accel/ivpu: Fix NOC firewall interrupt handling

The NOC firewall interrupt means that the HW prevented
unauthorized access to a protected resource, so there
is no need to trigger device reset in such case.

To facilitate security testing add firewall_irq_counter
debugfs file that tracks firewall interrupts.

Fixes: 8a27ad8 ("accel/ivpu: Split IP and buttress code")
Cc: stable@vger.kernel.org # v6.11+
Signed-off-by: Andrzej Kacprowski <Andrzej.Kacprowski@intel.com>
Reviewed-by: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241017144958.79327-1-jacek.lawrynowicz@linux.intel.com

drivers/accel/ivpu/ivpu_debugfs.c

@@ -108,6 +108,14 @@ static int reset_pending_show(struct seq_file *s, void *v)
 	return 0;
 }
 
+static int firewall_irq_counter_show(struct seq_file *s, void *v)
+{
+	struct ivpu_device *vdev = seq_to_ivpu(s);
+
+	seq_printf(s, "%d\n", atomic_read(&vdev->hw->firewall_irq_counter));
+	return 0;
+}
+
 static const struct drm_debugfs_info vdev_debugfs_list[] = {
 	{"bo_list", bo_list_show, 0},
 	{"fw_name", fw_name_show, 0},
@@ -116,6 +124,7 @@ static const struct drm_debugfs_info vdev_debugfs_list[] = {
 	{"last_bootmode", last_bootmode_show, 0},
 	{"reset_counter", reset_counter_show, 0},
 	{"reset_pending", reset_pending_show, 0},
+	{"firewall_irq_counter", firewall_irq_counter_show, 0},
 };
 
 static ssize_t

drivers/accel/ivpu/ivpu_hw.c

@@ -249,6 +249,7 @@ int ivpu_hw_init(struct ivpu_device *vdev)
 	platform_init(vdev);
 	wa_init(vdev);
 	timeouts_init(vdev);
+	atomic_set(&vdev->hw->firewall_irq_counter, 0);
 
 	return 0;
 }

drivers/accel/ivpu/ivpu_hw.h

@@ -52,6 +52,7 @@ struct ivpu_hw_info {
 	int dma_bits;
 	ktime_t d0i3_entry_host_ts;
 	u64 d0i3_entry_vpu_ts;
+	atomic_t firewall_irq_counter;
 };
 
 int ivpu_hw_init(struct ivpu_device *vdev);

drivers/accel/ivpu/ivpu_hw_ip.c

@@ -1062,7 +1062,10 @@ static void irq_wdt_mss_handler(struct ivpu_device *vdev)
 
 static void irq_noc_firewall_handler(struct ivpu_device *vdev)
 {
-	ivpu_pm_trigger_recovery(vdev, "NOC Firewall IRQ");
+	atomic_inc(&vdev->hw->firewall_irq_counter);
+
+	ivpu_dbg(vdev, IRQ, "NOC Firewall interrupt detected, counter %d\n",
+		 atomic_read(&vdev->hw->firewall_irq_counter));
 }
 
 /* Handler for IRQs from NPU core */