Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20180510' into staging

target-arm queue:
 * hw/arm/iotkit.c: fix minor memory leak
 * softfloat: fix wrong-exception-flags bug for multiply-add corner case
 * arm: isolate and clean up DTB generation
 * implement Arm v8.1-Atomics extension
 * Fix some bugs and missing instructions in the v8.2-FP16 extension

# gpg: Signature made Thu 10 May 2018 18:44:34 BST
# gpg:                using RSA key 3C2525ED14360CDE
# gpg: Good signature from "Peter Maydell <peter.maydell@linaro.org>"
# gpg:                 aka "Peter Maydell <pmaydell@gmail.com>"
# gpg:                 aka "Peter Maydell <pmaydell@chiark.greenend.org.uk>"
# Primary key fingerprint: E1A5 C593 CD41 9DE2 8E83  15CF 3C25 25ED 1436 0CDE

* remotes/pmaydell/tags/pull-target-arm-20180510: (21 commits)
  target/arm: Clear SVE high bits for FMOV
  target/arm: Fix float16 to/from int16
  target/arm: Implement vector shifted FCVT for fp16
  target/arm: Implement vector shifted SCVF/UCVF for fp16
  target/arm: Enable ARM_FEATURE_V8_ATOMICS for user-only
  target/arm: Implement CAS and CASP
  target/arm: Fill in disas_ldst_atomic
  target/arm: Introduce ARM_FEATURE_V8_ATOMICS and initial decode
  target/riscv: Use new atomic min/max expanders
  tcg: Use GEN_ATOMIC_HELPER_FN for opposite endian atomic add
  tcg: Introduce atomic helpers for integer min/max
  target/xtensa: Use new min/max expanders
  target/arm: Use new min/max expanders
  tcg: Introduce helpers for integer min/max
  atomic.h: Work around gcc spurious "unused value" warning
  make sure that we aren't overwriting mc->get_hotplug_handler by accident
  arm/boot: split load_dtb() from arm_load_kernel()
  platform-bus-device: use device plug callback instead of machine_done notifier
  pc: simplify MachineClass::get_hotplug_handler handling
  softfloat: Handle default NaN mode after pickNaNMulAdd, not before
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

# Conflicts:
#	target/riscv/translate.c

2 files changed, 82 insertions, 38 deletions

diff --git a/accel/tcg/atomic_template.h b/accel/tcg/atomic_template.h
index e022df4..3f41ef2 100644
--- a/accel/tcg/atomic_template.h
+++ b/accel/tcg/atomic_template.h
@@ -25,18 +25,22 @@
 #elif DATA_SIZE == 8
 # define SUFFIX     q
 # define DATA_TYPE  uint64_t
+# define SDATA_TYPE int64_t
 # define BSWAP      bswap64
 #elif DATA_SIZE == 4
 # define SUFFIX     l
 # define DATA_TYPE  uint32_t
+# define SDATA_TYPE int32_t
 # define BSWAP      bswap32
 #elif DATA_SIZE == 2
 # define SUFFIX     w
 # define DATA_TYPE  uint16_t
+# define SDATA_TYPE int16_t
 # define BSWAP      bswap16
 #elif DATA_SIZE == 1
 # define SUFFIX     b
 # define DATA_TYPE  uint8_t
+# define SDATA_TYPE int8_t
 # define BSWAP
 #else
 # error unsupported data size
@@ -118,6 +122,39 @@ GEN_ATOMIC_HELPER(or_fetch)
 GEN_ATOMIC_HELPER(xor_fetch)
 
 #undef GEN_ATOMIC_HELPER
+
+/* These helpers are, as a whole, full barriers.  Within the helper,
+ * the leading barrier is explicit and the trailing barrier is within
+ * cmpxchg primitive.
+ */
+#define GEN_ATOMIC_HELPER_FN(X, FN, XDATA_TYPE, RET)                \
+ABI_TYPE ATOMIC_NAME(X)(CPUArchState *env, target_ulong addr,       \
+                        ABI_TYPE xval EXTRA_ARGS)                   \
+{                                                                   \
+    ATOMIC_MMU_DECLS;                                               \
+    XDATA_TYPE *haddr = ATOMIC_MMU_LOOKUP;                          \
+    XDATA_TYPE cmp, old, new, val = xval;                           \
+    smp_mb();                                                       \
+    cmp = atomic_read__nocheck(haddr);                              \
+    do {                                                            \
+        old = cmp; new = FN(old, val);                              \
+        cmp = atomic_cmpxchg__nocheck(haddr, old, new);             \
+    } while (cmp != old);                                           \
+    ATOMIC_MMU_CLEANUP;                                             \
+    return RET;                                                     \
+}
+
+GEN_ATOMIC_HELPER_FN(fetch_smin, MIN, SDATA_TYPE, old)
+GEN_ATOMIC_HELPER_FN(fetch_umin, MIN,  DATA_TYPE, old)
+GEN_ATOMIC_HELPER_FN(fetch_smax, MAX, SDATA_TYPE, old)
+GEN_ATOMIC_HELPER_FN(fetch_umax, MAX,  DATA_TYPE, old)
+
+GEN_ATOMIC_HELPER_FN(smin_fetch, MIN, SDATA_TYPE, new)
+GEN_ATOMIC_HELPER_FN(umin_fetch, MIN,  DATA_TYPE, new)
+GEN_ATOMIC_HELPER_FN(smax_fetch, MAX, SDATA_TYPE, new)
+GEN_ATOMIC_HELPER_FN(umax_fetch, MAX,  DATA_TYPE, new)
+
+#undef GEN_ATOMIC_HELPER_FN
 #endif /* DATA SIZE >= 16 */
 
 #undef END
@@ -192,47 +229,45 @@ GEN_ATOMIC_HELPER(xor_fetch)
 
 #undef GEN_ATOMIC_HELPER
 
+/* These helpers are, as a whole, full barriers.  Within the helper,
+ * the leading barrier is explicit and the trailing barrier is within
+ * cmpxchg primitive.
+ */
+#define GEN_ATOMIC_HELPER_FN(X, FN, XDATA_TYPE, RET)                \
+ABI_TYPE ATOMIC_NAME(X)(CPUArchState *env, target_ulong addr,       \
+                        ABI_TYPE xval EXTRA_ARGS)                   \
+{                                                                   \
+    ATOMIC_MMU_DECLS;                                               \
+    XDATA_TYPE *haddr = ATOMIC_MMU_LOOKUP;                          \
+    XDATA_TYPE ldo, ldn, old, new, val = xval;                      \
+    smp_mb();                                                       \
+    ldn = atomic_read__nocheck(haddr);                              \
+    do {                                                            \
+        ldo = ldn; old = BSWAP(ldo); new = FN(old, val);            \
+        ldn = atomic_cmpxchg__nocheck(haddr, ldo, BSWAP(new));      \
+    } while (ldo != ldn);                                           \
+    ATOMIC_MMU_CLEANUP;                                             \
+    return RET;                                                     \
+}
+
+GEN_ATOMIC_HELPER_FN(fetch_smin, MIN, SDATA_TYPE, old)
+GEN_ATOMIC_HELPER_FN(fetch_umin, MIN,  DATA_TYPE, old)
+GEN_ATOMIC_HELPER_FN(fetch_smax, MAX, SDATA_TYPE, old)
+GEN_ATOMIC_HELPER_FN(fetch_umax, MAX,  DATA_TYPE, old)
+
+GEN_ATOMIC_HELPER_FN(smin_fetch, MIN, SDATA_TYPE, new)
+GEN_ATOMIC_HELPER_FN(umin_fetch, MIN,  DATA_TYPE, new)
+GEN_ATOMIC_HELPER_FN(smax_fetch, MAX, SDATA_TYPE, new)
+GEN_ATOMIC_HELPER_FN(umax_fetch, MAX,  DATA_TYPE, new)
+
 /* Note that for addition, we need to use a separate cmpxchg loop instead
    of bswaps for the reverse-host-endian helpers.  */
-ABI_TYPE ATOMIC_NAME(fetch_add)(CPUArchState *env, target_ulong addr,
-                         ABI_TYPE val EXTRA_ARGS)
-{
-    ATOMIC_MMU_DECLS;
-    DATA_TYPE *haddr = ATOMIC_MMU_LOOKUP;
-    DATA_TYPE ldo, ldn, ret, sto;
-
-    ldo = atomic_read__nocheck(haddr);
-    while (1) {
-        ret = BSWAP(ldo);
-        sto = BSWAP(ret + val);
-        ldn = atomic_cmpxchg__nocheck(haddr, ldo, sto);
-        if (ldn == ldo) {
-            ATOMIC_MMU_CLEANUP;
-            return ret;
-        }
-        ldo = ldn;
-    }
-}
+#define ADD(X, Y)   (X + Y)
+GEN_ATOMIC_HELPER_FN(fetch_add, ADD, DATA_TYPE, old)
+GEN_ATOMIC_HELPER_FN(add_fetch, ADD, DATA_TYPE, new)
+#undef ADD
 
-ABI_TYPE ATOMIC_NAME(add_fetch)(CPUArchState *env, target_ulong addr,
-                         ABI_TYPE val EXTRA_ARGS)
-{
-    ATOMIC_MMU_DECLS;
-    DATA_TYPE *haddr = ATOMIC_MMU_LOOKUP;
-    DATA_TYPE ldo, ldn, ret, sto;
-
-    ldo = atomic_read__nocheck(haddr);
-    while (1) {
-        ret = BSWAP(ldo) + val;
-        sto = BSWAP(ret);
-        ldn = atomic_cmpxchg__nocheck(haddr, ldo, sto);
-        if (ldn == ldo) {
-            ATOMIC_MMU_CLEANUP;
-            return ret;
-        }
-        ldo = ldn;
-    }
-}
+#undef GEN_ATOMIC_HELPER_FN
 #endif /* DATA_SIZE >= 16 */
 
 #undef END
@@ -241,5 +276,6 @@ ABI_TYPE ATOMIC_NAME(add_fetch)(CPUArchState *env, target_ulong addr,
 #undef BSWAP
 #undef ABI_TYPE
 #undef DATA_TYPE
+#undef SDATA_TYPE
 #undef SUFFIX
 #undef DATA_SIZE
diff --git a/accel/tcg/tcg-runtime.h b/accel/tcg/tcg-runtime.h
index 2536959..1bd39d1 100644
--- a/accel/tcg/tcg-runtime.h
+++ b/accel/tcg/tcg-runtime.h
@@ -125,11 +125,19 @@ GEN_ATOMIC_HELPERS(fetch_add)
 GEN_ATOMIC_HELPERS(fetch_and)
 GEN_ATOMIC_HELPERS(fetch_or)
 GEN_ATOMIC_HELPERS(fetch_xor)
+GEN_ATOMIC_HELPERS(fetch_smin)
+GEN_ATOMIC_HELPERS(fetch_umin)
+GEN_ATOMIC_HELPERS(fetch_smax)
+GEN_ATOMIC_HELPERS(fetch_umax)
 
 GEN_ATOMIC_HELPERS(add_fetch)
 GEN_ATOMIC_HELPERS(and_fetch)
 GEN_ATOMIC_HELPERS(or_fetch)
 GEN_ATOMIC_HELPERS(xor_fetch)
+GEN_ATOMIC_HELPERS(smin_fetch)
+GEN_ATOMIC_HELPERS(umin_fetch)
+GEN_ATOMIC_HELPERS(smax_fetch)
+GEN_ATOMIC_HELPERS(umax_fetch)
 
 GEN_ATOMIC_HELPERS(xchg)