Port to ARMv8 A64

Author: EmilioPeJu

context/switch-arm64.c

@@ -0,0 +1,111 @@
+/* This file is part of the Diamond cothread library.
+ *
+ * Copyright (C) 2010-2012 Michael Abbott, Diamond Light Source Ltd.
+ *
+ * The Diamond cothread library is free software; you can redistribute it
+ * and/or modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the License,
+ * or (at your option) any later version.
+ *
+ * The Diamond cothread library is distributed in the hope that it will be
+ * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * Contact:
+ *      Dr. Michael Abbott,
+ *      Diamond Light Source Ltd,
+ *      Diamond House,
+ *      Chilton,
+ *      Didcot,
+ *      Oxfordshire,
+ *      OX11 0DE
+ *      michael.abbott@diamond.ac.uk
+ */
+
+// Coroutine frame switching for ARMv8 64 bits
+
+#ifdef __ARM_NEON
+#define IF_NEON(code)    code
+#else
+#define IF_NEON(code)
+#endif
+
+__asm__(
+"       .text\n"
+
+// void * switch_frame(frame_t *old_frame, frame_t new_frame, void *arg)
+// Arguments on entry:
+//   x0      address of frame to be saved
+//   x1      frame to be loaded
+//   x2      Context argument to pass through
+
+FNAME(switch_frame)
+"       stp x19, x20, [sp, #-16]!\n"
+"       stp x21, x22, [sp, #-16]!\n"
+"       stp x23, x24, [sp, #-16]!\n"
+"       stp x25, x26, [sp, #-16]!\n"
+"       stp x27, x28, [sp, #-16]!\n"
+"       stp fp, lr, [sp, #-16]!\n"
+IF_NEON(
+"       stp d8, d9, [sp, #-16]!\n"
+"       stp d10, d11, [sp, #-16]!\n"
+"       stp d12, d13, [sp, #-16]!\n"
+"       stp d14, d15, [sp, #-16]!\n"
+)
+"       mov ip0, sp\n"
+"       str ip0, [x0]\n"
+"       mov sp, x1\n"
+"       mov x0, x2\n"
+IF_NEON(
+"       ldp d14, d15, [sp], #16\n"
+"       ldp d12, d13, [sp], #16\n"
+"       ldp d10, d11, [sp], #16\n"
+"       ldp d8, d9, [sp], #16\n"
+)
+"       ldp fp, lr, [sp], #16\n"
+"       ldp x27, x28, [sp], #16\n"
+"       ldp x25, x26, [sp], #16\n"
+"       ldp x23, x24, [sp], #16\n"
+"       ldp x21, x22, [sp], #16\n"
+"       ldp x19, x20, [sp], #16\n"
+"       br  lr\n"
+FSIZE(switch_frame)
+
+
+// frame_t create_frame(void *stack_base, frame_action_t action, void *context)
+// Arguments on entry:
+//   x0      initial base of stack
+//   x1      action routine
+//   x2      context argument to action
+FNAME(create_frame)
+"       stp x1, x2, [x0, #-16]!\n"
+"       mov ip0, lr\n"               // Save LR so can use same STP slot
+"       ldr lr, =action_entry\n"
+"       stp x19, x20, [x0, #-16]!\n"
+"       stp x21, x22, [x0, #-16]!\n"
+"       stp x23, x24, [x0, #-16]!\n"
+"       stp x25, x26, [x0, #-16]!\n"
+"       stp x27, x28, [x0, #-16]!\n"
+"       stp fp, lr, [x0, #-16]!\n"
+IF_NEON(
+"       stp d8, d9, [x0, #-16]!\n"
+"       stp d10, d11, [x0, #-16]!\n"
+"       stp d12, d13, [x0, #-16]!\n"
+"       stp d14, d15, [x0, #-16]!\n"
+)
+"       br  ip0\n"
+
+"action_entry:\n"
+        // Receive control after first switch to new frame.  Top of stack has
+        // the saved context and routine to call, switch argument is in r0.
+"       ldp x2, x3, [sp], #16\n"   // x2 <- action routine, x3 <- context
+"       mov x1, x3\n"
+"       mov lr, #0\n"              // Ensure no return from action
+"       br  x2\n"
+FSIZE(create_frame)
+);

context/switch.c

@@ -44,6 +44,8 @@
     #include "switch-x86.c"
 #elif defined(__x86_64__)
     #include "switch-x86_64.c"
+#elif defined(__aarch64__)  &&  defined(__unix__)
+    #include "switch-arm64.c"
 #elif defined(__arm__)  &&  defined(__unix__)
     #include "switch-arm.c"
 #elif defined(__ppc__)  &&  defined(__APPLE__)