[PATCH] accel/ivpu: Fix NOC firewall interrupt handling

[Jeffrey Hugo]

On 10/17/2024 8:49 AM, Jacek Lawrynowicz wrote:
> From: Andrzej Kacprowski <Andrzej.Kacprowski at intel.com>
> 
> 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: 8a27ad81f7d3 ("accel/ivpu: Split IP and buttress code")
> Cc: <stable at vger.kernel.org> # v6.11+
> Signed-off-by: Andrzej Kacprowski <Andrzej.Kacprowski at intel.com>
> Reviewed-by: Jacek Lawrynowicz <jacek.lawrynowicz at linux.intel.com>
> Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz at linux.intel.com>
> ---
>   drivers/accel/ivpu/ivpu_debugfs.c | 9 +++++++++
>   drivers/accel/ivpu/ivpu_hw.c      | 1 +
>   drivers/accel/ivpu/ivpu_hw.h      | 1 +
>   drivers/accel/ivpu/ivpu_hw_ip.c   | 5 ++++-
>   4 files changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/accel/ivpu/ivpu_debugfs.c b/drivers/accel/ivpu/ivpu_debugfs.c
> index 8958145c49adb..8180b95ed69dc 100644
> --- a/drivers/accel/ivpu/ivpu_debugfs.c
> +++ b/drivers/accel/ivpu/ivpu_debugfs.c
> @@ -116,6 +116,14 @@ 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},
> @@ -125,6 +133,7 @@ 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 int dvfs_mode_get(void *data, u64 *dvfs_mode)
> diff --git a/drivers/accel/ivpu/ivpu_hw.c b/drivers/accel/ivpu/ivpu_hw.c
> index 09ada8b500b99..4e1054f3466e8 100644
> --- a/drivers/accel/ivpu/ivpu_hw.c
> +++ b/drivers/accel/ivpu/ivpu_hw.c
> @@ -252,6 +252,7 @@ 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;
>   }
> diff --git a/drivers/accel/ivpu/ivpu_hw.h b/drivers/accel/ivpu/ivpu_hw.h
> index dc5518248c405..fc4dbfc980c81 100644
> --- a/drivers/accel/ivpu/ivpu_hw.h
> +++ b/drivers/accel/ivpu/ivpu_hw.h
> @@ -51,6 +51,7 @@ struct ivpu_hw_info {
>   	int dma_bits;
>   	ktime_t d0i3_entry_host_ts;
>   	u64 d0i3_entry_vpu_ts;
> +	atomic_t firewall_irq_counter;

Why atomic?

>   };
>   
>   int ivpu_hw_init(struct ivpu_device *vdev);
> diff --git a/drivers/accel/ivpu/ivpu_hw_ip.c b/drivers/accel/ivpu/ivpu_hw_ip.c
> index b9b16f4041434..029dd065614b2 100644
> --- a/drivers/accel/ivpu/ivpu_hw_ip.c
> +++ b/drivers/accel/ivpu/ivpu_hw_ip.c
> @@ -1073,7 +1073,10 @@ 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 */