Displaying 2 results from an estimated 2 matches for "vmci_q_read_pointer".
2015 Nov 12
0
[PATCH] VMCI: Use 32bit atomics for queue headers on X86_32
...lemented
+ * as a non locked cmpxchg8b, that may end up overwriting updates done
+ * by the VMCI device to the memory location. On 32bit SMP, the lock
+ * prefix will be used, so correctness isn't an issue, but using a
+ * 64bit operation still adds unnecessary overhead.
+ */
+static inline u64 vmci_q_read_pointer(atomic64_t *var)
+{
+#if defined(CONFIG_X86_32)
+ return atomic_read((atomic_t *)var);
+#else
+ return atomic64_read(var);
+#endif
+}
+
+/*
+ * Helper to set the value of a head or tail pointer. For X86_32, the
+ * pointer is treated as a 32bit value, since the pointer value
+ * never exceeds a 32b...
2015 Nov 12
0
[PATCH] VMCI: Use 32bit atomics for queue headers on X86_32
...lemented
+ * as a non locked cmpxchg8b, that may end up overwriting updates done
+ * by the VMCI device to the memory location. On 32bit SMP, the lock
+ * prefix will be used, so correctness isn't an issue, but using a
+ * 64bit operation still adds unnecessary overhead.
+ */
+static inline u64 vmci_q_read_pointer(atomic64_t *var)
+{
+#if defined(CONFIG_X86_32)
+ return atomic_read((atomic_t *)var);
+#else
+ return atomic64_read(var);
+#endif
+}
+
+/*
+ * Helper to set the value of a head or tail pointer. For X86_32, the
+ * pointer is treated as a 32bit value, since the pointer value
+ * never exceeds a 32b...