Module Name: src
Committed By: ozaki-r
Date: Thu Feb 1 03:15:29 UTC 2018
Modified Files:
src/share/man/man9: xcall.9
src/sys/kern: subr_xcall.c
src/sys/sys: xcall.h
Log Message:
Support arbitrary softint IPLs in high priority xcall
The high priority xcall supported only a softint of IPL_SOFTSERIAL. It meant
that it didn't work for xcall callbacks depending on lower IPLs than
IPL_SOFTSERIAL.
The change makes xcall have multiple softints of IPLs and allow users to specify
arbitrary IPLs. Users can specify an IPL by XC_HIGHPRI_IPL passed to the 1st
argument of xc_broadcast or xc_unicast.
Note that xcall still serves requests one by one (i.e., doesn't run them
concurrently) even if requests have different IPLs.
Proposed on tech-kern@
To generate a diff of this commit:
cvs rdiff -u -r1.11 -r1.12 src/share/man/man9/xcall.9
cvs rdiff -u -r1.20 -r1.21 src/sys/kern/subr_xcall.c
cvs rdiff -u -r1.5 -r1.6 src/sys/sys/xcall.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/share/man/man9/xcall.9
diff -u src/share/man/man9/xcall.9:1.11 src/share/man/man9/xcall.9:1.12
--- src/share/man/man9/xcall.9:1.11 Fri Jan 26 08:09:53 2018
+++ src/share/man/man9/xcall.9 Thu Feb 1 03:15:28 2018
@@ -1,4 +1,4 @@
-.\" $NetBSD: xcall.9,v 1.11 2018/01/26 08:09:53 ozaki-r Exp $
+.\" $NetBSD: xcall.9,v 1.12 2018/02/01 03:15:28 ozaki-r Exp $
.\"
.\" Copyright (c) 2010 The NetBSD Foundation, Inc.
.\" All rights reserved.
@@ -27,7 +27,7 @@
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
-.Dd January 26, 2018
+.Dd February 1, 2018
.Dt XCALL 9
.Os
.Sh NAME
@@ -87,7 +87,6 @@ also provides a mechanism for making
.Dq "high priority"
cross calls.
The function to be executed runs on the remote CPU within a
-.Dv IPL_SOFTSERIAL
software interrupt context, possibly interrupting other lower-priority
code running on the CPU.
.Sh NOTES
@@ -112,7 +111,18 @@ on for the cross-call to complete.
.Fa flags
should be
.Dv XC_HIGHPRI
+or
+.Fo XC_HIGHPRI_IPL
+.Fa ipl
+.Fc
for a "high priority" call, and 0 for a "low priority" call.
+.Dv XC_HIGHPRI
+uses an
+.Dv IPL_SOFTSERIAL
+software interrupt while
+.Fn XC_HIGHPRI_IPL
+uses a software interrupt with an IPL specified by
+.Fa ipl .
.Fn xc_broadcast
should not be called from interrupt context.
.It Fn xc_unicast "flags" "func" "arg1" "arg2" "ci"
Index: src/sys/kern/subr_xcall.c
diff -u src/sys/kern/subr_xcall.c:1.20 src/sys/kern/subr_xcall.c:1.21
--- src/sys/kern/subr_xcall.c:1.20 Wed Jun 21 07:39:04 2017
+++ src/sys/kern/subr_xcall.c Thu Feb 1 03:15:29 2018
@@ -1,4 +1,4 @@
-/* $NetBSD: subr_xcall.c,v 1.20 2017/06/21 07:39:04 martin Exp $ */
+/* $NetBSD: subr_xcall.c,v 1.21 2018/02/01 03:15:29 ozaki-r Exp $ */
/*-
* Copyright (c) 2007-2010 The NetBSD Foundation, Inc.
@@ -74,7 +74,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_xcall.c,v 1.20 2017/06/21 07:39:04 martin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_xcall.c,v 1.21 2018/02/01 03:15:29 ozaki-r Exp $");
#include <sys/types.h>
#include <sys/param.h>
@@ -98,6 +98,7 @@ typedef struct {
void * xc_arg2;
uint64_t xc_headp;
uint64_t xc_donep;
+ unsigned int xc_ipl;
} xc_state_t;
/* Bit indicating high (1) or low (0) priority. */
@@ -108,7 +109,7 @@ static xc_state_t xc_low_pri __cacheline
/* High priority xcall structures. */
static xc_state_t xc_high_pri __cacheline_aligned;
-static void * xc_sih __cacheline_aligned;
+static void * xc_sihs[4] __cacheline_aligned;
/* Event counters. */
static struct evcnt xc_unicast_ev __cacheline_aligned;
@@ -117,9 +118,24 @@ static struct evcnt xc_broadcast_ev __ca
static void xc_init(void);
static void xc_thread(void *);
-static inline uint64_t xc_highpri(xcfunc_t, void *, void *, struct cpu_info *);
+static inline uint64_t xc_highpri(xcfunc_t, void *, void *, struct cpu_info *,
+ unsigned int);
static inline uint64_t xc_lowpri(xcfunc_t, void *, void *, struct cpu_info *);
+/* The internal form of IPL */
+#define XC_IPL_MASK 0xff00
+/*
+ * Assign 0 to XC_IPL_SOFTSERIAL to treat IPL_SOFTSERIAL as the default value
+ * (just XC_HIGHPRI).
+ */
+#define XC_IPL_SOFTSERIAL 0
+#define XC_IPL_SOFTBIO 1
+#define XC_IPL_SOFTCLOCK 2
+#define XC_IPL_SOFTNET 3
+#define XC_IPL_MAX XC_IPL_SOFTNET
+
+CTASSERT(XC_IPL_MAX <= __arraycount(xc_sihs));
+
/*
* xc_init:
*
@@ -137,9 +153,19 @@ xc_init(void)
memset(xchi, 0, sizeof(xc_state_t));
mutex_init(&xchi->xc_lock, MUTEX_DEFAULT, IPL_SOFTSERIAL);
cv_init(&xchi->xc_busy, "xchicv");
- xc_sih = softint_establish(SOFTINT_SERIAL | SOFTINT_MPSAFE,
- xc__highpri_intr, NULL);
- KASSERT(xc_sih != NULL);
+
+#define SETUP_SOFTINT(xipl, sipl) do { \
+ xc_sihs[(xipl)] = softint_establish( (sipl) | SOFTINT_MPSAFE,\
+ xc__highpri_intr, NULL); \
+ KASSERT(xc_sihs[(xipl)] != NULL); \
+ } while (0)
+
+ SETUP_SOFTINT(XC_IPL_SOFTSERIAL, SOFTINT_SERIAL);
+ SETUP_SOFTINT(XC_IPL_SOFTBIO, SOFTINT_BIO);
+ SETUP_SOFTINT(XC_IPL_SOFTCLOCK, SOFTINT_CLOCK);
+ SETUP_SOFTINT(XC_IPL_SOFTNET, SOFTINT_NET);
+
+#undef SETUP_SOFTINT
evcnt_attach_dynamic(&xc_unicast_ev, EVCNT_TYPE_MISC, NULL,
"crosscall", "unicast");
@@ -148,6 +174,38 @@ xc_init(void)
}
/*
+ * Encode an IPL to a form that can be embedded into flags of xc_broadcast
+ * or xc_unicast.
+ */
+unsigned int
+xc_encode_ipl(int ipl)
+{
+
+ switch (ipl) {
+ case IPL_SOFTSERIAL:
+ return __SHIFTIN(XC_IPL_SOFTSERIAL, XC_IPL_MASK);
+ case IPL_SOFTBIO:
+ return __SHIFTIN(XC_IPL_SOFTBIO, XC_IPL_MASK);
+ case IPL_SOFTCLOCK:
+ return __SHIFTIN(XC_IPL_SOFTCLOCK, XC_IPL_MASK);
+ case IPL_SOFTNET:
+ return __SHIFTIN(XC_IPL_SOFTNET, XC_IPL_MASK);
+ }
+
+ panic("Invalid IPL: %d", ipl);
+}
+
+/*
+ * Extract an XC_IPL from flags of xc_broadcast or xc_unicast.
+ */
+static inline unsigned int
+xc_extract_ipl(unsigned int flags)
+{
+
+ return __SHIFTOUT(flags, XC_IPL_MASK);
+}
+
+/*
* xc_init_cpu:
*
* Initialize the cross-call subsystem. Called once for each CPU
@@ -176,13 +234,14 @@ xc_init_cpu(struct cpu_info *ci)
* Trigger a call on all CPUs in the system.
*/
uint64_t
-xc_broadcast(u_int flags, xcfunc_t func, void *arg1, void *arg2)
+xc_broadcast(unsigned int flags, xcfunc_t func, void *arg1, void *arg2)
{
KASSERT(!cpu_intr_p() && !cpu_softintr_p());
if ((flags & XC_HIGHPRI) != 0) {
- return xc_highpri(func, arg1, arg2, NULL);
+ int ipl = xc_extract_ipl(flags);
+ return xc_highpri(func, arg1, arg2, NULL, ipl);
} else {
return xc_lowpri(func, arg1, arg2, NULL);
}
@@ -194,7 +253,7 @@ xc_broadcast(u_int flags, xcfunc_t func,
* Trigger a call on one CPU.
*/
uint64_t
-xc_unicast(u_int flags, xcfunc_t func, void *arg1, void *arg2,
+xc_unicast(unsigned int flags, xcfunc_t func, void *arg1, void *arg2,
struct cpu_info *ci)
{
@@ -202,7 +261,8 @@ xc_unicast(u_int flags, xcfunc_t func, v
KASSERT(!cpu_intr_p() && !cpu_softintr_p());
if ((flags & XC_HIGHPRI) != 0) {
- return xc_highpri(func, arg1, arg2, ci);
+ int ipl = xc_extract_ipl(flags);
+ return xc_highpri(func, arg1, arg2, ci, ipl);
} else {
return xc_lowpri(func, arg1, arg2, ci);
}
@@ -329,8 +389,12 @@ xc_thread(void *cookie)
void
xc_ipi_handler(void)
{
+ xc_state_t *xc = & xc_high_pri;
+
+ KASSERT(xc->xc_ipl < __arraycount(xc_sihs));
+
/* Executes xc__highpri_intr() via software interrupt. */
- softint_schedule(xc_sih);
+ softint_schedule(xc_sihs[xc->xc_ipl]);
}
/*
@@ -376,7 +440,8 @@ xc__highpri_intr(void *dummy)
* Trigger a high priority call on one or more CPUs.
*/
static inline uint64_t
-xc_highpri(xcfunc_t func, void *arg1, void *arg2, struct cpu_info *ci)
+xc_highpri(xcfunc_t func, void *arg1, void *arg2, struct cpu_info *ci,
+ unsigned int ipl)
{
xc_state_t *xc = &xc_high_pri;
uint64_t where;
@@ -389,6 +454,7 @@ xc_highpri(xcfunc_t func, void *arg1, vo
xc->xc_arg1 = arg1;
xc->xc_arg2 = arg2;
xc->xc_headp += (ci ? 1 : ncpu);
+ xc->xc_ipl = ipl;
where = xc->xc_headp;
mutex_exit(&xc->xc_lock);
Index: src/sys/sys/xcall.h
diff -u src/sys/sys/xcall.h:1.5 src/sys/sys/xcall.h:1.6
--- src/sys/sys/xcall.h:1.5 Tue Feb 19 09:04:53 2013
+++ src/sys/sys/xcall.h Thu Feb 1 03:15:29 2018
@@ -1,4 +1,4 @@
-/* $NetBSD: xcall.h,v 1.5 2013/02/19 09:04:53 martin Exp $ */
+/* $NetBSD: xcall.h,v 1.6 2018/02/01 03:15:29 ozaki-r Exp $ */
/*-
* Copyright (c) 2007 The NetBSD Foundation, Inc.
@@ -33,7 +33,8 @@
#define _SYS_XCALL_H_
#ifdef _KERNEL
-#define XC_HIGHPRI 0x01 /* high priority */
+#define XC_HIGHPRI 0x01 /* high priority */
+#define XC_HIGHPRI_IPL(ipl) (XC_HIGHPRI | xc_encode_ipl(ipl))
typedef void (*xcfunc_t)(void *, void *);
@@ -49,6 +50,8 @@ uint64_t xc_broadcast(u_int, xcfunc_t, v
uint64_t xc_unicast(u_int, xcfunc_t, void *, void *, struct cpu_info *);
void xc_wait(uint64_t);
+unsigned int xc_encode_ipl(int);
+
#endif /* _KERNEL */
#endif /* _SYS_XCALL_H_ */
