[yocto] [meta-dpdk][PATCH] dpdk: Fix do_compile failure for qemux86 and qemux86-64

[zhe.he at windriver.com]

From: He Zhe <zhe.he at windriver.com>

DPDK_TARGET_MACHINE in bbappend in other layers forms the dpdk-internal variable
MACHINE_CFLAGS which is passed to dpdk compilation command line containing the
first -march parameter. And EXTRA_CFLAGS in dpdk.inc is passed to dpdk command
line containing the second -march parameter. By mistake, the first -march had
always overwritten the second one until the following commit of GCC v9.1.0
8c0f695d83d1 ("driver: Also prune joined switches with negation").

Since it was fixed, the second -march, which was core2 for qemux86-64 or
core2-32 for qemux86, began to take effect. But core2* does not have SSE4.2
feature which is required by some dpdk instruction optimization and thus cause
the following compilation failure.

9.1.0/include/smmintrin.h:179:1: error: inlining failed in call to always_inline
'_mm_blendv_epi8': target specific option mismatch
  179 | _mm_blendv_epi8 (__m128i __X, __m128i __Y, __m128i __M)
      | ^~~~~~~~~~~~~~~

This patch adds DPDK_EXTRA_CFLAGS to append appropriate -march, corei7 which is
minimum and clear and independent of host machine, to dpdk compilation command
line to overwrite all previous ones, without having to change dpdk source code.

Note that as we do not want to change the default tune core2* for qemux86*, this
patch just fixes the compilation error. It would probably not be able to run on
qemux86* with corei7 tune.

Signed-off-by: He Zhe <zhe.he at windriver.com>
---
 recipes-extended/dpdk/dpdk.inc | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/recipes-extended/dpdk/dpdk.inc b/recipes-extended/dpdk/dpdk.inc
index a0e081a..0275e0c 100644
--- a/recipes-extended/dpdk/dpdk.inc
+++ b/recipes-extended/dpdk/dpdk.inc
@@ -61,6 +61,9 @@ DPDK_RTE_TARGET_x86-64 = "x86_64-native-linuxapp-gcc"
 DPDK_RTE_TARGET_x86 = "i686-native-linuxapp-gcc"
 DPDK_RTE_TARGET_aarch64 = "arm64-${DPDK_TARGET_MACH}-linuxapp-gcc"
 export RTE_TARGET = "${DPDK_RTE_TARGET}"
+DPDK_EXTRA_CFLAGS = ""
+DPDK_EXTRA_CFLAGS_qemux86 ?= "-march=corei7"
+DPDK_EXTRA_CFLAGS_qemux86-64 ?= "-march=corei7"
 
 # The list of intel Comms platforms and their target machine
 # process mapping. The supported target machine is listed under
@@ -100,18 +103,18 @@ do_compile () {
 
 	cd ${S}/${RTE_TARGET}
 	oe_runmake EXTRA_LDFLAGS="-L${STAGING_LIBDIR} --hash-style=gnu" \
-		   EXTRA_CFLAGS="${HOST_CC_ARCH} ${TOOLCHAIN_OPTIONS} -I${STAGING_INCDIR}" \
+		   EXTRA_CFLAGS="${HOST_CC_ARCH} ${TOOLCHAIN_OPTIONS} ${DPDK_EXTRA_CFLAGS} -I${STAGING_INCDIR}" \
 		   CROSS="${TARGET_PREFIX}" \
 		   prefix=""  LDFLAGS="${TUNE_LDARGS}"  WERROR_FLAGS="-w" V=1
 
 	cd ${S}/examples/
 	oe_runmake EXTRA_LDFLAGS="-L${STAGING_LIBDIR} --hash-style=gnu -fuse-ld=bfd" \
-		   EXTRA_CFLAGS="${HOST_CC_ARCH} ${TOOLCHAIN_OPTIONS} -I${STAGING_INCDIR}" \
+		   EXTRA_CFLAGS="${HOST_CC_ARCH} ${TOOLCHAIN_OPTIONS} ${DPDK_EXTRA_CFLAGS} -I${STAGING_INCDIR}" \
 		   CROSS="${TARGET_PREFIX}" O="${S}/examples/$@/"
 
 	cd ${S}/test/
 	oe_runmake EXTRA_LDFLAGS="-L${STAGING_LIBDIR} --hash-style=gnu -fuse-ld=bfd" \
-		   EXTRA_CFLAGS="${HOST_CC_ARCH} ${TOOLCHAIN_OPTIONS} -I${STAGING_INCDIR}" \
+		   EXTRA_CFLAGS="${HOST_CC_ARCH} ${TOOLCHAIN_OPTIONS} ${DPDK_EXTRA_CFLAGS} -I${STAGING_INCDIR}" \
 		   CROSS="${TARGET_PREFIX}" O="${S}/test/$@/"
 }
 
-- 
2.7.4