linux/drivers/pci/vpd.c
Heiner Kallweit 2c208abd4f PCI/VPD: Use unaligned access helpers
Use unaligned access helpers to simplify the code.

Link: https://lore.kernel.org/r/0f1c7e21-5330-72ab-139d-f5ce3c65f04a@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2021-08-31 16:10:18 -05:00

552 lines
13 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 <asm/unaligned.h>
#include "pci.h"
#define PCI_VPD_LRDT_TAG_SIZE 3
#define PCI_VPD_SRDT_LEN_MASK 0x07
#define PCI_VPD_SRDT_TAG_SIZE 1
#define PCI_VPD_STIN_END 0x0f
#define PCI_VPD_INFO_FLD_HDR_SIZE 3
static u16 pci_vpd_lrdt_size(const u8 *lrdt)
{
return get_unaligned_le16(lrdt + 1);
}
static u8 pci_vpd_srdt_tag(const u8 *srdt)
{
return *srdt >> 3;
}
static u8 pci_vpd_srdt_size(const u8 *srdt)
{
return *srdt & PCI_VPD_SRDT_LEN_MASK;
}
static u8 pci_vpd_info_field_size(const u8 *info_field)
{
return info_field[2];
}
/* VPD access through PCI 2.2+ VPD capability */
static struct pci_dev *pci_get_func0_dev(struct pci_dev *dev)
{
return pci_get_slot(dev->bus, PCI_DEVFN(PCI_SLOT(dev->devfn), 0));
}
#define PCI_VPD_MAX_SIZE (PCI_VPD_ADDR_MASK + 1)
#define PCI_VPD_SZ_INVALID UINT_MAX
/**
* pci_vpd_size - determine actual size of Vital Product Data
* @dev: pci device struct
*/
static size_t pci_vpd_size(struct pci_dev *dev)
{
size_t off = 0, size;
unsigned char tag, header[1+2]; /* 1 byte tag, 2 bytes length */
/* Otherwise the following reads would fail. */
dev->vpd.len = PCI_VPD_MAX_SIZE;
while (pci_read_vpd(dev, off, 1, header) == 1) {
size = 0;
if (off == 0 && (header[0] == 0x00 || header[0] == 0xff))
goto error;
if (header[0] & PCI_VPD_LRDT) {
/* Large Resource Data Type Tag */
if (pci_read_vpd(dev, off + 1, 2, &header[1]) != 2) {
pci_warn(dev, "failed VPD read at offset %zu\n",
off + 1);
return off ?: PCI_VPD_SZ_INVALID;
}
size = pci_vpd_lrdt_size(header);
if (off + size > PCI_VPD_MAX_SIZE)
goto error;
off += PCI_VPD_LRDT_TAG_SIZE + size;
} else {
/* Short Resource Data Type Tag */
tag = pci_vpd_srdt_tag(header);
size = pci_vpd_srdt_size(header);
if (off + size > PCI_VPD_MAX_SIZE)
goto error;
off += PCI_VPD_SRDT_TAG_SIZE + size;
if (tag == PCI_VPD_STIN_END) /* End tag descriptor */
return off;
}
}
return off;
error:
pci_info(dev, "invalid VPD tag %#04x (size %zu) at offset %zu%s\n",
header[0], size, off, off == 0 ?
"; assume missing optional EEPROM" : "");
return off ?: PCI_VPD_SZ_INVALID;
}
/*
* 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.
* @set: if true wait for flag to be set, else wait for it to be cleared
*
* Returns 0 on success, negative values indicate error.
*/
static int pci_vpd_wait(struct pci_dev *dev, bool set)
{
struct pci_vpd *vpd = &dev->vpd;
unsigned long timeout = jiffies + msecs_to_jiffies(125);
unsigned long max_sleep = 16;
u16 status;
int ret;
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) == set)
return 0;
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 = 0;
loff_t end = pos + count;
u8 *buf = arg;
if (!vpd->cap)
return -ENODEV;
if (pos < 0)
return -EINVAL;
if (pos > vpd->len)
return 0;
if (end > vpd->len) {
end = vpd->len;
count = end - pos;
}
if (mutex_lock_killable(&vpd->lock))
return -EINTR;
while (pos < end) {
u32 val;
unsigned int i, skip;
if (fatal_signal_pending(current)) {
ret = -EINTR;
break;
}
ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR,
pos & ~3);
if (ret < 0)
break;
ret = pci_vpd_wait(dev, true);
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;
}
}
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 (!vpd->cap)
return -ENODEV;
if (pos < 0 || (pos & 3) || (count & 3))
return -EINVAL;
if (end > vpd->len)
return -EINVAL;
if (mutex_lock_killable(&vpd->lock))
return -EINTR;
while (pos < end) {
ret = pci_user_write_config_dword(dev, vpd->cap + PCI_VPD_DATA,
get_unaligned_le32(buf));
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;
ret = pci_vpd_wait(dev, false);
if (ret < 0)
break;
buf += sizeof(u32);
pos += sizeof(u32);
}
mutex_unlock(&vpd->lock);
return ret ? ret : count;
}
void pci_vpd_init(struct pci_dev *dev)
{
dev->vpd.cap = pci_find_capability(dev, PCI_CAP_ID_VPD);
mutex_init(&dev->vpd.lock);
if (!dev->vpd.len)
dev->vpd.len = pci_vpd_size(dev);
if (dev->vpd.len == PCI_VPD_SZ_INVALID)
dev->vpd.cap = 0;
}
static ssize_t vpd_read(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));
return pci_read_vpd(dev, off, count, buf);
}
static ssize_t vpd_write(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));
return pci_write_vpd(dev, off, count, buf);
}
static BIN_ATTR(vpd, 0600, vpd_read, vpd_write, 0);
static struct bin_attribute *vpd_attrs[] = {
&bin_attr_vpd,
NULL,
};
static umode_t vpd_attr_is_visible(struct kobject *kobj,
struct bin_attribute *a, int n)
{
struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
if (!pdev->vpd.cap)
return 0;
return a->attr.mode;
}
const struct attribute_group pci_dev_vpd_attr_group = {
.bin_attrs = vpd_attrs,
.is_bin_visible = vpd_attr_is_visible,
};
void *pci_vpd_alloc(struct pci_dev *dev, unsigned int *size)
{
unsigned int len = dev->vpd.len;
void *buf;
int cnt;
if (!dev->vpd.cap)
return ERR_PTR(-ENODEV);
buf = kmalloc(len, GFP_KERNEL);
if (!buf)
return ERR_PTR(-ENOMEM);
cnt = pci_read_vpd(dev, 0, len, buf);
if (cnt != len) {
kfree(buf);
return ERR_PTR(-EIO);
}
if (size)
*size = len;
return buf;
}
EXPORT_SYMBOL_GPL(pci_vpd_alloc);
static int pci_vpd_find_tag(const u8 *buf, unsigned int len, u8 rdt, unsigned int *size)
{
int i = 0;
/* look for LRDT tags only, end tag is the only SRDT tag */
while (i + PCI_VPD_LRDT_TAG_SIZE <= len && buf[i] & PCI_VPD_LRDT) {
unsigned int lrdt_len = pci_vpd_lrdt_size(buf + i);
u8 tag = buf[i];
i += PCI_VPD_LRDT_TAG_SIZE;
if (tag == rdt) {
if (i + lrdt_len > len)
lrdt_len = len - i;
if (size)
*size = lrdt_len;
return i;
}
i += lrdt_len;
}
return -ENOENT;
}
int pci_vpd_find_id_string(const u8 *buf, unsigned int len, unsigned int *size)
{
return pci_vpd_find_tag(buf, len, PCI_VPD_LRDT_ID_STRING, size);
}
EXPORT_SYMBOL_GPL(pci_vpd_find_id_string);
static 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;
}
/**
* 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)
{
ssize_t ret;
if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0) {
dev = pci_get_func0_dev(dev);
if (!dev)
return -ENODEV;
ret = pci_vpd_read(dev, pos, count, buf);
pci_dev_put(dev);
return ret;
}
return pci_vpd_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)
{
ssize_t ret;
if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0) {
dev = pci_get_func0_dev(dev);
if (!dev)
return -ENODEV;
ret = pci_vpd_write(dev, pos, count, buf);
pci_dev_put(dev);
return ret;
}
return pci_vpd_write(dev, pos, count, buf);
}
EXPORT_SYMBOL(pci_write_vpd);
int pci_vpd_find_ro_info_keyword(const void *buf, unsigned int len,
const char *kw, unsigned int *size)
{
int ro_start, infokw_start;
unsigned int ro_len, infokw_size;
ro_start = pci_vpd_find_tag(buf, len, PCI_VPD_LRDT_RO_DATA, &ro_len);
if (ro_start < 0)
return ro_start;
infokw_start = pci_vpd_find_info_keyword(buf, ro_start, ro_len, kw);
if (infokw_start < 0)
return infokw_start;
infokw_size = pci_vpd_info_field_size(buf + infokw_start);
infokw_start += PCI_VPD_INFO_FLD_HDR_SIZE;
if (infokw_start + infokw_size > len)
return -EINVAL;
if (size)
*size = infokw_size;
return infokw_start;
}
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
* 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_func0_dev(dev);
if (!f0)
return;
if (f0->vpd.cap && 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)
{
dev->vpd.len = PCI_VPD_SZ_INVALID;
pci_warn(dev, FW_BUG "disabling VPD access (can't determine size of non-standard VPD format)\n");
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0060, quirk_blacklist_vpd);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x007c, quirk_blacklist_vpd);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0413, quirk_blacklist_vpd);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0078, quirk_blacklist_vpd);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0079, quirk_blacklist_vpd);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0073, quirk_blacklist_vpd);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0071, quirk_blacklist_vpd);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x005b, quirk_blacklist_vpd);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x002f, quirk_blacklist_vpd);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x005d, quirk_blacklist_vpd);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x005f, quirk_blacklist_vpd);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATTANSIC, PCI_ANY_ID, quirk_blacklist_vpd);
/*
* The Amazon Annapurna Labs 0x0031 device id is reused for other non Root Port
* device types, so the quirk is registered for the PCI_CLASS_BRIDGE_PCI class.
*/
DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_VENDOR_ID_AMAZON_ANNAPURNA_LABS, 0x0031,
PCI_CLASS_BRIDGE_PCI, 8, quirk_blacklist_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)
dev->vpd.len = 8192;
else if (chip >= 0x4 && func < 0x8)
dev->vpd.len = 2048;
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_CHELSIO, PCI_ANY_ID,
quirk_chelsio_extend_vpd);
#endif