arch/risc-v/src/mpfs/mpfs_irq.c: Fix up_irqinitialize for warm reboot

It is possible that a PLIC IRQ is claimed but not completed at warm reset. This occurs at least if there is a fault in the middle of irq handler execution. To recover from such situation, we can complete all IRQ:s in PLIC; this completes any already claimed IRQ, but has no effect on IRQs which are not claimed or not enabled. Signed-off-by: Jukka Laitinen <[email protected]>
tiiuae · Jan 16, 2024 · 723dad7 · 723dad7
1 parent 15391f4
commit 723dad7
Showing 1 changed file with 13 additions and 7 deletions.
diff --git a/arch/risc-v/src/mpfs/mpfs_irq.c b/arch/risc-v/src/mpfs/mpfs_irq.c
@@ -50,6 +50,19 @@ void up_irqinitialize(void)
 
   up_irq_save();
 
+  /* Complete possibly claimed IRQs in PLIC (for current hart) in case
+   * of warm reboot, e.g. after a crash in the middle of IRQ handler.
+   * This has no effect on non-claimed or disabled interrupts.
+   */
+
+  uintptr_t claim_address = mpfs_plic_get_claimbase();
+
+  int irq;
+  for (irq = MPFS_IRQ_EXT_START; irq < NR_IRQS; irq++)
+    {
+      putreg32(irq - MPFS_IRQ_EXT_START, claim_address);
+    }
+
   /* Disable all global interrupts for current hart */
 
   uintptr_t iebase = mpfs_plic_get_iebase();
@@ -61,12 +74,6 @@ void up_irqinitialize(void)
   putreg32(0x0, iebase + 16);
   putreg32(0x0, iebase + 20);
 
-  /* Clear pendings in PLIC (for current hart) */
-
-  uintptr_t claim_address = mpfs_plic_get_claimbase();
-  uint32_t val = getreg32(claim_address);
-  putreg32(val, claim_address);
-
   /* Colorize the interrupt stack for debug purposes */
 
 #if defined(CONFIG_STACK_COLORATION) && CONFIG_ARCH_INTERRUPTSTACK > 15
@@ -77,7 +84,6 @@ void up_irqinitialize(void)
   /* Set priority for all global interrupts to 1 (lowest) */
 
   int id;
-
   for (id = 1; id <= NR_IRQS; id++)
     {
       putreg32(1, (uintptr_t)(MPFS_PLIC_PRIORITY + (4 * id)));