x86, pat: fix warn_on_once() while mapping 0-1MB range with /dev/mem

Jeff Mahoney reported:

> With Suse's hwinfo tool, on -tip:
> WARNING: at arch/x86/mm/pat.c:637 reserve_pfn_range+0x5b/0x26d()

reserve_pfn_range() is not tracking the memory range below 1MB
as non-RAM and as such is inconsistent with similar checks in
reserve_memtype() and free_memtype()

Rename the pagerange_is_ram() to pat_pagerange_is_ram() and add the
"track legacy 1MB region as non RAM" condition.

And also, fix reserve_pfn_range() to return -EINVAL, when the pfn
range is RAM. This is to be consistent with this API design.

Reported-and-tested-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 0 insertions, 19 deletions

diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index af750ab973b6..f45d5e29a72e 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -134,25 +134,6 @@ int page_is_ram(unsigned long pagenr)
         return 0;
 }
 
-int pagerange_is_ram(unsigned long start, unsigned long end)
-{
-        int ram_page = 0, not_rampage = 0;
-        unsigned long page_nr;
-
-        for (page_nr = (start >> PAGE_SHIFT); page_nr < (end >> PAGE_SHIFT);
-             ++page_nr) {
-                if (page_is_ram(page_nr))
-                        ram_page = 1;
-                else
-                        not_rampage = 1;
-
-                if (ram_page == not_rampage)
-                        return -1;
-        }
-
-        return ram_page;
-}
-
 /*
  * Fix up the linear direct mapping of the kernel to avoid cache attribute
  * conflicts.