[PATCH v3 net-next] ptp: Move from simple ida to xarray

[PATCH v3 net-next] ptp: Move from simple ida to xarray

[Kory Maincent]

Move from simple ida to xarray for storing and loading the ptp_clock
pointer. This prepares support for future hardware timestamp selection by
being able to link the ptp clock index to its pointer.

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
---

Change in v2:
- Update an err value missing.

Change in v3:
- Refactor err management.
---
 drivers/ptp/ptp_clock.c | 28 ++++++++++++++++------------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c
index 3aaf1a3430c5..8eebf1373ca3 100644
--- a/drivers/ptp/ptp_clock.c
+++ b/drivers/ptp/ptp_clock.c
@@ -31,7 +31,7 @@ struct class *ptp_class;
 
 static dev_t ptp_devt;
 
-static DEFINE_IDA(ptp_clocks_map);
+static DEFINE_XARRAY_ALLOC(ptp_clocks_map);
 
 /* time stamp event queue operations */
 
@@ -201,7 +201,7 @@ static void ptp_clock_release(struct device *dev)
 	bitmap_free(tsevq->mask);
 	kfree(tsevq);
 	debugfs_remove(ptp->debugfs_root);
-	ida_free(&ptp_clocks_map, ptp->index);
+	xa_erase(&ptp_clocks_map, ptp->index);
 	kfree(ptp);
 }
 
@@ -241,16 +241,16 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 		return ERR_PTR(-EINVAL);
 
 	/* Initialize a clock structure. */
-	err = -ENOMEM;
 	ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL);
-	if (ptp == NULL)
+	if (!ptp) {
+		err = -ENOMEM;
 		goto no_memory;
+	}
 
-	index = ida_alloc_max(&ptp_clocks_map, MINORMASK, GFP_KERNEL);
-	if (index < 0) {
-		err = index;
+	err = xa_alloc(&ptp_clocks_map, &index, ptp, xa_limit_31b,
+		       GFP_KERNEL);
+	if (err)
 		goto no_slot;
-	}
 
 	ptp->clock.ops = ptp_clock_ops;
 	ptp->info = info;
@@ -258,13 +258,17 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 	ptp->index = index;
 	INIT_LIST_HEAD(&ptp->tsevqs);
 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
-	if (!queue)
+	if (!queue) {
+		err = -ENOMEM;
 		goto no_memory_queue;
+	}
 	list_add_tail(&queue->qlist, &ptp->tsevqs);
 	spin_lock_init(&ptp->tsevqs_lock);
 	queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL);
-	if (!queue->mask)
+	if (!queue->mask) {
+		err = -ENOMEM;
 		goto no_memory_bitmap;
+	}
 	bitmap_set(queue->mask, 0, PTP_MAX_CHANNELS);
 	spin_lock_init(&queue->lock);
 	mutex_init(&ptp->pincfg_mux);
@@ -378,7 +382,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 	list_del(&queue->qlist);
 	kfree(queue);
 no_memory_queue:
-	ida_free(&ptp_clocks_map, index);
+	xa_erase(&ptp_clocks_map, index);
 no_slot:
 	kfree(ptp);
 no_memory:
@@ -511,7 +515,7 @@ static void __exit ptp_exit(void)
 {
 	class_destroy(ptp_class);
 	unregister_chrdev_region(ptp_devt, MINORMASK + 1);
-	ida_destroy(&ptp_clocks_map);
+	xa_destroy(&ptp_clocks_map);
 }
 
 static int __init ptp_init(void)
-- 
2.25.1

Re: [PATCH v3 net-next] ptp: Move from simple ida to xarray

[Przemek Kitszel]

On 3/11/24 14:59, Kory Maincent wrote:
> Move from simple ida to xarray for storing and loading the ptp_clock
> pointer. This prepares support for future hardware timestamp selection by
> being able to link the ptp clock index to its pointer.
> 
> Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
> ---
> 
> Change in v2:
> - Update an err value missing.
> 
> Change in v3:
> - Refactor err management.
> ---
>   drivers/ptp/ptp_clock.c | 28 ++++++++++++++++------------
>   1 file changed, 16 insertions(+), 12 deletions(-)
> 

sorry for not commenting more on v2 :/

As you change (the intent of*) underlying data structure you should also 
change included header file.

*ida is an xarray wrapper by now so the change is on semantic level only

> diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c
> index 3aaf1a3430c5..8eebf1373ca3 100644
> --- a/drivers/ptp/ptp_clock.c
> +++ b/drivers/ptp/ptp_clock.c
> @@ -31,7 +31,7 @@ struct class *ptp_class;
>   
>   static dev_t ptp_devt;
>   
> -static DEFINE_IDA(ptp_clocks_map);
> +static DEFINE_XARRAY_ALLOC(ptp_clocks_map);
>   
>   /* time stamp event queue operations */
>   
> @@ -201,7 +201,7 @@ static void ptp_clock_release(struct device *dev)
>   	bitmap_free(tsevq->mask);
>   	kfree(tsevq);
>   	debugfs_remove(ptp->debugfs_root);
> -	ida_free(&ptp_clocks_map, ptp->index);
> +	xa_erase(&ptp_clocks_map, ptp->index);
>   	kfree(ptp);
>   }
>   
> @@ -241,16 +241,16 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
>   		return ERR_PTR(-EINVAL);
>   
>   	/* Initialize a clock structure. */
> -	err = -ENOMEM;

you could remove 0-init of err in this commit too

>   	ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL);
> -	if (ptp == NULL)
> +	if (!ptp) {
> +		err = -ENOMEM;
>   		goto no_memory;
> +	}
>   

[snip]

Thanks a lot!
Only nitpicks left, so:
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>

Re: [PATCH v3 net-next] ptp: Move from simple ida to xarray

[Köry Maincent]

On Mon, 11 Mar 2024 15:17:15 +0100
Przemek Kitszel <przemyslaw.kitszel@intel.com> wrote:

> On 3/11/24 14:59, Kory Maincent wrote:
> > Move from simple ida to xarray for storing and loading the ptp_clock
> > pointer. This prepares support for future hardware timestamp selection by
> > being able to link the ptp clock index to its pointer.
> > 
> > Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
> > ---
> > 
> > Change in v2:
> > - Update an err value missing.
> > 
> > Change in v3:
> > - Refactor err management.
> > ---
> >   drivers/ptp/ptp_clock.c | 28 ++++++++++++++++------------
> >   1 file changed, 16 insertions(+), 12 deletions(-)
> >   
> 
> sorry for not commenting more on v2 :/

No worry, thanks for your review!!

Regards,
-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com