Re: [PATCH net-next v6 04/12] net: pse-pd: Add support for PSE power domains

[Oleksij Rempel <o.rempel@pengutronix.de>]

On Tue, Mar 04, 2025 at 11:18:53AM +0100, Kory Maincent wrote:
> +/**
> + * pse_flush_pw_ds - flush all PSE power domains of a PSE
> + * @pcdev: a pointer to the initialized PSE controller device
> + */
> +static void pse_flush_pw_ds(struct pse_controller_dev *pcdev)
> +{
> +	struct pse_power_domain *pw_d;
> +	int i;
> +
> +	for (i = 0; i < pcdev->nr_lines; i++) {
> +		if (!pcdev->pi[i].pw_d)
> +			continue;
> +
> +		pw_d = xa_load(&pse_pw_d_map, pcdev->pi[i].pw_d->id);
> +		if (pw_d) {
> +			regulator_put(pw_d->supply);
> +			xa_erase(&pse_pw_d_map, pw_d->id);
> +		}
> +	}
> +}
> +
> +/**
> + * devm_pse_alloc_pw_d - allocate a new PSE power domain for a device
> + * @dev: device that is registering this PSE power domain
> + *
> + * Return: Pointer to the newly allocated PSE power domain or error pointers
> + */
> +static struct pse_power_domain *devm_pse_alloc_pw_d(struct device *dev)
> +{
> +	struct pse_power_domain *pw_d;
> +	int index, ret;
> +
> +	pw_d = devm_kzalloc(dev, sizeof(*pw_d), GFP_KERNEL);
> +	if (!pw_d)
> +		return ERR_PTR(-ENOMEM);
> +
> +	ret = xa_alloc(&pse_pw_d_map, &index, pw_d, XA_LIMIT(1, INT_MAX), GFP_KERNEL);

#define PSE_PW_D_LIMIT INT_MAX

XA_LIMIT(1, PSE_PW_D_LIMIT)

> +	if (ret)
> +		return ERR_PTR(ret);
> +
> +	pw_d->id = index;
> +	return pw_d;
> +}
> +
> +/**
> + * pse_register_pw_ds - register the PSE power domains for a PSE
> + * @pcdev: a pointer to the PSE controller device
> + *
> + * Return: 0 on success and failure value on error
> + */
> +static int pse_register_pw_ds(struct pse_controller_dev *pcdev)
> +{
> +	int i;
> +
> +	for (i = 0; i < pcdev->nr_lines; i++) {
> +		struct regulator_dev *rdev = pcdev->pi[i].rdev;
> +		struct pse_power_domain *pw_d;
> +		struct regulator *supply;
> +		bool present = false;
> +		unsigned long index;
> +
> +		/* No regulator or regulator parent supply registered.
> +		 * We need a regulator parent to register a PSE power domain
> +		 */
> +		if (!rdev || !rdev->supply)
> +			continue;
> +

Should we use xa_lock() before iteration over the map?

> +		xa_for_each(&pse_pw_d_map, index, pw_d) {
> +			/* Power supply already registered as a PSE power
> +			 * domain.
> +			 */
> +			if (regulator_is_equal(pw_d->supply, rdev->supply)) {
> +				present = true;
> +				pcdev->pi[i].pw_d = pw_d;
> +				break;
> +			}
> +		}
> +		if (present)
> +			continue;
> +
> +		pw_d = devm_pse_alloc_pw_d(pcdev->dev);
> +		if (IS_ERR_OR_NULL(pw_d))
> +			return PTR_ERR(pw_d);

It is better to break the loop and roll back previous allocations.

> +
> +		supply = regulator_get(&rdev->dev, rdev->supply_name);
> +		if (IS_ERR(supply)) {
> +			xa_erase(&pse_pw_d_map, pw_d->id);
> +			return PTR_ERR(supply);

same here.

> +		}
> +
> +		pw_d->supply = supply;
> +		pcdev->pi[i].pw_d = pw_d;
> +	}
> +
> +	return 0;
> +}
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