[PATCH 28/36] PCI: Add pci_bus_extend/shrink_top()

Yinghai Lu
2012-03-01T03:08:41Z

extend or shrink bus and parent buses top (subordinate)

extended range is verified safe range, and stop at recorded parent_res.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
---
drivers/pci/probe.c | 36 ++++++++++++++++++++++++++++++++++++
1 files changed, 36 insertions(+), 0 deletions(-)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 1c07aba..96259f8 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -655,6 +655,42 @@ static void pci_fixup_parent_subordinate_busnr(struct pci_bus *child, int max)
}
}

+static void __devinit pci_bus_update_top(struct pci_bus *parent,
+ long size, struct resource *parent_res)
+{
+ struct resource *res;
+
+ if (!size)
+ return;
+
+ while (parent) {
+ res = &parent->busn_res;
+ if (res == parent_res)
+ break;
+ res->end += size;
+ parent->subordinate += size;
+ pci_write_config_byte(parent->self, PCI_SUBORDINATE_BUS,
+ parent->subordinate);
+ dev_printk(KERN_DEBUG, &parent->dev,
+ "busn_res: %s %02lx to %pR\n",
+ (size > 0) ? "extended" : "shrunk",
+ abs(size), res);
+ parent = parent->parent;
+ }
+}
+
+static void __devinit pci_bus_extend_top(struct pci_bus *parent,
+ long size, struct resource *parent_res)
+{
+ pci_bus_update_top(parent, size, parent_res);
+}
+
+static void __devinit pci_bus_shrink_top(struct pci_bus *parent,
+ long size, struct resource *parent_res)
+{
+ pci_bus_update_top(parent, -size, parent_res);
+}
+
/*
* If it's a bridge, configure it and scan the bus behind it.
* For CardBus bridges, we don't scan behind as the devices will
--
1.7.7