@@ -57,6 +57,16 @@
#define FFA_MY_VERSION MAKE_FFA_VERSION(FFA_MY_VERSION_MAJOR, \
FFA_MY_VERSION_MINOR)
+/*
+ * The FF-A specification explicitly works with 4K pages as a measure of
+ * memory size, for example, FFA_RXTX_MAP takes one parameter "RX/TX page
+ * count" which is the number of contiguous 4K pages allocated. Xen may use
+ * a different page size depending on the configuration to avoid confusion
+ * with PAGE_SIZE use a special define when it's a page size as in the FF-A
+ * specification.
+ */
+#define FFA_PAGE_SIZE SZ_4K
+
/*
* Flags and field values used for the MSG_SEND_DIRECT_REQ/RESP:
* BIT(31): Framework or partition message
@@ -261,6 +271,17 @@ static bool ffa_probe(void)
unsigned int major_vers;
unsigned int minor_vers;
+ /*
+ * FF-A often works in units of 4K pages and currently it's assumed
+ * that we can map memory using that granularity. See also the comment
+ * above the FFA_PAGE_SIZE define.
+ *
+ * It is possible to support a PAGE_SIZE larger than 4K in Xen, but
+ * until that is fully handled in this code make sure that we only use
+ * 4K page sizes.
+ */
+ BUILD_BUG_ON(PAGE_SIZE != FFA_PAGE_SIZE);
+
/*
* psci_init_smccc() updates this value with what's reported by EL-3
* or secure world.