Commit 36e097a8 authored Dec 18, 2013 by Bjorn Helgaas

PCI: Split out bridge window override of minimum allocation address



pci_bus_alloc_resource() avoids allocating space below the "min" supplied
by the caller (usually PCIBIOS_MIN_IO or PCIBIOS_MIN_MEM).  This is to
protect badly documented motherboard resources.  But if we're allocating
space inside an already-configured PCI-PCI bridge window, we ignore "min".

See 688d1918 ("pci: make bus resource start address override minimum IO
address").

This patch moves the check to make it more visible and simplify future
patches.  No functional change.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

parent 167b1f04

drivers/pci/bus.c

+11 −4

Original line number	Diff line number	Diff line
		@@ -147,11 +147,18 @@ pci_bus_alloc_resource(struct pci_bus bus, struct resource res,
		!(res->flags & IORESOURCE_PREFETCH))
		continue;

		/*
		* "min" is typically PCIBIOS_MIN_IO or PCIBIOS_MIN_MEM to
		* protect badly documented motherboard resources, but if
		* this is an already-configured bridge window, its start
		* overrides "min".
		*/
		if (r->start)
		min = r->start;

		/* Ok, try it out.. */
		ret = allocate_resource(r, res, size,
		r->start ? : min,
		max, align,
		alignf, alignf_data);
		ret = allocate_resource(r, res, size, min, max,
		align, alignf, alignf_data);
		if (ret == 0)
		break;
		}