walk system ram range

Originally, walk_memory_resource() was introduced to traverse all memory
of "System RAM" for detecting memory hotplug/unplug range.  For doing so,
flags of IORESOUCE_MEM|IORESOURCE_BUSY was used and this was enough for
memory hotplug.

But for using other purpose, /proc/kcore, this may includes some firmware
area marked as IORESOURCE_BUSY | IORESOUCE_MEM.  This patch makes the
check strict to find out busy "System RAM".

Note: PPC64 keeps their own walk_memory_resouce(), which walk through
ppc64's lmb informaton.  Because old kclist_add() is called per lmb, this
patch makes no difference in behavior, finally.

And this patch removes CONFIG_MEMORY_HOTPLUG check from this function.
Because pfn_valid() just show "there is memmap or not* and cannot be used
for "there is physical memory or not", this function is useful in generic
to scan physical memory range.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Américo Wang <xiyou.wangcong@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 2 insertions, 2 deletions

diff --git a/drivers/infiniband/hw/ehca/ehca_mrmw.c b/drivers/infiniband/hw/ehca/ehca_mrmw.c
index 7663a2a9f130..7550a534005c 100644
--- a/drivers/infiniband/hw/ehca/ehca_mrmw.c
+++ b/drivers/infiniband/hw/ehca/ehca_mrmw.c
@@ -2463,7 +2463,7 @@ int ehca_create_busmap(void)
         int ret;
 
         ehca_mr_len = 0;
-        ret = walk_memory_resource(0, 1ULL << MAX_PHYSMEM_BITS, NULL,
+        ret = walk_system_ram_range(0, 1ULL << MAX_PHYSMEM_BITS, NULL,
                                    ehca_create_busmap_callback);
         return ret;
 }
diff --git a/drivers/net/ehea/ehea_qmr.c b/drivers/net/ehea/ehea_qmr.c
index 3747457f5e69..bc7c5b7abb88 100644
--- a/drivers/net/ehea/ehea_qmr.c
+++ b/drivers/net/ehea/ehea_qmr.c
@@ -751,7 +751,7 @@ int ehea_create_busmap(void)
 
         mutex_lock(&ehea_busmap_mutex);
         ehea_mr_len = 0;
-        ret = walk_memory_resource(0, 1ULL << MAX_PHYSMEM_BITS, NULL,
+        ret = walk_system_ram_range(0, 1ULL << MAX_PHYSMEM_BITS, NULL,
                                    ehea_create_busmap_callback);
         mutex_unlock(&ehea_busmap_mutex);
         return ret;