[PATCH] platform/x86/intel/vsec: Remove a useless mutex

From: Christophe JAILLET
Date: Sat Nov 02 2024 - 12:01:20 EST


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)
---
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);
--
2.47.0