From: Emilio G. Cota Date: Mon, 27 Jun 2016 19:02:10 +0000 (-0400) Subject: target-arm: emulate SWP with atomic_xchg helper X-Git-Tag: qemu-xen-4.9.0-rc1~118^2~6 X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=cf12bce088f22b92bf62ffa0d7f6a3e951e355a9;p=qemu-xen.git target-arm: emulate SWP with atomic_xchg helper Signed-off-by: Emilio G. Cota Message-Id: <1467054136-10430-25-git-send-email-cota@braap.org> Signed-off-by: Richard Henderson --- diff --git a/target-arm/translate.c b/target-arm/translate.c index cc97d1ed46..7c32c9462a 100644 --- a/target-arm/translate.c +++ b/target-arm/translate.c @@ -8789,25 +8789,27 @@ static void disas_arm_insn(DisasContext *s, unsigned int insn) } tcg_temp_free_i32(addr); } else { + TCGv taddr; + TCGMemOp opc = s->be_data; + /* SWP instruction */ rm = (insn) & 0xf; - /* ??? This is not really atomic. However we know - we never have multiple CPUs running in parallel, - so it is good enough. */ - addr = load_reg(s, rn); - tmp = load_reg(s, rm); - tmp2 = tcg_temp_new_i32(); if (insn & (1 << 22)) { - gen_aa32_ld8u(s, tmp2, addr, get_mem_index(s)); - gen_aa32_st8(s, tmp, addr, get_mem_index(s)); + opc |= MO_UB; } else { - gen_aa32_ld32u(s, tmp2, addr, get_mem_index(s)); - gen_aa32_st32(s, tmp, addr, get_mem_index(s)); + opc |= MO_UL | MO_ALIGN; } - tcg_temp_free_i32(tmp); + + addr = load_reg(s, rn); + taddr = gen_aa32_addr(s, addr, opc); tcg_temp_free_i32(addr); - store_reg(s, rd, tmp2); + + tmp = load_reg(s, rm); + tcg_gen_atomic_xchg_i32(tmp, taddr, tmp, + get_mem_index(s), opc); + tcg_temp_free(taddr); + store_reg(s, rd, tmp); } } } else {