diff options
Diffstat (limited to 'drivers/pci/probe.c')
| -rw-r--r-- | drivers/pci/probe.c | 80 |
1 files changed, 52 insertions, 28 deletions
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 46ada5c098eb..eeb50bd62402 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -96,7 +96,7 @@ static void release_pcibus_dev(struct device *dev) static struct class pcibus_class = { .name = "pci_bus", .dev_release = &release_pcibus_dev, - .dev_attrs = pcibus_dev_attrs, + .dev_groups = pcibus_groups, }; static int __init pcibus_class_init(void) @@ -156,6 +156,8 @@ static inline unsigned long decode_bar(struct pci_dev *dev, u32 bar) return flags; } +#define PCI_COMMAND_DECODE_ENABLE (PCI_COMMAND_MEMORY | PCI_COMMAND_IO) + /** * pci_read_base - read a PCI BAR * @dev: the PCI device @@ -178,8 +180,10 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, /* No printks while decoding is disabled! */ if (!dev->mmio_always_on) { pci_read_config_word(dev, PCI_COMMAND, &orig_cmd); - pci_write_config_word(dev, PCI_COMMAND, - orig_cmd & ~(PCI_COMMAND_MEMORY | PCI_COMMAND_IO)); + if (orig_cmd & PCI_COMMAND_DECODE_ENABLE) { + pci_write_config_word(dev, PCI_COMMAND, + orig_cmd & ~PCI_COMMAND_DECODE_ENABLE); + } } res->name = pci_name(dev); @@ -293,7 +297,8 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, fail: res->flags = 0; out: - if (!dev->mmio_always_on) + if (!dev->mmio_always_on && + (orig_cmd & PCI_COMMAND_DECODE_ENABLE)) pci_write_config_word(dev, PCI_COMMAND, orig_cmd); if (bar_too_big) @@ -1491,24 +1496,23 @@ static int pcie_find_smpss(struct pci_dev *dev, void *data) if (!pci_is_pcie(dev)) return 0; - /* For PCIE hotplug enabled slots not connected directly to a - * PCI-E root port, there can be problems when hotplugging - * devices. This is due to the possibility of hotplugging a - * device into the fabric with a smaller MPS that the devices - * currently running have configured. Modifying the MPS on the - * running devices could cause a fatal bus error due to an - * incoming frame being larger than the newly configured MPS. - * To work around this, the MPS for the entire fabric must be - * set to the minimum size. Any devices hotplugged into this - * fabric will have the minimum MPS set. If the PCI hotplug - * slot is directly connected to the root port and there are not - * other devices on the fabric (which seems to be the most - * common case), then this is not an issue and MPS discovery - * will occur as normal. + /* + * We don't have a way to change MPS settings on devices that have + * drivers attached. A hot-added device might support only the minimum + * MPS setting (MPS=128). Therefore, if the fabric contains a bridge + * where devices may be hot-added, we limit the fabric MPS to 128 so + * hot-added devices will work correctly. + * + * However, if we hot-add a device to a slot directly below a Root + * Port, it's impossible for there to be other existing devices below + * the port. We don't limit the MPS in this case because we can + * reconfigure MPS on both the Root Port and the hot-added device, + * and there are no other devices involved. + * + * Note that this PCIE_BUS_SAFE path assumes no peer-to-peer DMA. */ - if (dev->is_hotplug_bridge && (!list_is_singular(&dev->bus->devices) || - (dev->bus->self && - pci_pcie_type(dev->bus->self) != PCI_EXP_TYPE_ROOT_PORT))) + if (dev->is_hotplug_bridge && + pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT) *smpss = 0; if (*smpss > dev->pcie_mpss) @@ -1583,6 +1587,22 @@ static void pcie_write_mrrs(struct pci_dev *dev) "with pci=pcie_bus_safe.\n"); } +static void pcie_bus_detect_mps(struct pci_dev *dev) +{ + struct pci_dev *bridge = dev->bus->self; + int mps, p_mps; + + if (!bridge) + return; + + mps = pcie_get_mps(dev); + p_mps = pcie_get_mps(bridge); + + if (mps != p_mps) + dev_warn(&dev->dev, "Max Payload Size %d, but upstream %s set to %d; if necessary, use \"pci=pcie_bus_safe\" and report a bug\n", + mps, pci_name(bridge), p_mps); +} + static int pcie_bus_configure_set(struct pci_dev *dev, void *data) { int mps, orig_mps; @@ -1590,13 +1610,18 @@ static int pcie_bus_configure_set(struct pci_dev *dev, void *data) if (!pci_is_pcie(dev)) return 0; + if (pcie_bus_config == PCIE_BUS_TUNE_OFF) { + pcie_bus_detect_mps(dev); + return 0; + } + mps = 128 << *(u8 *)data; orig_mps = pcie_get_mps(dev); pcie_write_mps(dev, mps); pcie_write_mrrs(dev); - dev_info(&dev->dev, "PCI-E Max Payload Size set to %4d/%4d (was %4d), " + dev_info(&dev->dev, "Max Payload Size set to %4d/%4d (was %4d), " "Max Read Rq %4d\n", pcie_get_mps(dev), 128 << dev->pcie_mpss, orig_mps, pcie_get_readrq(dev)); @@ -1607,25 +1632,25 @@ static int pcie_bus_configure_set(struct pci_dev *dev, void *data) * parents then children fashion. If this changes, then this code will not * work as designed. */ -void pcie_bus_configure_settings(struct pci_bus *bus, u8 mpss) +void pcie_bus_configure_settings(struct pci_bus *bus) { u8 smpss; - if (!pci_is_pcie(bus->self)) + if (!bus->self) return; - if (pcie_bus_config == PCIE_BUS_TUNE_OFF) + if (!pci_is_pcie(bus->self)) return; /* FIXME - Peer to peer DMA is possible, though the endpoint would need - * to be aware to the MPS of the destination. To work around this, + * to be aware of the MPS of the destination. To work around this, * simply force the MPS of the entire system to the smallest possible. */ if (pcie_bus_config == PCIE_BUS_PEER2PEER) smpss = 0; if (pcie_bus_config == PCIE_BUS_SAFE) { - smpss = mpss; + smpss = bus->self->pcie_mpss; pcie_find_smpss(bus->self, &smpss); pci_walk_bus(bus, pcie_find_smpss, &smpss); @@ -1979,7 +2004,6 @@ unsigned int __ref pci_rescan_bus(struct pci_bus *bus) max = pci_scan_child_bus(bus); pci_assign_unassigned_bus_resources(bus); - pci_enable_bridges(bus); pci_bus_add_devices(bus); return max; |