[RFC PATCH v1 17/22] PCI/pciehp: use PCI bus lock to avoid race conditions
From: Jiang Liu <hidden>
Date: 2012-08-07 16:21:10
Also in:
lkml
Subsystem:
pci subsystem, the rest · Maintainers:
Bjorn Helgaas, Linus Torvalds
This patch uses PCI bus lock mechanism to avoid race conditions when doing PCI device hotplug by pciehp driver. Signed-off-by: Jiang Liu <redacted> --- drivers/pci/hotplug/pciehp_pci.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)
diff --git a/drivers/pci/hotplug/pciehp_pci.c b/drivers/pci/hotplug/pciehp_pci.c
index 09cecaf..9536a9e 100644
--- a/drivers/pci/hotplug/pciehp_pci.c
+++ b/drivers/pci/hotplug/pciehp_pci.c@@ -42,18 +42,25 @@ int pciehp_configure_device(struct slot *p_slot) int num, fn; struct controller *ctrl = p_slot->ctrl; + if (pci_bus_lock_states(parent, PCI_BUS_STATE_WORKING) < 0) { + ctrl_dbg(ctrl, "Port has been removed\n"); + return -EINVAL; + } + dev = pci_get_slot(parent, PCI_DEVFN(0, 0)); if (dev) { ctrl_err(ctrl, "Device %s already exists " "at %04x:%02x:00, cannot hot-add\n", pci_name(dev), pci_domain_nr(parent), parent->number); pci_dev_put(dev); + pci_bus_unlock(parent); return -EINVAL; } num = pci_scan_slot(parent, PCI_DEVFN(0, 0)); if (num == 0) { ctrl_err(ctrl, "No new device found\n"); + pci_bus_unlock(parent); return -ENODEV; }
@@ -82,6 +89,7 @@ int pciehp_configure_device(struct slot *p_slot) } pci_bus_add_devices(parent); + pci_bus_unlock(parent); return 0; }
@@ -96,6 +104,11 @@ int pciehp_unconfigure_device(struct slot *p_slot) u16 command; struct controller *ctrl = p_slot->ctrl; + if (pci_bus_lock_states(parent, PCI_BUS_STATE_WORKING) < 0) { + ctrl_dbg(ctrl, "Port has been removed\n"); + return -EINVAL; + } + ctrl_dbg(ctrl, "%s: domain:bus:dev = %04x:%02x:00\n", __func__, pci_domain_nr(parent), parent->number); ret = pciehp_get_adapter_status(p_slot, &presence);
@@ -131,5 +144,7 @@ int pciehp_unconfigure_device(struct slot *p_slot) pci_dev_put(temp); } + pci_bus_unlock(parent); + return rc; }
--
1.7.9.5