riscv: add a return value to riscv_swint indicating whether a context…

… switch is required This commit fixes the regression from #13561 Change-Id: Ifb0623c0c60f7da55c762926e93cd1708c421ce6
apache · Sep 21, 2024 · cfab545 · cfab545
1 parent 72acec7
commit cfab545
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Showing 3 changed files with 8 additions and 7 deletions.
diff --git a/arch/risc-v/src/common/riscv_internal.h b/arch/risc-v/src/common/riscv_internal.h
@@ -109,6 +109,10 @@
 #define PMP_ACCESS_DENIED   (-1)    /* Access set and denied */
 #define PMP_ACCESS_FULL     (1)     /* Access set and allowed */
 
+/* Return values from riscv_swint */
+
+#define SWINT_CONTEXT_SWITCH (1)    /* Indicate we need context switch */
+
 #ifndef __ASSEMBLY__
 
 /* Use ASM as rv64ilp32 compiler generated address is limited */

diff --git a/arch/risc-v/src/common/riscv_swint.c b/arch/risc-v/src/common/riscv_swint.c
@@ -496,6 +496,7 @@ int riscv_swint(int irq, void *context, void *arg)
   if (regs != new_regs)
     {
       restore_critical_section(this_task(), this_cpu());
+      return SWINT_CONTEXT_SWITCH;
     }
 
   return OK;

diff --git a/arch/risc-v/src/common/supervisor/riscv_perform_syscall.c b/arch/risc-v/src/common/supervisor/riscv_perform_syscall.c
@@ -39,17 +39,17 @@ void *riscv_perform_syscall(uintreg_t *regs)
 {
   struct tcb_s *tcb;
   int cpu;
+  int ret;
 
   /* Set up the interrupt register set needed by swint() */
 
   up_set_current_regs(regs);
 
   /* Run the system call handler (swint) */
 
-  riscv_swint(0, regs, NULL);
-  tcb = this_task();
+  ret = riscv_swint(0, regs, NULL);
 
-  if (regs != tcb->xcp.regs)
+  if (ret == SWINT_CONTEXT_SWITCH)
     {
 #ifdef CONFIG_ARCH_ADDRENV
       /* Make sure that the address environment for the previously
@@ -69,10 +69,6 @@ void *riscv_perform_syscall(uintreg_t *regs)
       tcb = current_task(cpu);
       g_running_tasks[cpu] = tcb;
 
-      /* Restore the cpu lock */
-
-      restore_critical_section(tcb, cpu);
-
       /* If a context switch occurred while processing the interrupt then
        * current_regs may have change value.  If we return any value
        * different from the input regs, then the lower level will know