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PCI: Split out bridge window override of minimum allocation address

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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 688d191821 ("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>
This commit is contained in:
Bjorn Helgaas 2013-12-18 16:31:39 -07:00
parent 167b1f0490
commit 36e097a8a2
1 changed files with 11 additions and 4 deletions
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15
drivers/pci/bus.c
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@ -147,11 +147,18 @@ pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
!(res->flags & IORESOURCE_PREFETCH)) !(res->flags & IORESOURCE_PREFETCH))
continue; 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.. */ /* Ok, try it out.. */
ret = allocate_resource(r, res, size, ret = allocate_resource(r, res, size, min, max,
r->start ? : min, align, alignf, alignf_data);
max, align,
alignf, alignf_data);
if (ret == 0) if (ret == 0)
break; break;
} }