[PATCH 2/2] Makefile: Don't enable V-extension using -march option

[Anup Patel <apatel@ventanamicro.com>]

Enabling V-extension using -march option causes OpenSBI boot-time
hang with LLVM compiler.

As a work-around, don't enable V-extension using -march option and
instead use a custom OpenSBI specific define inform availability of
V-extension to lib/sbi/sbi_trap_v_ldst.c.

Fixes: c2acc5e5b0d8 ("lib: sbi_misaligned_ldst: Add handling of vector load/store")
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 Makefile                  | 8 ++++----
 lib/sbi/sbi_trap_v_ldst.c | 5 +++--
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/Makefile b/Makefile
index 5ac95a0f..7e0a1399 100644
--- a/Makefile
+++ b/Makefile
@@ -190,7 +190,7 @@ CC_SUPPORT_STRICT_ALIGN := $(shell $(CC) $(CLANG_TARGET) $(RELAX_FLAG) -nostdlib
 CC_SUPPORT_ZICSR_ZIFENCEI := $(shell $(CC) $(CLANG_TARGET) $(RELAX_FLAG) -nostdlib -march=rv$(OPENSBI_CC_XLEN)imafd_zicsr_zifencei -x c /dev/null -o /dev/null 2>&1 | grep -e "zicsr" -e "zifencei" > /dev/null && echo n || echo y)
 
 # Check whether the assembler and the compiler support the Vector extension
-CC_SUPPORT_VECT := $(shell echo | $(CC) -dM -E -march=rv$(OPENSBI_CC_XLEN)gv - | grep -q riscv.*vector && echo y || echo n)
+CC_SUPPORT_VECT := $(shell $(CC) $(CLANG_TARGET) $(RELAX_FLAG) -nostdlib -march=rv$(OPENSBI_CC_XLEN)gv -dM -E -x c /dev/null 2>&1 | grep -q riscv.*vector && echo y || echo n)
 
 ifneq ($(OPENSBI_LD_PIE),y)
 $(error Your linker does not support creating PIEs, opensbi requires this.)
@@ -298,9 +298,6 @@ endif
 ifndef PLATFORM_RISCV_ISA
   ifneq ($(PLATFORM_RISCV_TOOLCHAIN_DEFAULT), 1)
     PLATFORM_RISCV_ISA := rv$(PLATFORM_RISCV_XLEN)imafdc
-    ifeq ($(CC_SUPPORT_VECT), y)
-      PLATFORM_RISCV_ISA := $(PLATFORM_RISCV_ISA)v
-    endif
     ifeq ($(CC_SUPPORT_ZICSR_ZIFENCEI), y)
       PLATFORM_RISCV_ISA := $(PLATFORM_RISCV_ISA)_zicsr_zifencei
     endif
@@ -363,6 +360,9 @@ GENFLAGS	+=	$(firmware-genflags-y)
 CFLAGS		=	-g -Wall -Werror -ffreestanding -nostdlib -fno-stack-protector -fno-strict-aliasing -ffunction-sections -fdata-sections
 CFLAGS		+=	-fno-omit-frame-pointer -fno-optimize-sibling-calls
 # Optionally supported flags
+ifeq ($(CC_SUPPORT_VECT),y)
+CFLAGS		+=	-DOPENSBI_CC_SUPPORT_VECT -fno-tree-vectorize
+endif
 ifeq ($(CC_SUPPORT_SAVE_RESTORE),y)
 CFLAGS		+=	-mno-save-restore
 endif
diff --git a/lib/sbi/sbi_trap_v_ldst.c b/lib/sbi/sbi_trap_v_ldst.c
index 9929215c..75b79baa 100644
--- a/lib/sbi/sbi_trap_v_ldst.c
+++ b/lib/sbi/sbi_trap_v_ldst.c
@@ -17,7 +17,8 @@
 #include <sbi/sbi_unpriv.h>
 #include <sbi/sbi_trap.h>
 
-#ifdef __riscv_vector
+#ifdef OPENSBI_CC_SUPPORT_VECT
+
 #define VLEN_MAX 65536
 
 static inline void set_vreg(ulong vlenb, ulong which,
@@ -340,4 +341,4 @@ int sbi_misaligned_v_st_emulator(int wlen, union sbi_ldst_data in_val,
 {
 	return 0;
 }
-#endif /* __riscv_vector  */
+#endif /* OPENSBI_CC_SUPPORT_VECT  */
-- 
2.43.0