[PATCH] Create sysfs entries for PCI VPDI and VPDR tags

From: Jordan Hargrave
Date: Thu Feb 18 2016 - 15:08:34 EST

The VPD-R is a readonly area of the PCI Vital Product Data region.
There are some standard keywords for serial number, manufacturer,
and vendor-specific values. Dell Servers use a vendor-specific
tag to store number of ports and port mapping of partitioned NICs.

info = VPD-Info string
PN = Part Number
SN = Serial Number
MN = Manufacturer ID
Vx = Vendor-specific (x=0..9 A..Z)

This creates a sysfs subdirectory in the pci device: vpdattr with
'info', 'EC', 'SN', 'V0', etc. files containing the tag values.

Signed-off-by: Jordan Hargrave <Jordan_Hargrave@xxxxxxxx>
---
drivers/pci/pci-sysfs.c | 240 ++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 240 insertions(+)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index d750870..e5f3779 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1295,6 +1295,230 @@ static struct bin_attribute pcie_config_attr = {
.write = pci_write_config,
};

+static umode_t vpd_attr_exist(struct kobject *kobj,
+ struct attribute *attr, int n)
+{
+ struct device *dev;
+ struct pci_dev *pdev;
+ int i;
+
+ dev = container_of(kobj, struct device, kobj);
+ pdev = to_pci_dev(dev);
+
+ if (!strcmp(attr->name, "info"))
+ return pdev->vpdi_data ? S_IRUGO : 0;
+ if (pdev->vpdr_data == NULL)
+ return 0;
+ i = pci_vpd_find_info_keyword(pdev->vpdr_data, 0,
+ pdev->vpdr_len,
+ attr->name);
+ return i >= 0 ? S_IRUGO : 0;
+}
+
+static ssize_t vpd_attr_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct pci_dev *pdev;
+ int i, len;
+
+ pdev = to_pci_dev(dev);
+ if (!strcmp(attr->attr.name, "info")) {
+ if (pdev->vpdi_data == NULL)
+ return 0;
+ return scnprintf(buf, PAGE_SIZE, "%s\n",
+ pdev->vpdi_data);
+ }
+ if (pdev->vpdr_data == NULL)
+ return 0;
+ i = pci_vpd_find_info_keyword(pdev->vpdr_data, 0,
+ pdev->vpdr_len,
+ attr->attr.name);
+ if (i >= 0) {
+ len = pci_vpd_info_field_size(&pdev->vpdr_data[i]);
+ return scnprintf(buf, PAGE_SIZE, "%.*s\n", len,
+ pdev->vpdr_data + i +
+ PCI_VPD_INFO_FLD_HDR_SIZE);
+ }
+ return 0;
+}
+
+#define VPD_ATTR_RO(x) \
+static struct device_attribute vpd ## x = { \
+ .attr = { .name = #x, .mode = S_IRUGO | S_IWUSR }, \
+ .show = vpd_attr_show \
+}
+VPD_ATTR_RO(info);
+VPD_ATTR_RO(PN);
+VPD_ATTR_RO(EC);
+VPD_ATTR_RO(MN);
+VPD_ATTR_RO(SN);
+VPD_ATTR_RO(V0);
+VPD_ATTR_RO(V1);
+VPD_ATTR_RO(V2);
+VPD_ATTR_RO(V3);
+VPD_ATTR_RO(V4);
+VPD_ATTR_RO(V5);
+VPD_ATTR_RO(V6);
+VPD_ATTR_RO(V7);
+VPD_ATTR_RO(V8);
+VPD_ATTR_RO(V9);
+VPD_ATTR_RO(VA);
+VPD_ATTR_RO(VB);
+VPD_ATTR_RO(VC);
+VPD_ATTR_RO(VD);
+VPD_ATTR_RO(VE);
+VPD_ATTR_RO(VF);
+VPD_ATTR_RO(VG);
+VPD_ATTR_RO(VH);
+VPD_ATTR_RO(VI);
+VPD_ATTR_RO(VJ);
+VPD_ATTR_RO(VK);
+VPD_ATTR_RO(VL);
+VPD_ATTR_RO(VM);
+VPD_ATTR_RO(VN);
+VPD_ATTR_RO(VO);
+VPD_ATTR_RO(VP);
+VPD_ATTR_RO(VQ);
+VPD_ATTR_RO(VR);
+VPD_ATTR_RO(VS);
+VPD_ATTR_RO(VT);
+VPD_ATTR_RO(VU);
+VPD_ATTR_RO(VV);
+VPD_ATTR_RO(VW);
+VPD_ATTR_RO(VX);
+VPD_ATTR_RO(VY);
+VPD_ATTR_RO(VZ);
+
+static struct attribute *vpd_attributes[] = {
+ &vpdinfo.attr,
+ &vpdPN.attr,
+ &vpdEC.attr,
+ &vpdMN.attr,
+ &vpdSN.attr,
+ &vpdV0.attr,
+ &vpdV1.attr,
+ &vpdV2.attr,
+ &vpdV3.attr,
+ &vpdV4.attr,
+ &vpdV5.attr,
+ &vpdV6.attr,
+ &vpdV7.attr,
+ &vpdV8.attr,
+ &vpdV9.attr,
+ &vpdVA.attr,
+ &vpdVB.attr,
+ &vpdVC.attr,
+ &vpdVD.attr,
+ &vpdVE.attr,
+ &vpdVF.attr,
+ &vpdVG.attr,
+ &vpdVH.attr,
+ &vpdVI.attr,
+ &vpdVJ.attr,
+ &vpdVK.attr,
+ &vpdVL.attr,
+ &vpdVM.attr,
+ &vpdVN.attr,
+ &vpdVO.attr,
+ &vpdVP.attr,
+ &vpdVQ.attr,
+ &vpdVR.attr,
+ &vpdVS.attr,
+ &vpdVT.attr,
+ &vpdVU.attr,
+ &vpdVV.attr,
+ &vpdVW.attr,
+ &vpdVX.attr,
+ &vpdVY.attr,
+ &vpdVZ.attr,
+ NULL,
+};
+
+static struct attribute_group vpd_attr_group = {
+ .name = "vpdattr",
+ .attrs = vpd_attributes,
+ .is_visible = vpd_attr_exist,
+};
+
+
+static int pci_get_vpd_tag(struct pci_dev *dev, int off, int *len)
+{
+ u8 tag[3];
+ int rc, tlen;
+
+ *len = 0;
+ rc = pci_read_vpd(dev, off, 1, tag);
+ if (rc != 1)
+ return -ENOENT;
+ /* Ignore invalid/end tags */
+ if (tag[0] == 0x00 || tag[0] == 0xFF || tag[0] == 0x7F)
+ return -ENOENT;
+ if (tag[0] & PCI_VPD_LRDT) {
+ /* Large tag */
+ rc = pci_read_vpd(dev, off+1, 2, tag+1);
+ if (rc != 2)
+ return -ENOENT;
+ tlen = pci_vpd_lrdt_size(tag) +
+ PCI_VPD_LRDT_TAG_SIZE;
+ } else {
+ /* Small tag (shouldn't happen in VPD...) */
+ tlen = pci_vpd_srdt_size(tag) +
+ PCI_VPD_SRDT_TAG_SIZE;
+ tag[0] &= ~PCI_VPD_SRDT_LEN_MASK;
+ }
+ /* Verify VPD tag fits in area */
+ if (tlen + off > dev->vpd->len)
+ return -ENOENT;
+ *len = tlen;
+ return tag[0];
+}
+
+static int pci_load_vpdr(struct pci_dev *dev)
+{
+ int rlen, ilen, tag, rc;
+
+ /* Check for VPD-I tag */
+ tag = pci_get_vpd_tag(dev, 0, &ilen);
+ if (tag != PCI_VPD_LRDT_ID_STRING)
+ return -ENOENT;
+
+ /* Read VPDI string */
+ ilen -= PCI_VPD_LRDT_TAG_SIZE;
+ dev->vpdi_data = kzalloc(ilen + 1, GFP_ATOMIC);
+ if (dev->vpdi_data == NULL)
+ return -ENOMEM;
+ rc = pci_read_vpd(dev, PCI_VPD_LRDT_TAG_SIZE,
+ ilen, dev->vpdi_data);
+ if (rc != ilen)
+ goto error;
+ ilen += PCI_VPD_LRDT_TAG_SIZE;
+
+ /* Check for VPD-R tag */
+ tag = pci_get_vpd_tag(dev, ilen, &rlen);
+ if (tag != PCI_VPD_LRDT_RO_DATA)
+ return -ENOENT;
+
+ /* Read VPDR area */
+ rlen -= PCI_VPD_LRDT_TAG_SIZE;
+ dev->vpdr_len = rlen;
+ dev->vpdr_data = kzalloc(rlen, GFP_ATOMIC);
+ if (dev->vpdr_data == NULL)
+ return -ENOMEM;
+
+ rc = pci_read_vpd(dev, ilen + PCI_VPD_LRDT_TAG_SIZE,
+ rlen, dev->vpdr_data);
+ if (rc != rlen)
+ goto error;
+ if (sysfs_create_group(&dev->dev.kobj, &vpd_attr_group))
+ goto error;
+ return 0;
+ error:
+ kfree(dev->vpdi_data);
+ kfree(dev->vpdr_data);
+ dev->vpdr_data = NULL;
+ return -ENOENT;
+}
+
static ssize_t reset_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
@@ -1340,6 +1564,8 @@ static int pci_create_capabilities_sysfs(struct pci_dev *dev)
return retval;
}
dev->vpd->attr = attr;
+
+ pci_load_vpdr(dev);
}

/* Active State Power Management */
@@ -1356,6 +1582,13 @@ static int pci_create_capabilities_sysfs(struct pci_dev *dev)
error:
pcie_aspm_remove_sysfs_dev_files(dev);
if (dev->vpd && dev->vpd->attr) {
+ if (dev->vpdr_data) {
+ sysfs_remove_group(&dev->dev.kobj, &vpd_attr_group);
+ kfree(dev->vpdr_data);
+ dev->vpdr_data = NULL;
+ }
+ kfree(dev->vpdi_data);
+ dev->vpdi_data = NULL;
sysfs_remove_bin_file(&dev->dev.kobj, dev->vpd->attr);
kfree(dev->vpd->attr);
}
@@ -1438,6 +1671,13 @@ err:
static void pci_remove_capabilities_sysfs(struct pci_dev *dev)
{
if (dev->vpd && dev->vpd->attr) {
+ if (dev->vpdr_data) {
+ sysfs_remove_group(&dev->dev.kobj, &vpd_attr_group);
+ kfree(dev->vpdr_data);
+ dev->vpdr_data = NULL;
+ }
+ kfree(dev->vpdi_data);
+ dev->vpdi_data = NULL;
sysfs_remove_bin_file(&dev->dev.kobj, dev->vpd->attr);
kfree(dev->vpd->attr);
}
--
2.5.0