+#define EFX_MCDI_BUF_SIZE(_in_len, _out_len) \
+ EFX_P2ROUNDUP(size_t, \
+ MAX(MAX(_in_len, _out_len), (2 * sizeof (efx_dword_t))),\
+ sizeof (efx_dword_t))
+
+/*
+ * The buffer size must be a multiple of dword to ensure that MCDI works
+ * properly with Siena based boards (which use on-chip buffer). Also, it
+ * should be at minimum the size of two dwords to allow space for extended
+ * error responses if the request/response buffer sizes are smaller.
+ */
+#define EFX_MCDI_DECLARE_BUF(_name, _in_len, _out_len) \
+ uint8_t _name[EFX_MCDI_BUF_SIZE(_in_len, _out_len)] = {0}
+