174 lines
4.9 KiB
C
174 lines
4.9 KiB
C
#include <linux/pci.h>
|
|
#include <linux/module.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/ioport.h>
|
|
#include <linux/wait.h>
|
|
|
|
#include "pci.h"
|
|
|
|
/*
|
|
* This interrupt-safe spinlock protects all accesses to PCI
|
|
* configuration space.
|
|
*/
|
|
|
|
static DEFINE_SPINLOCK(pci_lock);
|
|
|
|
/*
|
|
* Wrappers for all PCI configuration access functions. They just check
|
|
* alignment, do locking and call the low-level functions pointed to
|
|
* by pci_dev->ops.
|
|
*/
|
|
|
|
#define PCI_byte_BAD 0
|
|
#define PCI_word_BAD (pos & 1)
|
|
#define PCI_dword_BAD (pos & 3)
|
|
|
|
#define PCI_OP_READ(size,type,len) \
|
|
int pci_bus_read_config_##size \
|
|
(struct pci_bus *bus, unsigned int devfn, int pos, type *value) \
|
|
{ \
|
|
int res; \
|
|
unsigned long flags; \
|
|
u32 data = 0; \
|
|
if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
|
|
spin_lock_irqsave(&pci_lock, flags); \
|
|
res = bus->ops->read(bus, devfn, pos, len, &data); \
|
|
*value = (type)data; \
|
|
spin_unlock_irqrestore(&pci_lock, flags); \
|
|
return res; \
|
|
}
|
|
|
|
#define PCI_OP_WRITE(size,type,len) \
|
|
int pci_bus_write_config_##size \
|
|
(struct pci_bus *bus, unsigned int devfn, int pos, type value) \
|
|
{ \
|
|
int res; \
|
|
unsigned long flags; \
|
|
if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
|
|
spin_lock_irqsave(&pci_lock, flags); \
|
|
res = bus->ops->write(bus, devfn, pos, len, value); \
|
|
spin_unlock_irqrestore(&pci_lock, flags); \
|
|
return res; \
|
|
}
|
|
|
|
PCI_OP_READ(byte, u8, 1)
|
|
PCI_OP_READ(word, u16, 2)
|
|
PCI_OP_READ(dword, u32, 4)
|
|
PCI_OP_WRITE(byte, u8, 1)
|
|
PCI_OP_WRITE(word, u16, 2)
|
|
PCI_OP_WRITE(dword, u32, 4)
|
|
|
|
EXPORT_SYMBOL(pci_bus_read_config_byte);
|
|
EXPORT_SYMBOL(pci_bus_read_config_word);
|
|
EXPORT_SYMBOL(pci_bus_read_config_dword);
|
|
EXPORT_SYMBOL(pci_bus_write_config_byte);
|
|
EXPORT_SYMBOL(pci_bus_write_config_word);
|
|
EXPORT_SYMBOL(pci_bus_write_config_dword);
|
|
|
|
/*
|
|
* The following routines are to prevent the user from accessing PCI config
|
|
* space when it's unsafe to do so. Some devices require this during BIST and
|
|
* we're required to prevent it during D-state transitions.
|
|
*
|
|
* We have a bit per device to indicate it's blocked and a global wait queue
|
|
* for callers to sleep on until devices are unblocked.
|
|
*/
|
|
static DECLARE_WAIT_QUEUE_HEAD(pci_ucfg_wait);
|
|
|
|
static noinline void pci_wait_ucfg(struct pci_dev *dev)
|
|
{
|
|
DECLARE_WAITQUEUE(wait, current);
|
|
|
|
__add_wait_queue(&pci_ucfg_wait, &wait);
|
|
do {
|
|
set_current_state(TASK_UNINTERRUPTIBLE);
|
|
spin_unlock_irq(&pci_lock);
|
|
schedule();
|
|
spin_lock_irq(&pci_lock);
|
|
} while (dev->block_ucfg_access);
|
|
__remove_wait_queue(&pci_ucfg_wait, &wait);
|
|
}
|
|
|
|
#define PCI_USER_READ_CONFIG(size,type) \
|
|
int pci_user_read_config_##size \
|
|
(struct pci_dev *dev, int pos, type *val) \
|
|
{ \
|
|
int ret = 0; \
|
|
u32 data = -1; \
|
|
if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
|
|
spin_lock_irq(&pci_lock); \
|
|
if (unlikely(dev->block_ucfg_access)) pci_wait_ucfg(dev); \
|
|
ret = dev->bus->ops->read(dev->bus, dev->devfn, \
|
|
pos, sizeof(type), &data); \
|
|
spin_unlock_irq(&pci_lock); \
|
|
*val = (type)data; \
|
|
return ret; \
|
|
}
|
|
|
|
#define PCI_USER_WRITE_CONFIG(size,type) \
|
|
int pci_user_write_config_##size \
|
|
(struct pci_dev *dev, int pos, type val) \
|
|
{ \
|
|
int ret = -EIO; \
|
|
if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
|
|
spin_lock_irq(&pci_lock); \
|
|
if (unlikely(dev->block_ucfg_access)) pci_wait_ucfg(dev); \
|
|
ret = dev->bus->ops->write(dev->bus, dev->devfn, \
|
|
pos, sizeof(type), val); \
|
|
spin_unlock_irq(&pci_lock); \
|
|
return ret; \
|
|
}
|
|
|
|
PCI_USER_READ_CONFIG(byte, u8)
|
|
PCI_USER_READ_CONFIG(word, u16)
|
|
PCI_USER_READ_CONFIG(dword, u32)
|
|
PCI_USER_WRITE_CONFIG(byte, u8)
|
|
PCI_USER_WRITE_CONFIG(word, u16)
|
|
PCI_USER_WRITE_CONFIG(dword, u32)
|
|
|
|
/**
|
|
* pci_block_user_cfg_access - Block userspace PCI config reads/writes
|
|
* @dev: pci device struct
|
|
*
|
|
* When user access is blocked, any reads or writes to config space will
|
|
* sleep until access is unblocked again. We don't allow nesting of
|
|
* block/unblock calls.
|
|
*/
|
|
void pci_block_user_cfg_access(struct pci_dev *dev)
|
|
{
|
|
unsigned long flags;
|
|
int was_blocked;
|
|
|
|
spin_lock_irqsave(&pci_lock, flags);
|
|
was_blocked = dev->block_ucfg_access;
|
|
dev->block_ucfg_access = 1;
|
|
spin_unlock_irqrestore(&pci_lock, flags);
|
|
|
|
/* If we BUG() inside the pci_lock, we're guaranteed to hose
|
|
* the machine */
|
|
BUG_ON(was_blocked);
|
|
}
|
|
EXPORT_SYMBOL_GPL(pci_block_user_cfg_access);
|
|
|
|
/**
|
|
* pci_unblock_user_cfg_access - Unblock userspace PCI config reads/writes
|
|
* @dev: pci device struct
|
|
*
|
|
* This function allows userspace PCI config accesses to resume.
|
|
*/
|
|
void pci_unblock_user_cfg_access(struct pci_dev *dev)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&pci_lock, flags);
|
|
|
|
/* This indicates a problem in the caller, but we don't need
|
|
* to kill them, unlike a double-block above. */
|
|
WARN_ON(!dev->block_ucfg_access);
|
|
|
|
dev->block_ucfg_access = 0;
|
|
wake_up_all(&pci_ucfg_wait);
|
|
spin_unlock_irqrestore(&pci_lock, flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(pci_unblock_user_cfg_access);
|