linux-stable/drivers/pci/vpd.c
Bert Kenward 6eaf278113 PCI/VPD: Check for VPD access completion before checking for timeout
Previously we checked the timeout before checking the VPD access completion
bit.  On a very heavily loaded system this can cause VPD access to timeout.
Check the completion bit before checking the timeout.

Signed-off-by: Bert Kenward <bkenward@solarflare.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-08-14 16:04:46 -05:00

647 lines
16 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* PCI VPD support
*
* Copyright (C) 2010 Broadcom Corporation.
*/
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/export.h>
#include <linux/sched/signal.h>
#include "pci.h"
/* VPD access through PCI 2.2+ VPD capability */
struct pci_vpd_ops {
ssize_t (*read)(struct pci_dev *dev, loff_t pos, size_t count, void *buf);
ssize_t (*write)(struct pci_dev *dev, loff_t pos, size_t count, const void *buf);
int (*set_size)(struct pci_dev *dev, size_t len);
};
struct pci_vpd {
const struct pci_vpd_ops *ops;
struct bin_attribute *attr; /* Descriptor for sysfs VPD entry */
struct mutex lock;
unsigned int len;
u16 flag;
u8 cap;
unsigned int busy:1;
unsigned int valid:1;
};
/**
* pci_read_vpd - Read one entry from Vital Product Data
* @dev: pci device struct
* @pos: offset in vpd space
* @count: number of bytes to read
* @buf: pointer to where to store result
*/
ssize_t pci_read_vpd(struct pci_dev *dev, loff_t pos, size_t count, void *buf)
{
if (!dev->vpd || !dev->vpd->ops)
return -ENODEV;
return dev->vpd->ops->read(dev, pos, count, buf);
}
EXPORT_SYMBOL(pci_read_vpd);
/**
* pci_write_vpd - Write entry to Vital Product Data
* @dev: pci device struct
* @pos: offset in vpd space
* @count: number of bytes to write
* @buf: buffer containing write data
*/
ssize_t pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, const void *buf)
{
if (!dev->vpd || !dev->vpd->ops)
return -ENODEV;
return dev->vpd->ops->write(dev, pos, count, buf);
}
EXPORT_SYMBOL(pci_write_vpd);
/**
* pci_set_vpd_size - Set size of Vital Product Data space
* @dev: pci device struct
* @len: size of vpd space
*/
int pci_set_vpd_size(struct pci_dev *dev, size_t len)
{
if (!dev->vpd || !dev->vpd->ops)
return -ENODEV;
return dev->vpd->ops->set_size(dev, len);
}
EXPORT_SYMBOL(pci_set_vpd_size);
#define PCI_VPD_MAX_SIZE (PCI_VPD_ADDR_MASK + 1)
/**
* pci_vpd_size - determine actual size of Vital Product Data
* @dev: pci device struct
* @old_size: current assumed size, also maximum allowed size
*/
static size_t pci_vpd_size(struct pci_dev *dev, size_t old_size)
{
size_t off = 0;
unsigned char header[1+2]; /* 1 byte tag, 2 bytes length */
while (off < old_size &&
pci_read_vpd(dev, off, 1, header) == 1) {
unsigned char tag;
if (header[0] & PCI_VPD_LRDT) {
/* Large Resource Data Type Tag */
tag = pci_vpd_lrdt_tag(header);
/* Only read length from known tag items */
if ((tag == PCI_VPD_LTIN_ID_STRING) ||
(tag == PCI_VPD_LTIN_RO_DATA) ||
(tag == PCI_VPD_LTIN_RW_DATA)) {
if (pci_read_vpd(dev, off+1, 2,
&header[1]) != 2) {
pci_warn(dev, "invalid large VPD tag %02x size at offset %zu",
tag, off + 1);
return 0;
}
off += PCI_VPD_LRDT_TAG_SIZE +
pci_vpd_lrdt_size(header);
}
} else {
/* Short Resource Data Type Tag */
off += PCI_VPD_SRDT_TAG_SIZE +
pci_vpd_srdt_size(header);
tag = pci_vpd_srdt_tag(header);
}
if (tag == PCI_VPD_STIN_END) /* End tag descriptor */
return off;
if ((tag != PCI_VPD_LTIN_ID_STRING) &&
(tag != PCI_VPD_LTIN_RO_DATA) &&
(tag != PCI_VPD_LTIN_RW_DATA)) {
pci_warn(dev, "invalid %s VPD tag %02x at offset %zu",
(header[0] & PCI_VPD_LRDT) ? "large" : "short",
tag, off);
return 0;
}
}
return 0;
}
/*
* Wait for last operation to complete.
* This code has to spin since there is no other notification from the PCI
* hardware. Since the VPD is often implemented by serial attachment to an
* EEPROM, it may take many milliseconds to complete.
*
* Returns 0 on success, negative values indicate error.
*/
static int pci_vpd_wait(struct pci_dev *dev)
{
struct pci_vpd *vpd = dev->vpd;
unsigned long timeout = jiffies + msecs_to_jiffies(125);
unsigned long max_sleep = 16;
u16 status;
int ret;
if (!vpd->busy)
return 0;
do {
ret = pci_user_read_config_word(dev, vpd->cap + PCI_VPD_ADDR,
&status);
if (ret < 0)
return ret;
if ((status & PCI_VPD_ADDR_F) == vpd->flag) {
vpd->busy = 0;
return 0;
}
if (fatal_signal_pending(current))
return -EINTR;
if (time_after(jiffies, timeout))
break;
usleep_range(10, max_sleep);
if (max_sleep < 1024)
max_sleep *= 2;
} while (true);
pci_warn(dev, "VPD access failed. This is likely a firmware bug on this device. Contact the card vendor for a firmware update\n");
return -ETIMEDOUT;
}
static ssize_t pci_vpd_read(struct pci_dev *dev, loff_t pos, size_t count,
void *arg)
{
struct pci_vpd *vpd = dev->vpd;
int ret;
loff_t end = pos + count;
u8 *buf = arg;
if (pos < 0)
return -EINVAL;
if (!vpd->valid) {
vpd->valid = 1;
vpd->len = pci_vpd_size(dev, vpd->len);
}
if (vpd->len == 0)
return -EIO;
if (pos > vpd->len)
return 0;
if (end > vpd->len) {
end = vpd->len;
count = end - pos;
}
if (mutex_lock_killable(&vpd->lock))
return -EINTR;
ret = pci_vpd_wait(dev);
if (ret < 0)
goto out;
while (pos < end) {
u32 val;
unsigned int i, skip;
ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR,
pos & ~3);
if (ret < 0)
break;
vpd->busy = 1;
vpd->flag = PCI_VPD_ADDR_F;
ret = pci_vpd_wait(dev);
if (ret < 0)
break;
ret = pci_user_read_config_dword(dev, vpd->cap + PCI_VPD_DATA, &val);
if (ret < 0)
break;
skip = pos & 3;
for (i = 0; i < sizeof(u32); i++) {
if (i >= skip) {
*buf++ = val;
if (++pos == end)
break;
}
val >>= 8;
}
}
out:
mutex_unlock(&vpd->lock);
return ret ? ret : count;
}
static ssize_t pci_vpd_write(struct pci_dev *dev, loff_t pos, size_t count,
const void *arg)
{
struct pci_vpd *vpd = dev->vpd;
const u8 *buf = arg;
loff_t end = pos + count;
int ret = 0;
if (pos < 0 || (pos & 3) || (count & 3))
return -EINVAL;
if (!vpd->valid) {
vpd->valid = 1;
vpd->len = pci_vpd_size(dev, vpd->len);
}
if (vpd->len == 0)
return -EIO;
if (end > vpd->len)
return -EINVAL;
if (mutex_lock_killable(&vpd->lock))
return -EINTR;
ret = pci_vpd_wait(dev);
if (ret < 0)
goto out;
while (pos < end) {
u32 val;
val = *buf++;
val |= *buf++ << 8;
val |= *buf++ << 16;
val |= *buf++ << 24;
ret = pci_user_write_config_dword(dev, vpd->cap + PCI_VPD_DATA, val);
if (ret < 0)
break;
ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR,
pos | PCI_VPD_ADDR_F);
if (ret < 0)
break;
vpd->busy = 1;
vpd->flag = 0;
ret = pci_vpd_wait(dev);
if (ret < 0)
break;
pos += sizeof(u32);
}
out:
mutex_unlock(&vpd->lock);
return ret ? ret : count;
}
static int pci_vpd_set_size(struct pci_dev *dev, size_t len)
{
struct pci_vpd *vpd = dev->vpd;
if (len == 0 || len > PCI_VPD_MAX_SIZE)
return -EIO;
vpd->valid = 1;
vpd->len = len;
return 0;
}
static const struct pci_vpd_ops pci_vpd_ops = {
.read = pci_vpd_read,
.write = pci_vpd_write,
.set_size = pci_vpd_set_size,
};
static ssize_t pci_vpd_f0_read(struct pci_dev *dev, loff_t pos, size_t count,
void *arg)
{
struct pci_dev *tdev = pci_get_slot(dev->bus,
PCI_DEVFN(PCI_SLOT(dev->devfn), 0));
ssize_t ret;
if (!tdev)
return -ENODEV;
ret = pci_read_vpd(tdev, pos, count, arg);
pci_dev_put(tdev);
return ret;
}
static ssize_t pci_vpd_f0_write(struct pci_dev *dev, loff_t pos, size_t count,
const void *arg)
{
struct pci_dev *tdev = pci_get_slot(dev->bus,
PCI_DEVFN(PCI_SLOT(dev->devfn), 0));
ssize_t ret;
if (!tdev)
return -ENODEV;
ret = pci_write_vpd(tdev, pos, count, arg);
pci_dev_put(tdev);
return ret;
}
static int pci_vpd_f0_set_size(struct pci_dev *dev, size_t len)
{
struct pci_dev *tdev = pci_get_slot(dev->bus,
PCI_DEVFN(PCI_SLOT(dev->devfn), 0));
int ret;
if (!tdev)
return -ENODEV;
ret = pci_set_vpd_size(tdev, len);
pci_dev_put(tdev);
return ret;
}
static const struct pci_vpd_ops pci_vpd_f0_ops = {
.read = pci_vpd_f0_read,
.write = pci_vpd_f0_write,
.set_size = pci_vpd_f0_set_size,
};
int pci_vpd_init(struct pci_dev *dev)
{
struct pci_vpd *vpd;
u8 cap;
cap = pci_find_capability(dev, PCI_CAP_ID_VPD);
if (!cap)
return -ENODEV;
vpd = kzalloc(sizeof(*vpd), GFP_ATOMIC);
if (!vpd)
return -ENOMEM;
vpd->len = PCI_VPD_MAX_SIZE;
if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0)
vpd->ops = &pci_vpd_f0_ops;
else
vpd->ops = &pci_vpd_ops;
mutex_init(&vpd->lock);
vpd->cap = cap;
vpd->busy = 0;
vpd->valid = 0;
dev->vpd = vpd;
return 0;
}
void pci_vpd_release(struct pci_dev *dev)
{
kfree(dev->vpd);
}
static ssize_t read_vpd_attr(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr, char *buf,
loff_t off, size_t count)
{
struct pci_dev *dev = to_pci_dev(kobj_to_dev(kobj));
if (bin_attr->size > 0) {
if (off > bin_attr->size)
count = 0;
else if (count > bin_attr->size - off)
count = bin_attr->size - off;
}
return pci_read_vpd(dev, off, count, buf);
}
static ssize_t write_vpd_attr(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr, char *buf,
loff_t off, size_t count)
{
struct pci_dev *dev = to_pci_dev(kobj_to_dev(kobj));
if (bin_attr->size > 0) {
if (off > bin_attr->size)
count = 0;
else if (count > bin_attr->size - off)
count = bin_attr->size - off;
}
return pci_write_vpd(dev, off, count, buf);
}
void pcie_vpd_create_sysfs_dev_files(struct pci_dev *dev)
{
int retval;
struct bin_attribute *attr;
if (!dev->vpd)
return;
attr = kzalloc(sizeof(*attr), GFP_ATOMIC);
if (!attr)
return;
sysfs_bin_attr_init(attr);
attr->size = 0;
attr->attr.name = "vpd";
attr->attr.mode = S_IRUSR | S_IWUSR;
attr->read = read_vpd_attr;
attr->write = write_vpd_attr;
retval = sysfs_create_bin_file(&dev->dev.kobj, attr);
if (retval) {
kfree(attr);
return;
}
dev->vpd->attr = attr;
}
void pcie_vpd_remove_sysfs_dev_files(struct pci_dev *dev)
{
if (dev->vpd && dev->vpd->attr) {
sysfs_remove_bin_file(&dev->dev.kobj, dev->vpd->attr);
kfree(dev->vpd->attr);
}
}
int pci_vpd_find_tag(const u8 *buf, unsigned int off, unsigned int len, u8 rdt)
{
int i;
for (i = off; i < len; ) {
u8 val = buf[i];
if (val & PCI_VPD_LRDT) {
/* Don't return success of the tag isn't complete */
if (i + PCI_VPD_LRDT_TAG_SIZE > len)
break;
if (val == rdt)
return i;
i += PCI_VPD_LRDT_TAG_SIZE +
pci_vpd_lrdt_size(&buf[i]);
} else {
u8 tag = val & ~PCI_VPD_SRDT_LEN_MASK;
if (tag == rdt)
return i;
if (tag == PCI_VPD_SRDT_END)
break;
i += PCI_VPD_SRDT_TAG_SIZE +
pci_vpd_srdt_size(&buf[i]);
}
}
return -ENOENT;
}
EXPORT_SYMBOL_GPL(pci_vpd_find_tag);
int pci_vpd_find_info_keyword(const u8 *buf, unsigned int off,
unsigned int len, const char *kw)
{
int i;
for (i = off; i + PCI_VPD_INFO_FLD_HDR_SIZE <= off + len;) {
if (buf[i + 0] == kw[0] &&
buf[i + 1] == kw[1])
return i;
i += PCI_VPD_INFO_FLD_HDR_SIZE +
pci_vpd_info_field_size(&buf[i]);
}
return -ENOENT;
}
EXPORT_SYMBOL_GPL(pci_vpd_find_info_keyword);
#ifdef CONFIG_PCI_QUIRKS
/*
* Quirk non-zero PCI functions to route VPD access through function 0 for
* devices that share VPD resources between functions. The functions are
* expected to be identical devices.
*/
static void quirk_f0_vpd_link(struct pci_dev *dev)
{
struct pci_dev *f0;
if (!PCI_FUNC(dev->devfn))
return;
f0 = pci_get_slot(dev->bus, PCI_DEVFN(PCI_SLOT(dev->devfn), 0));
if (!f0)
return;
if (f0->vpd && dev->class == f0->class &&
dev->vendor == f0->vendor && dev->device == f0->device)
dev->dev_flags |= PCI_DEV_FLAGS_VPD_REF_F0;
pci_dev_put(f0);
}
DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_INTEL, PCI_ANY_ID,
PCI_CLASS_NETWORK_ETHERNET, 8, quirk_f0_vpd_link);
/*
* If a device follows the VPD format spec, the PCI core will not read or
* write past the VPD End Tag. But some vendors do not follow the VPD
* format spec, so we can't tell how much data is safe to access. Devices
* may behave unpredictably if we access too much. Blacklist these devices
* so we don't touch VPD at all.
*/
static void quirk_blacklist_vpd(struct pci_dev *dev)
{
if (dev->vpd) {
dev->vpd->len = 0;
pci_warn(dev, FW_BUG "disabling VPD access (can't determine size of non-standard VPD format)\n");
}
}
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0060, quirk_blacklist_vpd);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x007c, quirk_blacklist_vpd);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0413, quirk_blacklist_vpd);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0078, quirk_blacklist_vpd);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0079, quirk_blacklist_vpd);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0073, quirk_blacklist_vpd);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0071, quirk_blacklist_vpd);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x005b, quirk_blacklist_vpd);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x002f, quirk_blacklist_vpd);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x005d, quirk_blacklist_vpd);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x005f, quirk_blacklist_vpd);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATTANSIC, PCI_ANY_ID,
quirk_blacklist_vpd);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_QLOGIC, 0x2261, quirk_blacklist_vpd);
/*
* For Broadcom 5706, 5708, 5709 rev. A nics, any read beyond the
* VPD end tag will hang the device. This problem was initially
* observed when a vpd entry was created in sysfs
* ('/sys/bus/pci/devices/<id>/vpd'). A read to this sysfs entry
* will dump 32k of data. Reading a full 32k will cause an access
* beyond the VPD end tag causing the device to hang. Once the device
* is hung, the bnx2 driver will not be able to reset the device.
* We believe that it is legal to read beyond the end tag and
* therefore the solution is to limit the read/write length.
*/
static void quirk_brcm_570x_limit_vpd(struct pci_dev *dev)
{
/*
* Only disable the VPD capability for 5706, 5706S, 5708,
* 5708S and 5709 rev. A
*/
if ((dev->device == PCI_DEVICE_ID_NX2_5706) ||
(dev->device == PCI_DEVICE_ID_NX2_5706S) ||
(dev->device == PCI_DEVICE_ID_NX2_5708) ||
(dev->device == PCI_DEVICE_ID_NX2_5708S) ||
((dev->device == PCI_DEVICE_ID_NX2_5709) &&
(dev->revision & 0xf0) == 0x0)) {
if (dev->vpd)
dev->vpd->len = 0x80;
}
}
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_BROADCOM,
PCI_DEVICE_ID_NX2_5706,
quirk_brcm_570x_limit_vpd);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_BROADCOM,
PCI_DEVICE_ID_NX2_5706S,
quirk_brcm_570x_limit_vpd);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_BROADCOM,
PCI_DEVICE_ID_NX2_5708,
quirk_brcm_570x_limit_vpd);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_BROADCOM,
PCI_DEVICE_ID_NX2_5708S,
quirk_brcm_570x_limit_vpd);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_BROADCOM,
PCI_DEVICE_ID_NX2_5709,
quirk_brcm_570x_limit_vpd);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_BROADCOM,
PCI_DEVICE_ID_NX2_5709S,
quirk_brcm_570x_limit_vpd);
static void quirk_chelsio_extend_vpd(struct pci_dev *dev)
{
int chip = (dev->device & 0xf000) >> 12;
int func = (dev->device & 0x0f00) >> 8;
int prod = (dev->device & 0x00ff) >> 0;
/*
* If this is a T3-based adapter, there's a 1KB VPD area at offset
* 0xc00 which contains the preferred VPD values. If this is a T4 or
* later based adapter, the special VPD is at offset 0x400 for the
* Physical Functions (the SR-IOV Virtual Functions have no VPD
* Capabilities). The PCI VPD Access core routines will normally
* compute the size of the VPD by parsing the VPD Data Structure at
* offset 0x000. This will result in silent failures when attempting
* to accesses these other VPD areas which are beyond those computed
* limits.
*/
if (chip == 0x0 && prod >= 0x20)
pci_set_vpd_size(dev, 8192);
else if (chip >= 0x4 && func < 0x8)
pci_set_vpd_size(dev, 2048);
}
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_CHELSIO, PCI_ANY_ID,
quirk_chelsio_extend_vpd);
#endif