target/ppc: Use atomic cmpxchg for STQCX

When running in a parallel context, we must use a helper in order
to perform the 128-bit atomic operation.  When running in a serial
context, do the compare before the store.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

1 files changed, 38 insertions, 0 deletions

diff --git a/target/ppc/mem_helper.c b/target/ppc/mem_helper.c
index 57e301e..8f0d86d 100644
--- a/target/ppc/mem_helper.c
+++ b/target/ppc/mem_helper.c
@@ -245,6 +245,44 @@ void helper_stq_be_parallel(CPUPPCState *env, target_ulong addr,
     Int128 val = int128_make128(lo, hi);
     helper_atomic_sto_be_mmu(env, addr, val, opidx, GETPC());
 }
+
+uint32_t helper_stqcx_le_parallel(CPUPPCState *env, target_ulong addr,
+                                  uint64_t new_lo, uint64_t new_hi,
+                                  uint32_t opidx)
+{
+    bool success = false;
+
+    if (likely(addr == env->reserve_addr)) {
+        Int128 oldv, cmpv, newv;
+
+        cmpv = int128_make128(env->reserve_val2, env->reserve_val);
+        newv = int128_make128(new_lo, new_hi);
+        oldv = helper_atomic_cmpxchgo_le_mmu(env, addr, cmpv, newv,
+                                             opidx, GETPC());
+        success = int128_eq(oldv, cmpv);
+    }
+    env->reserve_addr = -1;
+    return env->so + success * CRF_EQ_BIT;
+}
+
+uint32_t helper_stqcx_be_parallel(CPUPPCState *env, target_ulong addr,
+                                  uint64_t new_lo, uint64_t new_hi,
+                                  uint32_t opidx)
+{
+    bool success = false;
+
+    if (likely(addr == env->reserve_addr)) {
+        Int128 oldv, cmpv, newv;
+
+        cmpv = int128_make128(env->reserve_val2, env->reserve_val);
+        newv = int128_make128(new_lo, new_hi);
+        oldv = helper_atomic_cmpxchgo_be_mmu(env, addr, cmpv, newv,
+                                             opidx, GETPC());
+        success = int128_eq(oldv, cmpv);
+    }
+    env->reserve_addr = -1;
+    return env->so + success * CRF_EQ_BIT;
+}
 #endif
 
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