x86/boot: Fix kdump, cleanup aborted E820_PRAM max_pfn manipulation

In commit:

  ec776ef6bbe1 ("x86/mm: Add support for the non-standard protected e820 type")

Christoph references the original patch I wrote implementing pmem support.
The intent of the 'max_pfn' changes in that commit were to enable persistent
memory ranges to be covered by the struct page memmap by default.

However, that approach was abandoned when Christoph ported the patches [1], and
that functionality has since been replaced by devm_memremap_pages().

In the meantime, this max_pfn manipulation is confusing kdump [2] that
assumes that everything covered by the max_pfn is "System RAM".  This
results in kdump hanging or crashing.

 [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-March/000348.html
 [2]: https://bugzilla.redhat.com/show_bug.cgi?id=1351098

So fix it.

Reported-by: Zhang Yi <[email protected]>
Reported-by: Jeff Moyer <[email protected]>
Tested-by: Zhang Yi <[email protected]>
Signed-off-by: Dan Williams <[email protected]>
Reviewed-by: Jeff Moyer <[email protected]>
Cc: <[email protected]> # v4.1 and later kernels
Cc: Andrew Morton <[email protected]>
Cc: Boaz Harrosh <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Ross Zwisler <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Fixes: ec776ef6bbe1 ("x86/mm: Add support for the non-standard protected e820 type")
Link: http://lkml.kernel.org/r/147448744538.34910.11287693517367139607.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Ingo Molnar <[email protected]>

0 files changed, 0 insertions, 0 deletions