diff options
Diffstat (limited to 'drivers/pci/access.c')
| -rw-r--r-- | drivers/pci/access.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/drivers/pci/access.c b/drivers/pci/access.c index ba91a7e1751..3af0478c057 100644 --- a/drivers/pci/access.c +++ b/drivers/pci/access.c @@ -469,3 +469,205 @@ void pci_cfg_access_unlock(struct pci_dev *dev) raw_spin_unlock_irqrestore(&pci_lock, flags); } EXPORT_SYMBOL_GPL(pci_cfg_access_unlock); + +static inline int pcie_cap_version(const struct pci_dev *dev) +{ + return dev->pcie_flags_reg & PCI_EXP_FLAGS_VERS; +} + +static inline bool pcie_cap_has_devctl(const struct pci_dev *dev) +{ + return true; +} + +static inline bool pcie_cap_has_lnkctl(const struct pci_dev *dev) +{ + int type = pci_pcie_type(dev); + + return pcie_cap_version(dev) > 1 || + type == PCI_EXP_TYPE_ROOT_PORT || + type == PCI_EXP_TYPE_ENDPOINT || + type == PCI_EXP_TYPE_LEG_END; +} + +static inline bool pcie_cap_has_sltctl(const struct pci_dev *dev) +{ + int type = pci_pcie_type(dev); + + return pcie_cap_version(dev) > 1 || + type == PCI_EXP_TYPE_ROOT_PORT || + (type == PCI_EXP_TYPE_DOWNSTREAM && + dev->pcie_flags_reg & PCI_EXP_FLAGS_SLOT); +} + +static inline bool pcie_cap_has_rtctl(const struct pci_dev *dev) +{ + int type = pci_pcie_type(dev); + + return pcie_cap_version(dev) > 1 || + type == PCI_EXP_TYPE_ROOT_PORT || + type == PCI_EXP_TYPE_RC_EC; +} + +static bool pcie_capability_reg_implemented(struct pci_dev *dev, int pos) +{ + if (!pci_is_pcie(dev)) + return false; + + switch (pos) { + case PCI_EXP_FLAGS_TYPE: + return true; + case PCI_EXP_DEVCAP: + case PCI_EXP_DEVCTL: + case PCI_EXP_DEVSTA: + return pcie_cap_has_devctl(dev); + case PCI_EXP_LNKCAP: + case PCI_EXP_LNKCTL: + case PCI_EXP_LNKSTA: + return pcie_cap_has_lnkctl(dev); + case PCI_EXP_SLTCAP: + case PCI_EXP_SLTCTL: + case PCI_EXP_SLTSTA: + return pcie_cap_has_sltctl(dev); + case PCI_EXP_RTCTL: + case PCI_EXP_RTCAP: + case PCI_EXP_RTSTA: + return pcie_cap_has_rtctl(dev); + case PCI_EXP_DEVCAP2: + case PCI_EXP_DEVCTL2: + case PCI_EXP_LNKCAP2: + case PCI_EXP_LNKCTL2: + case PCI_EXP_LNKSTA2: + return pcie_cap_version(dev) > 1; + default: + return false; + } +} + +/* + * Note that these accessor functions are only for the "PCI Express + * Capability" (see PCIe spec r3.0, sec 7.8). They do not apply to the + * other "PCI Express Extended Capabilities" (AER, VC, ACS, MFVC, etc.) + */ +int pcie_capability_read_word(struct pci_dev *dev, int pos, u16 *val) +{ + int ret; + + *val = 0; + if (pos & 1) + return -EINVAL; + + if (pcie_capability_reg_implemented(dev, pos)) { + ret = pci_read_config_word(dev, pci_pcie_cap(dev) + pos, val); + /* + * Reset *val to 0 if pci_read_config_word() fails, it may + * have been written as 0xFFFF if hardware error happens + * during pci_read_config_word(). + */ + if (ret) + *val = 0; + return ret; + } + + /* + * For Functions that do not implement the Slot Capabilities, + * Slot Status, and Slot Control registers, these spaces must + * be hardwired to 0b, with the exception of the Presence Detect + * State bit in the Slot Status register of Downstream Ports, + * which must be hardwired to 1b. (PCIe Base Spec 3.0, sec 7.8) + */ + if (pci_is_pcie(dev) && pos == PCI_EXP_SLTSTA && + pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM) { + *val = PCI_EXP_SLTSTA_PDS; + } + + return 0; +} +EXPORT_SYMBOL(pcie_capability_read_word); + +int pcie_capability_read_dword(struct pci_dev *dev, int pos, u32 *val) +{ + int ret; + + *val = 0; + if (pos & 3) + return -EINVAL; + + if (pcie_capability_reg_implemented(dev, pos)) { + ret = pci_read_config_dword(dev, pci_pcie_cap(dev) + pos, val); + /* + * Reset *val to 0 if pci_read_config_dword() fails, it may + * have been written as 0xFFFFFFFF if hardware error happens + * during pci_read_config_dword(). + */ + if (ret) + *val = 0; + return ret; + } + + if (pci_is_pcie(dev) && pos == PCI_EXP_SLTCTL && + pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM) { + *val = PCI_EXP_SLTSTA_PDS; + } + + return 0; +} +EXPORT_SYMBOL(pcie_capability_read_dword); + +int pcie_capability_write_word(struct pci_dev *dev, int pos, u16 val) +{ + if (pos & 1) + return -EINVAL; + + if (!pcie_capability_reg_implemented(dev, pos)) + return 0; + + return pci_write_config_word(dev, pci_pcie_cap(dev) + pos, val); +} +EXPORT_SYMBOL(pcie_capability_write_word); + +int pcie_capability_write_dword(struct pci_dev *dev, int pos, u32 val) +{ + if (pos & 3) + return -EINVAL; + + if (!pcie_capability_reg_implemented(dev, pos)) + return 0; + + return pci_write_config_dword(dev, pci_pcie_cap(dev) + pos, 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 ret; + u16 val; + + ret = pcie_capability_read_word(dev, pos, &val); + if (!ret) { + val &= ~clear; + val |= set; + ret = pcie_capability_write_word(dev, pos, val); + } + + return ret; +} +EXPORT_SYMBOL(pcie_capability_clear_and_set_word); + +int pcie_capability_clear_and_set_dword(struct pci_dev *dev, int pos, + u32 clear, u32 set) +{ + int ret; + u32 val; + + ret = pcie_capability_read_dword(dev, pos, &val); + if (!ret) { + val &= ~clear; + val |= set; + ret = pcie_capability_write_dword(dev, pos, val); + } + + return ret; +} +EXPORT_SYMBOL(pcie_capability_clear_and_set_dword); |