[RFC 04/10] mm: vmalloc: support creating aligned vm areas

[David Stevens <stevensd@google.com>]

Expose a get_vm_area_node() function that supports passing an alignment
when allocating a vm area.

Signed-off-by: David Stevens <stevensd@google.com>
---
 include/linux/vmalloc.h |  2 ++
 mm/vmalloc.c            | 24 +++++++++++++++++++++++-
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index d87dc7f77f4e..5ed9c5b25026 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -246,6 +246,8 @@ static inline size_t get_vm_area_size(const struct vm_struct *area)
 extern struct vm_struct *get_vm_area(unsigned long size, unsigned long flags);
 extern struct vm_struct *get_vm_area_caller(unsigned long size,
 					unsigned long flags, const void *caller);
+extern struct vm_struct *get_vm_area_node(unsigned long size, unsigned long align,
+					  unsigned long flags, int node);
 extern struct vm_struct *__get_vm_area_caller(unsigned long size,
 					unsigned long flags,
 					unsigned long start, unsigned long end,
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index d39897300f29..059cd0748514 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -3280,7 +3280,7 @@ struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
  * @flags:	 %VM_IOREMAP for I/O mappings or VM_ALLOC
  *
  * Search an area of @size in the kernel virtual mapping area,
- * and reserved it for out purposes.  Returns the area descriptor
+ * and reserved it for our purposes.  Returns the area descriptor
  * on success or %NULL on failure.
  *
  * Return: the area descriptor on success or %NULL on failure.
@@ -3301,6 +3301,28 @@ struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
 				  NUMA_NO_NODE, GFP_KERNEL, caller);
 }
 
+/**
+ * get_vm_area_node - reserve a contiguous kernel virtual area
+ * @size:	 size of the area
+ * @align:	 alignment of the area
+ * @flags:	 %VM_IOREMAP for I/O mappings or VM_ALLOC
+ * @node:	 node from which to allocate data structures
+ *
+ * Search an area of @size in the kernel virtual mapping area,
+ * and reserve it for our purposes.  Returns the area descriptor
+ * on success or %NULL on failure.
+ *
+ * Return: the area descriptor on success or %NULL on failure.
+ */
+struct vm_struct *get_vm_area_node(unsigned long size, unsigned long align,
+				   unsigned long flags, int node)
+{
+	return __get_vm_area_node(size, align, PAGE_SHIFT, flags,
+				  VMALLOC_START, VMALLOC_END,
+				  node, GFP_KERNEL,
+				  __builtin_return_address(0));
+}
+
 /**
  * find_vm_area - find a continuous kernel virtual area
  * @addr:	  base address
-- 
2.55.0.897.gb25b4bd76c-goog