sched/group: addrenv: allocate current group for each cpu

Summary:
- In case of SMP and ADDRENV, allocate current group for each cpu
  - g_pid_current holds pid of the group and uses for addrenv switching
  - allocate g_group_current for each cpu in stead of g_pid_current
  - g_group_current is the array that pointed to the current task_group_s struct

Impact:
- ADDRENV=y and SMP=y

Testing:
- sabre-6quad:smp w/ qemu
- sabre-6quad:knsh w/ qemu
- sabre-6quad:knsh_smp w/ qemu (WIP)

Signed-off-by: Oki Minabe <minabe.oki@gmail.com>

sched/group/group.h

@@ -52,14 +52,14 @@ extern FAR struct task_group_s *g_grouphead;
 #endif
 
 #ifdef CONFIG_ARCH_ADDRENV
-/* This variable holds the PID of the current task group.  This ID is
+/* This variable holds the current task group.  This pointer is NULL
- * zero if the current task is a kernel thread that has no address
+ * if the current task is a kernel thread that has no address environment
- * environment (other than the kernel context).
+ * (other than the kernel context).
  *
  * This must only be accessed with interrupts disabled.
  */
 
-extern pid_t g_pid_current;
+extern FAR struct task_group_s *g_group_current[CONFIG_SMP_NCPUS];
 #endif
 
 /****************************************************************************

sched/group/group_addrenv.c

@@ -39,14 +39,14 @@
  * Public Data
  ****************************************************************************/
 
-/* This variable holds the PID of the current task group.  This ID is
+/* This variable holds the current task group.  This pointer is NULL
- * zero if the current task is a kernel thread that has no address
+ * if the current task is a kernel thread that has no address environment
- * environment (other than the kernel context).
+ * (other than the kernel context).
  *
  * This must only be accessed with interrupts disabled.
  */
 
-pid_t g_pid_current = INVALID_PROCESS_ID;
+FAR struct task_group_s *g_group_current[CONFIG_SMP_NCPUS];
 
 /****************************************************************************
  * Public Functions
@@ -85,7 +85,7 @@ int group_addrenv(FAR struct tcb_s *tcb)
   FAR struct task_group_s *group;
   FAR struct task_group_s *oldgroup;
   irqstate_t flags;
-  pid_t pid;
+  int cpu;
   int ret;
 
   /* NULL for the tcb means to use the TCB of the task at the head of the
@@ -111,34 +111,24 @@ int group_addrenv(FAR struct tcb_s *tcb)
       return OK;
     }
 
-  /* Get the PID of the group that needs the address environment */
-
-  pid = group->tg_pid;
-  DEBUGASSERT(pid != INVALID_PROCESS_ID);
-
   /* Are we going to change address environments? */
 
   flags = enter_critical_section();
-  if (pid != g_pid_current)
+
+  cpu = this_cpu();
+  oldgroup = g_group_current[cpu];
+  if (group != oldgroup)
     {
       /* Yes.. Is there a current address environment in place? */
 
-      if (g_pid_current != INVALID_PROCESS_ID)
+      if (oldgroup)
         {
-          /* Find the old group with this ID. */
+          /* We need to flush the D-Cache and Invalidate the I-Cache for
+           * the group whose environment is disappearing.
+           */
 
-          oldgroup = group_findbypid(g_pid_current);
+          DEBUGASSERT((oldgroup->tg_flags & GROUP_FLAG_ADDRENV) != 0);
-          DEBUGASSERT(oldgroup &&
+          up_addrenv_coherent(&oldgroup->tg_addrenv);
-                      (oldgroup->tg_flags & GROUP_FLAG_ADDRENV) != 0);
-
-          if (oldgroup)
-            {
-              /* We need to flush the D-Cache and Invalidate the I-Cache for
-               * the group whose environment is disappearing.
-               */
-
-              up_addrenv_coherent(&oldgroup->tg_addrenv);
-            }
         }
 
       /* Instantiate the new address environment (removing the old
@@ -155,7 +145,7 @@ int group_addrenv(FAR struct tcb_s *tcb)
 
       /* Save the new, current group */
 
-      g_pid_current = pid;
+      g_group_current[cpu] = group;
     }
 
   leave_critical_section(flags);

sched/group/group_leave.c

@@ -130,6 +130,7 @@ static inline void group_release(FAR struct task_group_s *group)
 {
 #ifdef CONFIG_ARCH_ADDRENV
   save_addrenv_t oldenv;
+  int i;
 #endif
 
 #if CONFIG_TLS_TASK_NELEM > 0
@@ -248,7 +249,13 @@ static inline void group_release(FAR struct task_group_s *group)
 
   /* Mark no address environment */
 
-  g_pid_current = INVALID_PROCESS_ID;
+  for (i = 0; i < CONFIG_SMP_NCPUS; i++)
+    {
+      if (group == g_group_current[i])
+        {
+          g_group_current[i] = NULL;
+        }
+    }
 
   /* Restore the previous addrenv */