Hook Linux's PCI probe and remove callbacks

Hijack the pci_bus_type probe and remove callbacks.  This option only
requires modification to the Xen specific part of Linux.

Signed-off-by: Joshua LeVasseur <joshua.levasseur@netronome.com>

diff --git a/drivers/xen/core/Makefile b/drivers/xen/core/Makefile
index 25fdd462cdd29090eaa6ddc191c60a67e888a437..4291628b1747e4ebb84488648a8040248a0c4528 100644 (file)
--- a/drivers/xen/core/Makefile
+++ b/drivers/xen/core/Makefile
@@ -4,6 +4,7 @@
 
 obj-y := evtchn.o gnttab.o features.o reboot.o machine_reboot.o firmware.o
 
+obj-$(CONFIG_PCI)              += pci.o
 obj-$(CONFIG_PROC_FS)          += xen_proc.o
 obj-$(CONFIG_SYS_HYPERVISOR)   += hypervisor_sysfs.o
 obj-$(CONFIG_HOTPLUG_CPU)      += cpu_hotplug.o

diff --git a/drivers/xen/core/pci.c b/drivers/xen/core/pci.c
new file mode 100644 (file)
index 0000000..d693db1
--- /dev/null
+++ b/drivers/xen/core/pci.c
@@ -0,0 +1,61 @@
+/*
+ * vim:shiftwidth=8:noexpandtab
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <xen/interface/physdev.h>
+
+static int (*pci_bus_probe)(struct device *dev);
+static int (*pci_bus_remove)(struct device *dev);
+
+static int pci_bus_probe_wrapper(struct device *dev)
+{
+       int r;
+       struct pci_dev *pci_dev = to_pci_dev(dev);
+       struct physdev_manage_pci manage_pci;
+       manage_pci.bus = pci_dev->bus->number;
+       manage_pci.devfn = pci_dev->devfn;
+
+       r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add, &manage_pci);
+       if (r)
+               return r;
+
+       r = pci_bus_probe(dev);
+       if (r)
+               HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_remove, &manage_pci);
+
+       return r;
+}
+
+static int pci_bus_remove_wrapper(struct device *dev)
+{
+       int r;
+       struct pci_dev *pci_dev = to_pci_dev(dev);
+       struct physdev_manage_pci manage_pci;
+       manage_pci.bus = pci_dev->bus->number;
+       manage_pci.devfn = pci_dev->devfn;
+
+       r = pci_bus_remove(dev);
+       /* dev and pci_dev are no longer valid!! */
+
+       HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_remove, &manage_pci);
+       return r;
+}
+
+static int __init hook_pci_bus(void)
+{
+       if (!is_running_on_xen() || !is_initial_xendomain())
+               return 0;
+
+       pci_bus_probe = pci_bus_type.probe;
+       pci_bus_type.probe = pci_bus_probe_wrapper;
+
+       pci_bus_remove = pci_bus_type.remove;
+       pci_bus_type.remove = pci_bus_remove_wrapper;
+
+       return 0;
+}
+
+core_initcall(hook_pci_bus);