Use new PCI interfaces to simplify xen-pcifront implementation:
1) Use pci_create_root_bus() instead of pci_scan_bus_parented()
because pci_scan_bus_parented() is marked as __deprecated.This
also gets rid of a duplicated call of pci_bus_start_devices().
2) Use pci_stop_root_bus() and pci_remove_root_bus() instead of
open-coded private implementation.
3) Use pci_set_host_bridge_release() to release data structures
associated with PCI root buses.
4) Use pci_bus_get()/pci_bus_put() to manage PCI root bus reference
count.
This is also a preparation for coming PCI bus lock enhancement.
Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
Cc: linux-pci@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
drivers/pci/xen-pcifront.c | 81 ++++++++++++++++++++++------------------------
1 file changed, 39 insertions(+), 42 deletions(-)
diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c
index 816cf94..6aa2c0f 100644
--- a/drivers/pci/xen-pcifront.c
+++ b/drivers/pci/xen-pcifront.c
@@ -25,11 +25,6 @@
#define INVALID_GRANT_REF (0)
#define INVALID_EVTCHN (-1)
-struct pci_bus_entry {
- struct list_head list;
- struct pci_bus *bus;
-};
-
#define _PDEVB_op_active (0)
#define PDEVB_op_active (1 << (_PDEVB_op_active))
@@ -47,12 +42,12 @@ struct pcifront_device {
struct xen_pci_sharedinfo *sh_info;
struct work_struct op_work;
unsigned long flags;
-
};
struct pcifront_sd {
int domain;
struct pcifront_device *pdev;
+ struct resource busn_res;
};
static inline struct pcifront_device *
@@ -67,6 +62,12 @@ static inline void pcifront_init_sd(struct pcifront_sd *sd,
{
sd->domain = domain;
sd->pdev = pdev;
+
+ /* Xen pci-backend doesn't export P2P bridges */
+ sd->busn_res.start = bus;
+ sd->busn_res.end = bus;
+ sd->busn_res.flags = IORESOURCE_BUS;
+ sd->busn_res.name = "PCI busn";
}
static DEFINE_SPINLOCK(pcifront_dev_lock);
@@ -441,12 +442,19 @@ static int pcifront_scan_bus(struct pcifront_device *pdev,
return 0;
}
+static void pcifront_release_sd(struct pci_host_bridge *bridge)
+{
+ struct pcifront_sd *sd = bridge->release_data;
+
+ kfree(sd);
+}
+
static int pcifront_scan_root(struct pcifront_device *pdev,
unsigned int domain, unsigned int bus)
{
struct pci_bus *b;
struct pcifront_sd *sd = NULL;
- struct pci_bus_entry *bus_entry = NULL;
+ LIST_HEAD(resources);
int err = 0;
#ifndef CONFIG_PCI_DOMAINS
@@ -463,16 +471,18 @@ static int pcifront_scan_root(struct pcifront_device *pdev,
dev_info(&pdev->xdev->dev, "Creating PCI Frontend Bus %04x:%02x\n",
domain, bus);
- bus_entry = kmalloc(sizeof(*bus_entry), GFP_KERNEL);
- sd = kmalloc(sizeof(*sd), GFP_KERNEL);
- if (!bus_entry || !sd) {
+ sd = kzalloc(sizeof(*sd), GFP_KERNEL);
+ if (!sd) {
err = -ENOMEM;
goto err_out;
}
pcifront_init_sd(sd, domain, bus, pdev);
- b = pci_scan_bus_parented(&pdev->xdev->dev, bus,
- &pcifront_bus_ops, sd);
+ pci_add_resource(&resources, &ioport_resource);
+ pci_add_resource(&resources, &iomem_resource);
+ pci_add_resource(&resources, &sd->busn_res);
+ b = pci_create_root_bus(&pdev->xdev->dev, bus, &pcifront_bus_ops,
+ sd, &resources);
if (!b) {
dev_err(&pdev->xdev->dev,
"Error creating PCI Frontend Bus!\n");
@@ -480,12 +490,14 @@ static int pcifront_scan_root(struct pcifront_device *pdev,
goto err_out;
}
- bus_entry->bus = b;
+ pci_set_host_bridge_release(to_pci_host_bridge(b->bridge),
+ pcifront_release_sd, sd);
- list_add(&bus_entry->list, &pdev->root_buses);
-
- /* pci_scan_bus_parented skips devices which do not have a have
- * devfn==0. The pcifront_scan_bus enumerates all devfn. */
+ /*
+ * Every PCI physical device should have function 0, but that's not
+ * true for xen.
+ * So use pcifront_scan_bus() instead of pci_scan_child_bus().
+ */
err = pcifront_scan_bus(pdev, domain, bus, b);
/* Claim resources before going "live" with our devices */
@@ -497,7 +509,6 @@ static int pcifront_scan_root(struct pcifront_device *pdev,
return err;
err_out:
- kfree(bus_entry);
kfree(sd);
return err;
@@ -539,35 +550,19 @@ static int pcifront_rescan_root(struct pcifront_device *pdev,
return err;
}
-static void free_root_bus_devs(struct pci_bus *bus)
-{
- struct pci_dev *dev;
-
- while (!list_empty(&bus->devices)) {
- dev = container_of(bus->devices.next, struct pci_dev,
- bus_list);
- dev_dbg(&dev->dev, "removing device\n");
- pci_stop_and_remove_bus_device(dev);
- }
-}
-
static void pcifront_free_roots(struct pcifront_device *pdev)
{
- struct pci_bus_entry *bus_entry, *t;
+ struct pcifront_sd *sd;
+ struct pci_bus *bus;
dev_dbg(&pdev->xdev->dev, "cleaning up root buses\n");
- list_for_each_entry_safe(bus_entry, t, &pdev->root_buses, list) {
- list_del(&bus_entry->list);
-
- free_root_bus_devs(bus_entry->bus);
-
- kfree(bus_entry->bus->sysdata);
-
- device_unregister(bus_entry->bus->bridge);
- pci_remove_bus(bus_entry->bus);
-
- kfree(bus_entry);
+ for_each_pci_root_bus(bus) {
+ sd = bus->sysdata;
+ if (sd->pdev == pdev) {
+ pci_stop_root_bus(bus);
+ pci_remove_root_bus(bus);
+ }
}
}
@@ -670,6 +665,7 @@ static irqreturn_t pcifront_handler_aer(int irq, void *dev)
schedule_pcifront_aer_op(pdev);
return IRQ_HANDLED;
}
+
static int pcifront_connect_and_init_dma(struct pcifront_device *pdev)
{
int err = 0;
@@ -705,6 +701,7 @@ static void pcifront_disconnect(struct pcifront_device *pdev)
spin_unlock(&pcifront_dev_lock);
}
+
static struct pcifront_device *alloc_pdev(struct xenbus_device *xdev)
{
struct pcifront_device *pdev;
--
1.8.1.2
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