vmalloc: add @align to vm_area_register_early()

Impact: allow larger alignment for early vmalloc area allocation

Some early vmalloc users might want larger alignment, for example, for
custom large page mapping.  Add @align to vm_area_register_early().
While at it, drop docbook comment on non-existent @size.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>

1 files changed, 7 insertions, 4 deletions

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 224eca9650a8..366ae9ea6af2 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -995,7 +995,7 @@ EXPORT_SYMBOL(vm_map_ram);
 /**
  * vm_area_register_early - register vmap area early during boot
  * @vm: vm_struct to register
- * @size: size of area to register
+ * @align: requested alignment
  *
  * This function is used to register kernel vm area before
  * vmalloc_init() is called.  @vm->size and @vm->flags should contain
@@ -1004,12 +1004,15 @@ EXPORT_SYMBOL(vm_map_ram);
  *
  * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
  */
-void __init vm_area_register_early(struct vm_struct *vm)
+void __init vm_area_register_early(struct vm_struct *vm, size_t align)
 {
         static size_t vm_init_off __initdata;
+        unsigned long addr;
+
+        addr = ALIGN(VMALLOC_START + vm_init_off, align);
+        vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
 
-        vm->addr = (void *)VMALLOC_START + vm_init_off;
-        vm_init_off = PFN_ALIGN(vm_init_off + vm->size);
+        vm->addr = (void *)addr;
 
         vm->next = vmlist;
         vmlist = vm;