diff options
| -rw-r--r-- | drivers/pci/access.c | 20 | ||||
| -rw-r--r-- | drivers/pci/probe.c | 1 | ||||
| -rw-r--r-- | include/linux/pci.h | 34 |
3 files changed, 50 insertions, 5 deletions
diff --git a/drivers/pci/access.c b/drivers/pci/access.c index 708c7529647f..3d20f9c51efe 100644 --- a/drivers/pci/access.c +++ b/drivers/pci/access.c @@ -491,8 +491,8 @@ int pcie_capability_write_dword(struct pci_dev *dev, int pos, u32 val) } EXPORT_SYMBOL(pcie_capability_write_dword); -int pcie_capability_clear_and_set_word(struct pci_dev *dev, int pos, - u16 clear, u16 set) +int pcie_capability_clear_and_set_word_unlocked(struct pci_dev *dev, int pos, + u16 clear, u16 set) { int ret; u16 val; @@ -506,7 +506,21 @@ int pcie_capability_clear_and_set_word(struct pci_dev *dev, int pos, return ret; } -EXPORT_SYMBOL(pcie_capability_clear_and_set_word); +EXPORT_SYMBOL(pcie_capability_clear_and_set_word_unlocked); + +int pcie_capability_clear_and_set_word_locked(struct pci_dev *dev, int pos, + u16 clear, u16 set) +{ + unsigned long flags; + int ret; + + spin_lock_irqsave(&dev->pcie_cap_lock, flags); + ret = pcie_capability_clear_and_set_word_unlocked(dev, pos, clear, set); + spin_unlock_irqrestore(&dev->pcie_cap_lock, flags); + + return ret; +} +EXPORT_SYMBOL(pcie_capability_clear_and_set_word_locked); int pcie_capability_clear_and_set_dword(struct pci_dev *dev, int pos, u32 clear, u32 set) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index e3a1dc6432bc..843e4a58788e 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2312,6 +2312,7 @@ struct pci_dev *pci_alloc_dev(struct pci_bus *bus) .end = -1, }; + spin_lock_init(&dev->pcie_cap_lock); #ifdef CONFIG_PCI_MSI raw_spin_lock_init(&dev->msi_lock); #endif diff --git a/include/linux/pci.h b/include/linux/pci.h index 4ea8de6890be..eccaf1abea79 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -466,6 +466,7 @@ struct pci_dev { pci_dev_flags_t dev_flags; atomic_t enable_cnt; /* pci_enable_device has been called */ + spinlock_t pcie_cap_lock; /* Protects RMW ops in capability accessors */ u32 saved_config_space[16]; /* Config space saved at suspend time */ struct hlist_head saved_cap_space; int rom_attr_enabled; /* Display of ROM attribute enabled? */ @@ -1209,11 +1210,40 @@ int pcie_capability_read_word(struct pci_dev *dev, int pos, u16 *val); int pcie_capability_read_dword(struct pci_dev *dev, int pos, u32 *val); int pcie_capability_write_word(struct pci_dev *dev, int pos, u16 val); int pcie_capability_write_dword(struct pci_dev *dev, int pos, u32 val); -int pcie_capability_clear_and_set_word(struct pci_dev *dev, int pos, - u16 clear, u16 set); +int pcie_capability_clear_and_set_word_unlocked(struct pci_dev *dev, int pos, + u16 clear, u16 set); +int pcie_capability_clear_and_set_word_locked(struct pci_dev *dev, int pos, + u16 clear, u16 set); int pcie_capability_clear_and_set_dword(struct pci_dev *dev, int pos, u32 clear, u32 set); +/** + * pcie_capability_clear_and_set_word - RMW accessor for PCI Express Capability Registers + * @dev: PCI device structure of the PCI Express device + * @pos: PCI Express Capability Register + * @clear: Clear bitmask + * @set: Set bitmask + * + * Perform a Read-Modify-Write (RMW) operation using @clear and @set + * bitmasks on PCI Express Capability Register at @pos. Certain PCI Express + * Capability Registers are accessed concurrently in RMW fashion, hence + * require locking which is handled transparently to the caller. + */ +static inline int pcie_capability_clear_and_set_word(struct pci_dev *dev, + int pos, + u16 clear, u16 set) +{ + switch (pos) { + case PCI_EXP_LNKCTL: + case PCI_EXP_RTCTL: + return pcie_capability_clear_and_set_word_locked(dev, pos, + clear, set); + default: + return pcie_capability_clear_and_set_word_unlocked(dev, pos, + clear, set); + } +} + static inline int pcie_capability_set_word(struct pci_dev *dev, int pos, u16 set) { |