On Mon, Mar 23, 2015 at 8:34 PM, Yijing Wang <wangyijing@xxxxxxxxxx> wrote:
Introduce pci_host_bridge_list to manage pci host
bridges in system, this make us have the ability
to check whether the new host would conflict with
existing one. Then we could remove bus alreay exist
check in __pci_create_root_bus().
Can we use bus_type instead?
Then we can use bus_find_device for the host_bridge enumeration.
Please refer the patches that I sent out couple years ago.
Thanks
Yinghai
Subject: [PATCH] PCI: Add dummy bus_type for pci_host_bridge
Need to use it for looping registered host_bridges, and kill
pci_root_buses list later.
Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
---
drivers/pci/pci-driver.c | 10 ++++++++++
drivers/pci/probe.c | 1 +
include/linux/pci.h | 2 ++
3 files changed, 13 insertions(+)
Index: linux-2.6/include/linux/pci.h
===================================================================
--- linux-2.6.orig/include/linux/pci.h
+++ linux-2.6/include/linux/pci.h
@@ -735,6 +735,7 @@ enum pcie_bus_config_types {
extern enum pcie_bus_config_types pcie_bus_config;
+extern struct bus_type pci_host_bridge_bus_type;
extern struct bus_type pci_bus_type;
/* Do NOT directly access these two variables, unless you are arch-specific PCI
@@ -808,6 +809,7 @@ void pci_stop_root_bus(struct pci_bus *b
void pci_remove_root_bus(struct pci_bus *bus);
void pci_setup_cardbus(struct pci_bus *bus);
void pci_sort_breadthfirst(void);
+#define dev_is_pci_host_bridge(d) ((d)->bus == &pci_host_bridge_bus_type)
#define dev_is_pci(d) ((d)->bus == &pci_bus_type)
#define dev_is_pf(d) ((dev_is_pci(d) ? to_pci_dev(d)->is_physfn : false))
#define dev_num_vf(d) ((dev_is_pci(d) ? pci_num_vf(to_pci_dev(d)) : 0))
Index: linux-2.6/drivers/pci/pci-driver.c
===================================================================
--- linux-2.6.orig/drivers/pci/pci-driver.c
+++ linux-2.6/drivers/pci/pci-driver.c
@@ -1408,6 +1408,16 @@ struct bus_type pci_bus_type = {
};
EXPORT_SYMBOL(pci_bus_type);
+struct bus_type pci_host_bridge_bus_type = {
+ .name = "pci_host_bridge",
+};
+
+static int __init pci_host_bridge_driver_init(void)
+{
+ return bus_register(&pci_host_bridge_bus_type);
+}
+postcore_initcall(pci_host_bridge_driver_init);
+
static int __init pci_driver_init(void)
{
return bus_register(&pci_bus_type);
Index: linux-2.6/drivers/pci/probe.c
===================================================================
--- linux-2.6.orig/drivers/pci/probe.c
+++ linux-2.6/drivers/pci/probe.c
@@ -1949,6 +1949,7 @@ struct pci_bus *pci_create_root_bus(stru
goto err_out;
bridge->dev.parent = parent;
+ bridge->dev.bus = &pci_host_bridge_bus_type;
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);
Subject: [PATCH] PCI: Add for_each_pci_host_bridge() and pci_get_next_host_bridge
Now we have pci_root_buses list, and there is lots of iteration with
list_of_each of it, that is not safe after we add pci root bus hotplug
support after booting stage.
Also pci_find_next_bus is pretty misleading name, and it is only finding
next root bus instead of regular pci bus.
Add pci_get_next_host_bridge and use bus_find_device in driver core to
iterate host bridge and the same time get root bus.
In folllowing patches will replace searching root bus with searching host_bridge.
after using with that host-bridge, will need to call put device to release
reference if break early from the loop.
After those replacing, we even could kill pci_root_buses list.
-v2: fixes compiling error when CONFIG_PCI is not defined that Fengguang found.
Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
---
drivers/pci/search.c | 24 ++++++++++++++++++++++++
include/linux/pci.h | 9 +++++++++
2 files changed, 33 insertions(+)
Index: linux-2.6/include/linux/pci.h
===================================================================
--- linux-2.6.orig/include/linux/pci.h
+++ linux-2.6/include/linux/pci.h
@@ -409,6 +409,8 @@ struct pci_host_bridge {
};
#define to_pci_host_bridge(n) container_of(n, struct pci_host_bridge, dev)
+#define for_each_pci_host_bridge(d) while ((d = pci_get_next_host_bridge(d)) != NULL)
+
void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
void (*release_fn)(struct pci_host_bridge *),
void *release_data);
@@ -831,6 +833,7 @@ int pci_find_ht_capability(struct pci_de
int pci_find_next_ht_capability(struct pci_dev *dev, int pos, int ht_cap);
struct pci_bus *pci_find_next_bus(const struct pci_bus *from);
+struct pci_host_bridge *pci_get_next_host_bridge(struct pci_host_bridge *from);
struct pci_dev *pci_get_device(unsigned int vendor, unsigned int device,
struct pci_dev *from);
struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device,
@@ -1447,6 +1450,12 @@ static inline int pci_domain_nr(struct p
static inline struct pci_dev *pci_dev_get(struct pci_dev *dev) { return NULL; }
static inline int pci_get_new_domain_nr(void) { return -ENOSYS; }
+static inline struct pci_host_bridge *pci_get_next_host_bridge(
+ struct pci_host_bridge *host_bridge)
+{
+ return NULL;
+}
+
#define dev_is_pci(d) (false)
#define dev_is_pf(d) (false)
#define dev_num_vf(d) (0)
Index: linux-2.6/drivers/pci/search.c
===================================================================
--- linux-2.6.orig/drivers/pci/search.c
+++ linux-2.6/drivers/pci/search.c
@@ -231,6 +231,30 @@ struct pci_dev *pci_get_domain_bus_and_s
}
EXPORT_SYMBOL(pci_get_domain_bus_and_slot);
+static int match_pci_host_bridge(struct device *dev, void *data)
+{
+ return 1;
+}
+
+struct pci_host_bridge *pci_get_next_host_bridge(struct pci_host_bridge *from)
+{
+ struct device *dev;
+ struct device *dev_start = NULL;
+ struct pci_host_bridge *bridge = NULL;
+
+ WARN_ON(in_interrupt());
+ if (from)
+ dev_start = &from->dev;
+ dev = bus_find_device(&pci_host_bridge_bus_type, dev_start, NULL,
+ match_pci_host_bridge);
+ if (dev)
+ bridge = to_pci_host_bridge(dev);
+ if (from)
+ put_device(&from->dev);
+ return bridge;
+}
+EXPORT_SYMBOL_GPL(pci_get_next_host_bridge);
+
static int match_pci_dev_by_id(struct device *dev, void *data)
{
struct pci_dev *pdev = to_pci_dev(dev);
