Commit 6107e5cb authored by Heiner Kallweit's avatar Heiner Kallweit Committed by Bjorn Helgaas
Browse files

PCI/VPD: Add pci_vpd_check_csum() 

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: default avatarHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent 9e515c9f

drivers/pci/vpd.c

+23 −0
Original line number Diff line number Diff line
@@ -413,6 +413,29 @@ int pci_vpd_find_ro_info_keyword(const void *buf, unsigned int len, 
}

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

include/linux/pci.h

+9 −0
Original line number Diff line number Diff line
@@ -2376,6 +2376,15 @@ int pci_vpd_find_info_keyword(const u8 *buf, unsigned int off, 
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;