From e419ddeabe7edd89650a19f411f928eea12b35b1 Mon Sep 17 00:00:00 2001 From: Greg Ungerer Date: Mon, 13 Nov 2023 23:32:09 +1000 Subject: m68k: Use kernel's generic muldi3 libgcc function Use the kernels own generic lib/muldi3.c implementation of muldi3 for 68K machines. Some 68K CPUs support 64bit multiplies so move the arch specific umul_ppmm() macro into a header file that is included by lib/muldi3.c. That way it can take advantage of the single instruction when available. There does not appear to be any existing mechanism for the generic lib/muldi3.c code to pick up an external arch definition of umul_ppmm(). Create an arch specific libgcc.h that can optionally be included by the system include/linux/libgcc.h to allow for this. Somewhat oddly there is also a similar definition of umul_ppmm() in the non-architecture code in lib/crypto/mpi/longlong.h for a wide range or machines. Its presence ends up complicating the include setup and means not being able to use something like compiler.h instead. Actually there is a few other defines of umul_ppmm() macros spread around in various architectures, but not directly usable for the m68k case. Signed-off-by: Greg Ungerer Link: https://lore.kernel.org/20231113133209.1367286-1-gerg@linux-m68k.org Reviewed-by: Geert Uytterhoeven Reviewed-by: Arnd Bergmann Signed-off-by: Geert Uytterhoeven --- include/linux/libgcc.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux/libgcc.h') diff --git a/include/linux/libgcc.h b/include/linux/libgcc.h index fc388da6a027..0d68f9d6a6a7 100644 --- a/include/linux/libgcc.h +++ b/include/linux/libgcc.h @@ -34,4 +34,8 @@ long long notrace __lshrdi3(long long u, word_type b); long long notrace __muldi3(long long u, long long v); word_type notrace __ucmpdi2(unsigned long long a, unsigned long long b); +#ifdef CONFIG_HAVE_ARCH_LIBGCC_H +#include +#endif + #endif /* __ASM_LIBGCC_H */ -- cgit v1.2.3