Commit 928bea96 authored by Yinghai Lu's avatar Yinghai Lu Committed by Bjorn Helgaas
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PCI: Delay enabling bridges until they're needed



We currently enable PCI bridges after scanning a bus and assigning
resources.  This is often done in arch code.

This patch changes this so we don't enable a bridge until necessary, i.e.,
until we enable a PCI device behind the bridge.  We do this in the generic
pci_enable_device() path, so this also removes the arch-specific code to
enable bridges.

[bhelgaas: changelog]
Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent 55ed83a6
......@@ -525,11 +525,6 @@ void pci_common_init_dev(struct device *parent, struct hw_pci *hw)
* Assign resources.
*/
pci_bus_assign_resources(bus);
/*
* Enable bridges
*/
pci_enable_bridges(bus);
}
/*
......
......@@ -319,7 +319,6 @@ static int __init mcf_pci_init(void)
pci_fixup_irqs(pci_common_swizzle, mcf_pci_map_irq);
pci_bus_size_bridges(rootbus);
pci_bus_assign_resources(rootbus);
pci_enable_bridges(rootbus);
return 0;
}
......
......@@ -113,7 +113,6 @@ static void pcibios_scanbus(struct pci_controller *hose)
if (!pci_has_flag(PCI_PROBE_ONLY)) {
pci_bus_size_bridges(bus);
pci_bus_assign_resources(bus);
pci_enable_bridges(bus);
}
}
}
......
......@@ -69,7 +69,6 @@ static void pcibios_scanbus(struct pci_channel *hose)
pci_bus_size_bridges(bus);
pci_bus_assign_resources(bus);
pci_enable_bridges(bus);
} else {
pci_free_resource_list(&resources);
}
......
......@@ -527,9 +527,6 @@ static int acpi_pci_root_add(struct acpi_device *device,
if (system_state != SYSTEM_BOOTING) {
pcibios_resource_survey_bus(root->bus);
pci_assign_unassigned_bus_resources(root->bus);
/* need to after hot-added ioapic is registered */
pci_enable_bridges(root->bus);
}
pci_bus_add_devices(root->bus);
......
......@@ -1590,7 +1590,6 @@ lba_driver_probe(struct parisc_device *dev)
lba_dump_res(&lba_dev->hba.lmmio_space, 2);
#endif
}
pci_enable_bridges(lba_bus);
/*
** Once PCI register ops has walked the bus, access to config
......
......@@ -216,24 +216,6 @@ void pci_bus_add_devices(const struct pci_bus *bus)
}
}
void pci_enable_bridges(struct pci_bus *bus)
{
struct pci_dev *dev;
int retval;
list_for_each_entry(dev, &bus->devices, bus_list) {
if (dev->subordinate) {
if (!pci_is_enabled(dev)) {
retval = pci_enable_device(dev);
if (retval)
dev_err(&dev->dev, "Error enabling bridge (%d), continuing\n", retval);
pci_set_master(dev);
}
pci_enable_bridges(dev->subordinate);
}
}
}
/** pci_walk_bus - walk devices on/under bus, calling callback.
* @top bus whose devices should be walked
* @cb callback to be called for each device found
......@@ -301,4 +283,3 @@ EXPORT_SYMBOL(pci_bus_put);
EXPORT_SYMBOL(pci_bus_alloc_resource);
EXPORT_SYMBOL_GPL(pci_bus_add_device);
EXPORT_SYMBOL(pci_bus_add_devices);
EXPORT_SYMBOL(pci_enable_bridges);
......@@ -723,7 +723,6 @@ static int __ref enable_device(struct acpiphp_slot *slot)
acpiphp_sanitize_bus(bus);
acpiphp_set_hpp_values(bus);
acpiphp_set_acpi_region(slot);
pci_enable_bridges(bus);
list_for_each_entry(dev, &bus->devices, bus_list) {
/* Assume that newly added devices are powered on already. */
......
......@@ -1145,6 +1145,24 @@ int pci_reenable_device(struct pci_dev *dev)
return 0;
}
static void pci_enable_bridge(struct pci_dev *dev)
{
int retval;
if (!dev)
return;
pci_enable_bridge(dev->bus->self);
if (pci_is_enabled(dev))
return;
retval = pci_enable_device(dev);
if (retval)
dev_err(&dev->dev, "Error enabling bridge (%d), continuing\n",
retval);
pci_set_master(dev);
}
static int pci_enable_device_flags(struct pci_dev *dev, unsigned long flags)
{
int err;
......@@ -1165,6 +1183,8 @@ static int pci_enable_device_flags(struct pci_dev *dev, unsigned long flags)
if (atomic_inc_return(&dev->enable_cnt) > 1)
return 0; /* already enabled */
pci_enable_bridge(dev->bus->self);
/* only skip sriov related */
for (i = 0; i <= PCI_ROM_RESOURCE; i++)
if (dev->resource[i].flags & flags)
......
......@@ -1979,7 +1979,6 @@ 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;
......
......@@ -1440,7 +1440,7 @@ pci_assign_unassigned_root_bus_resources(struct pci_bus *bus)
/* any device complain? */
if (list_empty(&fail_head))
goto enable_and_dump;
goto dump;
if (tried_times >= pci_try_num) {
if (enable_local == undefined)
......@@ -1449,7 +1449,7 @@ pci_assign_unassigned_root_bus_resources(struct pci_bus *bus)
dev_info(&bus->dev, "Automatically enabled pci realloc, if you have problem, try booting with pci=realloc=off\n");
free_list(&fail_head);
goto enable_and_dump;
goto dump;
}
dev_printk(KERN_DEBUG, &bus->dev,
......@@ -1482,10 +1482,7 @@ pci_assign_unassigned_root_bus_resources(struct pci_bus *bus)
goto again;
enable_and_dump:
/* Depth last, update the hardware. */
pci_enable_bridges(bus);
dump:
/* dump the resource on buses */
pci_bus_dump_resources(bus);
}
......@@ -1556,7 +1553,6 @@ void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge)
if (retval)
dev_err(&bridge->dev, "Error reenabling bridge (%d)\n", retval);
pci_set_master(bridge);
pci_enable_bridges(parent);
}
EXPORT_SYMBOL_GPL(pci_assign_unassigned_bridge_resources);
......
......@@ -91,7 +91,6 @@ int __ref cb_alloc(struct pcmcia_socket *s)
if (s->tune_bridge)
s->tune_bridge(s, bus);
pci_enable_bridges(bus);
pci_bus_add_devices(bus);
return 0;
......
......@@ -1043,7 +1043,6 @@ int __must_check pci_bus_alloc_resource(struct pci_bus *bus,
resource_size_t,
resource_size_t),
void *alignf_data);
void pci_enable_bridges(struct pci_bus *bus);
/* Proper probing supporting hot-pluggable devices */
int __must_check __pci_register_driver(struct pci_driver *, struct module *,
......
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