OpenCloudOS-Kernel/drivers/pci/vpd.c

433 lines
8.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* File: vpd.c
* Purpose: Provide 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 */
/**
* 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;
while (time_before(jiffies, timeout)) {
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;
usleep_range(10, max_sleep);
if (max_sleep < 1024)
max_sleep *= 2;
}
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);
}
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);