diff options
Diffstat (limited to 'drivers/pci/access.c')
-rw-r--r-- | drivers/pci/access.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/drivers/pci/access.c b/drivers/pci/access.c index 24a76de49f4..ea16805a153 100644 --- a/drivers/pci/access.c +++ b/drivers/pci/access.c @@ -2,6 +2,8 @@ #include <linux/module.h> #include <linux/ioport.h> +#include "pci.h" + /* * This interrupt-safe spinlock protects all accesses to PCI * configuration space. @@ -60,3 +62,92 @@ 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); + +static u32 pci_user_cached_config(struct pci_dev *dev, int pos) +{ + u32 data; + + data = dev->saved_config_space[pos/sizeof(dev->saved_config_space[0])]; + data >>= (pos % sizeof(dev->saved_config_space[0])) * 8; + return data; +} + +#define PCI_USER_READ_CONFIG(size,type) \ +int pci_user_read_config_##size \ + (struct pci_dev *dev, int pos, type *val) \ +{ \ + unsigned long flags; \ + int ret = 0; \ + u32 data = -1; \ + if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \ + spin_lock_irqsave(&pci_lock, flags); \ + if (likely(!dev->block_ucfg_access)) \ + ret = dev->bus->ops->read(dev->bus, dev->devfn, \ + pos, sizeof(type), &data); \ + else if (pos < sizeof(dev->saved_config_space)) \ + data = pci_user_cached_config(dev, pos); \ + spin_unlock_irqrestore(&pci_lock, flags); \ + *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) \ +{ \ + unsigned long flags; \ + int ret = -EIO; \ + if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \ + spin_lock_irqsave(&pci_lock, flags); \ + if (likely(!dev->block_ucfg_access)) \ + ret = dev->bus->ops->write(dev->bus, dev->devfn, \ + pos, sizeof(type), val); \ + spin_unlock_irqrestore(&pci_lock, flags); \ + 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 + * + * This function blocks any userspace PCI config accesses from occurring. + * When blocked, any writes will be bit bucketed and reads will return the + * data saved using pci_save_state for the first 64 bytes of config + * space and return 0xff for all other config reads. + **/ +void pci_block_user_cfg_access(struct pci_dev *dev) +{ + unsigned long flags; + + pci_save_state(dev); + + /* spinlock to synchronize with anyone reading config space now */ + spin_lock_irqsave(&pci_lock, flags); + dev->block_ucfg_access = 1; + spin_unlock_irqrestore(&pci_lock, flags); +} +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; + + /* spinlock to synchronize with anyone reading saved config space */ + spin_lock_irqsave(&pci_lock, flags); + dev->block_ucfg_access = 0; + spin_unlock_irqrestore(&pci_lock, flags); +} +EXPORT_SYMBOL_GPL(pci_unblock_user_cfg_access); |