Module Name:    src
Committed By:   rmind
Date:           Wed Jun  6 22:22:42 UTC 2012

Modified Files:
        src/sys/arch/xen/x86: cpu.c x86_xpmap.c
        src/sys/kern: subr_kcpuset.c
        src/sys/sys: kcpuset.h

Log Message:
Few fixes for Xen:
- cpu_load_pmap: use atomic kcpuset(9) operations; fixes rare crashes.
- Add kcpuset_copybits(9) and replace xen_kcpuset2bits().  Avoids incorrect
  ncpu problem in early boot.  Also, micro-optimises xen_mcast_invlpg() and
  xen_mcast_tlbflush() routines.

Tested by chs@.


To generate a diff of this commit:
cvs rdiff -u -r1.91 -r1.92 src/sys/arch/xen/x86/cpu.c
cvs rdiff -u -r1.43 -r1.44 src/sys/arch/xen/x86/x86_xpmap.c
cvs rdiff -u -r1.5 -r1.6 src/sys/kern/subr_kcpuset.c
cvs rdiff -u -r1.5 -r1.6 src/sys/sys/kcpuset.h

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

Modified files:

Index: src/sys/arch/xen/x86/cpu.c
diff -u src/sys/arch/xen/x86/cpu.c:1.91 src/sys/arch/xen/x86/cpu.c:1.92
--- src/sys/arch/xen/x86/cpu.c:1.91	Fri Apr 20 22:23:25 2012
+++ src/sys/arch/xen/x86/cpu.c	Wed Jun  6 22:22:41 2012
@@ -1,4 +1,4 @@
-/*	$NetBSD: cpu.c,v 1.91 2012/04/20 22:23:25 rmind Exp $	*/
+/*	$NetBSD: cpu.c,v 1.92 2012/06/06 22:22:41 rmind Exp $	*/
 /* NetBSD: cpu.c,v 1.18 2004/02/20 17:35:01 yamt Exp  */
 
 /*-
@@ -66,7 +66,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: cpu.c,v 1.91 2012/04/20 22:23:25 rmind Exp $");
+__KERNEL_RCSID(0, "$NetBSD: cpu.c,v 1.92 2012/06/06 22:22:41 rmind Exp $");
 
 #include "opt_ddb.h"
 #include "opt_multiprocessor.h"
@@ -1110,10 +1110,11 @@ cpu_load_pmap(struct pmap *pmap, struct 
 
 #if defined(__x86_64__) || defined(PAE)
 	struct cpu_info *ci = curcpu();
+	cpuid_t cid = cpu_index(ci);
 
 	mutex_enter(&ci->ci_kpm_mtx);
 	/* make new pmap visible to pmap_kpm_sync_xcall() */
-	kcpuset_set(pmap->pm_xen_ptp_cpus, cpu_index(ci));
+	kcpuset_atomic_set(pmap->pm_xen_ptp_cpus, cid);
 #endif
 #ifdef i386
 #ifdef PAE
@@ -1166,9 +1167,9 @@ cpu_load_pmap(struct pmap *pmap, struct 
 #endif /* __x86_64__ */
 #if defined(__x86_64__) || defined(PAE)
 	/* old pmap no longer visible to pmap_kpm_sync_xcall() */
-	if (oldpmap != pmap_kernel())
-		kcpuset_clear(oldpmap->pm_xen_ptp_cpus, cpu_index(ci));
-
+	if (oldpmap != pmap_kernel()) {
+		kcpuset_atomic_clear(oldpmap->pm_xen_ptp_cpus, cid);
+	}
 	mutex_exit(&ci->ci_kpm_mtx);
 #endif
 }

Index: src/sys/arch/xen/x86/x86_xpmap.c
diff -u src/sys/arch/xen/x86/x86_xpmap.c:1.43 src/sys/arch/xen/x86/x86_xpmap.c:1.44
--- src/sys/arch/xen/x86/x86_xpmap.c:1.43	Fri Apr 20 22:23:25 2012
+++ src/sys/arch/xen/x86/x86_xpmap.c	Wed Jun  6 22:22:41 2012
@@ -1,4 +1,4 @@
-/*	$NetBSD: x86_xpmap.c,v 1.43 2012/04/20 22:23:25 rmind Exp $	*/
+/*	$NetBSD: x86_xpmap.c,v 1.44 2012/06/06 22:22:41 rmind Exp $	*/
 
 /*
  * Copyright (c) 2006 Mathieu Ropert <m...@adviseo.fr>
@@ -69,7 +69,7 @@
 
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: x86_xpmap.c,v 1.43 2012/04/20 22:23:25 rmind Exp $");
+__KERNEL_RCSID(0, "$NetBSD: x86_xpmap.c,v 1.44 2012/06/06 22:22:41 rmind Exp $");
 
 #include "opt_xen.h"
 #include "opt_ddb.h"
@@ -361,32 +361,14 @@ xpq_queue_invlpg(vaddr_t va)
 		panic("xpq_queue_invlpg");
 }
 
-#if defined(_LP64) &&  MAXCPUS > 64
-#error "XEN/amd64 uses 64 bit masks"
-#elsif !defined(_LP64) && MAXCPUS > 32
-#error "XEN/i386 uses 32 bit masks"
-#else
-/* XXX: Inefficient. */
-static u_long
-xen_kcpuset2bits(kcpuset_t *kc)
-{
-	u_long bits = 0;
-
-	for (cpuid_t i = 0; i < ncpu; i++) {
-		if (kcpuset_isset(kc, i)) {
-			bits |= 1 << i;
-		}
-	}
-	return bits;
-}
-#endif
-
 void
 xen_mcast_invlpg(vaddr_t va, kcpuset_t *kc)
 {
-	u_long xcpumask = xen_kcpuset2bits(kc);
+	u_long xcpumask = 0;
 	mmuext_op_t op;
 
+	kcpuset_copybits(kc, &xcpumask, sizeof(xcpumask));
+
 	/* Flush pending page updates */
 	xpq_flush_queue();
 
@@ -423,9 +405,11 @@ xen_bcast_invlpg(vaddr_t va)
 void
 xen_mcast_tlbflush(kcpuset_t *kc)
 {
-	u_long xcpumask = xen_kcpuset2bits(kc);
+	u_long xcpumask = 0;
 	mmuext_op_t op;
 
+	kcpuset_copybits(kc, &xcpumask, sizeof(xcpumask));
+
 	/* Flush pending page updates */
 	xpq_flush_queue();
 

Index: src/sys/kern/subr_kcpuset.c
diff -u src/sys/kern/subr_kcpuset.c:1.5 src/sys/kern/subr_kcpuset.c:1.6
--- src/sys/kern/subr_kcpuset.c:1.5	Fri Apr 20 22:23:25 2012
+++ src/sys/kern/subr_kcpuset.c	Wed Jun  6 22:22:41 2012
@@ -1,4 +1,4 @@
-/*	$NetBSD: subr_kcpuset.c,v 1.5 2012/04/20 22:23:25 rmind Exp $	*/
+/*	$NetBSD: subr_kcpuset.c,v 1.6 2012/06/06 22:22:41 rmind Exp $	*/
 
 /*-
  * Copyright (c) 2011 The NetBSD Foundation, Inc.
@@ -41,7 +41,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_kcpuset.c,v 1.5 2012/04/20 22:23:25 rmind Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_kcpuset.c,v 1.6 2012/06/06 22:22:41 rmind Exp $");
 
 #include <sys/param.h>
 #include <sys/types.h>
@@ -301,6 +301,15 @@ kcpuset_copyout(kcpuset_t *kcp, cpuset_t
 	return copyout(kcp, ucp, len);
 }
 
+void
+kcpuset_copybits(const kcpuset_t *kcp, void *bitfield, size_t len)
+{
+	size_t rlen = MIN(kc_bitsize, len);
+
+	KASSERT(kcp != NULL);
+	memcpy(bitfield, kcp->bits, rlen);
+}
+
 /*
  * Routines to change bit field - zero, fill, copy, set, unset, etc.
  */

Index: src/sys/sys/kcpuset.h
diff -u src/sys/sys/kcpuset.h:1.5 src/sys/sys/kcpuset.h:1.6
--- src/sys/sys/kcpuset.h:1.5	Fri Apr 20 22:23:25 2012
+++ src/sys/sys/kcpuset.h	Wed Jun  6 22:22:41 2012
@@ -1,4 +1,4 @@
-/*	$NetBSD: kcpuset.h,v 1.5 2012/04/20 22:23:25 rmind Exp $	*/
+/*	$NetBSD: kcpuset.h,v 1.6 2012/06/06 22:22:41 rmind Exp $	*/
 
 /*-
  * Copyright (c) 2008, 2011 The NetBSD Foundation, Inc.
@@ -50,6 +50,7 @@ void		kcpuset_unuse(kcpuset_t *, kcpuset
 
 int		kcpuset_copyin(const cpuset_t *, kcpuset_t *, size_t);
 int		kcpuset_copyout(kcpuset_t *, cpuset_t *, size_t);
+void		kcpuset_copybits(const kcpuset_t *, void *, size_t);
 
 void		kcpuset_zero(kcpuset_t *);
 void		kcpuset_fill(kcpuset_t *);

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