diff options
Diffstat (limited to 'drivers/pci/pci.c')
| -rw-r--r-- | drivers/pci/pci.c | 200 |
1 files changed, 181 insertions, 19 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 42922dae29be..4edfa4f5f65e 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -796,7 +796,9 @@ static inline bool platform_pci_need_resume(struct pci_dev *dev) static inline bool platform_pci_bridge_d3(struct pci_dev *dev) { - return pci_platform_pm ? pci_platform_pm->bridge_d3(dev) : false; + if (pci_platform_pm && pci_platform_pm->bridge_d3) + return pci_platform_pm->bridge_d3(dev); + return false; } /** @@ -991,15 +993,11 @@ static void __pci_start_power_transition(struct pci_dev *dev, pci_power_t state) if (state == PCI_D0) { pci_platform_power_transition(dev, PCI_D0); /* - * Mandatory power management transition delays, see - * PCI Express Base Specification Revision 2.0 Section - * 6.6.1: Conventional Reset. Do not delay for - * devices powered on/off by corresponding bridge, - * because have already delayed for the bridge. + * Mandatory power management transition delays are handled in + * pci_pm_resume_noirq() and pci_pm_runtime_resume() of the + * corresponding bridge. */ if (dev->runtime_d3cold) { - if (dev->d3cold_delay && !dev->imm_ready) - msleep(dev->d3cold_delay); /* * When powering on a bridge from D3cold, the * whole hierarchy may be powered on into @@ -4573,14 +4571,17 @@ static int pci_pm_reset(struct pci_dev *dev, int probe) return pci_dev_wait(dev, "PM D3->D0", PCIE_RESET_READY_POLL_MS); } + /** - * pcie_wait_for_link - Wait until link is active or inactive + * pcie_wait_for_link_delay - Wait until link is active or inactive * @pdev: Bridge device * @active: waiting for active or inactive? + * @delay: Delay to wait after link has become active (in ms) * * Use this to wait till link becomes active or inactive. */ -bool pcie_wait_for_link(struct pci_dev *pdev, bool active) +static bool pcie_wait_for_link_delay(struct pci_dev *pdev, bool active, + int delay) { int timeout = 1000; bool ret; @@ -4588,10 +4589,10 @@ bool pcie_wait_for_link(struct pci_dev *pdev, bool active) /* * Some controllers might not implement link active reporting. In this - * case, we wait for 1000 + 100 ms. + * case, we wait for 1000 ms + any delay requested by the caller. */ if (!pdev->link_active_reporting) { - msleep(1100); + msleep(timeout + delay); return true; } @@ -4617,13 +4618,144 @@ bool pcie_wait_for_link(struct pci_dev *pdev, bool active) timeout -= 10; } if (active && ret) - msleep(100); + msleep(delay); else if (ret != active) pci_info(pdev, "Data Link Layer Link Active not %s in 1000 msec\n", active ? "set" : "cleared"); return ret == active; } +/** + * pcie_wait_for_link - Wait until link is active or inactive + * @pdev: Bridge device + * @active: waiting for active or inactive? + * + * Use this to wait till link becomes active or inactive. + */ +bool pcie_wait_for_link(struct pci_dev *pdev, bool active) +{ + return pcie_wait_for_link_delay(pdev, active, 100); +} + +/* + * Find maximum D3cold delay required by all the devices on the bus. The + * spec says 100 ms, but firmware can lower it and we allow drivers to + * increase it as well. + * + * Called with @pci_bus_sem locked for reading. + */ +static int pci_bus_max_d3cold_delay(const struct pci_bus *bus) +{ + const struct pci_dev *pdev; + int min_delay = 100; + int max_delay = 0; + + list_for_each_entry(pdev, &bus->devices, bus_list) { + if (pdev->d3cold_delay < min_delay) + min_delay = pdev->d3cold_delay; + if (pdev->d3cold_delay > max_delay) + max_delay = pdev->d3cold_delay; + } + + return max(min_delay, max_delay); +} + +/** + * pci_bridge_wait_for_secondary_bus - Wait for secondary bus to be accessible + * @dev: PCI bridge + * + * Handle necessary delays before access to the devices on the secondary + * side of the bridge are permitted after D3cold to D0 transition. + * + * For PCIe this means the delays in PCIe 5.0 section 6.6.1. For + * conventional PCI it means Tpvrh + Trhfa specified in PCI 3.0 section + * 4.3.2. + */ +void pci_bridge_wait_for_secondary_bus(struct pci_dev *dev) +{ + struct pci_dev *child; + int delay; + + if (pci_dev_is_disconnected(dev)) + return; + + if (!pci_is_bridge(dev) || !dev->bridge_d3) + return; + + down_read(&pci_bus_sem); + + /* + * We only deal with devices that are present currently on the bus. + * For any hot-added devices the access delay is handled in pciehp + * board_added(). In case of ACPI hotplug the firmware is expected + * to configure the devices before OS is notified. + */ + if (!dev->subordinate || list_empty(&dev->subordinate->devices)) { + up_read(&pci_bus_sem); + return; + } + + /* Take d3cold_delay requirements into account */ + delay = pci_bus_max_d3cold_delay(dev->subordinate); + if (!delay) { + up_read(&pci_bus_sem); + return; + } + + child = list_first_entry(&dev->subordinate->devices, struct pci_dev, + bus_list); + up_read(&pci_bus_sem); + + /* + * Conventional PCI and PCI-X we need to wait Tpvrh + Trhfa before + * accessing the device after reset (that is 1000 ms + 100 ms). In + * practice this should not be needed because we don't do power + * management for them (see pci_bridge_d3_possible()). + */ + if (!pci_is_pcie(dev)) { + pci_dbg(dev, "waiting %d ms for secondary bus\n", 1000 + delay); + msleep(1000 + delay); + return; + } + + /* + * For PCIe downstream and root ports that do not support speeds + * greater than 5 GT/s need to wait minimum 100 ms. For higher + * speeds (gen3) we need to wait first for the data link layer to + * become active. + * + * However, 100 ms is the minimum and the PCIe spec says the + * software must allow at least 1s before it can determine that the + * device that did not respond is a broken device. There is + * evidence that 100 ms is not always enough, for example certain + * Titan Ridge xHCI controller does not always respond to + * configuration requests if we only wait for 100 ms (see + * https://bugzilla.kernel.org/show_bug.cgi?id=203885). + * + * Therefore we wait for 100 ms and check for the device presence. + * If it is still not present give it an additional 100 ms. + */ + if (!pcie_downstream_port(dev)) + return; + + if (pcie_get_speed_cap(dev) <= PCIE_SPEED_5_0GT) { + pci_dbg(dev, "waiting %d ms for downstream link\n", delay); + msleep(delay); + } else { + pci_dbg(dev, "waiting %d ms for downstream link, after activation\n", + delay); + if (!pcie_wait_for_link_delay(dev, true, delay)) { + /* Did not train, no need to wait any further */ + return; + } + } + + if (!pci_device_is_present(child)) { + pci_dbg(child, "waiting additional %d ms to become accessible\n", delay); + msleep(delay); + } +} + void pci_reset_secondary_bus(struct pci_dev *dev) { u16 ctrl; @@ -5820,10 +5952,29 @@ int pci_set_vga_state(struct pci_dev *dev, bool decode, return 0; } +#ifdef CONFIG_ACPI +bool pci_pr3_present(struct pci_dev *pdev) +{ + struct acpi_device *adev; + + if (acpi_disabled) + return false; + + adev = ACPI_COMPANION(&pdev->dev); + if (!adev) + return false; + + return adev->power.flags.power_resources && + acpi_has_method(adev->handle, "_PR3"); +} +EXPORT_SYMBOL_GPL(pci_pr3_present); +#endif + /** * pci_add_dma_alias - Add a DMA devfn alias for a device * @dev: the PCI device for which alias is added - * @devfn: alias slot and function + * @devfn_from: alias slot and function + * @nr_devfns: number of subsequent devfns to alias * * This helper encodes an 8-bit devfn as a bit number in dma_alias_mask * which is used to program permissible bus-devfn source addresses for DMA @@ -5839,18 +5990,29 @@ int pci_set_vga_state(struct pci_dev *dev, bool decode, * cannot be left as a userspace activity). DMA aliases should therefore * be configured via quirks, such as the PCI fixup header quirk. */ -void pci_add_dma_alias(struct pci_dev *dev, u8 devfn) +void pci_add_dma_alias(struct pci_dev *dev, u8 devfn_from, unsigned nr_devfns) { + int devfn_to; + + nr_devfns = min(nr_devfns, (unsigned) MAX_NR_DEVFNS - devfn_from); + devfn_to = devfn_from + nr_devfns - 1; + if (!dev->dma_alias_mask) - dev->dma_alias_mask = bitmap_zalloc(U8_MAX, GFP_KERNEL); + dev->dma_alias_mask = bitmap_zalloc(MAX_NR_DEVFNS, GFP_KERNEL); if (!dev->dma_alias_mask) { pci_warn(dev, "Unable to allocate DMA alias mask\n"); return; } - set_bit(devfn, dev->dma_alias_mask); - pci_info(dev, "Enabling fixed DMA alias to %02x.%d\n", - PCI_SLOT(devfn), PCI_FUNC(devfn)); + bitmap_set(dev->dma_alias_mask, devfn_from, nr_devfns); + + if (nr_devfns == 1) + pci_info(dev, "Enabling fixed DMA alias to %02x.%d\n", + PCI_SLOT(devfn_from), PCI_FUNC(devfn_from)); + else if (nr_devfns > 1) + pci_info(dev, "Enabling fixed DMA alias for devfn range from %02x.%d to %02x.%d\n", + PCI_SLOT(devfn_from), PCI_FUNC(devfn_from), + PCI_SLOT(devfn_to), PCI_FUNC(devfn_to)); } bool pci_devs_are_dma_aliases(struct pci_dev *dev1, struct pci_dev *dev2) |