From d4b98bac3c304e3bed612c79680fc2226ddb7e9a Mon Sep 17 00:00:00 2001
From: Yunsup Lee <yunsup@cs.berkeley.edu>
Date: Thu, 6 Feb 2014 00:10:59 -0800
Subject: fix vector exceptions on rocket

---
 v/entry.S | 16 +++++++++++++++-
 v/vm.c    | 23 -----------------------
 2 files changed, 15 insertions(+), 24 deletions(-)

diff --git a/v/entry.S b/v/entry.S
index 7b9230d..6933771 100644
--- a/v/entry.S
+++ b/v/entry.S
@@ -152,7 +152,21 @@ trap_entry:
   and   ra,ra,SR_EA
   beqz  ra, 2f
   addi  x2,x2,38*REGBYTES
-  vxcptsave x2
+
+  # rocket currently doesn't support vxcptsave/vxcptrestore natively
+  csrr  x3,impl 
+  li    x4,IMPL_ROCKET
+  bne   x3,x4,3f
+  vgetcfg x4
+  sd    x4,0(x2)
+  vgetvl x4
+  sd    x4,8(x2)
+  addi  x2,x2,16
+  vxcptevac x2
+  j     2f
+
+  # native vxcptsave
+3:vxcptsave x2
 2:jal   handle_trap
 
   # when coming from kernel, continue below its stack
diff --git a/v/vm.c b/v/vm.c
index 415c7e5..e28dd45 100644
--- a/v/vm.c
+++ b/v/vm.c
@@ -99,16 +99,6 @@ void handle_fault(unsigned long addr)
   __builtin___clear_cache(0,0);
 }
 
-static void emulate_vxcptsave(trapframe_t* tf)
-{
-  long* where = (long*)tf->gpr[(tf->insn >> 15) & 0x1F];
-
-  where[0] = vgetcfg();
-  where[1] = vgetvl();
-  vxcptevac(&where[2]);
-  fence();
-}
-
 static void do_vxcptrestore(long* where)
 {
   vsetcfg(where[0]);
@@ -157,13 +147,6 @@ static void do_vxcptrestore(long* where)
   }
 }
 
-static void emulate_vxcptrestore(trapframe_t* tf)
-{
-  long* where = (long*)tf->gpr[(tf->insn >> 15) & 0x1F];
-  vxcptkill();
-  do_vxcptrestore(where);
-}
-
 static void restore_vector(trapframe_t* tf)
 {
   if (read_csr(impl) == IMPL_ROCKET)
@@ -192,12 +175,6 @@ void handle_trap(trapframe_t* tf)
 
     if (tf->insn == fssr)
       terminate(1); // FP test on non-FP hardware.  "succeed."
-#if 0
-    else if ((tf->insn & 0xF83FFFFF) == 0x37B)
-      emulate_vxcptsave(tf);
-    else if ((tf->insn & 0xF83FFFFF) == 0x77B)
-      emulate_vxcptrestore(tf);
-#endif
     else
       assert(0);
     tf->epc += 4;
-- 
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