xtensa: g_current_regs is only used to determine if we are in irq,

with other functionalities removed. reason: by doing this we can reduce context switch time, When we exit from an interrupt handler, we directly use tcb->xcp.regs before text data bss dec hex filename 178368 876 130604 309848 4ba58 nuttx after text data bss dec hex filename 178120 876 130212 309208 4b7d8 nuttx szie change -248 Signed-off-by: hujun5 <[email protected]>
hujun260 · Sep 27, 2024 · 7ebe788 · 7ebe788
1 parent 981fd0c
commit 7ebe788
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Showing 6 changed files with 52 additions and 354 deletions.
diff --git a/arch/xtensa/src/common/xtensa.h b/arch/xtensa/src/common/xtensa.h
@@ -103,13 +103,6 @@
 #define IDLETHREAD_STACKSIZE  ((CONFIG_IDLETHREAD_STACKSIZE + 15) & ~15)
 #define IDLETHREAD_STACKWORDS (IDLETHREAD_STACKSIZE >> 2)
 
-/* In the Xtensa model, the state is saved in stack,
- * only a reference stored in TCB.
- */
-
-#define xtensa_savestate(regs)    ((regs) = up_current_regs())
-#define xtensa_restorestate(regs) up_set_current_regs(regs)
-
 /* Context switching via system calls ***************************************/
 
 #define xtensa_context_restore(regs)\

diff --git a/arch/xtensa/src/common/xtensa_cpupause.c b/arch/xtensa/src/common/xtensa_cpupause.c
@@ -102,11 +102,7 @@ int up_cpu_paused_save(void)
   sched_note_cpu_paused(tcb);
 #endif
 
-  /* Save the current context at current_regs into the TCB at the head
-   * of the assigned task list for this CPU.
-   */
-
-  xtensa_savestate(tcb->xcp.regs);
+  UNUSED(tcb);
 
   return OK;
 }
@@ -186,11 +182,7 @@ int up_cpu_paused_restore(void)
 
   nxsched_resume_scheduler(tcb);
 
-  /* Then switch contexts.  Any necessary address environment changes
-   * will be made when the interrupt returns.
-   */
-
-  xtensa_restorestate(tcb->xcp.regs);
+  UNUSED(tcb);
 
   return OK;
 }

diff --git a/arch/xtensa/src/common/xtensa_irqdispatch.c b/arch/xtensa/src/common/xtensa_irqdispatch.c
@@ -44,6 +44,8 @@
 
 uint32_t *xtensa_irq_dispatch(int irq, uint32_t *regs)
 {
+  struct tcb_s *tcb = this_task();
+
 #ifdef CONFIG_SUPPRESS_INTERRUPTS
   board_autoled_on(LED_INIRQ);
   PANIC();
@@ -62,15 +64,23 @@ uint32_t *xtensa_irq_dispatch(int irq, uint32_t *regs)
 
   up_set_current_regs(regs);
 
+  if (irq != XTENSA_IRQ_SWINT)
+    {
+      /* we are not trigger by syscall */
+
+      tcb->xcp.regs = regs;
+    }
+
   /* Deliver the IRQ */
 
   irq_dispatch(irq, regs);
+  tcb = this_task();
 
   /* Check for a context switch.  If a context switch occurred, then
    * current_regs will have a different value than it did on entry.
    */
 
-  if (regs != up_current_regs())
+  if (regs != tcb->xcp.regs)
     {
 #ifdef CONFIG_ARCH_ADDRENV
       /* Make sure that the address environment for the previously
@@ -92,14 +102,8 @@ uint32_t *xtensa_irq_dispatch(int irq, uint32_t *regs)
        * crashes.
        */
 
-      g_running_tasks[this_cpu()] = this_task();
-    }
-
-  /* Restore the cpu lock */
-
-  if (regs != up_current_regs())
-    {
-      regs = up_current_regs();
+      g_running_tasks[this_cpu()] = tcb;
+      regs = tcb->xcp.regs;
     }
 
   /* Set current_regs to NULL to indicate that we are no longer in an