Added function to gather the speed cap for a device and return a mask to supported speeds. The function is divided into an interface and a weak implementation so that architecture-specific functions can be called.
This is the first step in moving function drm_pcie_get_speed_cap_mask from the drm subsystem to the pci one.
Signed-off-by: Lucas Kannebley Tavares lucaskt@linux.vnet.ibm.com --- drivers/pci/pci.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 6 ++++++ 2 files changed, 50 insertions(+), 0 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index b099e00..d94ab79 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3931,6 +3931,50 @@ static int __init pci_setup(char *str) } early_param("pci", pci_setup);
+int __weak pcibios_get_speed_cap_mask(struct pci_dev *dev, u32 *mask) +{ + struct pci_dev *root; + u32 lnkcap, lnkcap2; + + *mask = 0; + if (!dev) + return -EINVAL; + + root = dev->bus->self; + + /* we've been informed via and serverworks don't make the cut */ + if (root->vendor == PCI_VENDOR_ID_VIA || + root->vendor == PCI_VENDOR_ID_SERVERWORKS) + return -EINVAL; + + pcie_capability_read_dword(root, PCI_EXP_LNKCAP, &lnkcap); + pcie_capability_read_dword(root, PCI_EXP_LNKCAP2, &lnkcap2); + + if (lnkcap2) { /* PCIe r3.0-compliant */ + if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_2_5GB) + *mask |= PCIE_SPEED_25; + if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_5_0GB) + *mask |= PCIE_SPEED_50; + if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_8_0GB) + *mask |= PCIE_SPEED_80; + } else { /* pre-r3.0 */ + if (lnkcap & PCI_EXP_LNKCAP_SLS_2_5GB) + *mask |= PCIE_SPEED_25; + if (lnkcap & PCI_EXP_LNKCAP_SLS_5_0GB) + *mask |= (PCIE_SPEED_25 | PCIE_SPEED_50); + } + + dev_info(&dev->dev, "probing gen 2 caps for device %x:%x = %x/%x\n", + root->vendor, root->device, lnkcap, lnkcap2); + return 0; +} + +int pcie_get_speed_cap_mask(struct pci_dev *dev, u32 *mask) +{ + return pcibios_get_speed_cap_mask(dev, mask); +} +EXPORT_SYMBOL(pcie_get_speed_cap_mask); + EXPORT_SYMBOL(pci_reenable_device); EXPORT_SYMBOL(pci_enable_device_io); EXPORT_SYMBOL(pci_enable_device_mem); diff --git a/include/linux/pci.h b/include/linux/pci.h index 2461033a..24a2f63 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1861,4 +1861,10 @@ static inline struct eeh_dev *pci_dev_to_eeh_dev(struct pci_dev *pdev) */ struct pci_dev *pci_find_upstream_pcie_bridge(struct pci_dev *pdev);
+#define PCIE_SPEED_25 1 +#define PCIE_SPEED_50 2 +#define PCIE_SPEED_80 4 + +extern int pcie_get_speed_cap_mask(struct pci_dev *dev, u32 *speed_mask); + #endif /* LINUX_PCI_H */