From df3da04880b45b059b8b064c2dd67289a793109e Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Thu, 10 Oct 2019 13:31:59 -0700 Subject: [PATCH] mips: Fix unroll macro when building with Clang Building with Clang errors after commit 6baaeadae911 ("MIPS: Provide unroll() macro, use it for cache ops") since the GCC_VERSION macro is defined in include/linux/compiler-gcc.h, which is only included in compiler.h when using GCC: In file included from arch/mips/kernel/mips-mt.c:20: ./arch/mips/include/asm/r4kcache.h:254:1: error: use of undeclared identifier 'GCC_VERSION'; did you mean 'S_VERSION'? __BUILD_BLAST_CACHE(i, icache, Index_Invalidate_I, Hit_Invalidate_I, 32, ) ^ ./arch/mips/include/asm/r4kcache.h:219:4: note: expanded from macro '__BUILD_BLAST_CACHE' cache_unroll(32, kernel_cache, indexop, ^ ./arch/mips/include/asm/r4kcache.h:203:2: note: expanded from macro 'cache_unroll' unroll(times, _cache_op, insn, op, (addr) + (i++ * (lsize))); ^ ./arch/mips/include/asm/unroll.h:28:15: note: expanded from macro 'unroll' BUILD_BUG_ON(GCC_VERSION >= 40700 && \ ^ Use CONFIG_GCC_VERSION, which will always be set by Kconfig. Additionally, Clang 8 had improvements around __builtin_constant_p so use that as a lower limit for this check with Clang (although MIPS wasn't buildable until Clang 9); building a kernel with Clang 9.0.0 has no issues after this change. Fixes: 6baaeadae911 ("MIPS: Provide unroll() macro, use it for cache ops") Link: https://github.com/ClangBuiltLinux/linux/issues/736 Signed-off-by: Nathan Chancellor Signed-off-by: Paul Burton Cc: Ralf Baechle Cc: James Hogan Cc: linux-mips@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: clang-built-linux@googlegroups.com Cc: Nick Desaulniers --- arch/mips/include/asm/unroll.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/mips/include/asm/unroll.h b/arch/mips/include/asm/unroll.h index df1cdcf..c628747d 100644 --- a/arch/mips/include/asm/unroll.h +++ b/arch/mips/include/asm/unroll.h @@ -25,7 +25,8 @@ * generate reasonable code for the switch statement, \ * so we skip the sanity check for those compilers. \ */ \ - BUILD_BUG_ON(GCC_VERSION >= 40700 && \ + BUILD_BUG_ON((CONFIG_GCC_VERSION >= 40700 || \ + CONFIG_CLANG_VERSION >= 80000) && \ !__builtin_constant_p(times)); \ \ switch (times) { \ -- 2.7.4