[PATCH 3.2 23/46] s390/hugetlb: add hugepages_supported define

Ben Hutchings
2016-06-12T21:35:55Z

From: Dominik Dingel <dingel@linux.vnet.ibm.com>

commit 7f9be77555bb2e52de84e9dddf7b4eb20cc6e171 upstream.

On s390 we only can enable hugepages if the underlying hardware/hypervisor
also does support this. Common code now would assume this to be
signaled by setting HPAGE_SHIFT to 0. But on s390, where we only
support one hugepage size, there is a link between HPAGE_SHIFT and
pageblock_order.

So instead of setting HPAGE_SHIFT to 0, we will implement the check for
the hardware capability.

Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/s390/include/asm/hugetlb.h | 1 +
1 file changed, 1 insertion(+)

--- a/arch/s390/include/asm/hugetlb.h
+++ b/arch/s390/include/asm/hugetlb.h
@@ -14,6 +14,7 @@

#define is_hugepage_only_range(mm, addr, len) 0
#define hugetlb_free_pgd_range free_pgd_range
+#define hugepages_supported() (MACHINE_HAS_HPAGE)

void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte);