[PATCH rtems-lwip v1 4/9] lwip: Add support for SMP systems

[Kinsey Moore]

For BSPs that support SMP, the sys_arch_protect and sys_arch_unprotect
calls must use a global mutex instead of a local CPU interrupt disable
to protect critical sections.
---
 uLan/ports/os/rtems/arch/sys_arch.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/uLan/ports/os/rtems/arch/sys_arch.c b/uLan/ports/os/rtems/arch/sys_arch.c
index fa344a1..d51810b 100644
--- a/uLan/ports/os/rtems/arch/sys_arch.c
+++ b/uLan/ports/os/rtems/arch/sys_arch.c
@@ -57,10 +57,22 @@ sys_now()
   return temp;
 }
 
+#ifdef __rtems__
+#if RTEMS_SMP
+sys_mutex_t sys_arch_mutex;
+#endif
+#endif
+
 void
 sys_init(void)
 {
   //  Is called to initialize the sys_arch layer.
+#ifdef __rtems__
+#if RTEMS_SMP
+  // initialize global sys arch protect mutex
+  sys_mutex_new(&sys_arch_mutex);
+#endif
+#endif
   return;
 }
 
@@ -364,16 +376,25 @@ sys_request_irq(unsigned int irqnum, sys_irq_handler_t handler,
 sys_prot_t
 sys_arch_protect()
 {
+#if RTEMS_SMP
+  sys_mutex_lock(&sys_arch_mutex);
+  return 0;
+#else
   sys_prot_t pval;
 
   rtems_interrupt_disable(pval);
   return pval;
+#endif
 }
 
 void
 sys_arch_unprotect(sys_prot_t pval)
 {
+#if RTEMS_SMP
+  sys_mutex_unlock(&sys_arch_mutex);
+#else
   rtems_interrupt_enable(pval);
+#endif
 }
 err_t
 sys_mbox_trypost_fromisr(sys_mbox_t *q, void *msg)
-- 
2.30.2