radix tree test suite: add some more functionality

IDR needs more functionality from the kernel: kmalloc()/kfree(), and
xchg().

Link: http://lkml.kernel.org/r/1480369871-5271-67-git-send-email-mawilcox@linuxonhyperv.com
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tools/testing/radix-tree/linux/kernel.h

@@ -8,6 +8,7 @@
 #include <limits.h>
 
 #include "../../include/linux/compiler.h"
+#include "../../include/linux/err.h"
 #include "../../../include/linux/kconfig.h"
 
 #ifdef BENCHMARK
@@ -58,4 +59,6 @@ static inline int in_interrupt(void)
 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
 #define round_down(x, y) ((x) & ~__round_mask(x, y))
 
+#define xchg(ptr, x)	uatomic_xchg(ptr, x)
+
 #endif /* _KERNEL_H */

tools/testing/radix-tree/linux/slab.h

@@ -7,6 +7,9 @@
 #define SLAB_PANIC 2
 #define SLAB_RECLAIM_ACCOUNT    0x00020000UL            /* Objects are reclaimable */
 
+void *kmalloc(size_t size, gfp_t);
+void kfree(void *);
+
 struct kmem_cache {
 	int size;
 	void (*ctor)(void *);