[PATCH v3 12/30] PCI: Introduce pci_host_bridge_ops to support host specific operations

Yijing Wang
2015-02-26T01:29:29Z

Now we have weak functions like pcibios_root_bridge_prepare()
to setup pci host bridge, We could introduce pci_host_bridge_ops
which contain host bridge specific ops to setup pci_host_bridge.
Then host bridge driver could add pci_host_bridge_ops hooks
intead of weak function to setup pci_host_bridge.
This patch add following pci_host_bridge_ops hooks:

pci_host_bridge_ops {
/* set root bus speed, some platform need this like powerpc */
void (*phb_set_root_bus_speed)(struct pci_host_bridge *host);
/* setup pci_host_bridge before pci_host_bridge be added to driver core */
int (*phb_prepare)(struct pci_host_bridge *host);
/* platform specific of scan hook to scan pci device */
void (*phb_of_scan_bus)(struct pci_host_bridge *);
}
We could easily extend it to support different host bridge
specific operations.

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
---
drivers/pci/host-bridge.c | 12 ++++++++++--
drivers/pci/probe.c | 17 +++++++++++------
include/linux/pci.h | 12 ++++++++++--
3 files changed, 31 insertions(+), 10 deletions(-)

diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c
index b42a4bb..4a2baa2 100644
--- a/drivers/pci/host-bridge.c
+++ b/drivers/pci/host-bridge.c
@@ -23,8 +23,8 @@ static void pci_release_host_bridge_dev(struct device *dev)
}

struct pci_host_bridge *pci_create_host_bridge(
- struct device *parent, u32 db,
- struct list_head *resources, void *sysdata)
+ struct device *parent, u32 db, struct list_head *resources,
+ void *sysdata, struct pci_host_bridge_ops *ops)
{
int error;
int bus = PCI_BUSNUM(db);
@@ -56,6 +56,7 @@ struct pci_host_bridge *pci_create_host_bridge(
}
mutex_unlock(&phb_mutex);

+ host->ops = ops;
host->dev.parent = parent;
INIT_LIST_HEAD(&host->windows);
host->dev.release = pci_release_host_bridge_dev;
@@ -63,6 +64,13 @@ struct pci_host_bridge *pci_create_host_bridge(
dev_set_name(&host->dev, "pci%04x:%02x", host->domain,
host->busnum);

+ if (host->ops && host->ops->phb_prepare) {
+ error = host->ops->phb_prepare(host);
+ if(error) {
+ kfree(host);
+ return NULL;
+ }
+ }
error = device_register(&host->dev);
if (error) {
put_device(&host->dev);
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 45056cb..8cec6ab 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1888,6 +1888,8 @@ static struct pci_bus *__pci_create_root_bus(

bridge->bus = b;
b->bridge = get_device(&bridge->dev);
+ if (bridge->ops && bridge->ops->phb_set_root_bus_speed)
+ bridge->ops->phb_set_root_bus_speed(bridge);
error = pcibios_root_bridge_prepare(bridge);
if (error)
goto err_out;
@@ -1953,7 +1955,7 @@ struct pci_bus *pci_create_root_bus(struct device *parent, u32 db,
{
struct pci_host_bridge *host;

- host = pci_create_host_bridge(parent, db, resources, sysdata);
+ host = pci_create_host_bridge(parent, db, resources, sysdata, NULL);
if (!host)
return NULL;

@@ -2050,10 +2052,13 @@ static struct pci_bus *__pci_scan_root_bus(
pci_bus_insert_busn_res(b, b->number, 255);
}

- max = pci_scan_child_bus(b);
-
- if (!found)
- pci_bus_update_busn_res_end(b, max);
+ if (host->ops && host->ops->phb_of_scan_bus) {
+ host->ops->phb_of_scan_bus(host);
+ } else {
+ max = pci_scan_child_bus(b);
+ if (!found)
+ pci_bus_update_busn_res_end(b, max);
+ }

return b;
}
@@ -2063,7 +2068,7 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, u32 db,
{
struct pci_host_bridge *host;

- host = pci_create_host_bridge(parent, db, resources, sysdata);
+ host = pci_create_host_bridge(parent, db, resources, sysdata, NULL);
if (!host)
return NULL;

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 74e038d..a4b56e0 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -400,6 +400,13 @@ static inline int pci_channel_offline(struct pci_dev *pdev)
return (pdev->error_state != pci_channel_io_normal);
}

+struct pci_host_bridge;
+struct pci_host_bridge_ops {
+ void (*phb_set_root_bus_speed)(struct pci_host_bridge *host);
+ int (*phb_prepare)(struct pci_host_bridge *host);
+ void (*phb_of_scan_bus)(struct pci_host_bridge *);
+};
+
struct pci_host_bridge {
u16 domain;
u16 busnum;
@@ -407,6 +414,7 @@ struct pci_host_bridge {
struct pci_bus *bus; /* root bus */
struct list_head windows; /* resource_entry */
struct list_head list;
+ struct pci_host_bridge_ops *ops;
void (*release_fn)(struct pci_host_bridge *);
void *release_data;
};
@@ -418,8 +426,8 @@ void pci_set_host_bridge_release(struct pci_host_bridge *bridge,

int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge);
struct pci_host_bridge *pci_create_host_bridge(
- struct device *parent, u32 dombus,
- struct list_head *resources, void *sysdata);
+ struct device *parent, u32 dombus, struct list_head *resources,
+ void *sysdata, struct pci_host_bridge_ops *ops);
/*
* The first PCI_BRIDGE_RESOURCE_NUM PCI bus resources (those that correspond
* to P2P or CardBus bridge windows) go in a table. Additional ones (for
--
1.7.1