diff options
Diffstat (limited to 'drivers/pci/pci.c')
| -rw-r--r-- | drivers/pci/pci.c | 115 |
1 files changed, 95 insertions, 20 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index af0cc3456dc1..b0002daa50f3 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -52,6 +52,7 @@ static void pci_pme_list_scan(struct work_struct *work); static LIST_HEAD(pci_pme_list); static DEFINE_MUTEX(pci_pme_list_mutex); static DECLARE_DELAYED_WORK(pci_pme_work, pci_pme_list_scan); +static DEFINE_MUTEX(pci_bridge_mutex); struct pci_pme_device { struct list_head list; @@ -514,7 +515,7 @@ EXPORT_SYMBOL(pci_find_resource); */ struct pci_dev *pci_find_pcie_root_port(struct pci_dev *dev) { - struct pci_dev *bridge, *highest_pcie_bridge = NULL; + struct pci_dev *bridge, *highest_pcie_bridge = dev; bridge = pci_upstream_bridge(dev); while (bridge && pci_is_pcie(bridge)) { @@ -892,7 +893,9 @@ EXPORT_SYMBOL_GPL(__pci_complete_power_transition); * -EINVAL if the requested state is invalid. * -EIO if device does not support PCI PM or its PM capabilities register has a * wrong version, or device doesn't support the requested state. + * 0 if the transition is to D1 or D2 but D1 and D2 are not supported. * 0 if device already is in the requested state. + * 0 if the transition is to D3 but D3 is not supported. * 0 if device's power state has been successfully changed. */ int pci_set_power_state(struct pci_dev *dev, pci_power_t state) @@ -1348,10 +1351,16 @@ static void pci_enable_bridge(struct pci_dev *dev) if (bridge) pci_enable_bridge(bridge); + /* + * Hold pci_bridge_mutex to prevent a race when enabling two + * devices below the bridge simultaneously. The race may cause a + * PCI_COMMAND_MEMORY update to be lost (see changelog). + */ + mutex_lock(&pci_bridge_mutex); if (pci_is_enabled(dev)) { if (!dev->is_busmaster) pci_set_master(dev); - return; + goto end; } retval = pci_enable_device(dev); @@ -1359,6 +1368,8 @@ static void pci_enable_bridge(struct pci_dev *dev) dev_err(&dev->dev, "Error enabling bridge (%d), continuing\n", retval); pci_set_master(dev); +end: + mutex_unlock(&pci_bridge_mutex); } static int pci_enable_device_flags(struct pci_dev *dev, unsigned long flags) @@ -1383,7 +1394,7 @@ static int pci_enable_device_flags(struct pci_dev *dev, unsigned long flags) return 0; /* already enabled */ bridge = pci_upstream_bridge(dev); - if (bridge) + if (bridge && !pci_is_enabled(bridge)) pci_enable_bridge(bridge); /* only skip sriov related */ @@ -1912,6 +1923,13 @@ int pci_enable_wake(struct pci_dev *dev, pci_power_t state, bool enable) { int ret = 0; + /* + * Bridges can only signal wakeup on behalf of subordinate devices, + * but that is set up elsewhere, so skip them. + */ + if (pci_has_subordinate(dev)) + return 0; + /* Don't do the same thing twice in a row for one device. */ if (!!enable == !!dev->wakeup_prepared) return 0; @@ -3811,27 +3829,49 @@ int pci_wait_for_pending_transaction(struct pci_dev *dev) } EXPORT_SYMBOL(pci_wait_for_pending_transaction); -/* - * We should only need to wait 100ms after FLR, but some devices take longer. - * Wait for up to 1000ms for config space to return something other than -1. - * Intel IGD requires this when an LCD panel is attached. We read the 2nd - * dword because VFs don't implement the 1st dword. - */ static void pci_flr_wait(struct pci_dev *dev) { - int i = 0; + int delay = 1, timeout = 60000; u32 id; - do { - msleep(100); + /* + * Per PCIe r3.1, sec 6.6.2, a device must complete an FLR within + * 100ms, but may silently discard requests while the FLR is in + * progress. Wait 100ms before trying to access the device. + */ + msleep(100); + + /* + * After 100ms, the device should not silently discard config + * requests, but it may still indicate that it needs more time by + * responding to them with CRS completions. The Root Port will + * generally synthesize ~0 data to complete the read (except when + * CRS SV is enabled and the read was for the Vendor ID; in that + * case it synthesizes 0x0001 data). + * + * Wait for the device to return a non-CRS completion. Read the + * Command register instead of Vendor ID so we don't have to + * contend with the CRS SV value. + */ + pci_read_config_dword(dev, PCI_COMMAND, &id); + while (id == ~0) { + if (delay > timeout) { + dev_warn(&dev->dev, "not ready %dms after FLR; giving up\n", + 100 + delay - 1); + return; + } + + if (delay > 1000) + dev_info(&dev->dev, "not ready %dms after FLR; waiting\n", + 100 + delay - 1); + + msleep(delay); + delay *= 2; pci_read_config_dword(dev, PCI_COMMAND, &id); - } while (i++ < 10 && id == ~0); + } - if (id == ~0) - dev_warn(&dev->dev, "Failed to return from FLR\n"); - else if (i > 1) - dev_info(&dev->dev, "Required additional %dms to return from FLR\n", - (i - 1) * 100); + if (delay > 1000) + dev_info(&dev->dev, "ready %dms after FLR\n", 100 + delay - 1); } /** @@ -4260,6 +4300,41 @@ int pci_reset_function(struct pci_dev *dev) EXPORT_SYMBOL_GPL(pci_reset_function); /** + * pci_reset_function_locked - quiesce and reset a PCI device function + * @dev: PCI device to reset + * + * Some devices allow an individual function to be reset without affecting + * other functions in the same device. The PCI device must be responsive + * to PCI config space in order to use this function. + * + * This function does not just reset the PCI portion of a device, but + * clears all the state associated with the device. This function differs + * from __pci_reset_function() in that it saves and restores device state + * over the reset. It also differs from pci_reset_function() in that it + * requires the PCI device lock to be held. + * + * Returns 0 if the device function was successfully reset or negative if the + * device doesn't support resetting a single function. + */ +int pci_reset_function_locked(struct pci_dev *dev) +{ + int rc; + + rc = pci_probe_reset_function(dev); + if (rc) + return rc; + + pci_dev_save_and_disable(dev); + + rc = __pci_reset_function_locked(dev); + + pci_dev_restore(dev); + + return rc; +} +EXPORT_SYMBOL_GPL(pci_reset_function_locked); + +/** * pci_try_reset_function - quiesce and reset a PCI device function * @dev: PCI device to reset * @@ -5363,8 +5438,8 @@ static int of_pci_bus_find_domain_nr(struct device *parent) use_dt_domains = 0; domain = pci_get_new_domain_nr(); } else { - dev_err(parent, "Node %s has inconsistent \"linux,pci-domain\" property in DT\n", - parent->of_node->full_name); + dev_err(parent, "Node %pOF has inconsistent \"linux,pci-domain\" property in DT\n", + parent->of_node); domain = -1; } |