On Wed, Nov 19, 2014 at 02:09:12AM +0000, Yijing Wang wrote:

quoted

quoted

 struct pci_host_bridge *pci_create_host_bridge(
-		struct device *parent, u32 db, 
-		struct pci_ops *ops, void *sysdata, 
-		struct list_head *resources)
+		struct device *parent, u32 db, struct pci_ops *ops, 
+		struct pci_host_info *info)
 {
 	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) {

@@ -53,7 +51,7 @@ struct pci_host_bridge *pci_create_host_bridge(
 	if (!host)
 		return NULL;
 
-	host->sysdata = sysdata;
+	host->sysdata = info->arg;
 	host->busnum = PCI_BUSNUM(db);
 	host->domain = PCI_DOMAIN(db);
 	host->ops = ops;

@@ -63,18 +61,23 @@ struct pci_host_bridge *pci_create_host_bridge(
 
 	/* this is hack, just for build, will be removed later*/

Why do you need this hack? Just for calling pci_domain_nr() ?

Yes, it's temporary code, we need domain number here for pci host bridge register.

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quoted

 	b = kzalloc(sizeof(*b), GFP_KERNEL);
-	b->sysdata = sysdata;
+	b->sysdata = host->sysdata;
 	pci_bus_assign_domain_nr(b, parent);
 	host->domain = pci_domain_nr(b);
+	kfree(b);
 

...

quoted

quoted

+static int pci_default_init_res(struct pci_host_bridge *host,
+		struct pci_host_info *info)
+{
+	struct pci_host_bridge_window *window, *n;
+
+	if (info->res_type != PCI_HOST_RES_DEFAULT) 
+		list_for_each_entry_safe(window, n, info->resources,
+				list)
+			list_move_tail(&window->list, &host->windows);
+	else
+		info->res_type = PCI_HOST_RES_DEFAULT;

I'm confused about this assignment. Isn't this a nop as the else part
means info->res_type *is* PCI_HOST_RES_DEFAULT?

No, in this patch, host drivers pass a pci host bridge resources init hook
in pci_host_info *info, and we call this info->init_res() in pci_create_host_bridge().

+struct pci_host_info {
+	u8 res_type;
+	void *arg;
+	struct list_head *resources; /*just for build, will clean up later */
+	int (*init_res)(struct pci_host_bridge *host,
+			struct pci_host_info *info);
+};
+

That's not what I've asked! Your code does:

	if (info->res_type != PCI_HOST_RES_DEFAULT)
		....
	else /* info->res_type == PCI_HOST_RES_DEFAULT)
		info->res_type = PCI_HOST_RES_DEFAULT;

info->res_type is already == PCI_HOST_RES_DEFAULT in the else side, assignment is a NOP?

quoted

quoted

+
+	return 0;
+}

...

quoted

quoted

@@ -2038,8 +2057,13 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, u32 db,
 	bool found = false;
 	struct pci_host_bridge *host;
 	int max;
+	struct pci_host_info info;
+	
+	info.arg = sysdata;
+	info.resources = resources;
+	info.init_res = pci_default_init_res;

I have mixed feelings about this patch. While it is heading in the right direction
of moving pci_host_bridge relevant information towards the right user, I don't think
you picked up the right set to move. The resource list is going to be copied into
internal pci_host_bridge list anyway, keeping another copy is not helpful *and*
you have increased the code size.

I think for now we should aim to get the *missing* data into pci_host_bridge: MSI
controllers and PCI domain/segment. Then we can do more cleanup.

Hi Liviu, I agree with you here, the changes to resources stuff seems not a perfect
solution. In my patch 6, we could pass pci domain nr by u32 PCI_DOMBUS(domain, bus) argument,
and store it in pci_host_bridge. For msi controller, we couldn't save the msi_controller
in pci_host_bridge. Before we assume one pci host bridge only had one msi_controller,
but now something changes, Jiang introduce hierarchy irq domain in x86, and now
one pci host bridge may has more than one msi_controller. So I prefer to add a
function to pci_host_bridge something like

struct msi_controller *pci_get_msi_controller(struct pci_dev *dev)

Yes, good idea.

quoted

quoted

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

@@ -2070,6 +2094,47 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, u32 db,
 }
 EXPORT_SYMBOL(pci_scan_root_bus);
 
+struct pci_host_bridge *pci_scan_host_bridge(
+		struct device *parent, u32 db, struct pci_ops *ops,
+		struct pci_host_info *info)
+{
+	struct pci_host_bridge_window *window;
+	bool found = false;
+	struct pci_host_bridge *host;
+	int max;
+
+	host = pci_create_host_bridge(parent, db, ops, info);
+	if (!host)
+		return NULL;
+
+	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(&host->bus->dev,
+		 "No busn resource found for root bus, will use [bus %02x-ff]\n",
+			host->busnum);
+		pci_bus_insert_busn_res(host->bus, host->busnum, 255);
+	}
+
+	max = pci_scan_child_bus(host->bus);
+	if (!found)
+		pci_bus_update_busn_res_end(host->bus, max);
+
+	return host;
+
+}
+EXPORT_SYMBOL(pci_scan_host_bridge);
+
 /**
  * pci_rescan_bus_bridge_resize - scan a PCI bus for devices.
  * @bridge: PCI bridge for the bus to scan

diff --git a/include/linux/pci.h b/include/linux/pci.h
index daa7f40..a51f5f5 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h

@@ -412,6 +412,21 @@ struct pci_host_bridge {
 	void *release_data;
 };
 
+struct pci_host_info {
+	u8 res_type;
+	void *arg;
+	struct list_head *resources; /*just for build, will clean up later */
+	int (*init_res)(struct pci_host_bridge *host, 
+			struct pci_host_info *info);
+};
+
+static inline void init_pci_host_info(struct pci_host_info *info)
+{
+	memset(info, 0 , sizeof(*info));
+}

Where is this used?

Host driver uses it to init pci_host_info.

Might be worth adding it that patch rather than here.

Best regards,
Liviu

quoted

quoted

+
+#define PCI_HOST_RES_DEFAULT	0x2
+

Magic number?

Hmmm, I will rework pci host bridge resources stuff.

quoted

Best regards,
Liviu

quoted

 #define	to_pci_host_bridge(n) container_of(n, struct pci_host_bridge, dev)
 void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
 		     void (*release_fn)(struct pci_host_bridge *),

@@ -420,7 +435,7 @@ 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 db, struct pci_ops *ops, 
-		void *sys, struct list_head *resources);
+		struct pci_host_info *info);
 /*
  * 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

@@ -785,6 +800,9 @@ void pci_bus_release_busn_res(struct pci_bus *b);
 struct pci_bus *pci_scan_root_bus(struct device *parent, u32 bus,
 					     struct pci_ops *ops, void *sysdata,
 					     struct list_head *resources);
+struct pci_host_bridge *pci_scan_host_bridge(struct device *parent,
+		u32 db, struct pci_ops *ops,
+		struct pci_host_info *info);
 struct pci_bus *pci_add_new_bus(struct pci_bus *parent, struct pci_dev *dev,
 				int busnr);
 void pcie_update_link_speed(struct pci_bus *bus, u16 link_status);

-- 
1.7.1

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-- 
Thanks!
Yijing

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-- 
====================
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