From: Jan Beulich <jbeulich@suse.com>
To: "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>
Cc: "Andrew Cooper" <andrew.cooper3@citrix.com>,
"George Dunlap" <George.Dunlap@eu.citrix.com>,
"Ian Jackson" <iwj@xenproject.org>,
"Julien Grall" <julien@xen.org>, "Wei Liu" <wl@xen.org>,
"Stefano Stabellini" <sstabellini@kernel.org>,
"Roger Pau Monné" <roger.pau@citrix.com>
Subject: [PATCH v6 3/3] evtchn: type adjustments
Date: Thu, 27 May 2021 13:28:59 +0200 [thread overview]
Message-ID: <8f7b57da-cd10-5f96-62fe-1a6e28c8981f@suse.com> (raw)
In-Reply-To: <01bbf3d4-ca6a-e837-91fe-b34aa014564c@suse.com>
First of all avoid "long" when "int" suffices, i.e. in particular when
merely conveying error codes. 32-bit values are slightly cheaper to
deal with on x86, and their processing is at least no more expensive on
Arm. Where possible use evtchn_port_t for port numbers and unsigned int
for other unsigned quantities in adjacent code. In evtchn_set_priority()
eliminate a local variable altogether instead of changing its type.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
v6: Re-base for re-ordering / shrinking of series.
v4: New.
--- a/xen/common/event_channel.c
+++ b/xen/common/event_channel.c
@@ -284,13 +284,12 @@ void evtchn_free(struct domain *d, struc
xsm_evtchn_close_post(chn);
}
-static long evtchn_alloc_unbound(evtchn_alloc_unbound_t *alloc)
+static int evtchn_alloc_unbound(evtchn_alloc_unbound_t *alloc)
{
struct evtchn *chn;
struct domain *d;
- int port;
+ int port, rc;
domid_t dom = alloc->dom;
- long rc;
d = rcu_lock_domain_by_any_id(dom);
if ( d == NULL )
@@ -342,13 +341,13 @@ static void double_evtchn_unlock(struct
evtchn_write_unlock(rchn);
}
-static long evtchn_bind_interdomain(evtchn_bind_interdomain_t *bind)
+static int evtchn_bind_interdomain(evtchn_bind_interdomain_t *bind)
{
struct evtchn *lchn, *rchn;
struct domain *ld = current->domain, *rd;
- int lport, rport = bind->remote_port;
+ int lport, rc;
+ evtchn_port_t rport = bind->remote_port;
domid_t rdom = bind->remote_dom;
- long rc;
if ( (rd = rcu_lock_domain_by_any_id(rdom)) == NULL )
return -ESRCH;
@@ -484,12 +483,12 @@ int evtchn_bind_virq(evtchn_bind_virq_t
}
-static long evtchn_bind_ipi(evtchn_bind_ipi_t *bind)
+static int evtchn_bind_ipi(evtchn_bind_ipi_t *bind)
{
struct evtchn *chn;
struct domain *d = current->domain;
- int port, vcpu = bind->vcpu;
- long rc = 0;
+ int port, rc = 0;
+ unsigned int vcpu = bind->vcpu;
if ( domain_vcpu(d, vcpu) == NULL )
return -ENOENT;
@@ -543,16 +542,16 @@ static void unlink_pirq_port(struct evtc
}
-static long evtchn_bind_pirq(evtchn_bind_pirq_t *bind)
+static int evtchn_bind_pirq(evtchn_bind_pirq_t *bind)
{
struct evtchn *chn;
struct domain *d = current->domain;
struct vcpu *v = d->vcpu[0];
struct pirq *info;
- int port = 0, pirq = bind->pirq;
- long rc;
+ int port = 0, rc;
+ unsigned int pirq = bind->pirq;
- if ( (pirq < 0) || (pirq >= d->nr_pirqs) )
+ if ( pirq >= d->nr_pirqs )
return -EINVAL;
if ( !is_hvm_domain(d) && !pirq_access_permitted(d, pirq) )
@@ -608,7 +607,7 @@ int evtchn_close(struct domain *d1, int
{
struct domain *d2 = NULL;
struct evtchn *chn1 = _evtchn_from_port(d1, port1), *chn2;
- long rc = 0;
+ int rc = 0;
if ( !chn1 )
return -EINVAL;
@@ -959,7 +958,7 @@ int evtchn_status(evtchn_status_t *statu
domid_t dom = status->dom;
int port = status->port;
struct evtchn *chn;
- long rc = 0;
+ int rc = 0;
d = rcu_lock_domain_by_any_id(dom);
if ( d == NULL )
@@ -1025,11 +1024,11 @@ int evtchn_status(evtchn_status_t *statu
}
-long evtchn_bind_vcpu(unsigned int port, unsigned int vcpu_id)
+int evtchn_bind_vcpu(evtchn_port_t port, unsigned int vcpu_id)
{
struct domain *d = current->domain;
struct evtchn *chn;
- long rc = 0;
+ int rc = 0;
struct vcpu *v;
/* Use the vcpu info to prevent speculative out-of-bound accesses */
@@ -1168,12 +1167,11 @@ int evtchn_reset(struct domain *d, bool
return rc;
}
-static long evtchn_set_priority(const struct evtchn_set_priority *set_priority)
+static int evtchn_set_priority(const struct evtchn_set_priority *set_priority)
{
struct domain *d = current->domain;
- unsigned int port = set_priority->port;
- struct evtchn *chn = _evtchn_from_port(d, port);
- long ret;
+ struct evtchn *chn = _evtchn_from_port(d, set_priority->port);
+ int ret;
if ( !chn )
return -EINVAL;
@@ -1189,7 +1187,7 @@ static long evtchn_set_priority(const st
long do_event_channel_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
{
- long rc;
+ int rc;
switch ( cmd )
{
--- a/xen/include/xen/event.h
+++ b/xen/include/xen/event.h
@@ -54,7 +54,7 @@ void send_guest_pirq(struct domain *, co
int evtchn_send(struct domain *d, unsigned int lport);
/* Bind a local event-channel port to the specified VCPU. */
-long evtchn_bind_vcpu(unsigned int port, unsigned int vcpu_id);
+int evtchn_bind_vcpu(evtchn_port_t port, unsigned int vcpu_id);
/* Bind a VIRQ. */
int evtchn_bind_virq(evtchn_bind_virq_t *bind, evtchn_port_t port);
next prev parent reply other threads:[~2021-05-27 11:29 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-27 11:27 [PATCH v6 0/3] evtchn: (not so) recent XSAs follow-on Jan Beulich
2021-05-27 11:28 ` [PATCH v6 1/3] evtchn: slightly defer lock acquire where possible Jan Beulich
2021-05-27 13:46 ` Roger Pau Monné
2021-05-27 18:48 ` Julien Grall
2021-05-28 8:30 ` Roger Pau Monné
2021-05-28 10:23 ` Jan Beulich
2021-05-28 10:48 ` Julien Grall
2021-05-28 13:31 ` Roger Pau Monné
2021-05-28 13:41 ` Jan Beulich
2021-05-28 14:26 ` Julien Grall
2021-06-01 11:54 ` Jan Beulich
2021-06-07 18:15 ` Julien Grall
2021-05-27 11:28 ` [PATCH v6 2/3] evtchn: add helper for port_is_valid() + evtchn_from_port() Jan Beulich
2021-05-27 11:28 ` Jan Beulich [this message]
2021-05-27 13:52 ` [PATCH v6 3/3] evtchn: type adjustments Roger Pau Monné
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