Subject: [Patch V1 3/6] genirq: Introduce msi_irq_domain_{alloc|free}_irqs()

From: [email-masked] (Yijing Wang)
Date: Thu, 13 Nov 2014 20:34:49 +0800

Gerry, this patch seems to be the same as last one.

On 2014/11/13 19:43, Jiang Liu wrote:
> Introduce msi_irq_domain_{alloc|free}_irqs() to alloc/free interrupts
> from irqdomain for generic MSI interrupts.
> 
> Signed-off-by: Jiang Liu <[email-masked]>
> ---
>  include/linux/msi.h |   35 ++++++++++++++++++++++++++++++
>  kernel/irq/msi.c    |   59 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 94 insertions(+)
> 
> diff --git a/include/linux/msi.h b/include/linux/msi.h
> index 714716a3ffdd..6b356a1410b2 100644
> --- a/include/linux/msi.h
> +++ b/include/linux/msi.h
> @@ -3,6 +3,7 @@
>  
>  #include <linux/kobject.h>
>  #include <linux/list.h>
> +#include <asm/hw_irq.h>		/* for msi_alloc_info_t */
>  
>  struct msi_msg {
>  	u32	address_lo;	/* low 32 bits of msi message address */
> @@ -100,7 +101,26 @@ struct irq_chip;
>  struct device_node;
>  struct msi_domain_info;
>  
> +#ifndef NUM_MSI_ALLOC_SCRATCHPAD_REGS
> +#define NUM_MSI_ALLOC_SCRATCHPAD_REGS	2
> +#endif
> +
> +/*
> + * Default structure for MSI interrupt allocation.
> + * Arch may overwrite it by define msi_alloc_info_t.
> + */
> +struct msi_alloc_info {
> +	struct msi_desc *desc;
> +	irq_hw_number_t hwirq;
> +	long		scratchpad[NUM_MSI_ALLOC_SCRATCHPAD_REGS];
> +};
> +
> +#ifndef msi_alloc_info_t
> +typedef struct msi_alloc_info msi_alloc_info_t;
> +#endif
> +
>  struct msi_domain_ops {
> +	/* Callbacks for msi_create_irq_domain() */
>  	void		(*calc_hwirq)(struct msi_domain_info *info, void *arg,
>  				      struct msi_desc *desc);
>  	irq_hw_number_t	(*get_hwirq)(struct msi_domain_info *info, void *arg);
> @@ -111,6 +131,19 @@ struct msi_domain_ops {
>  	void		(*msi_free)(struct irq_domain *domain,
>  				    struct msi_domain_info *info,
>  				    unsigned int virq);
> +
> +	/* Callbacks for msi_irq_domain_alloc_irqs() based on msi_descs */
> +	int		(*msi_check)(struct irq_domain *domain,
> +				     struct msi_domain_info *info,
> +				     struct device *dev);
> +	int		(*msi_prepare)(struct irq_domain *domain,
> +				       struct device *dev,
> +				       msi_alloc_info_t *arg);
> +	void		(*msi_finish)(msi_alloc_info_t *arg, int retval);
> +	void		(*set_desc)(msi_alloc_info_t *arg,
> +				    struct msi_desc *desc);
> +	int		(*handle_error)(struct irq_domain *domain,
> +					struct msi_desc *desc, int error);
>  };
>  
>  struct msi_domain_info {
> @@ -125,6 +158,8 @@ int msi_domain_set_affinity(struct irq_data *data, const struct cpumask *mask,
>  struct irq_domain *msi_create_irq_domain(struct device_node *of_node,
>  					 struct msi_domain_info *info,
>  					 struct irq_domain *parent);
> +int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev);
> +void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev);
>  struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain);
>  
>  #endif /* CONFIG_GENERIC_MSI_IRQ_DOMAIN */
> diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
> index 94d6d87ee23e..0b6665de3a60 100644
> --- a/kernel/irq/msi.c
> +++ b/kernel/irq/msi.c
> @@ -13,6 +13,9 @@
>  #include <linux/irqdomain.h>
>  #include <linux/msi.h>
>  
> +/* Temparory solution for building, will be removed later */
> +#include <linux/pci.h>
> +
>  void __get_cached_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
>  {
>  	*msg = entry->msg;
> @@ -124,6 +127,62 @@ struct irq_domain *msi_create_irq_domain(struct device_node *of_node,
>  	return domain;
>  }
>  
> +int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev)
> +{
> +	int i, ret, virq = -1;
> +	msi_alloc_info_t arg;
> +	struct msi_desc *desc;
> +	struct msi_domain_info *info = domain->host_data;
> +	struct msi_domain_ops *ops = info->ops;
> +
> +	ret = ops->msi_check(domain, info, dev);
> +	if (ret == 0)
> +		ret = ops->msi_prepare(domain, dev, &arg);
> +	if (ret)
> +		return ret;
> +
> +	for_each_msi_entry(desc, dev) {
> +		ops->set_desc(&arg, desc);
> +
> +		virq = __irq_domain_alloc_irqs(domain, -1, desc->nvec_used,
> +					       dev_to_node(dev), &arg, false);
> +		if (virq < 0) {
> +			ret = -ENOSPC;
> +			if (ops->handle_error)
> +				ret = ops->handle_error(domain, desc, ret);
> +			if (ops->msi_finish)
> +				ops->msi_finish(&arg, ret);
> +			return ret;
> +		}
> +
> +		for (i = 0; i < desc->nvec_used; i++)
> +			irq_set_msi_desc_off(virq, i, desc);
> +	}
> +
> +	if (ops->msi_finish)
> +		ops->msi_finish(&arg, 0);
> +
> +	for_each_msi_entry(desc, dev) {
> +		if (desc->nvec_used == 1)
> +			dev_dbg(dev, "irq %d for MSI\n", virq);
> +		else
> +			dev_dbg(dev, "irq [%d-%d] for MSI\n",
> +				virq, virq + desc->nvec_used - 1);
> +	}
> +
> +	return 0;
> +}
> +
> +void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev)
> +{
> +	struct msi_desc *desc;
> +
> +	for_each_msi_entry(desc, dev) {
> +		irq_domain_free_irqs(desc->irq, desc->nvec_used);
> +		desc->irq = 0;
> +	}
> +}
> +
>  struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain)
>  {
>  	return (struct msi_domain_info *)domain->host_data;
> 

-- 
Thanks!
Yijing