Re: [PATCH V4 1/2] PCI: pcibus address to resource converting take bus directly

quoted

For allocating resource under bus path, we do have dev pass along,
and we could just use bus instead. Also, we'd like to make function
find_pci_host_bridge() global so that some platforms (e.g. PPC) can
access the pci host bridge directly.

This patch appears to have multiple unrelated changes:

 - change "struct pci_bus *bus" to "struct pci_bus *root_bus"
 - change find_pci_host_bridge() argument from dev to bus
 - fiddle with pcibios_bus_to_resource() and pcibios_resource_to_bus()

Leave those questions to Yinghai.

These should be split out to make your patches easier to review.

I will split it for easy review :-)

What's the rationale for preferring the pci_bus over the pci_dev?

We probablly need retrieve the pci_host_bridge through pci_bus
and pci_dev. When converting pci_dev to pci_host_bridge, we can
simply pass "pci_dev->bus".

Thanks,
Gavin

quoted

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
---
 drivers/pci/host-bridge.c |   34 +++++++++++++++++++++-------------
 include/linux/pci.h       |    4 ++++
 2 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c
index a68dc61..4ccf477 100644
--- a/drivers/pci/host-bridge.c
+++ b/drivers/pci/host-bridge.c

@@ -9,22 +9,19 @@

 #include "pci.h"

-static struct pci_bus *find_pci_root_bus(struct pci_dev *dev)
+static struct pci_bus *find_pci_root_bus(struct pci_bus *bus)
 {
-       struct pci_bus *bus;
-
-       bus = dev->bus;
       while (bus->parent)
               bus = bus->parent;

       return bus;
 }

-static struct pci_host_bridge *find_pci_host_bridge(struct pci_dev *dev)
+struct pci_host_bridge *find_pci_host_bridge(struct pci_bus *bus)
 {
-       struct pci_bus *bus = find_pci_root_bus(dev);
+       struct pci_bus *root_bus = find_pci_root_bus(bus);

-       return to_pci_host_bridge(bus->bridge);
+       return to_pci_host_bridge(root_bus->bridge);
 }

 void pci_set_host_bridge_release(struct pci_host_bridge *bridge,

@@ -40,10 +37,11 @@ static bool resource_contains(struct resource *res1, struct resource *res2)

       return res1->start <= res2->start && res1->end >= res2->end;
 }

-void pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,
-                            struct resource *res)
+void __pcibios_resource_to_bus(struct pci_bus *bus,
+                                     struct pci_bus_region *region,
+                                     struct resource *res)
 {
-       struct pci_host_bridge *bridge = find_pci_host_bridge(dev);
+       struct pci_host_bridge *bridge = find_pci_host_bridge(bus);
       struct pci_host_bridge_window *window;
       resource_size_t offset = 0;

@@ -60,6 +58,11 @@ void pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,

       region->start = res->start - offset;
       region->end = res->end - offset;
 }
+void pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,
+                            struct resource *res)
+{
+       __pcibios_resource_to_bus(dev->bus, region, res);
+}
 EXPORT_SYMBOL(pcibios_resource_to_bus);

 static bool region_contains(struct pci_bus_region *region1,

@@ -68,10 +71,10 @@ static bool region_contains(struct pci_bus_region *region1,

       return region1->start <= region2->start && region1->end >= region2->end;
 }

-void pcibios_bus_to_resource(struct pci_dev *dev, struct resource *res,
-                            struct pci_bus_region *region)
+static void __pcibios_bus_to_resource(struct pci_bus *bus, struct resource *res,
+                                     struct pci_bus_region *region)
 {
-       struct pci_host_bridge *bridge = find_pci_host_bridge(dev);
+       struct pci_host_bridge *bridge = find_pci_host_bridge(bus);
       struct pci_host_bridge_window *window;
       resource_size_t offset = 0;

@@ -93,4 +96,9 @@ void pcibios_bus_to_resource(struct pci_dev *dev, struct resource *res,

       res->start = region->start + offset;
       res->end = region->end + offset;
 }
+void pcibios_bus_to_resource(struct pci_dev *dev, struct resource *res,
+                            struct pci_bus_region *region)
+{
+       __pcibios_bus_to_resource(dev->bus, res, region);
+}
 EXPORT_SYMBOL(pcibios_bus_to_resource);

diff --git a/include/linux/pci.h b/include/linux/pci.h
index fefb4e1..2b559f1 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h

@@ -385,6 +385,7 @@ struct pci_host_bridge {

 };

 #define        to_pci_host_bridge(n) container_of(n, struct pci_host_bridge, dev)
+struct pci_host_bridge *find_pci_host_bridge(struct pci_bus *bus);
 void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
                    void (*release_fn)(struct pci_host_bridge *),
                    void *release_data);

@@ -657,6 +658,9 @@ void pci_fixup_cardbus(struct pci_bus *);

 /* Generic PCI functions used internally */

+void __pcibios_resource_to_bus(struct pci_bus *bus,
+                              struct pci_bus_region *region,
+                              struct resource *res);
 void pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,
                            struct resource *res);
 void pcibios_bus_to_resource(struct pci_dev *dev, struct resource *res,
--
1.7.9.5