Hi,
On 2-Nov-24 4:59 PM, Christophe JAILLET wrote:
> ida_alloc()/ida_free() don't need any mutex, so remove this one.
>
> It was introduced by commit 9a90ea7d3784 ("platform/x86/intel/vsec: Use
> mutex for ida_alloc() and ida_free()").
>
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> ---
> See:
> https://elixir.bootlin.com/linux/v6.11.2/source/lib/idr.c#L375
> https://elixir.bootlin.com/linux/v6.11.2/source/lib/idr.c#L484
>
> Review with care. This patch is clearly the opposite of the one in Fixes
> which states that locking IS needed.
> IIUC, idr_ functions need locking, but not ida_.
>
> If I'm wrong, could you elaborate why? (because many other places will
> need to be fixed and the doc certainly needs updating)
This is my bad, looking at the ida docs they clearly state
no locking is necessary.
Back then I was working on / reviewing some other stuff using
idr which does need locking and I likely simply confused the 2
and suggested for the locking to be added.
Anyways dropping the locking looks good to me:
Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Regards,
Hans
> ---
> drivers/platform/x86/intel/vsec.c | 6 ------
> 1 file changed, 6 deletions(-)
>
> diff --git a/drivers/platform/x86/intel/vsec.c b/drivers/platform/x86/intel/vsec.c
> index 7b5cc9993974..9e0f8e38178c 100644
> --- a/drivers/platform/x86/intel/vsec.c
> +++ b/drivers/platform/x86/intel/vsec.c
> @@ -79,17 +79,13 @@ static void intel_vsec_remove_aux(void *data)
> auxiliary_device_uninit(data);
> }
>
> -static DEFINE_MUTEX(vsec_ida_lock);
> -
> static void intel_vsec_dev_release(struct device *dev)
> {
> struct intel_vsec_device *intel_vsec_dev = dev_to_ivdev(dev);
>
> xa_erase(&auxdev_array, intel_vsec_dev->id);
>
> - mutex_lock(&vsec_ida_lock);
> ida_free(intel_vsec_dev->ida, intel_vsec_dev->auxdev.id);
> - mutex_unlock(&vsec_ida_lock);
>
> kfree(intel_vsec_dev->resource);
> kfree(intel_vsec_dev);
> @@ -113,9 +109,7 @@ int intel_vsec_add_aux(struct pci_dev *pdev, struct device *parent,
> return ret;
> }
>
> - mutex_lock(&vsec_ida_lock);
> id = ida_alloc(intel_vsec_dev->ida, GFP_KERNEL);
> - mutex_unlock(&vsec_ida_lock);
> if (id < 0) {
> xa_erase(&auxdev_array, intel_vsec_dev->id);
> kfree(intel_vsec_dev->resource);
