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)
return flags;
}
+#define PCI_COMMAND_DECODE_ENABLE (PCI_COMMAND_MEMORY | PCI_COMMAND_IO)
+
/**
* pci_read_base - read a PCI BAR
* @dev: the PCI device
/* 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);
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)
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)
"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;
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));
* 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);
max = pci_scan_child_bus(bus);
pci_assign_unassigned_bus_resources(bus);
- pci_enable_bridges(bus);
pci_bus_add_devices(bus);
return max;
projects / karo-tx-linux.git / blobdiff