Unverified Commit 4525462d authored by Charlie Jenkins's avatar Charlie Jenkins Committed by Palmer Dabbelt
Browse files

riscv: lib: Check if output in asm goto supported 



The output field of an asm goto statement is not supported by all
compilers. If it is not supported, fallback to the non-optimized code.

Signed-off-by: default avatarCharlie Jenkins <charlie@rivosinc.com>
Fixes: a04c192e ("riscv: Add checksum library")
Link: https://lore.kernel.org/r/20240118-csum_remove_output_operands_asm_goto-v2-1-5d1b73cf93d4@rivosinc.com


Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent 66f962d8

arch/riscv/lib/csum.c

+2 −0
Original line number Diff line number Diff line
@@ -156,6 +156,7 @@ do_csum_with_alignment(const unsigned char *buff, int len) 
	end = (const unsigned long *)(buff + len);

	csum = do_csum_common(ptr, end, data);



#ifdef CC_HAS_ASM_GOTO_TIED_OUTPUT

	/*

	 * Zbb support saves 6 instructions, so not worth checking without

	 * alternatives if supported
@@ -214,6 +215,7 @@ do_csum_with_alignment(const unsigned char *buff, int len) 
		return csum >> 16;

	}

no_zbb:

#endif /* CC_HAS_ASM_GOTO_TIED_OUTPUT */

#ifndef CONFIG_32BIT

	csum += ror64(csum, 32);

	csum >>= 32;