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PCI/VPD: Add pci_read/write_vpd_any()

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In certain cases we need a variant of pci_read_vpd()/pci_write_vpd() that
does not check against dev->vpd.len. Such cases are:

  - Reading VPD if dev->vpd.len isn't set yet (in pci_vpd_size())

  - Devices that map non-VPD information to arbitrary places in VPD address
    space (example: Chelsio T3 EEPROM write-protect flag)

Therefore add pci_read_vpd_any() and pci_write_vpd_any() that check against
PCI_VPD_MAX_SIZE only.

Link: https://lore.kernel.org/r/93ecce28-a158-f02a-d134-8afcaced8efe@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Heiner Kallweit 2021-09-10 08:22:06 +02:00 committed by Bjorn Helgaas
parent e4e737bb5c
commit bf2928c7a2
2 changed files with 52 additions and 22 deletions
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72
drivers/pci/vpd.c
View file

@ -156,9 +156,10 @@ static int pci_vpd_wait(struct pci_dev *dev, bool set)
}
static ssize_t pci_vpd_read(struct pci_dev *dev, loff_t pos, size_t count,
void *arg)
void *arg, bool check_size)
{
struct pci_vpd *vpd = &dev->vpd;
unsigned int max_len = check_size ? vpd->len : PCI_VPD_MAX_SIZE;
int ret = 0;
loff_t end = pos + count;
u8 *buf = arg;
@ -169,11 +170,11 @@ static ssize_t pci_vpd_read(struct pci_dev *dev, loff_t pos, size_t count,
if (pos < 0)
return -EINVAL;
if (pos > vpd->len)
if (pos >= max_len)
return 0;
if (end > vpd->len) {
end = vpd->len;
if (end > max_len) {
end = max_len;
count = end - pos;
}
@ -217,9 +218,10 @@ static ssize_t pci_vpd_read(struct pci_dev *dev, loff_t pos, size_t count,
}
static ssize_t pci_vpd_write(struct pci_dev *dev, loff_t pos, size_t count,
const void *arg)
const void *arg, bool check_size)
{
struct pci_vpd *vpd = &dev->vpd;
unsigned int max_len = check_size ? vpd->len : PCI_VPD_MAX_SIZE;
const u8 *buf = arg;
loff_t end = pos + count;
int ret = 0;
@ -230,7 +232,7 @@ static ssize_t pci_vpd_write(struct pci_dev *dev, loff_t pos, size_t count,
if (pos < 0 || (pos & 3) || (count & 3))
return -EINVAL;
if (end > vpd->len)
if (end > max_len)
return -EINVAL;
if (mutex_lock_killable(&vpd->lock))
@ -381,6 +383,24 @@ static int pci_vpd_find_info_keyword(const u8 *buf, unsigned int off,
return -ENOENT;
}
static ssize_t __pci_read_vpd(struct pci_dev *dev, loff_t pos, size_t count, void *buf,
bool check_size)
{
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, check_size);
pci_dev_put(dev);
return ret;
}
return pci_vpd_read(dev, pos, count, buf, check_size);
}
/**
* pci_read_vpd - Read one entry from Vital Product Data
* @dev: PCI device struct
@ -389,6 +409,20 @@ static int pci_vpd_find_info_keyword(const u8 *buf, unsigned int off,
* @buf: pointer to where to store result
*/
ssize_t pci_read_vpd(struct pci_dev *dev, loff_t pos, size_t count, void *buf)
{
return __pci_read_vpd(dev, pos, count, buf, true);
}
EXPORT_SYMBOL(pci_read_vpd);
/* Same, but allow to access any address */
ssize_t pci_read_vpd_any(struct pci_dev *dev, loff_t pos, size_t count, void *buf)
{
return __pci_read_vpd(dev, pos, count, buf, false);
}
EXPORT_SYMBOL(pci_read_vpd_any);
static ssize_t __pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count,
const void *buf, bool check_size)
{
ssize_t ret;
@ -397,14 +431,13 @@ ssize_t pci_read_vpd(struct pci_dev *dev, loff_t pos, size_t count, void *buf)
if (!dev)
return -ENODEV;
ret = pci_vpd_read(dev, pos, count, buf);
ret = pci_vpd_write(dev, pos, count, buf, check_size);
pci_dev_put(dev);
return ret;
}
return pci_vpd_read(dev, pos, count, buf);
return pci_vpd_write(dev, pos, count, buf, check_size);
}
EXPORT_SYMBOL(pci_read_vpd);
/**
* pci_write_vpd - Write entry to Vital Product Data
@ -415,22 +448,17 @@ EXPORT_SYMBOL(pci_read_vpd);
*/
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);
return __pci_write_vpd(dev, pos, count, buf, true);
}
EXPORT_SYMBOL(pci_write_vpd);
/* Same, but allow to access any address */
ssize_t pci_write_vpd_any(struct pci_dev *dev, loff_t pos, size_t count, const void *buf)
{
return __pci_write_vpd(dev, pos, count, buf, false);
}
EXPORT_SYMBOL(pci_write_vpd_any);
int pci_vpd_find_ro_info_keyword(const void *buf, unsigned int len,
const char *kw, unsigned int *size)
{

2
include/linux/pci.h
View file

@ -1350,6 +1350,8 @@ void pci_unlock_rescan_remove(void);
/* Vital Product Data routines */
ssize_t pci_read_vpd(struct pci_dev *dev, loff_t pos, size_t count, void *buf);
ssize_t pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, const void *buf);
ssize_t pci_read_vpd_any(struct pci_dev *dev, loff_t pos, size_t count, void *buf);
ssize_t pci_write_vpd_any(struct pci_dev *dev, loff_t pos, size_t count, const void *buf);
/* Helper functions for low-level code (drivers/pci/setup-[bus,res].c) */
resource_size_t pcibios_retrieve_fw_addr(struct pci_dev *dev, int idx);