1 files changed, 19 insertions, 8 deletions
diff --git a/pk/frontend.c b/pk/frontend.c
index 3771bca..0929d54 100644
--- a/pk/frontend.c
+++ b/pk/frontend.c
@@ -3,14 +3,30 @@
 #include "pk.h"
 #include "atomic.h"
 #include "frontend.h"
+#include "sbi.h"
+#include "mcall.h"
 #include <stdint.h>
 
+uint64_t tohost_sync(unsigned dev, unsigned cmd, uint64_t payload)
+{
+  uint64_t fromhost;
+  __sync_synchronize();
+
+  sbi_device_message m = {dev, cmd, payload}, *p;
+  do_mcall(MCALL_SEND_DEVICE_REQUEST, &m);
+  while ((p = (void*)do_mcall(MCALL_RECEIVE_DEVICE_RESPONSE)) == 0);
+  kassert(p == &m);
+
+  __sync_synchronize();
+  return m.data;
+}
+
 long frontend_syscall(long n, long a0, long a1, long a2, long a3, long a4, long a5, long a6)
 {
   static volatile uint64_t magic_mem[8];
 
   static spinlock_t lock = SPINLOCK_INIT;
-  long irq = spinlock_lock_irqsave(&lock);
+  spinlock_lock(&lock);
 
   magic_mem[0] = n;
   magic_mem[1] = a0;
@@ -21,15 +37,10 @@ long frontend_syscall(long n, long a0, long a1, long a2, long a3, long a4, long
   magic_mem[6] = a5;
   magic_mem[7] = a6;
 
-  mb();
-
-  write_csr(tohost, magic_mem);
-  while (swap_csr(fromhost, 0) == 0);
-
-  mb();
+  tohost_sync(0, 0, (uintptr_t)magic_mem);
 
   long ret = magic_mem[0];
 
-  spinlock_unlock_irqrestore(&lock, irq);
+  spinlock_unlock(&lock);
   return ret;
 }