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| author |   Heiner Kallweit <hkallweit1@gmail.com> | 2021-08-20 15:32:42 -0500 |
|---|---|---|
| committer |   Bjorn Helgaas <bhelgaas@google.com> | 2021-08-20 15:48:47 -0500 |
| commit | 6107e5cb907cffc5576cc1297847f9fc69a8d5d9 (patch) | |
| tree | 298f8f2585311874a1b60faa149fc009d1cbb5b0 /drivers/pci/vpd.c | |
| parent | PCI/VPD: Add pci_vpd_find_ro_info_keyword() (diff) | |
| download | linux-dev-6107e5cb907cffc5576cc1297847f9fc69a8d5d9.tar.xz linux-dev-6107e5cb907cffc5576cc1297847f9fc69a8d5d9.zip | |
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: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci/vpd.c')
| -rw-r--r-- | drivers/pci/vpd.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/drivers/pci/vpd.c b/drivers/pci/vpd.c index b1d012900f1e..01e57594781e 100644 --- a/drivers/pci/vpd.c +++ b/drivers/pci/vpd.c @@ -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 |