[PATCH v2 10/30] PCI: Introduce pci_host_bridge_list to manage host bridges

Yijing Wang
2015-01-21T02:39:50Z

Introduce pci_host_bridge_list to manage pci host
bridges in system, so we could detect whether
the host in domain:bus is alreay registered.
Then we could remove bus alreay exist test in
__pci_create_root_bus().

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
---
drivers/pci/host-bridge.c | 24 +++++++++++++++++++++++-
drivers/pci/probe.c | 8 +-------
include/linux/pci.h | 1 +
3 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c
index 8897581..0de21d5 100644
--- a/drivers/pci/host-bridge.c
+++ b/drivers/pci/host-bridge.c
@@ -8,6 +8,9 @@

#include "pci.h"

+static LIST_HEAD(pci_host_bridge_list);
+static DEFINE_MUTEX(phb_mutex);
+
static void pci_release_host_bridge_dev(struct device *dev)
{
struct pci_host_bridge *bridge = to_pci_host_bridge(dev);
@@ -25,7 +28,7 @@ struct pci_host_bridge *pci_create_host_bridge(
int error;
int bus = PCI_BUSNUM(db);
int domain = PCI_DOMAIN(db);
- struct pci_host_bridge *host;
+ struct pci_host_bridge *host, *temp;
struct pci_host_bridge_window *window, *n;

host = kzalloc(sizeof(*host), GFP_KERNEL);
@@ -40,6 +43,18 @@ struct pci_host_bridge *pci_create_host_bridge(
*/
pci_host_assign_domain_nr(host);

+ mutex_lock(&phb_mutex);
+ list_for_each_entry(temp, &pci_host_bridge_list, list)
+ if (temp->domain == host->domain
+ && temp->busnum == host->busnum) {
+ dev_dbg(&host->dev, "pci host bridge pci%04x:%02x exist\n",
+ host->domain, host->busnum);
+ mutex_unlock(&phb_mutex);
+ kfree(host);
+ return NULL;
+ }
+ mutex_unlock(&phb_mutex);
+
host->dev.parent = parent;
INIT_LIST_HEAD(&host->windows);
host->dev.release = pci_release_host_bridge_dev;
@@ -55,12 +70,19 @@ struct pci_host_bridge *pci_create_host_bridge(
list_for_each_entry_safe(window, n, resources, list)
list_move_tail(&window->list, &host->windows);

+ mutex_lock(&phb_mutex);
+ list_add_tail(&host->list, &pci_host_bridge_list);
+ mutex_unlock(&phb_mutex);
return host;
}
EXPORT_SYMBOL(pci_create_host_bridge);

void pci_free_host_bridge(struct pci_host_bridge *host)
{
+ mutex_lock(&phb_mutex);
+ list_del(&host->list);
+ mutex_unlock(&phb_mutex);
+
device_unregister(&host->dev);
}

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 8f97872..4015841 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1869,7 +1869,7 @@ static struct pci_bus *__pci_create_root_bus(
void *sysdata)
{
int error;
- struct pci_bus *b, *b2;
+ struct pci_bus *b;
struct pci_host_bridge_window *window;
struct device *parent;
struct resource *res;
@@ -1886,12 +1886,6 @@ static struct pci_bus *__pci_create_root_bus(
b->ops = ops;
b->number = b->busn_res.start = bridge->busnum;
pci_bus_assign_domain_nr(b, parent);
- b2 = pci_find_bus(pci_domain_nr(b), b->number);
- if (b2) {
- /* If we already got to this bus through a different bridge, ignore it */
- dev_dbg(&b2->dev, "bus already known\n");
- goto err_out;
- }

bridge->bus = b;
b->bridge = get_device(&bridge->dev);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index d991bd2..5ee0033 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -406,6 +406,7 @@ struct pci_host_bridge {
u16 busnum;
struct device dev;
struct pci_bus *bus; /* root bus */
+ struct list_head list;
struct list_head windows; /* pci_host_bridge_windows */
void (*release_fn)(struct pci_host_bridge *);
void *release_data;
--
1.7.1