>On 12/18/2015 03:02 PM, Alexander Duyck wrote: >> On Fri, Dec 18, 2015 at 5:57 AM, Hannes Reinecke <[email protected]> wrote: >>> On 12/18/2015 02:49 PM, Alexander Duyck wrote: >>>> >>>> On Fri, Dec 18, 2015 at 12:35 AM, Hannes Reinecke <[email protected]> wrote: >>>>> >>>>> PCI-2.2 VPD entries have a maximum size of 32k, but might actually >>>>> be smaller than that. To figure out the actual size one has to read >>>>> the VPD area until the 'end marker' is reached. >>>>> Trying to read VPD data beyond that marker results in 'interesting' >>>>> effects, from simple read errors to crashing the card. And to make >>>>> matters worse not every PCI card implements this properly, leaving >>>>> us with no 'end' marker or even completely invalid data. >>>>> This path modifies the size of the VPD attribute to the available >>>>> size, or set it to '0' if no valid data could be read. >>>> >>>> >>>> This isn't what I had in mind. There is no need to add an f0 version >>>> of the size function. The size for all functions other than function >>>> 0 when the F0 flag is set is 0. We aren't going to be reading their >>>> VPD, we only read the VPD region of function 0. >>>> >>> Ah. (I'm a bit confused about the proposed action for VPD other than >>> function 0). >>> So the idea here is to _disallow_ access to VPDs from functions other than >>> '0' unless these functions have different PCI IDs? >> >> If you take a look at the F0 functions what they do is bypass the VPD >> of the functions other than function 0. As such setting the size to 0 >> should really have no effect since the VPD of the function isn't >> actually read if the F0 flag is set. >> >Setting the size to '0' effectively inhibits you to read the VPD >data. So if we were to return '0' for PCI devices with the F0 bit >set we will never ever to be able to read (or write) _any_ VPD data >for that PCI device/function. >Which would be rendering all these F0 accessors pointless, and we >might as well remove them. >
I had posted a patch recently to enable exposing the VPD-R valyes to sysfs. I need access to these to parse into systemd for network naming (biosdevname style names). The VPD-R is a readonly area contained within the PCI Vital Product data. There are some standard and vendor-specific keys stored in this region. PN = Part Number SN = Serial Number MN = Manufacturer ID Vx = Vendor-specific (x=0..9 A..Z) Biosdevname/Systemd will use these VPD keys for determining Network partitioning and port numbers for NIC cards Signed-off-by: Jordan Hargrave <[email protected]> --- drivers/pci/pci-sysfs.c | 216 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 2 + 2 files changed, 218 insertions(+), 0 deletions(-) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index eead54c..4966ece 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -1295,6 +1295,210 @@ 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; + const char *name; + int i; + + dev = container_of(kobj, struct device, kobj); + pdev = to_pci_dev(dev); + + name = attr->name; + if (pdev->vpdr_data == NULL) + return 0; + i = pci_vpd_find_info_keyword(pdev->vpdr_data, 0, + pdev->vpdr_len, 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; + const char *name; + char kv_data[257] = { 0 }; + int i, len; + + pdev = to_pci_dev(dev); + name = attr->attr.name; + if (pdev->vpdr_data == NULL) + return 0; + i = pci_vpd_find_info_keyword(pdev->vpdr_data, 0, + pdev->vpdr_len, name); + if (i >= 0) { + len = pci_vpd_info_field_size(&pdev->vpdr_data[i]); + memcpy(kv_data, pdev->vpdr_data + i + + PCI_VPD_INFO_FLD_HDR_SIZE, len); + return scnprintf(buf, PAGE_SIZE, "%s\n", kv_data); + } + return 0; +} + +#define VPD_ATTR_RO(x) \ +struct device_attribute vpd ## x = { \ + .attr = { .name = #x, .mode = S_IRUGO | S_IWUSR }, \ + .show = vpd_attr_show \ +} + +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[] = { + &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 = "vpdr", + .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; + /* Quirk Atheros cards, reading VPD hangs system for 20s */ + if (dev->vendor == PCI_VENDOR_ID_ATHEROS || + dev->vendor == PCI_VENDOR_ID_ATTANSIC) + return -ENOENT; + rc = pci_read_vpd(dev, off, 1, tag); + if (rc != 1) + return -ENOENT; + if (tag[0] == 0x00 || tag[0] == 0xFF || tag[0] == 0x7F) + return -ENOENT; + if (tag[0] & PCI_VPD_LRDT) { + 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 { + 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 and VPD-R tag */ + tag = pci_get_vpd_tag(dev, 0, &ilen); + if (tag != PCI_VPD_LRDT_ID_STRING) + return -ENOENT; + tag = pci_get_vpd_tag(dev, ilen, &rlen); + if (tag != PCI_VPD_LRDT_RO_DATA) + return -ENOENT; + + 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->vpdr_data); + dev->vpdr_len = 0; + return -ENOENT; +} + static ssize_t reset_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { @@ -1340,6 +1544,8 @@ 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 +1562,11 @@ 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; + } sysfs_remove_bin_file(&dev->dev.kobj, dev->vpd->attr); kfree(dev->vpd->attr); } @@ -1438,6 +1649,11 @@ 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; + } sysfs_remove_bin_file(&dev->dev.kobj, dev->vpd->attr); kfree(dev->vpd->attr); } diff --git a/include/linux/pci.h b/include/linux/pci.h index 6ae25aa..699cf11 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -372,6 +372,8 @@ struct pci_dev { const struct attribute_group **msi_irq_groups; #endif struct pci_vpd *vpd; + int vpdr_len; + u8 *vpdr_data; #ifdef CONFIG_PCI_ATS union { struct pci_sriov *sriov; /* SR-IOV capability related */ -- 1.7.1 >Hence my confusion. > >Cheers, > >Hannes >-- >Dr. Hannes Reinecke zSeries & Storage >[email protected] +49 911 74053 688 >SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg >GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton >HRB 21284 (AG Nürnberg) >-- >To unsubscribe from this list: send the line "unsubscribe linux-pci" in >the body of a message to [email protected] >More majordomo info at http://vger.kernel.org/majordomo-info.html >-- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
