target/hppa: Fix atomic_store_3 for STBY

The parallel version of STBY did not take host endianness into
account, and also computed the incorrect address for STBY_E.

Bswap twice to handle the merge and store.  Compute mask inside
the function rather than as a parameter.  Force align the address,
rather than subtracting one.

Generalize the function to system mode by using probe_access().

Cc: qemu-stable@nongnu.org
Tested-by: Helge Deller <deller@gmx.de>
Reported-by: Helge Deller <deller@gmx.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

target/hppa/op_helper.c

@@ -57,26 +57,29 @@ void HELPER(tcond)(CPUHPPAState *env, target_ureg cond)
     }
 }
 
-static void atomic_store_3(CPUHPPAState *env, target_ulong addr, uint32_t val,
-                           uint32_t mask, uintptr_t ra)
+static void atomic_store_3(CPUHPPAState *env, target_ulong addr,
+                           uint32_t val, uintptr_t ra)
 {
-#ifdef CONFIG_USER_ONLY
-    uint32_t old, new, cmp;
+    int mmu_idx = cpu_mmu_index(env, 0);
+    uint32_t old, new, cmp, mask, *haddr;
+    void *vaddr;
+
+    vaddr = probe_access(env, addr, 3, MMU_DATA_STORE, mmu_idx, ra);
+    if (vaddr == NULL) {
+        cpu_loop_exit_atomic(env_cpu(env), ra);
+    }
+    haddr = (uint32_t *)((uintptr_t)vaddr & -4);
+    mask = addr & 1 ? 0x00ffffffu : 0xffffff00u;
 
-    uint32_t *haddr = g2h(env_cpu(env), addr - 1);
     old = *haddr;
     while (1) {
-        new = (old & ~mask) | (val & mask);
+        new = be32_to_cpu((cpu_to_be32(old) & ~mask) | (val & mask));
         cmp = qatomic_cmpxchg(haddr, old, new);
         if (cmp == old) {
             return;
         }
         old = cmp;
     }
-#else
-    /* FIXME -- we can do better.  */
-    cpu_loop_exit_atomic(env_cpu(env), ra);
-#endif
 }
 
 static void do_stby_b(CPUHPPAState *env, target_ulong addr, target_ureg val,
@@ -92,7 +95,7 @@ static void do_stby_b(CPUHPPAState *env, target_ulong addr, target_ureg val,
     case 1:
         /* The 3 byte store must appear atomic.  */
         if (parallel) {
-            atomic_store_3(env, addr, val, 0x00ffffffu, ra);
+            atomic_store_3(env, addr, val, ra);
         } else {
             cpu_stb_data_ra(env, addr, val >> 16, ra);
             cpu_stw_data_ra(env, addr + 1, val, ra);
@@ -122,7 +125,7 @@ static void do_stby_e(CPUHPPAState *env, target_ulong addr, target_ureg val,
     case 3:
         /* The 3 byte store must appear atomic.  */
         if (parallel) {
-            atomic_store_3(env, addr - 3, val, 0xffffff00u, ra);
+            atomic_store_3(env, addr - 3, val, ra);
         } else {
             cpu_stw_data_ra(env, addr - 3, val >> 16, ra);
             cpu_stb_data_ra(env, addr - 1, val >> 8, ra);

tests/tcg/hppa/Makefile.target

@@ -12,3 +12,8 @@ run-signals: signals
 	$(call skip-test, $<, "BROKEN awaiting vdso support")
 run-plugin-signals-with-%:
 	$(call skip-test, $<, "BROKEN awaiting vdso support")
+
+VPATH += $(SRC_PATH)/tests/tcg/hppa
+TESTS += stby
+
+stby: CFLAGS += -pthread

tests/tcg/hppa/stby.c

@@ -0,0 +1,87 @@
+/* Test STBY */
+
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+struct S {
+    unsigned a;
+    unsigned b;
+    unsigned c;
+};
+
+static void check(const struct S *s, unsigned e,
+                  const char *which, const char *insn, int ofs)
+{
+    int err = 0;
+
+    if (s->a != 0) {
+        fprintf(stderr, "%s %s %d: garbage before word 0x%08x\n",
+                which, insn, ofs, s->a);
+        err = 1;
+    }
+    if (s->c != 0) {
+        fprintf(stderr, "%s %s %d: garbage after word 0x%08x\n",
+                which, insn, ofs, s->c);
+        err = 1;
+    }
+    if (s->b != e) {
+        fprintf(stderr, "%s %s %d: 0x%08x != 0x%08x\n",
+                which, insn, ofs, s->b, e);
+        err = 1;
+    }
+
+    if (err) {
+        exit(1);
+    }
+}
+
+#define TEST(INSN, OFS, E)                                         \
+    do {                                                           \
+        s.b = 0;                                                   \
+        asm volatile(INSN " %1, " #OFS "(%0)"                      \
+                     : : "r"(&s.b), "r" (0x11223344) : "memory");  \
+        check(&s, E, which, INSN, OFS);                            \
+    } while (0)
+
+static void test(const char *which)
+{
+    struct S s = { };
+
+    TEST("stby,b", 0, 0x11223344);
+    TEST("stby,b", 1, 0x00223344);
+    TEST("stby,b", 2, 0x00003344);
+    TEST("stby,b", 3, 0x00000044);
+
+    TEST("stby,e", 0, 0x00000000);
+    TEST("stby,e", 1, 0x11000000);
+    TEST("stby,e", 2, 0x11220000);
+    TEST("stby,e", 3, 0x11223300);
+}
+
+static void *child(void *x)
+{
+    return NULL;
+}
+
+int main()
+{
+    int err;
+    pthread_t thr;
+
+    /* Run test in serial mode */
+    test("serial");
+
+    /* Create a dummy thread to start parallel mode. */
+    err = pthread_create(&thr, NULL, child, NULL);
+    if (err != 0) {
+        fprintf(stderr, "pthread_create: %s\n", strerror(err));
+        return 2;
+    }
+
+    /* Run test in parallel mode */
+    test("parallel");
+    return 0;
+}