[PATCH V2 3/3] s390/mm: Define arch_get_mappable_range()

From: Anshuman Khandual
Date: Thu Dec 17 2020 - 10:29:42 EST


This overrides arch_get_mappabble_range() on s390 platform which will be
used with recently added generic framework. It modifies the existing range
check in vmem_add_mapping() using arch_get_mappable_range(). It also adds a
VM_BUG_ON() check that would ensure that memhp_range_allowed() has already
been called on the hotplug path.

Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: linux-s390@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Acked-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
---
arch/s390/mm/init.c | 1 +
arch/s390/mm/vmem.c | 15 ++++++++++++++-
2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 77767850d0d0..e0e78234ae57 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -291,6 +291,7 @@ int arch_add_memory(int nid, u64 start, u64 size,
if (WARN_ON_ONCE(params->pgprot.pgprot != PAGE_KERNEL.pgprot))
return -EINVAL;

+ VM_BUG_ON(!memhp_range_allowed(start, size, 1));
rc = vmem_add_mapping(start, size);
if (rc)
return rc;
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index b239f2ba93b0..e10e563ad2b4 100644
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -4,6 +4,7 @@
* Author(s): Heiko Carstens <heiko.carstens@xxxxxxxxxx>
*/

+#include <linux/memory_hotplug.h>
#include <linux/memblock.h>
#include <linux/pfn.h>
#include <linux/mm.h>
@@ -532,11 +533,23 @@ void vmem_remove_mapping(unsigned long start, unsigned long size)
mutex_unlock(&vmem_mutex);
}

+struct range arch_get_mappable_range(void)
+{
+ struct range memhp_range;
+
+ memhp_range.start = 0;
+ memhp_range.end = VMEM_MAX_PHYS;
+ return memhp_range;
+}
+
int vmem_add_mapping(unsigned long start, unsigned long size)
{
+ struct range range;
int ret;

- if (start + size > VMEM_MAX_PHYS ||
+ range = arch_get_mappable_range();
+ if (start < range.start ||
+ start + size > range.end ||
start + size < start)
return -ERANGE;

--
2.20.1