Let's perform all checking + offlining + removing under
device_hotplug_lock, so nobody can mess with these devices via
sysfs concurrently.
Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org>
Cc: Paul Mackerras <pau...@samba.org>
Cc: Michael Ellerman <m...@ellerman.id.au>
Cc: Rashmica Gupta <rashmic...@gmail.com>
Cc: Balbir Singh <bsinghar...@gmail.com>
Cc: Michael Neuling <mi...@neuling.org>
Reviewed-by: Pavel Tatashin <pavel.tatas...@microsoft.com>
Reviewed-by: Rashmica Gupta <rashmic...@gmail.com>
Acked-by: Balbir Singh <bsinghar...@gmail.com>
Signed-off-by: David Hildenbrand <da...@redhat.com>
---
arch/powerpc/platforms/powernv/memtrace.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/platforms/powernv/memtrace.c
b/arch/powerpc/platforms/powernv/memtrace.c
index fdd48f1a39f7..84d038ed3882 100644
--- a/arch/powerpc/platforms/powernv/memtrace.c
+++ b/arch/powerpc/platforms/powernv/memtrace.c
@@ -70,6 +70,7 @@ static int change_memblock_state(struct memory_block *mem,
void *arg)
return 0;
}
+/* called with device_hotplug_lock held */
static bool memtrace_offline_pages(u32 nid, u64 start_pfn, u64 nr_pages)
{
u64 end_pfn = start_pfn + nr_pages - 1;
@@ -110,6 +111,7 @@ static u64 memtrace_alloc_node(u32 nid, u64 size)
/* Trace memory needs to be aligned to the size */
end_pfn = round_down(end_pfn - nr_pages, nr_pages);
+ lock_device_hotplug();
for (base_pfn = end_pfn; base_pfn > start_pfn; base_pfn -= nr_pages) {
if (memtrace_offline_pages(nid, base_pfn, nr_pages) == true) {
/*
@@ -118,7 +120,6 @@ static u64 memtrace_alloc_node(u32 nid, u64 size)
* we never try to remove memory that spans two iomem
* resources.
*/
- lock_device_hotplug();
end_pfn = base_pfn + nr_pages;
for (pfn = base_pfn; pfn < end_pfn; pfn += bytes>>
PAGE_SHIFT) {
__remove_memory(nid, pfn << PAGE_SHIFT, bytes);
@@ -127,6 +128,7 @@ static u64 memtrace_alloc_node(u32 nid, u64 size)
return base_pfn << PAGE_SHIFT;
}
}
+ unlock_device_hotplug();
return 0;
}
--
2.17.1
