Signed-off-by: Paolo Bonzini <[email protected]>
---
util/coroutine-asm.c | 34 ++++++++++++++++++++++++++++++++++
1 file changed, 34 insertions(+)
diff --git a/util/coroutine-asm.c b/util/coroutine-asm.c
index de68e98622..a9a80e9c71 100644
--- a/util/coroutine-asm.c
+++ b/util/coroutine-asm.c
@@ -41,7 +41,7 @@ typedef struct {
void *sp;
/*
- * aarch64: instruction pointer
+ * aarch64, s390x: instruction pointer
*/
void *scratch;
@@ -161,6 +161,40 @@ static void start_switch_fiber(void **fake_stack_save,
(to)->scratch = (void *) coroutine_trampoline;
\
(void) CO_SWITCH_RET(from, to, (uintptr_t) to);
\
} while(0)
+
+#elif defined __s390x__
+#define CO_SWITCH_RET(from, to, action) ({
\
+ register uintptr_t action_ __asm__("r2") = action;
\
+ register void *from_ __asm__("r1") = from;
\
+ register void *to_ __asm__("r3") = to;
\
+ register void *pc_ __asm__("r4") = to->scratch;
\
+ void *save_r13;
\
+ asm volatile(
\
+ "stg %%r13, %[SAVE_R13]\n"
\
+ "stg %%r15, %[SP](%%r1)\n" /* save source SP */
\
+ "lg %%r15, %[SP](%%r3)\n" /* load destination SP */
\
+ "bras %%r3, 1f\n" /* source PC will be after the BR */
\
+ "1: aghi %%r3, 12\n" /* 4 */
\
+ "stg %%r3, %[SCRATCH](%%r1)\n" /* 6 save switch-back PC */
\
+ "br %%r4\n" /* 2 jump to destination PC */
\
+ "lg %%r13, %[SAVE_R13]\n"
\
+ : "+r" (action_), "+r" (from_), "+r" (to_), "+r" (pc_),
\
+ [SAVE_R13] "+m" (r13)
\
+ : [SP] "i" (offsetof(CoroutineAsm, sp)),
\
+ [SCRATCH] "i" (offsetof(CoroutineAsm, scratch))
\
+ : "r0", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r14",
\
+ "a2", "a3", "a4", "a5", "a6", "a7",
\
+ "a8", "a9", "a10", "a11", "a12", "a13", "a14", "a15",
\
+ "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",
\
+ "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15", "memory");
\
+ action_;
\
+})
+
+#define CO_SWITCH_NEW(from, to) do {
\
+ (to)->scratch = (void *) coroutine_trampoline;
\
+ (to)->sp -= 160;
\
+ (void) CO_SWITCH_RET(from, to, (uintptr_t) to);
\
+} while(0)
#else
#error coroutine-asm.c not ported to this architecture.
#endif
--
2.21.0
