eal/arm: fix clang build of native target

When doing Clang build with '-mcpu=native' on N1 platform, build failed
with:
../lib/librte_eal/arm/include/rte_atomic_64.h:76:39:
	error: instruction requires: lse
__ATOMIC128_CAS_OP(__cas_128_release, "caspl")

This is because native detection for Neoverse N1 was added in Clang-11.
Prior version of Clang's assembler doesn't know LSE support on hardware.
Fixed this for Clang earlier than version 11 by specifying architecture
for assembler.
Referred to [1] for this fix.

Fixes: 7e2c3e17fe ("eal/arm64: add 128-bit atomic compare exchange")
Cc: stable@dpdk.org

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e0d5896bd356cd577f9710a02d7a474cdf58426b

Signed-off-by: Ruifeng Wang <ruifeng.wang@arm.com>
Reviewed-by: Jerin Jacob <jerinj@marvell.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
This commit is contained in:
Ruifeng Wang 2020-11-12 18:31:57 +08:00 committed by Thomas Monjalon
parent 2d0a972cd6
commit 8fce34cd0a

View File

@ -46,6 +46,8 @@ rte_atomic_thread_fence(int memorder)
/*------------------------ 128 bit atomic operations -------------------------*/
#if defined(__ARM_FEATURE_ATOMICS) || defined(RTE_ARM_FEATURE_ATOMICS)
#define __LSE_PREAMBLE ".arch armv8-a+lse\n"
#define __ATOMIC128_CAS_OP(cas_op_name, op_string) \
static __rte_noinline rte_int128_t \
cas_op_name(rte_int128_t *dst, rte_int128_t old, rte_int128_t updated) \
@ -59,6 +61,7 @@ cas_op_name(rte_int128_t *dst, rte_int128_t old, rte_int128_t updated) \
register uint64_t x2 __asm("x2") = (uint64_t)updated.val[0]; \
register uint64_t x3 __asm("x3") = (uint64_t)updated.val[1]; \
asm volatile( \
__LSE_PREAMBLE \
op_string " %[old0], %[old1], %[upd0], %[upd1], [%[dst]]" \
: [old0] "+r" (x0), \
[old1] "+r" (x1) \
@ -76,6 +79,7 @@ __ATOMIC128_CAS_OP(__cas_128_acquire, "caspa")
__ATOMIC128_CAS_OP(__cas_128_release, "caspl")
__ATOMIC128_CAS_OP(__cas_128_acq_rel, "caspal")
#undef __LSE_PREAMBLE
#undef __ATOMIC128_CAS_OP
#endif