resources: fix x86info results ioremap.c:226 __ioremap_caller+0xf2/0x2d6() WARNINGs
commitd68612b257b5f4ea2e6535859c5a26b10011a9df
authorSuresh Siddha <suresh.b.siddha@intel.com>
Tue, 28 Oct 2008 18:45:42 +0000 (28 11:45 -0700)
committerIngo Molnar <mingo@elte.hu>
Tue, 28 Oct 2008 18:56:17 +0000 (28 19:56 +0100)
treeabbc11c7ec95d97d11c9c7f9e0e87fd4ef0b4a58
parente946217e4fdaa67681bbabfa8e6b18641921f750
resources: fix x86info results ioremap.c:226 __ioremap_caller+0xf2/0x2d6() WARNINGs

Impact: avoid false-positive WARN_ON()

Andi Kleen reported:
> When running x86info on a 2.6.27-git8 system I get
>
> resource map sanity check conflict: 0x9e000 0x9efff 0x10000 0x9e7ff System RAM
> ------------[ cut here ]------------
> WARNING: at /home/lsrc/linux/arch/x86/mm/ioremap.c:226 __ioremap_caller+0xf2/0x2d6()
> ...

Some of the pages below the 1MB ISA addresses will be shared typically by both
BIOS and system usable RAM. For example:
BIOS-e820: 0000000000000000 - 000000000009f800 (usable)
BIOS-e820: 000000000009f800 - 00000000000a0000 (reserved)

x86info reads the low physical address using /dev/mem, which internally
uses ioremap() for accessing non RAM pages. ioremap() of such low
pages conflicts with multiple resource entities leading to the
above warning.

Change the iomem_map_sanity_check() to allow mapping a page spanning multiple
resource entities (minimum granularity that one can map is a page anyhow).

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
kernel/resource.c