mm: provide init_mm mm_context initializer

Provide an INIT_MM_CONTEXT intializer macro which can be used to
statically initialize mm_struct:mm_context of init_mm.  This way we can
get rid of code which will do the initialization at run time (on s390).

In addition the current code can be found at a place where it is not
expected.  So let's have a common initializer which architectures
can use if needed.

This is based on a patch from Suzuki Poulose.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Suzuki Poulose <suzuki@in.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 11 insertions, 4 deletions

diff --git a/arch/s390/include/asm/mmu.h b/arch/s390/include/asm/mmu.h
index 03be99919d62..99e3409102b9 100644
--- a/arch/s390/include/asm/mmu.h
+++ b/arch/s390/include/asm/mmu.h
@@ -13,4 +13,9 @@ typedef struct {
         int alloc_pgste; /* cloned contexts will have extended page tables */
 } mm_context_t;
 
+#define INIT_MM_CONTEXT(name)                                                 \
+        .context.list_lock    = __SPIN_LOCK_UNLOCKED(name.context.list_lock), \
+        .context.crst_list    = LIST_HEAD_INIT(name.context.crst_list),       \
+        .context.pgtable_list = LIST_HEAD_INIT(name.context.pgtable_list),
+
 #endif
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index 90165e7ca04e..34c43f23b28c 100644
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -332,10 +332,6 @@ void __init vmem_map_init(void)
         unsigned long start, end;
         int i;
 
-        spin_lock_init(&init_mm.context.list_lock);
-        INIT_LIST_HEAD(&init_mm.context.crst_list);
-        INIT_LIST_HEAD(&init_mm.context.pgtable_list);
-        init_mm.context.noexec = 0;
         ro_start = ((unsigned long)&_stext) & PAGE_MASK;
         ro_end = PFN_ALIGN((unsigned long)&_eshared);
         for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
diff --git a/mm/init-mm.c b/mm/init-mm.c
index 57aba0da9668..1d29cdfe8ebb 100644
--- a/mm/init-mm.c
+++ b/mm/init-mm.c
@@ -7,6 +7,11 @@
 
 #include <asm/atomic.h>
 #include <asm/pgtable.h>
+#include <asm/mmu.h>
+
+#ifndef INIT_MM_CONTEXT
+#define INIT_MM_CONTEXT(name)
+#endif
 
 struct mm_struct init_mm = {
         .mm_rb          = RB_ROOT,
@@ -17,4 +22,5 @@ struct mm_struct init_mm = {
         .page_table_lock =  __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock),
         .mmlist         = LIST_HEAD_INIT(init_mm.mmlist),
         .cpu_vm_mask    = CPU_MASK_ALL,
+        INIT_MM_CONTEXT(init_mm)
 };