[PATCH 09/28] PCI: Separate pci_host_bridge creation out of pci_create_root_bus()

Yijing Wang
2015-01-16T03:47:29Z

We want to make a generic pci_host_bridge, then we could
place common PCI infos like domain number in it. 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().

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
---
drivers/pci/host-bridge.c | 78 +++++++++++++++++++++++++++++
drivers/pci/probe.c | 121 +++++++++++++++++++--------------------------
include/linux/pci.h | 6 ++-
3 files changed, 134 insertions(+), 71 deletions(-)

diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c
index 0e5f3c9..c9ee582 100644
--- a/drivers/pci/host-bridge.c
+++ b/drivers/pci/host-bridge.c
@@ -8,6 +8,84 @@

#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);
+
+ 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, *temp;
+ struct pci_host_bridge_window *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 argu u32 db.
+ */
+ 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
+ && host->busnum == temp->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;
+ 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;
+ }
+
+ 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);
+}
+
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 50f58b3..2e0b952 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 +1864,35 @@ 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 pci_host_bridge_window *window, *n;
+ struct pci_bus *b;
+ struct pci_host_bridge_window *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);
- 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 +1901,11 @@ 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,
+ bridge->busnum);
error = device_register(&b->dev);
if (error)
- goto class_dev_reg_err;
+ goto err_out;

pcibios_add_bus(b);

@@ -1961,12 +1918,11 @@ 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 */
- list_for_each_entry_safe(window, n, resources, list) {
- list_move_tail(&window->list, &bridge->windows);
+ list_for_each_entry(window, &bridge->windows, list) {
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, bridge->busnum, res->end);
else
pci_bus_add_resource(b, res, 0);
if (offset) {
@@ -1988,14 +1944,23 @@ 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 +2024,33 @@ 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 pci_host_bridge_window *window;
bool found = false;
struct pci_bus *b;
int max;

- list_for_each_entry(window, resources, list)
+ list_for_each_entry(window, &host->windows, list)
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, host->busnum, 255);
}

max = pci_scan_child_bus(b);
@@ -2091,6 +2060,18 @@ 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 1b9c799..5ee0033 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -403,8 +403,10 @@ struct pci_host_bridge_window {

struct pci_host_bridge {
u16 domain;
+ 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;
@@ -416,7 +418,8 @@ 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 +777,7 @@ 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