[PATCH v3 09/30] PCI: Separate pci_host_bridge creation out of pci_create_root_bus()

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

This patch separate pci_host_bridge creation out
of pci_create_root_bus(), and try to make a generic
pci_host_bridge, then we could place generic PCI
infos like domain number in it. Also Ripping out
pci_host_bridge creation from pci_create_root_bus()
make code more better readability. Further more,
we could use the generic pci_host_bridge to hold
host bridge specific operations like
pcibios_root_bridge_prepare(). The changes are
transparent to platform host bridge drivers.

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
---
drivers/pci/host-bridge.c | 56 ++++++++++++++++++++++
drivers/pci/probe.c | 114 ++++++++++++++++++++-------------------------
include/linux/pci.h | 5 ++-
3 files changed, 110 insertions(+), 65 deletions(-)

diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c
index 39b2dbe..f304f26 100644
--- a/drivers/pci/host-bridge.c
+++ b/drivers/pci/host-bridge.c
@@ -8,6 +8,62 @@

#include "pci.h"

+static void pci_release_host_bridge_dev(struct device *dev)
+{
+ struct pci_host_bridge *bridge = to_pci_host_bridge(dev);
+
+ if (bridge->release_fn)
+ bridge->release_fn(bridge);
+
+ pci_free_resource_list(&bridge->windows);
+ kfree(bridge);
+}
+
+struct pci_host_bridge *pci_create_host_bridge(
+ struct device *parent, u32 db, struct list_head *resources)
+{
+ int error;
+ int bus = PCI_BUSNUM(db);
+ int domain = PCI_DOMAIN(db);
+ struct pci_host_bridge *host;
+ struct resource_entry *window, *n;
+
+ host = kzalloc(sizeof(*host), GFP_KERNEL);
+ if (!host)
+ return NULL;
+
+ host->busnum = bus;
+ host->domain = domain;
+ /* If support CONFIG_PCI_DOMAINS_GENERIC, use
+ * pci_host_assign_domain_nr() to assign domain
+ * number instead PCI_DOMAIN(db).
+ */
+ pci_host_assign_domain_nr(host);
+
+ host->dev.parent = parent;
+ INIT_LIST_HEAD(&host->windows);
+ host->dev.release = pci_release_host_bridge_dev;
+ dev_set_name(&host->dev, "pci%04x:%02x", host->domain,
+ host->busnum);
+
+ error = device_register(&host->dev);
+ if (error) {
+ put_device(&host->dev);
+ return NULL;
+ }
+
+ resource_list_for_each_entry_safe(window, n, resources)
+ list_move_tail(&window->node, &host->windows);
+
+ return host;
+}
+EXPORT_SYMBOL(pci_create_host_bridge);
+
+void pci_free_host_bridge(struct pci_host_bridge *host)
+{
+ device_unregister(&host->dev);
+}
+
static struct pci_bus *find_pci_root_bus(struct pci_bus *bus)
{
while (bus->parent)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index ef57da1..20e9206 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -502,31 +502,6 @@ static struct pci_bus *pci_alloc_bus(struct pci_bus *parent)
return b;
}

-static void pci_release_host_bridge_dev(struct device *dev)
-{
- struct pci_host_bridge *bridge = to_pci_host_bridge(dev);
-
- if (bridge->release_fn)
- bridge->release_fn(bridge);
-
- pci_free_resource_list(&bridge->windows);
-
- kfree(bridge);
-}
-
-static struct pci_host_bridge *pci_alloc_host_bridge(struct pci_bus *b)
-{
- struct pci_host_bridge *bridge;
-
- bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
- if (!bridge)
- return NULL;
-
- INIT_LIST_HEAD(&bridge->windows);
- bridge->bus = b;
- return bridge;
-}
-
static const unsigned char pcix_bus_speed[] = {
PCI_SPEED_UNKNOWN, /* 0 */
PCI_SPEED_66MHz_PCIX, /* 1 */
@@ -1889,54 +1864,41 @@ void __weak pcibios_remove_bus(struct pci_bus *bus)
{
}

-struct pci_bus *pci_create_root_bus(struct device *parent, u32 db,
- struct pci_ops *ops, void *sysdata, struct list_head *resources)
+static struct pci_bus *__pci_create_root_bus(
+ struct pci_host_bridge *bridge, struct pci_ops *ops,
+ void *sysdata)
{
int error;
- struct pci_host_bridge *bridge;
struct pci_bus *b, *b2;
- struct resource_entry *window, *n;
+ struct resource_entry *window;
+ struct device *parent;
struct resource *res;
resource_size_t offset;
char bus_addr[64];
char *fmt;
- u8 bus = PCI_BUSNUM(db);

+ parent = bridge->dev.parent;
b = pci_alloc_bus(NULL);
if (!b)
return NULL;

b->sysdata = sysdata;
b->ops = ops;
- b->number = b->busn_res.start = bus;
+ b->number = b->busn_res.start = bridge->busnum;
pci_bus_assign_domain_nr(b, parent);
- b2 = pci_find_bus(pci_domain_nr(b), bus);
+ 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 = pci_alloc_host_bridge(b);
- if (!bridge)
- goto err_out;
-
- bridge->domain = PCI_DOMAIN(db);
- bridge->dev.parent = parent;
- bridge->dev.release = pci_release_host_bridge_dev;
- dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(b), bus);
+ bridge->bus = b;
+ b->bridge = get_device(&bridge->dev);
error = pcibios_root_bridge_prepare(bridge);
- if (error) {
- kfree(bridge);
+ if (error)
goto err_out;
- }

- error = device_register(&bridge->dev);
- if (error) {
- put_device(&bridge->dev);
- goto err_out;
- }
- b->bridge = get_device(&bridge->dev);
device_enable_async_suspend(b->bridge);
pci_set_bus_of_node(b);

@@ -1945,10 +1907,11 @@ struct pci_bus *pci_create_root_bus(struct device *parent, u32 db,

b->dev.class = &pcibus_class;
b->dev.parent = b->bridge;
- dev_set_name(&b->dev, "%04x:%02x", pci_domain_nr(b), bus);
+ dev_set_name(&b->dev, "%04x:%02x", bridge->domain,
+ b->number);
error = device_register(&b->dev);
if (error)
- goto class_dev_reg_err;
+ goto err_out;

pcibios_add_bus(b);

@@ -1961,12 +1924,11 @@ struct pci_bus *pci_create_root_bus(struct device *parent, u32 db,
printk(KERN_INFO "PCI host bridge to bus %s\n", dev_name(&b->dev));

/* Add initial resources to the bus */
- resource_list_for_each_entry_safe(window, n, resources) {
- list_move_tail(&window->node, &bridge->windows);
+ resource_list_for_each_entry(window, &bridge->windows) {
res = window->res;
offset = window->offset;
if (res->flags & IORESOURCE_BUS)
- pci_bus_insert_busn_res(b, bus, res->end);
+ pci_bus_insert_busn_res(b, b->number, res->end);
else
pci_bus_add_resource(b, res, 0);
if (offset) {
@@ -1988,14 +1950,23 @@ struct pci_bus *pci_create_root_bus(struct device *parent, u32 db,

return b;

-class_dev_reg_err:
- put_device(&bridge->dev);
- device_unregister(&bridge->dev);
err_out:
kfree(b);
return NULL;
}

+struct pci_bus *pci_create_root_bus(struct device *parent, u32 db,
+ struct pci_ops *ops, void *sysdata, struct list_head *resources)
+{
+ struct pci_host_bridge *host;
+
+ host = pci_create_host_bridge(parent, db, resources);
+ if (!host)
+ return NULL;
+
+ return __pci_create_root_bus(host, ops, sysdata);
+}
+
int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int bus_max)
{
struct resource *res = &b->busn_res;
@@ -2059,29 +2030,32 @@ void pci_bus_release_busn_res(struct pci_bus *b)
res, ret ? "can not be" : "is");
}

-struct pci_bus *pci_scan_root_bus(struct device *parent, u32 db,
- struct pci_ops *ops, void *sysdata, struct list_head *resources)
+static struct pci_bus *__pci_scan_root_bus(
+ struct pci_host_bridge *host, struct pci_ops *ops,
+ void *sysdata)
{
struct resource_entry *window;
bool found = false;
struct pci_bus *b;
int max;

- resource_list_for_each_entry(window, resources)
+ resource_list_for_each_entry(window, &host->windows)
if (window->res->flags & IORESOURCE_BUS) {
found = true;
break;
}

- b = pci_create_root_bus(parent, db, ops, sysdata, resources);
- if (!b)
+ b = __pci_create_root_bus(host, ops, sysdata);
+ if (!b) {
+ pci_free_host_bridge(host);
return NULL;
+ }

if (!found) {
dev_info(&b->dev,
"No busn resource found for root bus, will use [bus %02x-ff]\n",
- PCI_BUSNUM(db));
- pci_bus_insert_busn_res(b, PCI_BUSNUM(db), 255);
+ host->busnum);
+ pci_bus_insert_busn_res(b, b->number, 255);
}

max = pci_scan_child_bus(b);
@@ -2091,6 +2065,18 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, u32 db,

return b;
}
+
+struct pci_bus *pci_scan_root_bus(struct device *parent, u32 db,
+ struct pci_ops *ops, void *sysdata, struct list_head *resources)
+{
+ struct pci_host_bridge *host;
+
+ host = pci_create_host_bridge(parent, db, resources);
+ if (!host)
+ return NULL;
+
+ return __pci_scan_root_bus(host, ops, sysdata);
+}
EXPORT_SYMBOL(pci_scan_root_bus);

struct pci_bus *pci_scan_bus_legacy(u32 db, struct pci_ops *ops,
diff --git a/include/linux/pci.h b/include/linux/pci.h
index efd9917..13b6b25 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -402,6 +402,7 @@ static inline int pci_channel_offline(struct pci_dev *pdev)

struct pci_host_bridge {
u16 domain;
+ u16 busnum;
struct device dev;
struct pci_bus *bus; /* root bus */
struct list_head windows; /* resource_entry */
@@ -415,7 +416,8 @@ void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
void *release_data);

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);
/*
* 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
@@ -774,6 +776,7 @@ struct pci_bus *pci_scan_bus_legacy(u32 dombus, struct pci_ops *ops, void *sysda
struct pci_bus *pci_create_root_bus(struct device *parent, u32 dombus,
struct pci_ops *ops, void *sysdata,
struct list_head *resources);
+void pci_free_host_bridge(struct pci_host_bridge *host);
int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int busmax);
int pci_bus_update_busn_res_end(struct pci_bus *b, int busmax);
void pci_bus_release_busn_res(struct pci_bus *b);
--
1.7.1