[Qemu-devel] [RFC 03/30] cpu_ldst: add cpu_cmpxchg helpers

["Emilio G. Cota" <cota@braap.org>]

Signed-off-by: Emilio G. Cota <cota@braap.org>
---
 include/exec/cpu_atomic_template.h          | 56 +++++++++++++++++++++++++++++
 include/exec/cpu_atomic_useronly_template.h | 39 ++++++++++++++++++++
 include/exec/cpu_ldst_template.h            |  2 ++
 include/exec/cpu_ldst_useronly_template.h   |  2 ++
 4 files changed, 99 insertions(+)
 create mode 100644 include/exec/cpu_atomic_template.h
 create mode 100644 include/exec/cpu_atomic_useronly_template.h

diff --git a/include/exec/cpu_atomic_template.h b/include/exec/cpu_atomic_template.h
new file mode 100644
index 0000000..13f4ffd
--- /dev/null
+++ b/include/exec/cpu_atomic_template.h
@@ -0,0 +1,56 @@
+#include "tcg/tcg.h"
+
+static inline DATA_TYPE
+glue(glue(glue(cpu_cmpxchg, SUFFIX), MEMSUFFIX),
+     _ra)(CPUArchState *env, target_ulong ptr, DATA_TYPE old, DATA_TYPE new,
+          uintptr_t ra)
+{
+    target_ulong addr;
+    TCGMemOpIdx oi;
+    int page_index;
+    DATA_TYPE ret;
+    int mmu_idx;
+
+    addr = ptr;
+    page_index = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
+    mmu_idx = CPU_MMU_INDEX;
+    if (unlikely(env->tlb_table[mmu_idx][page_index].addr_write !=
+                 (addr & (TARGET_PAGE_MASK | (DATA_SIZE - 1))))) {
+        oi = make_memop_idx(SHIFT, mmu_idx);
+        ret = glue(glue(helper_cmpxchg, SUFFIX), MMUSUFFIX)(env, addr, old, new,
+                                                            oi, ra);
+    } else {
+        uintptr_t hostaddr = addr + env->tlb_table[mmu_idx][page_index].addend;
+
+        ret = atomic_cmpxchg((DATA_TYPE *)hostaddr, old, new);
+    }
+    return ret;
+}
+
+/* define cmpxchgo once ldq and stq have been defined */
+#if DATA_SIZE == 8
+/* returns true on success, false on failure */
+static inline bool
+glue(glue(cpu_cmpxchgo, MEMSUFFIX), _ra)(CPUArchState *env, target_ulong ptr,
+                                         uint64_t *old_lo, uint64_t *old_hi,
+                                         uint64_t new_lo, uint64_t new_hi,
+                                         uintptr_t retaddr)
+{
+    uint64_t orig_lo, orig_hi;
+    bool ret = true;
+
+    tcg_cmpxchg_lock(ptr);
+    orig_lo = glue(glue(cpu_ldq, MEMSUFFIX), _ra)(env, ptr, retaddr);
+    orig_hi = glue(glue(cpu_ldq, MEMSUFFIX), _ra)(env, ptr + 8, retaddr);
+    if (orig_lo == *old_lo && orig_hi == *old_hi) {
+        glue(glue(cpu_stq, MEMSUFFIX), _ra)(env, ptr, new_lo, retaddr);
+        glue(glue(cpu_stq, MEMSUFFIX), _ra)(env, ptr + 8, new_hi, retaddr);
+    } else {
+        *old_lo = orig_lo;
+        *old_hi = orig_hi;
+        ret = false;
+    }
+    tcg_cmpxchg_unlock();
+    return ret;
+}
+#endif
diff --git a/include/exec/cpu_atomic_useronly_template.h b/include/exec/cpu_atomic_useronly_template.h
new file mode 100644
index 0000000..c7c0a3e
--- /dev/null
+++ b/include/exec/cpu_atomic_useronly_template.h
@@ -0,0 +1,39 @@
+#include "tcg/tcg.h"
+
+static inline DATA_TYPE
+glue(glue(glue(cpu_cmpxchg, SUFFIX), MEMSUFFIX),
+     _ra)(CPUArchState *env, target_ulong ptr, DATA_TYPE old, DATA_TYPE new,
+          uintptr_t ra)
+{
+    DATA_TYPE *hostaddr = g2h(ptr);
+
+    return atomic_cmpxchg(hostaddr, old, new);
+}
+
+/* define cmpxchgo once ldq and stq have been defined */
+#if DATA_SIZE == 8
+/* returns true on success, false on failure */
+static inline bool
+glue(glue(cpu_cmpxchgo, MEMSUFFIX),
+     _ra)(CPUArchState *env, target_ulong ptr, uint64_t *old_lo,
+          uint64_t *old_hi, uint64_t new_lo, uint64_t new_hi, uintptr_t retaddr)
+{
+    uint64_t *hostaddr = g2h(ptr);
+    uint64_t orig_lo, orig_hi;
+    bool ret = true;
+
+    tcg_cmpxchg_lock(ptr);
+    orig_lo = *hostaddr;
+    orig_hi = *(hostaddr + 1);
+    if (orig_lo == *old_lo && orig_hi == *old_hi) {
+        *hostaddr = new_lo;
+        *(hostaddr + 1) = new_hi;
+    } else {
+        *old_lo = orig_lo;
+        *old_hi = orig_hi;
+        ret = false;
+    }
+    tcg_cmpxchg_unlock();
+    return ret;
+}
+#endif
diff --git a/include/exec/cpu_ldst_template.h b/include/exec/cpu_ldst_template.h
index eaf69a1..2329b66 100644
--- a/include/exec/cpu_ldst_template.h
+++ b/include/exec/cpu_ldst_template.h
@@ -194,6 +194,8 @@ glue(glue(cpu_st, SUFFIX), MEMSUFFIX)(CPUArchState *env, target_ulong ptr,
     glue(glue(glue(cpu_st, SUFFIX), MEMSUFFIX), _ra)(env, ptr, v, 0);
 }
 
+#include "exec/cpu_atomic_template.h"
+
 #endif /* !SOFTMMU_CODE_ACCESS */
 
 #undef RES_TYPE
diff --git a/include/exec/cpu_ldst_useronly_template.h b/include/exec/cpu_ldst_useronly_template.h
index b1378bf..e16f892 100644
--- a/include/exec/cpu_ldst_useronly_template.h
+++ b/include/exec/cpu_ldst_useronly_template.h
@@ -118,6 +118,8 @@ glue(glue(glue(cpu_st, SUFFIX), MEMSUFFIX), _ra)(CPUArchState *env,
 {
     glue(glue(cpu_st, SUFFIX), MEMSUFFIX)(env, ptr, v);
 }
+
+#include "exec/cpu_atomic_useronly_template.h"
 #endif
 
 #undef RES_TYPE
-- 
2.5.0