Implement hf_call with assembly inline rather than entire function.
This should allow the compiler to inline and better optimise it.
Bug: 132429380
Change-Id: I4adf5adbc59ebd71bb2b8effecb07ce16bca49cc
diff --git a/driver/linux b/driver/linux
index 3e669bc..474c439 160000
--- a/driver/linux
+++ b/driver/linux
@@ -1 +1 @@
-Subproject commit 3e669bc98235cbaf0addc3176711ad28b62a17eb
+Subproject commit 474c4396e72c33692b0cd40eeb0f3ac7c76fe0f7
diff --git a/inc/vmapi/hf/call.h b/inc/vmapi/hf/call.h
index d04b914..67c8e35 100644
--- a/inc/vmapi/hf/call.h
+++ b/inc/vmapi/hf/call.h
@@ -46,7 +46,7 @@
* This function must be implemented to trigger the architecture specific
* mechanism to call to the hypervisor.
*/
-int64_t hf_call(size_t arg0, size_t arg1, size_t arg2, size_t arg3);
+int64_t hf_call(uint64_t arg0, uint64_t arg1, uint64_t arg2, uint64_t arg3);
/**
* Returns the VM's own ID.
diff --git a/src/arch/aarch64/hftest/BUILD.gn b/src/arch/aarch64/hftest/BUILD.gn
index e5bcedc..78d89c7 100644
--- a/src/arch/aarch64/hftest/BUILD.gn
+++ b/src/arch/aarch64/hftest/BUILD.gn
@@ -24,7 +24,7 @@
# Make a call to the hypervisor from a VM.
source_set("hf_call") {
sources = [
- "hf_call.S",
+ "hf_call.c",
]
}
diff --git a/src/arch/aarch64/hftest/hf_call.S b/src/arch/aarch64/hftest/hf_call.S
deleted file mode 100644
index 86dd7a6..0000000
--- a/src/arch/aarch64/hftest/hf_call.S
+++ /dev/null
@@ -1,21 +0,0 @@
-/*
- * Copyright 2018 The Hafnium Authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-.section .text.hf_call, "ax"
-.global hf_call
-hf_call:
- hvc #0
- ret
diff --git a/src/arch/aarch64/hftest/hf_call.c b/src/arch/aarch64/hftest/hf_call.c
new file mode 100644
index 0000000..3085ff1
--- /dev/null
+++ b/src/arch/aarch64/hftest/hf_call.c
@@ -0,0 +1,42 @@
+/*
+ * Copyright 2019 The Hafnium Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "hf/call.h"
+#include "hf/types.h"
+
+int64_t hf_call(uint64_t arg0, uint64_t arg1, uint64_t arg2, uint64_t arg3)
+{
+ register uint64_t r0 __asm__("x0") = arg0;
+ register uint64_t r1 __asm__("x1") = arg1;
+ register uint64_t r2 __asm__("x2") = arg2;
+ register uint64_t r3 __asm__("x3") = arg3;
+
+ /*
+ * We currently implement SMCCC 1.0, which specifies that the callee can
+ * use x4–x17 as scratch registers. If we move to SMCCC 1.1 then this
+ * will change.
+ */
+ __asm__ volatile(
+ "hvc #0"
+ : /* Output registers, also used as inputs ('+' constraint). */
+ "+r"(r0), "+r"(r1), "+r"(r2), "+r"(r3)
+ :
+ : /* Clobber registers. */
+ "x4", "x5", "x6", "x7", "x8", "x9", "x10", "x11", "x12", "x13",
+ "x14", "x15", "x16", "x17");
+
+ return r0;
+}
