PCI: prepare pci=realloc for multiple options

Let the user could enable and disable with pci=realloc=on or pci=realloc=off

Also
1. move variable and functions near the place they are used.
2. change macro to function
3. change related functions and variable to static and _init
4. update parameter description accordingly.

This will let us add a config option to control default behavior, and
still allow the user to turn off automatic reallocation if it fails on
their platform until a permanent solution is found.

-v2: still honor pci=realloc, and treat it as pci=realloc=on
     also use enum instead of ...
-v3: update kernel-paramenters.txt according to Jesse.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 7 insertions, 2 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 7fb7a4b161ff..7dc523e082a2 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2109,8 +2109,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                                 the default.
                                 off: Turn ECRC off
                                 on: Turn ECRC on.
-                realloc         reallocate PCI resources if allocations done by BIOS
-                                are erroneous.
+                realloc=        Enable/disable reallocating PCI bridge resources
+                                if allocations done by BIOS are too small to
+                                accommodate resources required by all child
+                                devices.
+                                off: Turn realloc off
+                                on: Turn realloc on
+                realloc         same as realloc=on
 
         pcie_aspm=      [PCIE] Forcibly enable or disable PCIe Active State Power
                         Management.