[RFC PATCH 07/16] PCI: Separate pci_host_bridge creation out of pci_create_root_bus()

Yijing Wang
2014-11-17T09:45:55Z

There are some common PCI infos like domain, msi_controller, these
infos are saved in arch PCI sysdata, and lots arch specific functions
like pci_domain_nr() and pcibios_msi_controller() required.
We could separate pci_host_bridge creation out of pci_create_root_bus(),
then we could put the common infos in, then we could eliminate
the arch specifc functions.

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
---
drivers/pci/host-bridge.c | 99 +++++++++++++++++++++++++++++++++
drivers/pci/probe.c | 134 ++++++++++++++++----------------------------
include/linux/pci.h | 11 +++-
3 files changed, 158 insertions(+), 86 deletions(-)

diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c
index 0e5f3c9..e31604f 100644
--- a/drivers/pci/host-bridge.c
+++ b/drivers/pci/host-bridge.c
@@ -8,6 +8,105 @@

#include "pci.h"

+LIST_HEAD(pci_host_bridge_list);
+DECLARE_RWSEM(pci_host_bridge_sem);
+
+static struct resource busn_resource = {
+ .name = "PCI busn",
+ .start = 0,
+ .end = 255,
+ .flags = IORESOURCE_BUS,
+};
+
+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 pci_ops *ops, void *sysdata,
+ struct list_head *resources)
+{
+ int error;
+ struct pci_bus *b;
+ struct pci_host_bridge *host, *h;
+ struct pci_host_bridge_window *window, *n;
+
+ down_read(&pci_host_bridge_sem);
+ list_for_each_entry(h, &pci_host_bridge_list, list) {
+ if (h->domain = PCI_DOMAIN(db) &&
+ h->busnum = PCI_BUSNUM(db)) {
+ dev_dbg(&h->dev, "pci host bridge exist\n");
+ up_read(&pci_host_bridge_sem);
+ return NULL;
+ }
+ }
+ up_read(&pci_host_bridge_sem);
+
+ host = kzalloc(sizeof(*host), GFP_KERNEL);
+ if (!host)
+ return NULL;
+
+ host->sysdata = sysdata;
+ host->busnum = PCI_BUSNUM(db);
+ host->domain = PCI_DOMAIN(db);
+ host->ops = ops;
+ host->dev.parent = parent;
+ INIT_LIST_HEAD(&host->windows);
+ host->dev.release = pci_release_host_bridge_dev;
+
+ /* this is hack, just for build, will be removed later*/
+ b = kzalloc(sizeof(*b), GFP_KERNEL);
+ b->sysdata = sysdata;
+ pci_bus_assign_domain_nr(b, parent);
+ host->domain = pci_domain_nr(b);
+
+ if (!resources) {
+ /* Use default IO/MEM/BUS resources*/
+ pci_add_resource(&host->windows, &ioport_resource);
+ pci_add_resource(&host->windows, &iomem_resource);
+ pci_add_resource(&host->windows, &busn_resource);
+ } else {
+ list_for_each_entry_safe(window, n, resources, list)
+ list_move_tail(&window->list, &host->windows);
+ }
+
+ dev_set_name(&host->dev, "pci%04x:%02x", host->domain,
+ host->busnum);
+ error = pcibios_root_bridge_prepare(host);
+ if(error) {
+ kfree(host);
+ return NULL;
+ }
+
+ error = device_register(&host->dev);
+ if (error) {
+ put_device(&host->dev);
+ return NULL;
+ }
+
+ down_write(&pci_host_bridge_sem);
+ list_add_tail(&host->list, &pci_host_bridge_list);
+ up_write(&pci_host_bridge_sem);
+ return host;
+}
+EXPORT_SYMBOL(pci_create_host_bridge);
+
+void pci_free_host_bridge(struct pci_host_bridge *host)
+{
+ down_write(&pci_host_bridge_sem);
+ list_del(&host->list);
+ up_write(&pci_host_bridge_sem);
+
+ 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 adf4d09..d472da4 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -17,13 +17,6 @@
#define CARDBUS_LATENCY_TIMER 176 /* secondary latency timer */
#define CARDBUS_RESERVE_BUSNR 3

-static struct resource busn_resource = {
- .name = "PCI busn",
- .start = 0,
- .end = 255,
- .flags = IORESOURCE_BUS,
-};
-
/* Ugh. Need to stop exporting this to modules. */
LIST_HEAD(pci_root_buses);
EXPORT_SYMBOL(pci_root_buses);
@@ -508,31 +501,6 @@ 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 */
@@ -1895,52 +1863,33 @@ 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)
+struct pci_bus *__pci_create_root_bus(struct pci_host_bridge *bridge)
{
int error;
- struct pci_host_bridge *bridge;
struct pci_bus *b, *b2;
- struct pci_host_bridge_window *window, *n;
+ struct pci_host_bridge_window *window;
struct resource *res;
resource_size_t offset;
char bus_addr[64];
char *fmt;
- u8 bus = PCI_BUSNUM(db);
+ struct device *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->sysdata = bridge->sysdata;
+ b->ops = bridge->ops;
+ b->number = b->busn_res.start = bridge->busnum;
pci_bus_assign_domain_nr(b, parent);
- b2 = pci_find_bus(pci_domain_nr(b), bus);
+ bridge->domain = pci_domain_nr(b);
+ b2 = pci_find_bus(pci_domain_nr(b), bridge->busnum);
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->dev.parent = parent;
- bridge->dev.release = pci_release_host_bridge_dev;
- dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(b), bus);
- error = pcibios_root_bridge_prepare(bridge);
- if (error) {
- kfree(bridge);
- 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);
@@ -1950,7 +1899,7 @@ 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", pci_domain_nr(b), b->number);
error = device_register(&b->dev);
if (error)
goto class_dev_reg_err;
@@ -1966,12 +1915,11 @@ 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, b->number, res->end);
else
pci_bus_add_resource(b, res, 0);
if (offset) {
@@ -2001,6 +1949,25 @@ err_out:
return NULL;
}

+struct pci_bus *pci_create_root_bus(struct device *parent, u32 bus,
+ struct pci_ops *ops, void *sysdata, struct list_head *resources)
+{
+ struct pci_host_bridge *host;
+
+ host = pci_create_host_bridge(parent, bus, ops,
+ sysdata ,resources);
+ if (!host)
+ return NULL;
+
+ host->bus = __pci_create_root_bus(host);
+ if (!host->bus) {
+ pci_free_host_bridge(host);
+ return NULL;
+ }
+
+ return host->bus;
+}
+
int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int bus_max)
{
struct resource *res = &b->busn_res;
@@ -2069,40 +2036,37 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, u32 db,
{
struct pci_host_bridge_window *window;
bool found = false;
- struct pci_bus *b;
- LIST_HEAD(default_res);
+ struct pci_host_bridge *host;
int max;

- if (!resources) {
- pci_add_resource(&default_res, &ioport_resource);
- pci_add_resource(&default_res, &iomem_resource);
- pci_add_resource(&default_res, &busn_resource);
- } else {
- list_for_each_entry(window, resources, list)
- if (window->res->flags & IORESOURCE_BUS) {
- found = true;
- break;
- }
- }
+ host = pci_create_host_bridge(parent, db, ops, sysdata, resources);
+ if (!host)
+ return NULL;

- b = pci_create_root_bus(parent, db, ops, sysdata,
- resources ? resources : &default_res);
- if (!b)
+ list_for_each_entry(window, &host->windows, list)
+ if (window->res->flags & IORESOURCE_BUS) {
+ found = true;
+ break;
+ }
+
+ host->bus = __pci_create_root_bus(host);
+ if (!host->bus) {
+ pci_free_host_bridge(host);
return NULL;
+ }

if (!found) {
- dev_info(&b->dev,
+ dev_info(&host->bus->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);
+ pci_bus_insert_busn_res(host->bus, PCI_BUSNUM(db), 255);
}

- max = pci_scan_child_bus(b);
-
+ max = pci_scan_child_bus(host->bus);
if (!found)
- pci_bus_update_busn_res_end(b, max);
+ pci_bus_update_busn_res_end(host->bus, max);

- return b;
+ return host->bus;
}
EXPORT_SYMBOL(pci_scan_root_bus);

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 8b11b38..daa7f40 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -402,7 +402,12 @@ struct pci_host_bridge_window {
struct pci_host_bridge {
struct device dev;
struct pci_bus *bus; /* root bus */
+ struct list_head list;
struct list_head windows; /* pci_host_bridge_windows */
+ int busnum;
+ int domain;
+ void *sysdata;
+ struct pci_ops *ops;
void (*release_fn)(struct pci_host_bridge *);
void *release_data;
};
@@ -413,7 +418,9 @@ 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 db, struct pci_ops *ops,
+ void *sys, 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
@@ -770,6 +777,8 @@ void pci_bus_add_devices(const struct pci_bus *bus);
struct pci_bus *pci_create_root_bus(struct device *parent, u32 bus,
struct pci_ops *ops, void *sysdata,
struct list_head *resources);
+struct pci_bus *__pci_create_root_bus(struct pci_host_bridge *host);
+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