diff options
| -rw-r--r-- | drivers/pci/pci.c | 58 | ||||
| -rw-r--r-- | drivers/pci/pci.h | 1 | ||||
| -rw-r--r-- | drivers/pci/probe.c | 3 | ||||
| -rw-r--r-- | include/linux/pci.h | 10 | ||||
| -rw-r--r-- | include/uapi/linux/pci_regs.h | 1 |
5 files changed, 56 insertions, 17 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 7d85c04fbba2..3d67e8b50ba2 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -6189,38 +6189,64 @@ u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev, EXPORT_SYMBOL(pcie_bandwidth_available); /** - * pcie_get_speed_cap - query for the PCI device's link speed capability + * pcie_get_supported_speeds - query Supported Link Speed Vector * @dev: PCI device to query * - * Query the PCI device speed capability. Return the maximum link speed - * supported by the device. + * Query @dev supported link speeds. + * + * Implementation Note in PCIe r6.0 sec 7.5.3.18 recommends determining + * supported link speeds using the Supported Link Speeds Vector in the Link + * Capabilities 2 Register (when available). + * + * Link Capabilities 2 was added in PCIe r3.0, sec 7.8.18. + * + * Without Link Capabilities 2, i.e., prior to PCIe r3.0, Supported Link + * Speeds field in Link Capabilities is used and only 2.5 GT/s and 5.0 GT/s + * speeds were defined. + * + * For @dev without Supported Link Speed Vector, the field is synthesized + * from the Max Link Speed field in the Link Capabilities Register. + * + * Return: Supported Link Speeds Vector (+ reserved 0 at LSB). */ -enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev) +u8 pcie_get_supported_speeds(struct pci_dev *dev) { u32 lnkcap2, lnkcap; + u8 speeds; /* - * Link Capabilities 2 was added in PCIe r3.0, sec 7.8.18. The - * implementation note there recommends using the Supported Link - * Speeds Vector in Link Capabilities 2 when supported. - * - * Without Link Capabilities 2, i.e., prior to PCIe r3.0, software - * should use the Supported Link Speeds field in Link Capabilities, - * where only 2.5 GT/s and 5.0 GT/s speeds were defined. + * Speeds retain the reserved 0 at LSB before PCIe Supported Link + * Speeds Vector to allow using SLS Vector bit defines directly. */ pcie_capability_read_dword(dev, PCI_EXP_LNKCAP2, &lnkcap2); + speeds = lnkcap2 & PCI_EXP_LNKCAP2_SLS; /* PCIe r3.0-compliant */ - if (lnkcap2) - return PCIE_LNKCAP2_SLS2SPEED(lnkcap2); + if (speeds) + return speeds; pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap); + + /* Synthesize from the Max Link Speed field */ if ((lnkcap & PCI_EXP_LNKCAP_SLS) == PCI_EXP_LNKCAP_SLS_5_0GB) - return PCIE_SPEED_5_0GT; + speeds = PCI_EXP_LNKCAP2_SLS_5_0GB | PCI_EXP_LNKCAP2_SLS_2_5GB; else if ((lnkcap & PCI_EXP_LNKCAP_SLS) == PCI_EXP_LNKCAP_SLS_2_5GB) - return PCIE_SPEED_2_5GT; + speeds = PCI_EXP_LNKCAP2_SLS_2_5GB; - return PCI_SPEED_UNKNOWN; + return speeds; +} + +/** + * pcie_get_speed_cap - query for the PCI device's link speed capability + * @dev: PCI device to query + * + * Query the PCI device speed capability. + * + * Return: the maximum link speed supported by the device. + */ +enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev) +{ + return PCIE_LNKCAP2_SLS2SPEED(dev->supported_speeds); } EXPORT_SYMBOL(pcie_get_speed_cap); diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 14d00ce45bfa..d0a46ecf7289 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -373,6 +373,7 @@ static inline int pcie_dev_speed_mbps(enum pci_bus_speed speed) return -EINVAL; } +u8 pcie_get_supported_speeds(struct pci_dev *dev); const char *pci_speed_string(enum pci_bus_speed speed); enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev); enum pcie_link_width pcie_get_width_cap(struct pci_dev *dev); diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 4f68414c3086..af153a8e8225 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1947,6 +1947,9 @@ int pci_setup_device(struct pci_dev *dev) set_pcie_untrusted(dev); + if (pci_is_pcie(dev)) + dev->supported_speeds = pcie_get_supported_speeds(dev); + /* "Unknown power state" */ dev->current_state = PCI_UNKNOWN; diff --git a/include/linux/pci.h b/include/linux/pci.h index be5ed534c39c..99c6fa30d25b 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -318,7 +318,14 @@ struct pci_sriov; struct pci_p2pdma; struct rcec_ea; -/* The pci_dev structure describes PCI devices */ +/* struct pci_dev - describes a PCI device + * + * @supported_speeds: PCIe Supported Link Speeds Vector (+ reserved 0 at + * LSB). 0 when the supported speeds cannot be + * determined (e.g., for Root Complex Integrated + * Endpoints without the relevant Capability + * Registers). + */ struct pci_dev { struct list_head bus_list; /* Node in per-bus list */ struct pci_bus *bus; /* Bus this device is on */ @@ -522,6 +529,7 @@ struct pci_dev { struct npem *npem; /* Native PCIe Enclosure Management */ #endif u16 acs_cap; /* ACS Capability offset */ + u8 supported_speeds; /* Supported Link Speeds Vector */ phys_addr_t rom; /* Physical address if not from BAR */ size_t romlen; /* Length if not from BAR */ /* diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h index 12323b3334a9..f3c9de0a497c 100644 --- a/include/uapi/linux/pci_regs.h +++ b/include/uapi/linux/pci_regs.h @@ -678,6 +678,7 @@ #define PCI_EXP_DEVSTA2 0x2a /* Device Status 2 */ #define PCI_CAP_EXP_RC_ENDPOINT_SIZEOF_V2 0x2c /* end of v2 EPs w/o link */ #define PCI_EXP_LNKCAP2 0x2c /* Link Capabilities 2 */ +#define PCI_EXP_LNKCAP2_SLS 0x000000fe /* Supported Link Speeds Vector */ #define PCI_EXP_LNKCAP2_SLS_2_5GB 0x00000002 /* Supported Speed 2.5GT/s */ #define PCI_EXP_LNKCAP2_SLS_5_0GB 0x00000004 /* Supported Speed 5GT/s */ #define PCI_EXP_LNKCAP2_SLS_8_0GB 0x00000008 /* Supported Speed 8GT/s */ |