s390/mm: limit number of real-space gmap shadows
authorDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Mon, 2 May 2016 10:10:17 +0000 (12:10 +0200)
committerChristian Borntraeger <borntraeger@de.ibm.com>
Mon, 20 Jun 2016 07:55:07 +0000 (09:55 +0200)
commit717c05554afa69a36398a57dac64b95972f138d5
treef713b8b2a0d8e43c3903e062e1e6c4a5fa8c32e5
parent3218f7094b6b583f4f01bffcf84572c6beacdcc2
s390/mm: limit number of real-space gmap shadows

We have no known user of real-space designation and only support it to
be architecture compliant.

Gmap shadows with real-space designation are never unshadowed
automatically, as there is nothing to protect for the top level table.

So let's simply limit the number of such shadows to one by removing
existing ones on creation of another one.

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
arch/s390/mm/gmap.c