Re: [PATCH 07/13] xen/events: add struct evtchn_ops for the low-level port operations

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Fri, Sep 13, 2013 at 05:59:55PM +0100, David Vrabel wrote:
> From: David Vrabel <david.vrabel@citrix.com>
> 
> evtchn_ops contains the low-level operations that access the shared
> data structures.  This allows alternate ABIs to be supported.

Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> 
> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
> ---
>  drivers/xen/events/events.c          |    4 ++
>  drivers/xen/events/events_internal.h |   62 +++++++++++++++++++++++++++++----
>  drivers/xen/events/n-level.c         |   32 +++++++++++++----
>  3 files changed, 82 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/xen/events/events.c b/drivers/xen/events/events.c
> index 2700c12..8ecde63 100644
> --- a/drivers/xen/events/events.c
> +++ b/drivers/xen/events/events.c
> @@ -61,6 +61,8 @@
>  
>  #include "events_internal.h"
>  
> +const struct evtchn_ops *evtchn_ops;
> +
>  /*
>   * This lock protects updates to the following mapping and reference-count
>   * arrays. The lock does not need to be acquired to read the mapping tables.
> @@ -1518,6 +1520,8 @@ void __init xen_init_IRQ(void)
>  {
>  	int i;
>  
> +	xen_evtchn_init_nlevel();
> +
>  	evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq),
>  				    GFP_KERNEL);
>  	BUG_ON(!evtchn_to_irq);
> diff --git a/drivers/xen/events/events_internal.h b/drivers/xen/events/events_internal.h
> index 79ac70b..513c34d 100644
> --- a/drivers/xen/events/events_internal.h
> +++ b/drivers/xen/events/events_internal.h
> @@ -54,21 +54,67 @@ struct irq_info {
>  #define PIRQ_NEEDS_EOI	(1 << 0)
>  #define PIRQ_SHAREABLE	(1 << 1)
>  
> +struct evtchn_ops {
> +	void (*bind_to_cpu)(struct irq_info *info, int cpu);
> +
> +	void (*clear_pending)(int port);
> +	void (*set_pending)(int port);
> +	bool (*is_pending)(int port);
> +	bool (*test_and_set_mask)(int port);
> +	void (*mask)(int port);
> +	void (*unmask)(int port);
> +
> +	void (*handle_events)(int cpu);
> +};
> +
> +extern const struct evtchn_ops *evtchn_ops;
> +
>  extern int *evtchn_to_irq;
>  
>  struct irq_info *info_for_irq(unsigned irq);
>  unsigned cpu_from_irq(unsigned irq);
>  unsigned cpu_from_evtchn(unsigned int evtchn);
>  
> -void xen_evtchn_port_bind_to_cpu(struct irq_info *info, int cpu);
> +static inline void xen_evtchn_port_bind_to_cpu(struct irq_info *info, int cpu)
> +{
> +	evtchn_ops->bind_to_cpu(info, cpu);
> +}
> +
> +static inline void clear_evtchn(int port)
> +{
> +	evtchn_ops->clear_pending(port);
> +}
> +
> +static inline void set_evtchn(int port)
> +{
> +	evtchn_ops->set_pending(port);
> +}
> +
> +static inline bool test_evtchn(int port)
> +{
> +	return evtchn_ops->is_pending(port);
> +}
> +
> +static inline bool test_and_set_mask(int port)
> +{
> +	return evtchn_ops->test_and_set_mask(port);
> +}
> +
> +static inline void mask_evtchn(int port)
> +{
> +	return evtchn_ops->mask(port);
> +}
> +
> +static inline void unmask_evtchn(int port)
> +{
> +	return evtchn_ops->unmask(port);
> +}
>  
> -void clear_evtchn(int port);
> -void set_evtchn(int port);
> -int test_evtchn(int port);
> -int test_and_set_mask(int port);
> -void mask_evtchn(int port);
> -void unmask_evtchn(int port);
> +static inline void xen_evtchn_handle_events(int cpu)
> +{
> +	return evtchn_ops->handle_events(cpu);
> +}
>  
> -void xen_evtchn_handle_events(int cpu);
> +void xen_evtchn_init_nlevel(void);
>  
>  #endif /* #ifndef __EVENTS_INTERNAL_H__ */
> diff --git a/drivers/xen/events/n-level.c b/drivers/xen/events/n-level.c
> index b86a853..6c0662e 100644
> --- a/drivers/xen/events/n-level.c
> +++ b/drivers/xen/events/n-level.c
> @@ -39,43 +39,43 @@
>  static DEFINE_PER_CPU(xen_ulong_t [NR_EVENT_CHANNELS/BITS_PER_EVTCHN_WORD],
>  		      cpu_evtchn_mask);
>  
> -void xen_evtchn_port_bind_to_cpu(struct irq_info *info, int cpu)
> +static void nlevel_bind_to_cpu(struct irq_info *info, int cpu)
>  {
>  	clear_bit(info->evtchn, BM(per_cpu(cpu_evtchn_mask, info->cpu)));
>  	set_bit(info->evtchn, BM(per_cpu(cpu_evtchn_mask, cpu)));
>  }
>  
> -void clear_evtchn(int port)
> +static void nlevel_clear_pending(int port)
>  {
>  	struct shared_info *s = HYPERVISOR_shared_info;
>  	sync_clear_bit(port, BM(&s->evtchn_pending[0]));
>  }
>  
> -void set_evtchn(int port)
> +static void nlevel_set_pending(int port)
>  {
>  	struct shared_info *s = HYPERVISOR_shared_info;
>  	sync_set_bit(port, BM(&s->evtchn_pending[0]));
>  }
>  
> -int test_evtchn(int port)
> +static bool nlevel_is_pending(int port)
>  {
>  	struct shared_info *s = HYPERVISOR_shared_info;
>  	return sync_test_bit(port, BM(&s->evtchn_pending[0]));
>  }
>  
> -int test_and_set_mask(int port)
> +static bool nlevel_test_and_set_mask(int port)
>  {
>  	struct shared_info *s = HYPERVISOR_shared_info;
>  	return sync_test_and_set_bit(port, BM(&s->evtchn_mask[0]));
>  }
>  
> -void mask_evtchn(int port)
> +static void nlevel_mask(int port)
>  {
>  	struct shared_info *s = HYPERVISOR_shared_info;
>  	sync_set_bit(port, BM(&s->evtchn_mask[0]));
>  }
>  
> -void unmask_evtchn(int port)
> +static void nlevel_unmask(int port)
>  {
>  	struct shared_info *s = HYPERVISOR_shared_info;
>  	unsigned int cpu = get_cpu();
> @@ -141,7 +141,7 @@ static inline xen_ulong_t active_evtchns(unsigned int cpu,
>   * a bitset of words which contain pending event bits.  The second
>   * level is a bitset of pending events themselves.
>   */
> -void xen_evtchn_handle_events(int cpu)
> +static void nlevel_handle_events(int cpu)
>  {
>  	xen_ulong_t pending_words;
>  	int start_word_idx, start_bit_idx;
> @@ -320,3 +320,19 @@ irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
>  
>  	return IRQ_HANDLED;
>  }
> +
> +static const struct evtchn_ops evtchn_ops_nlevel = {
> +	.bind_to_cpu       = nlevel_bind_to_cpu,
> +	.clear_pending     = nlevel_clear_pending,
> +	.set_pending       = nlevel_set_pending,
> +	.is_pending        = nlevel_is_pending,
> +	.test_and_set_mask = nlevel_test_and_set_mask,
> +	.mask              = nlevel_mask,
> +	.unmask            = nlevel_unmask,
> +	.handle_events     = nlevel_handle_events,
> +};
> +
> +void __init xen_evtchn_init_nlevel(void)
> +{
> +	evtchn_ops = &evtchn_ops_nlevel;
> +}
> -- 
> 1.7.2.5
>