x86/mm: Move warning from __ioremap_check_ram() to the call site

__ioremap_check_ram() has a WARN_ONCE() which is emitted when the
given pfn range is not RAM. The warning is bogus in two aspects:

- it never triggers since walk_system_ram_range() only calls
  __ioremap_check_ram() for RAM ranges.

- the warning message is wrong as it says: "ioremap on RAM' after it
  established that the pfn range is not RAM.

Move the WARN_ONCE() to __ioremap_caller(), and update the message to
include the address range so we get an actual warning when something
tries to ioremap system RAM.

[ tglx: Massaged changelog ]

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1437088996-28511-2-git-send-email-toshi.kani@hp.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index cc5ccc4..fd3df0d 100644 (file)
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -63,8 +63,6 @@ static int __ioremap_check_ram(unsigned long start_pfn, unsigned long nr_pages,
                    !PageReserved(pfn_to_page(start_pfn + i)))
                        return 1;
 
-       WARN_ONCE(1, "ioremap on RAM pfn 0x%lx\n", start_pfn);
-
        return 0;
 }
 
@@ -131,8 +129,11 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr,
                pfn      = phys_addr >> PAGE_SHIFT;
                last_pfn = last_addr >> PAGE_SHIFT;
                if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL,
-                                         __ioremap_check_ram) == 1)
+                                         __ioremap_check_ram) == 1) {
+                       WARN_ONCE(1, "ioremap on RAM at 0x%llx - 0x%llx\n",
+                                       phys_addr, last_addr);
                        return NULL;
+               }
        }
        /*
         * Mappings have to be page-aligned