diff options
Diffstat (limited to 'drivers/pci/pcie')
| -rw-r--r-- | drivers/pci/pcie/ptm.c | 31 |
1 files changed, 29 insertions, 2 deletions
diff --git a/drivers/pci/pcie/ptm.c b/drivers/pci/pcie/ptm.c index a14ac94b96dc..bab8ac63c4f3 100644 --- a/drivers/pci/pcie/ptm.c +++ b/drivers/pci/pcie/ptm.c @@ -19,13 +19,29 @@ static void pci_ptm_info(struct pci_dev *dev) { - dev_info(&dev->dev, "PTM enabled%s\n", dev->ptm_root ? " (root)" : ""); + char clock_desc[8]; + + switch (dev->ptm_granularity) { + case 0: + snprintf(clock_desc, sizeof(clock_desc), "unknown"); + break; + case 255: + snprintf(clock_desc, sizeof(clock_desc), ">254ns"); + break; + default: + snprintf(clock_desc, sizeof(clock_desc), "%udns", + dev->ptm_granularity); + break; + } + dev_info(&dev->dev, "PTM enabled%s, %s granularity\n", + dev->ptm_root ? " (root)" : "", clock_desc); } void pci_ptm_init(struct pci_dev *dev) { int pos; u32 cap, ctrl; + u8 local_clock; struct pci_dev *ups; if (!pci_is_pcie(dev)) @@ -45,6 +61,7 @@ void pci_ptm_init(struct pci_dev *dev) return; pci_read_config_dword(dev, pos + PCI_PTM_CAP, &cap); + local_clock = (cap & PCI_PTM_GRANULARITY_MASK) >> 8; /* * There's no point in enabling PTM unless it's enabled in the @@ -55,14 +72,20 @@ void pci_ptm_init(struct pci_dev *dev) ups = pci_upstream_bridge(dev); if (ups && ups->ptm_enabled) { ctrl = PCI_PTM_CTRL_ENABLE; + if (ups->ptm_granularity == 0) + dev->ptm_granularity = 0; + else if (ups->ptm_granularity > local_clock) + dev->ptm_granularity = ups->ptm_granularity; } else { if (cap & PCI_PTM_CAP_ROOT) { ctrl = PCI_PTM_CTRL_ENABLE | PCI_PTM_CTRL_ROOT; dev->ptm_root = 1; + dev->ptm_granularity = local_clock; } else return; } + ctrl |= dev->ptm_granularity << 8; pci_write_config_dword(dev, pos + PCI_PTM_CTRL, ctrl); dev->ptm_enabled = 1; @@ -98,18 +121,22 @@ int pci_enable_ptm(struct pci_dev *dev, u8 *granularity) ups = pci_upstream_bridge(dev); if (!ups || !ups->ptm_enabled) return -EINVAL; + + dev->ptm_granularity = ups->ptm_granularity; } else if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) { + dev->ptm_granularity = 0; } else return -EINVAL; ctrl = PCI_PTM_CTRL_ENABLE; + ctrl |= dev->ptm_granularity << 8; pci_write_config_dword(dev, pos + PCI_PTM_CTRL, ctrl); dev->ptm_enabled = 1; pci_ptm_info(dev); if (granularity) - *granularity = 0; + *granularity = dev->ptm_granularity; return 0; } EXPORT_SYMBOL(pci_enable_ptm); |