Commit 1c9cf9b2 authored Jul 16, 2015 by Toshi Kani Committed by Thomas Gleixner Jul 22, 2015

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>

parent cd369c22

arch/x86/mm/ioremap.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -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;
		}

		@@ -131,9 +129,12 @@ 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
		*/

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