On 2014/11/18 23:30, Liviu Dudau wrote:

On Mon, Nov 17, 2014 at 10:21:41AM +0000, Yijing Wang wrote:

quoted

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.

Please Cc: Yinghai Lu and Jiang Liu on future versions.

More comments on the conversion of pci_create_root_bus():

That's my mistake, will add CC Yinghai and Jiang in next version.

quoted

Signed-off-by: Yijing Wang <redacted>
---

...

quoted

+
+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,

I don't thinks it is worth moving the buses' pci_ops into pci_host_bridge. It
might be more useful to have pci_host_bridge specific ops here.

Because we want to create pci_host_bridge before pci root bus creation,
so when we scan the root bus and child buses, we use pci_host_bridge as
the only argument, and another pci_host_info will be addes in later patch,
which one support carry the pci_host_bridge ops.

quoted

+               struct list_head *resources)
+{
+       int error;
+       struct pci_bus *b;
+       struct pci_host_bridge *host, *h;

...

quoted

-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;

I think bridge should be the b->sysdata here. 

? what's the meaning?

quoted

+       b->ops = bridge->ops;

See comment above why I don't think this is necessary.

quoted

+       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);

Do you really want to overwrite the bridge's domain with the one from a bus that
could possibly be rejected a couple of lines further down?

As an asside: if we are doing the split of pci_host_bridge from root bus creation
it is worth in my opinion to move the domain setup in pci_create_host_bridge()
and stop fiddling with it here.

Hi Liviu, these lines just temporary, I will remove it after all host drivers
save its domain in pci_host_bridge.

Otherwise it looks to me like you are heading in the right direction.

Thanks!
Yijing.

Best regards,
Liviu

quoted

+       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

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-- 
Thanks!
Yijing