
+
+ return csum ? -EILSEQ : 0;
+}
+EXPORT_SYMBOL_GPL(pci_vpd_check_csum);
+
#ifdef CONFIG_PCI_QUIRKS
/*
* Quirk non-zero PCI functions to route VPD access through function 0 for
int pci_vpd_find_ro_info_keyword(const void *buf, unsigned int len,
const char *kw, unsigned int *size);
+/**
+ * pci_vpd_check_csum - Check VPD checksum
+ * @buf: Pointer to buffered VPD data
+ * @len: VPD size
+ *
+ * Returns 1 if VPD has no checksum, otherwise 0 or an errno
+ */
+int pci_vpd_check_csum(const void *buf, unsigned int len);
+
/* PCI <-> OF binding helpers */
#ifdef CONFIG_OF
struct device_node;