[PATCH v10 16/29] PCI: Introduce pci_bus_child_max_busnr()

From: Yijing Wang
Date: Tue Apr 21 2015 - 07:42:50 EST


Sometimes, we want to know the highest reserved
busnr for children bus. Because parent's bus->busn_res
may have padding in it. For example, some host drivers
don't know the bus end, so they supply the bus
resource (root_bus, 255), they want to update the
max bus number after pci scan complete. But pci scan
functions won't return the actual max bus number.
So we could use pci_bus_child_max_busnr() to find
that.

Signed-off-by: Fengguang Wu <fengguang.wu@xxxxxxxxx>
Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx>
---
drivers/pci/hotplug/acpiphp_glue.c | 29 +----------------------------
drivers/pci/pci.c | 27 +++++++++++++++++++++++++--
include/linux/pci.h | 2 +-
3 files changed, 27 insertions(+), 31 deletions(-)

diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index bcb90e4..84f2584 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -397,33 +397,6 @@ static void cleanup_bridge(struct acpiphp_bridge *bridge)
acpi_unlock_hp_context();
}

-/**
- * acpiphp_max_busnr - return the highest reserved bus number under the given bus.
- * @bus: bus to start search with
- */
-static unsigned char acpiphp_max_busnr(struct pci_bus *bus)
-{
- struct pci_bus *tmp;
- unsigned char max, n;
-
- /*
- * pci_bus_max_busnr will return the highest
- * reserved busnr for all these children.
- * that is equivalent to the bus->subordinate
- * value. We don't want to use the parent's
- * bus->subordinate value because it could have
- * padding in it.
- */
- max = bus->busn_res.start;
-
- list_for_each_entry(tmp, &bus->children, node) {
- n = pci_bus_max_busnr(tmp);
- if (n > max)
- max = n;
- }
- return max;
-}
-
static void acpiphp_set_acpi_region(struct acpiphp_slot *slot)
{
struct acpiphp_func *func;
@@ -489,7 +462,7 @@ static void enable_slot(struct acpiphp_slot *slot)
LIST_HEAD(add_list);

acpiphp_rescan_slot(slot);
- max = acpiphp_max_busnr(bus);
+ max = pci_bus_child_max_busnr(bus);
for (pass = 0; pass < 2; pass++) {
list_for_each_entry(dev, &bus->devices, bus_list) {
if (PCI_SLOT(dev->devfn) != slot->device)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 95ea445..d5cbea8 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -108,7 +108,7 @@ static bool pcie_ari_disabled;
* Given a PCI bus, returns the highest PCI bus number present in the set
* including the given PCI bus and its list of child PCI buses.
*/
-unsigned char pci_bus_max_busnr(struct pci_bus *bus)
+static unsigned char pci_bus_max_busnr(struct pci_bus *bus)
{
struct pci_bus *tmp;
unsigned char max, n;
@@ -121,7 +121,30 @@ unsigned char pci_bus_max_busnr(struct pci_bus *bus)
}
return max;
}
-EXPORT_SYMBOL_GPL(pci_bus_max_busnr);
+
+unsigned char pci_bus_child_max_busnr(struct pci_bus *bus)
+{
+ struct pci_bus *tmp;
+ unsigned char max, n;
+
+ /*
+ * pci_bus_max_busnr will return the highest
+ * reserved busnr for all these children.
+ * that is equivalent to the bus->subordinate
+ * value. We don't want to use the parent's
+ * bus->subordinate value because it could have
+ * padding in it.
+ */
+ max = bus->busn_res.start;
+
+ list_for_each_entry(tmp, &bus->children, node) {
+ n = pci_bus_max_busnr(tmp);
+ if (n > max)
+ max = n;
+ }
+ return max;
+}
+EXPORT_SYMBOL_GPL(pci_bus_child_max_busnr);

#ifdef CONFIG_HAS_IOMEM
void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 13edbf1..a82595a 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1188,7 +1188,7 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max,
void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
void *userdata);
int pci_cfg_space_size(struct pci_dev *dev);
-unsigned char pci_bus_max_busnr(struct pci_bus *bus);
+unsigned char pci_bus_child_max_busnr(struct pci_bus *bus);
void pci_setup_bridge(struct pci_bus *bus);
resource_size_t pcibios_window_alignment(struct pci_bus *bus,
unsigned long type);
--
1.7.1

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