Re: [patch 08/37] genirq/msi: Provide msi_device_populate/destroy_sysfs()

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Sat, 27 Nov 2021 02:20:19 +0100 (CET)
Thomas Gleixner <tglx@linutronix.de> wrote:

> Add new allocation functions which can be activated by domain info
> flags. They store the groups pointer in struct msi_device_data.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

A few trivial comments...

> ---
>  include/linux/msi.h |   12 +++++++++++-
>  kernel/irq/msi.c    |   42 ++++++++++++++++++++++++++++++++++++++++--
>  2 files changed, 51 insertions(+), 3 deletions(-)
> 
> --- a/include/linux/msi.h
> +++ b/include/linux/msi.h
> @@ -174,9 +174,11 @@ struct msi_desc {
>  /**
>   * msi_device_data - MSI per device data
>   * @lock:		Spinlock to protect register access
> + * @attrs:		Pointer to the sysfs attribute group
>   */
>  struct msi_device_data {
> -	raw_spinlock_t		lock;
> +	raw_spinlock_t			lock;

Trivial: Move the alignment change back to patch 2.

> +	const struct attribute_group    **attrs;
>  };
>  
>  int msi_setup_device_data(struct device *dev);
> @@ -242,10 +244,16 @@ void pci_msi_mask_irq(struct irq_data *d
>  void pci_msi_unmask_irq(struct irq_data *data);
>  
>  #ifdef CONFIG_SYSFS
> +int msi_device_populate_sysfs(struct device *dev);
> +void msi_device_destroy_sysfs(struct device *dev);
> +
>  const struct attribute_group **msi_populate_sysfs(struct device *dev);
>  void msi_destroy_sysfs(struct device *dev,
>  		       const struct attribute_group **msi_irq_groups);
>  #else
> +static inline int msi_device_populate_sysfs(struct device *dev) { return 0; }
> +static inline void msi_device_destroy_sysfs(struct device *dev) { }
> +
>  static inline const struct attribute_group **msi_populate_sysfs(struct device *dev)
>  {
>  	return NULL;
> @@ -393,6 +401,8 @@ enum {
>  	MSI_FLAG_MUST_REACTIVATE	= (1 << 5),
>  	/* Is level-triggered capable, using two messages */
>  	MSI_FLAG_LEVEL_CAPABLE		= (1 << 6),
> +	/* Populate sysfs on alloc() and destroy it on free() */
> +	MSI_FLAG_DEV_SYSFS		= (1 << 7),
>  };
>  
>  int msi_domain_set_affinity(struct irq_data *data, const struct cpumask *mask,
> --- a/kernel/irq/msi.c
> +++ b/kernel/irq/msi.c
> @@ -214,6 +214,20 @@ const struct attribute_group **msi_popul
>  }
>  
>  /**
> + * msi_device_populate_sysfs - Populate msi_irqs sysfs entries for a device
> + * @dev:	The device(PCI, platform etc) which will get sysfs entries

Space after device

> + */
> +int msi_device_populate_sysfs(struct device *dev)
> +{
> +	const struct attribute_group **group = msi_populate_sysfs(dev);
> +
> +	if (IS_ERR(group))
> +		return PTR_ERR(group);
> +	dev->msi.data->attrs = group;
> +	return 0;
> +}
> +
> +/**
>   * msi_destroy_sysfs - Destroy msi_irqs sysfs entries for devices
>   * @dev:		The device(PCI, platform etc) who will remove sysfs entries
>   * @msi_irq_groups:	attribute_group for device msi_irqs entries
> @@ -239,6 +253,17 @@ void msi_destroy_sysfs(struct device *de
>  		kfree(msi_irq_groups);
>  	}
>  }
> +
> +/**
> + * msi_device_destroy_sysfs - Destroy msi_irqs sysfs entries for a device
> + * @dev:		The device(PCI, platform etc) for which to remove
> + *			sysfs entries
> + */
> +void msi_device_destroy_sysfs(struct device *dev)
> +{
> +	msi_destroy_sysfs(dev, dev->msi.data->attrs);
> +	dev->msi.data->attrs = NULL;
> +}
>  #endif
>  
>  #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
> @@ -686,8 +711,19 @@ int msi_domain_alloc_irqs(struct irq_dom
>  {
>  	struct msi_domain_info *info = domain->host_data;
>  	struct msi_domain_ops *ops = info->ops;
> +	int ret;
>  
> -	return ops->domain_alloc_irqs(domain, dev, nvec);
> +	ret = ops->domain_alloc_irqs(domain, dev, nvec);
> +	if (ret)
> +		return ret;
> +
> +	if (!(info->flags & MSI_FLAG_DEV_SYSFS))
> +		return 0;
> +
> +	ret = msi_device_populate_sysfs(dev);
> +	if (ret)
> +		msi_domain_free_irqs(domain, dev);
> +	return ret;
>  }
>  
>  void __msi_domain_free_irqs(struct irq_domain *domain, struct device *dev)
> @@ -726,7 +762,9 @@ void msi_domain_free_irqs(struct irq_dom
>  	struct msi_domain_info *info = domain->host_data;
>  	struct msi_domain_ops *ops = info->ops;
>  
> -	return ops->domain_free_irqs(domain, dev);
> +	if (info->flags & MSI_FLAG_DEV_SYSFS)
> +		msi_device_destroy_sysfs(dev);
> +	ops->domain_free_irqs(domain, dev);
>  }
>  
>  /**
> 
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