[RFC PATCH V5 05/15] evtchn: add d->max_evtchns

[Wei Liu <wei.liu2@citrix.com>]

This variable indicates the maximum number of event channels a domain can use.

Also replace MAX_EVTCHNS macro with inline function which will be used to
calculate max event channels in the future.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
 xen/common/event_channel.c |    5 +++--
 xen/common/schedule.c      |    2 +-
 xen/include/xen/event.h    |    7 ++++++-
 xen/include/xen/sched.h    |    2 +-
 4 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/xen/common/event_channel.c b/xen/common/event_channel.c
index 54ae281..ebe8278 100644
--- a/xen/common/event_channel.c
+++ b/xen/common/event_channel.c
@@ -166,7 +166,7 @@ static int get_free_port(struct domain *d)
         if ( evtchn_from_port(d, port)->state == ECS_FREE )
             return port;
 
-    if ( port == MAX_EVTCHNS(d) )
+    if ( port == d->max_evtchns )
         return -ENOSPC;
 
     if ( unlikely(group_from_port(d, port)  == NULL ) )
@@ -1153,6 +1153,7 @@ const static struct evtchn_port_ops evtchn_2l_ops = {
 int evtchn_init(struct domain *d)
 {
     spin_lock_init(&d->event_lock);
+    d->max_evtchns = max_evtchns(d);
     if ( get_free_port(d) != 0 )
         return -EINVAL;
     evtchn_from_port(d, 0)->state = ECS_RESERVED;
@@ -1248,7 +1249,7 @@ static void domain_dump_evtchn_info(struct domain *d)
 
     spin_lock(&d->event_lock);
 
-    for ( port = 1; port < MAX_EVTCHNS(d); ++port )
+    for ( port = 1; port < d->max_evtchns; ++port )
     {
         const struct evtchn *chn;
         char *ssid;
diff --git a/xen/common/schedule.c b/xen/common/schedule.c
index 6362e64..2e4a8d4 100644
--- a/xen/common/schedule.c
+++ b/xen/common/schedule.c
@@ -698,7 +698,7 @@ static long do_poll(struct sched_poll *sched_poll)
             goto out;
 
         rc = -EINVAL;
-        if ( port >= MAX_EVTCHNS(d) )
+        if ( port >= d->max_evtchns )
             goto out;
 
         rc = 0;
diff --git a/xen/include/xen/event.h b/xen/include/xen/event.h
index d3ee5e0..6e4d533 100644
--- a/xen/include/xen/event.h
+++ b/xen/include/xen/event.h
@@ -15,6 +15,11 @@
 #include <asm/bitops.h>
 #include <asm/event.h>
 
+static inline unsigned int max_evtchns(struct domain *d)
+{
+    return BITS_PER_EVTCHN_WORD(d) * BITS_PER_EVTCHN_WORD(d);
+}
+
 /*
  * send_guest_vcpu_virq: Notify guest via a per-VCPU VIRQ.
  *  @v:        VCPU to which virtual IRQ should be sent
@@ -86,7 +91,7 @@ void notify_via_xen_event_channel(struct domain *ld, int lport);
 #define bucket_from_port(d,p) \
     ((group_from_port(d,p))[((p)%EVTCHNS_PER_GROUP)/EVTCHNS_PER_BUCKET])
 #define port_is_valid(d,p)    \
-    (((p) >= 0) && ((p) < MAX_EVTCHNS(d)) && \
+    (((p) >= 0) && ((p) < d->max_evtchns) && \
      (group_from_port(d,p) != NULL) && \
      (bucket_from_port(d,p) != NULL))
 #define evtchn_from_port(d,p) \
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index 1cd289e..f89e9c5 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -50,7 +50,6 @@ extern struct domain *dom0;
 #else
 #define BITS_PER_EVTCHN_WORD(d) (has_32bit_shinfo(d) ? 32 : BITS_PER_XEN_ULONG)
 #endif
-#define MAX_EVTCHNS(d) (BITS_PER_EVTCHN_WORD(d) * BITS_PER_EVTCHN_WORD(d))
 /*
  * To make sure EVTCHNS_PER_BUCKET is at least 1 for 32 bit build,
  * NR_EVTCHN_GROUPS * BUCKETES_PER_GROUP should be <= 1024.
@@ -271,6 +270,7 @@ struct domain
     struct evtchn  **evtchn[NR_EVTCHN_GROUPS];
     const struct evtchn_port_ops *evtchn_ops;
     spinlock_t       event_lock;
+    unsigned int     max_evtchns;
 
     struct grant_table *grant_table;
 
-- 
1.7.10.4