xtensa: remove the get_order() implementation

As the get_order() implemented by xtensa supporting 'nsau'
instruction seems be the same as the generic implementation
in include/asm-generic/getorder.h when size is not a constant
value as the generic implementation calling the fls*() is also
utilizing the 'nsau' instruction for xtensa.

So remove the get_order() implemented by xtensa, as using the
generic implementation may enable the compiler to do the
computing when size is a constant value instead of runtime
computing and enable the using of get_order() in BUILD_BUG_ON()
macro in next patch.

CC: Andrew Morton <akpm@linux-foundation.org>
CC: Linux-MM <linux-mm@kvack.org>
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Link: https://patch.msgid.link/20241028115343.3405838-6-linyunsheng@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 0 insertions, 18 deletions

diff --git a/arch/xtensa/include/asm/page.h b/arch/xtensa/include/asm/page.h
index 4db56ef052d2..8665d57991dd 100644
--- a/arch/xtensa/include/asm/page.h
+++ b/arch/xtensa/include/asm/page.h
@@ -109,26 +109,8 @@ typedef struct page *pgtable_t;
 #define __pgd(x)	((pgd_t) { (x) } )
 #define __pgprot(x)	((pgprot_t) { (x) } )
 
-/*
- * Pure 2^n version of get_order
- * Use 'nsau' instructions if supported by the processor or the generic version.
- */
-
-#if XCHAL_HAVE_NSA
-
-static inline __attribute_const__ int get_order(unsigned long size)
-{
-	int lz;
-	asm ("nsau %0, %1" : "=r" (lz) : "r" ((size - 1) >> PAGE_SHIFT));
-	return 32 - lz;
-}
-
-#else
-
 # include <asm-generic/getorder.h>
 
-#endif
-
 struct page;
 struct vm_area_struct;
 extern void clear_page(void *page);