[PATCH] RISC-V: Avoid coupling the T-Head CMOs and Zicbom

[Palmer Dabbelt]

We could make the T-Head CMOs depend on a new-enough assembler to have
Zicbom, but it's not strictly necessary because the T-Head CMOs
circumvent the assembler.

Fixes: 8f7e001e0325 ("RISC-V: Clean up the Zicbom block size probing")
Cc: stable at vger.kernel.org
Reported-by: kernel test robot <lkp at intel.com>
Reported-by: Conor Dooley <conor.dooley at microchip.com>
Signed-off-by: Palmer Dabbelt <palmer at rivosinc.com>
---
 arch/riscv/include/asm/cacheflush.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/include/asm/cacheflush.h b/arch/riscv/include/asm/cacheflush.h
index a89c005b4bbf..273ece6b622f 100644
--- a/arch/riscv/include/asm/cacheflush.h
+++ b/arch/riscv/include/asm/cacheflush.h
@@ -42,8 +42,12 @@ void flush_icache_mm(struct mm_struct *mm, bool local);
 
 #endif /* CONFIG_SMP */
 
-#ifdef CONFIG_RISCV_ISA_ZICBOM
+/*
+ * The T-Head CMO errata internally probe the CBOM block size, but otherwise
+ * don't depend on Zicbom.
+ */
 extern unsigned int riscv_cbom_block_size;
+#ifdef CONFIG_RISCV_ISA_ZICBOM
 void riscv_init_cbom_blocksize(void);
 #else
 static inline void riscv_init_cbom_blocksize(void) { }
-- 
2.34.1