export __get_user_pages_fast() function
This function is used by KVM to pin process's page in the atomic context.
Define the 'weak' function to avoid other architecture not support it
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/mm/util.c b/mm/util.c
index 4735ea4..73dac81 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -245,6 +245,19 @@
}
#endif
+/*
+ * Like get_user_pages_fast() except its IRQ-safe in that it won't fall
+ * back to the regular GUP.
+ * If the architecture not support this fucntion, simply return with no
+ * page pinned
+ */
+int __attribute__((weak)) __get_user_pages_fast(unsigned long start,
+ int nr_pages, int write, struct page **pages)
+{
+ return 0;
+}
+EXPORT_SYMBOL_GPL(__get_user_pages_fast);
+
/**
* get_user_pages_fast() - pin user pages in memory
* @start: starting user address