From: Jiang Liu <liuj97@gmail.com>
To: Bjorn Helgaas <bhelgaas@google.com>,
Don Dutile <ddutile@redhat.com>, Yinghai Lu <yinghai@kernel.org>,
Greg KH <gregkh@linuxfoundation.org>,
Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>,
Taku Izumi <izumi.taku@jp.fujitsu.com>,
"Rafael J . Wysocki" <rjw@sisk.pl>,
Yijing Wang <wangyijing@huawei.com>,
Xinwei Hu <huxinwei@huawei.com>,
linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
Jiang Liu <liuj97@gmail.com>
Subject: [RFC PATCH v1 09/22] PCI: enhance PCI probe logic to support PCI bus lock mechanism
Date: Wed, 8 Aug 2012 00:10:49 +0800 [thread overview]
Message-ID: <1344355862-2726-10-git-send-email-jiang.liu@huawei.com> (raw)
In-Reply-To: <1344355862-2726-1-git-send-email-jiang.liu@huawei.com>
This patch enhances PCI probe logic to support PCI bus lock mechanism.
Signed-off-by: Jiang Liu <liuj97@gmail.com>
---
drivers/pci/probe.c | 65 +++++++++++++++++++++++++++++++++++++++------------
1 file changed, 50 insertions(+), 15 deletions(-)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 1f64e8d..e6b40d0 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -460,6 +460,8 @@ static struct pci_bus * pci_alloc_bus(void)
b->max_bus_speed = PCI_SPEED_UNKNOWN;
b->cur_bus_speed = PCI_SPEED_UNKNOWN;
device_initialize(&b->dev);
+ atomic_set(&b->state,
+ PCI_BUS_STATE_INITIALIZED | PCI_BUS_STATE_LOCK);
}
return b;
}
@@ -753,14 +755,21 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max,
* However, we continue to descend down the hierarchy and
* scan remaining child buses.
*/
- child = pci_find_bus(pci_domain_nr(bus), secondary);
- if (!child) {
+ child = __pci_get_and_lock_bus(pci_domain_nr(bus), secondary,
+ PCI_BUS_STATE_MASK);
+ if (child) {
+ if (pci_bus_get_state(child) > PCI_BUS_STATE_WORKING) {
+ pci_unlock_and_put_bus(child);
+ goto out;
+ }
+ } else {
child = pci_add_new_bus(bus, dev, secondary);
if (!child)
goto out;
child->primary = primary;
pci_bus_insert_busn_res(child, secondary, subordinate);
child->bridge_ctl = bctl;
+ pci_bus_get(child);
}
cmax = pci_scan_child_bus(child);
@@ -792,12 +801,19 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max,
/* Prevent assigning a bus number that already exists.
* This can happen when a bridge is hot-plugged, so in
* this case we only re-scan this bus. */
- child = pci_find_bus(pci_domain_nr(bus), max+1);
- if (!child) {
+ child = __pci_get_and_lock_bus(pci_domain_nr(bus), secondary,
+ PCI_BUS_STATE_MASK);
+ if (child) {
+ if (pci_bus_get_state(child) > PCI_BUS_STATE_WORKING) {
+ pci_unlock_and_put_bus(child);
+ goto out;
+ }
+ } else {
child = pci_add_new_bus(bus, dev, ++max);
if (!child)
goto out;
pci_bus_insert_busn_res(child, max, 0xff);
+ pci_bus_get(child);
}
buses = (buses & 0xff000000)
| ((unsigned int)(child->primary) << 0)
@@ -896,6 +912,8 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max,
bus = bus->parent;
}
+ pci_unlock_and_put_bus(child);
+
out:
pci_write_config_word(dev, PCI_BRIDGE_CONTROL, bctl);
@@ -1605,11 +1623,14 @@ unsigned int __devinit pci_scan_child_bus(struct pci_bus *bus)
* After performing arch-dependent fixup of the bus, look behind
* all PCI-to-PCI bridges on this bus.
*/
- if (!bus->is_added) {
+ if (pci_bus_get_state(bus) < PCI_BUS_STATE_WORKING) {
dev_dbg(&bus->dev, "fixups for bus\n");
pcibios_fixup_bus(bus);
- if (pci_is_root_bus(bus))
+ if (pci_is_root_bus(bus)) {
+ pci_bus_change_state(bus, PCI_BUS_STATE_REGISTERED,
+ PCI_BUS_STATE_WORKING, false);
bus->is_added = 1;
+ }
}
for (pass=0; pass < 2; pass++)
@@ -1630,6 +1651,11 @@ unsigned int __devinit pci_scan_child_bus(struct pci_bus *bus)
return max;
}
+/*
+ * Create a PCI root bus and return with the new root bus locked.
+ * Caller needs to call pci_bus_unlock() to unlock the new root bus after
+ * scanning and configuring children under the new root bus.
+ */
struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
struct pci_ops *ops, void *sysdata, struct list_head *resources)
{
@@ -1716,6 +1742,9 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
list_add_tail(&b->node, &pci_root_buses);
up_write(&pci_bus_sem);
+ pci_bus_change_state(b, PCI_BUS_STATE_INITIALIZED,
+ PCI_BUS_STATE_REGISTERED, false);
+
return b;
class_dev_reg_err:
@@ -1724,7 +1753,7 @@ class_dev_reg_err:
bridge_dev_reg_err:
kfree(bridge);
err_out:
- kfree(b);
+ pci_unlock_and_put_bus(b);
return NULL;
}
@@ -1827,6 +1856,8 @@ struct pci_bus * __devinit pci_scan_root_bus(struct device *parent, int bus,
pci_bus_update_busn_res_end(b, max);
pci_bus_add_devices(b);
+ pci_bus_unlock(b);
+
return b;
}
EXPORT_SYMBOL(pci_scan_root_bus);
@@ -1842,10 +1873,12 @@ struct pci_bus * __devinit pci_scan_bus_parented(struct device *parent,
pci_add_resource(&resources, &iomem_resource);
pci_add_resource(&resources, &busn_resource);
b = pci_create_root_bus(parent, bus, ops, sysdata, &resources);
- if (b)
+ if (b) {
pci_scan_child_bus(b);
- else
+ pci_bus_unlock(b);
+ } else {
pci_free_resource_list(&resources);
+ }
return b;
}
EXPORT_SYMBOL(pci_scan_bus_parented);
@@ -1863,6 +1896,7 @@ struct pci_bus * __devinit pci_scan_bus(int bus, struct pci_ops *ops,
if (b) {
pci_scan_child_bus(b);
pci_bus_add_devices(b);
+ pci_bus_unlock(b);
} else {
pci_free_resource_list(&resources);
}
@@ -1884,14 +1918,15 @@ EXPORT_SYMBOL(pci_scan_bus);
*/
unsigned int __ref pci_rescan_bus_bridge_resize(struct pci_dev *bridge)
{
- unsigned int max;
+ unsigned int max = -1;
struct pci_bus *bus = bridge->subordinate;
- max = pci_scan_child_bus(bus);
-
- pci_assign_unassigned_bridge_resources(bridge);
-
- pci_bus_add_devices(bus);
+ if (pci_bus_lock_states(bus, PCI_BUS_STATE_WORKING) > 0) {
+ max = pci_scan_child_bus(bus);
+ pci_assign_unassigned_bridge_resources(bridge);
+ pci_bus_add_devices(bus);
+ pci_bus_unlock(bus);
+ }
return max;
}
--
1.7.9.5
next prev parent reply other threads:[~2012-08-07 16:10 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-07 16:10 [RFC PATCH v1 00/22] introduce PCI bus lock to serialize PCI hotplug operations Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 01/22] PCI: use pci_get_domain_bus_and_slot() to avoid race conditions Jiang Liu
2012-09-11 22:00 ` Bjorn Helgaas
2012-09-12 8:37 ` Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 02/22] PCI: trivial cleanups for drivers/pci/remove.c Jiang Liu
2012-09-11 22:03 ` Bjorn Helgaas
2012-09-12 8:50 ` Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 03/22] PCI: change PCI device management code to better follow device model Jiang Liu
2012-09-11 22:03 ` Bjorn Helgaas
2012-08-07 16:10 ` [RFC PATCH v1 04/22] PCI: split PCI bus device registration into two stages Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 05/22] PCI: introduce pci_bus_{get|put}() to manage PCI bus reference count Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 06/22] PCI: use a global lock to serialize PCI root bridge hotplug operations Jiang Liu
2012-09-11 22:57 ` Bjorn Helgaas
2012-09-12 15:42 ` Jiang Liu
2012-09-12 16:51 ` Bjorn Helgaas
2012-09-13 16:00 ` [PATCH 1/2] PCI: introduce root bridge hotplug safe interfaces to walk root buses Jiang Liu
2012-09-13 17:40 ` Bjorn Helgaas
2012-09-17 15:55 ` Jiang Liu
2012-09-17 16:24 ` Bjorn Helgaas
2012-09-18 21:39 ` Bjorn Helgaas
2012-09-21 16:07 ` [PATCH v4] PCI: introduce two interfaces to walk PCI buses Jiang Liu
2012-09-26 20:14 ` Bjorn Helgaas
2012-09-13 16:00 ` [PATCH 2/2] PCI: remove host bridge hotplug unsafe interface pci_get_next_bus() Jiang Liu
2012-09-17 15:51 ` [RFC PATCH v1 06/22] PCI: use a global lock to serialize PCI root bridge hotplug operations Jiang Liu
2012-09-20 18:49 ` Paul E. McKenney
2012-08-07 16:10 ` [RFC PATCH v1 07/22] PCI: introduce PCI bus lock to serialize PCI " Jiang Liu
2012-09-11 23:24 ` Bjorn Helgaas
2012-08-07 16:10 ` [RFC PATCH v1 08/22] PCI: introduce hotplug safe search interfaces for PCI bus/device Jiang Liu
2012-08-07 16:10 ` Jiang Liu [this message]
2012-08-07 16:10 ` [RFC PATCH v1 10/22] PCI: enhance PCI bus specific logic to support PCI bus lock mechanism Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 11/22] PCI: enhance PCI resource assignment " Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 12/22] PCI: enhance PCI remove " Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 13/22] PCI: make each PCI device hold a reference to its parent PCI bus Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 14/22] PCI/sysfs: use PCI bus lock to avoid race conditions Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 15/22] PCI/eeepc: " Jiang Liu
2012-09-11 23:18 ` Bjorn Helgaas
2012-09-12 14:24 ` [PATCH] eeepc-laptop: fix device reference count leakage in eeepc_rfkill_hotplug() Jiang Liu
2012-09-12 19:59 ` Bjorn Helgaas
2012-08-07 16:10 ` [RFC PATCH v1 16/22] PCI/asus-wmi: use PCI bus lock to avoid race conditions Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 17/22] PCI/pciehp: " Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 18/22] PCI/acpiphp: " Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 19/22] PCI/x86: enable PCI bus lock mechanism for x86 platforms Jiang Liu
2012-09-11 23:22 ` Bjorn Helgaas
2012-09-12 9:56 ` Jiang Liu
2012-08-07 16:11 ` [RFC PATCH v1 20/22] PCI/IA64: enable PCI bus lock mechanism for IA64 platforms Jiang Liu
2012-08-07 16:11 ` [RFC PATCH v1 21/22] PCI: cleanups for PCI bus lock implementation Jiang Liu
2012-09-11 23:21 ` Bjorn Helgaas
2012-09-12 8:58 ` Jiang Liu
2012-08-07 16:11 ` [RFC PATCH v1 22/22] PCI: unexport pci_root_buses Jiang Liu
2012-08-07 18:11 ` [RFC PATCH v1 00/22] introduce PCI bus lock to serialize PCI hotplug operations Don Dutile
2012-08-08 15:49 ` Jiang Liu
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