[src/trunk]: src/sys/arch Make cross-cpu pte access MP safe.

[cherry <cherry%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/dc045b2aa560
branches:  trunk
changeset: 772584:dc045b2aa560
user:      cherry <cherry%NetBSD.org@localhost>
date:      Mon Jan 09 13:04:13 2012 +0000

description:
Make cross-cpu pte access MP safe.
XXX: review cases of use of pmap_set_pte() vs direct use of xpq_queue_pte_update()

diffstat:

 sys/arch/amd64/include/pmap.h |  33 +++++++++++++++++++--------------
 sys/arch/i386/include/pmap.h  |  31 ++++++++++++++++++-------------
 sys/arch/xen/x86/x86_xpmap.c  |   7 +++++--
 3 files changed, 42 insertions(+), 29 deletions(-)

diffs (212 lines):

diff -r 596ee488adf0 -r dc045b2aa560 sys/arch/amd64/include/pmap.h
--- a/sys/arch/amd64/include/pmap.h     Mon Jan 09 12:58:49 2012 +0000
+++ b/sys/arch/amd64/include/pmap.h     Mon Jan 09 13:04:13 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pmap.h,v 1.28 2011/11/06 15:18:18 cherry Exp $ */
+/*     $NetBSD: pmap.h,v 1.29 2012/01/09 13:04:13 cherry Exp $ */
 
 /*
  * Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -263,6 +263,8 @@
     atomic_and_ulong((volatile unsigned long *)p, ~(b))
 #define pmap_pte_flush()               /* nothing */
 #else
+extern kmutex_t pte_lock;
+
 static __inline pt_entry_t
 pmap_pa2pte(paddr_t pa)
 {
@@ -277,54 +279,57 @@
 static __inline void
 pmap_pte_set(pt_entry_t *pte, pt_entry_t npte)
 {
-       int s = splvm();
+       mutex_enter(&pte_lock);
        xpq_queue_pte_update(xpmap_ptetomach(pte), npte);
-       splx(s);
+       mutex_exit(&pte_lock);
 }
 
 static __inline pt_entry_t
 pmap_pte_cas(volatile pt_entry_t *ptep, pt_entry_t o, pt_entry_t n)
 {
-       int s = splvm();
+       pt_entry_t opte;
 
-       pt_entry_t opte = *ptep;
-
+       mutex_enter(&pte_lock);
+       opte = *ptep;
        if (opte == o) {
                xpq_queue_pte_update(xpmap_ptetomach(__UNVOLATILE(ptep)), n);
                xpq_flush_queue();
        }
-       splx(s);
+
+       mutex_exit(&pte_lock);
        return opte;
 }
 
 static __inline pt_entry_t
 pmap_pte_testset(volatile pt_entry_t *pte, pt_entry_t npte)
 {
-       int s = splvm();
-       pt_entry_t opte = *pte;
+       pt_entry_t opte;
+
+       mutex_enter(&pte_lock);
+       opte = *pte;
        xpq_queue_pte_update(xpmap_ptetomach(__UNVOLATILE(pte)), npte);
        xpq_flush_queue();
-       splx(s);
+       mutex_exit(&pte_lock);
        return opte;
 }
 
 static __inline void
 pmap_pte_setbits(volatile pt_entry_t *pte, pt_entry_t bits)
 {
-       int s = splvm();
+       mutex_enter(&pte_lock);
        xpq_queue_pte_update(xpmap_ptetomach(__UNVOLATILE(pte)), (*pte) | bits);
        xpq_flush_queue();
-       splx(s);
+       mutex_exit(&pte_lock);
 }
 
 static __inline void
 pmap_pte_clearbits(volatile pt_entry_t *pte, pt_entry_t bits)
 {      
-       int s = splvm();
+       mutex_enter(&pte_lock);
        xpq_queue_pte_update(xpmap_ptetomach(__UNVOLATILE(pte)),
            (*pte) & ~bits);
        xpq_flush_queue();
-       splx(s);
+       mutex_exit(&pte_lock);
 }
 
 static __inline void
diff -r 596ee488adf0 -r dc045b2aa560 sys/arch/i386/include/pmap.h
--- a/sys/arch/i386/include/pmap.h      Mon Jan 09 12:58:49 2012 +0000
+++ b/sys/arch/i386/include/pmap.h      Mon Jan 09 13:04:13 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pmap.h,v 1.112 2011/11/06 15:18:18 cherry Exp $        */
+/*     $NetBSD: pmap.h,v 1.113 2012/01/09 13:04:13 cherry Exp $        */
 
 /*
  * Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -354,6 +354,8 @@
 #endif /* PAE */
 
 #else /* XEN */
+extern kmutex_t pte_lock;
+
 static __inline pt_entry_t
 pmap_pa2pte(paddr_t pa)
 {
@@ -368,54 +370,57 @@
 static __inline void
 pmap_pte_set(pt_entry_t *pte, pt_entry_t npte)
 {
-       int s = splvm();
+       mutex_enter(&pte_lock);
        xpq_queue_pte_update(xpmap_ptetomach(pte), npte);
-       splx(s);
+       mutex_exit(&pte_lock);
 }
 
 static __inline pt_entry_t
 pmap_pte_cas(volatile pt_entry_t *ptep, pt_entry_t o, pt_entry_t n)
 {
-       int s = splvm();
-       pt_entry_t opte = *ptep;
+       pt_entry_t opte;
 
+       mutex_enter(&pte_lock);
+       opte = *ptep;
        if (opte == o) {
                xpq_queue_pte_update(xpmap_ptetomach(__UNVOLATILE(ptep)), n);
                xpq_flush_queue();
        }
-       splx(s);
+       mutex_exit(&pte_lock);
        return opte;
 }
 
 static __inline pt_entry_t
 pmap_pte_testset(volatile pt_entry_t *pte, pt_entry_t npte)
 {
-       int s = splvm();
-       pt_entry_t opte = *pte;
+       pt_entry_t opte;
+
+       mutex_enter(&pte_lock);
+       opte = *pte;
        xpq_queue_pte_update(xpmap_ptetomach(__UNVOLATILE(pte)),
            npte);
        xpq_flush_queue();
-       splx(s);
+       mutex_exit(&pte_lock);
        return opte;
 }
 
 static __inline void
 pmap_pte_setbits(volatile pt_entry_t *pte, pt_entry_t bits)
 {
-       int s = splvm();
+       mutex_enter(&pte_lock);
        xpq_queue_pte_update(xpmap_ptetomach(__UNVOLATILE(pte)), (*pte) | bits);
        xpq_flush_queue();
-       splx(s);
+       mutex_exit(&pte_lock);
 }
 
 static __inline void
 pmap_pte_clearbits(volatile pt_entry_t *pte, pt_entry_t bits)
 {      
-       int s = splvm();
+       mutex_enter(&pte_lock);
        xpq_queue_pte_update(xpmap_ptetomach(__UNVOLATILE(pte)),
            (*pte) & ~bits);
        xpq_flush_queue();
-       splx(s);
+       mutex_exit(&pte_lock);
 }
 
 static __inline void
diff -r 596ee488adf0 -r dc045b2aa560 sys/arch/xen/x86/x86_xpmap.c
--- a/sys/arch/xen/x86/x86_xpmap.c      Mon Jan 09 12:58:49 2012 +0000
+++ b/sys/arch/xen/x86/x86_xpmap.c      Mon Jan 09 13:04:13 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: x86_xpmap.c,v 1.36 2011/11/06 15:18:19 cherry Exp $    */
+/*     $NetBSD: x86_xpmap.c,v 1.37 2012/01/09 13:04:13 cherry Exp $    */
 
 /*
  * Copyright (c) 2006 Mathieu Ropert <mro%adviseo.fr@localhost>
@@ -69,7 +69,7 @@
 
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: x86_xpmap.c,v 1.36 2011/11/06 15:18:19 cherry Exp $");
+__KERNEL_RCSID(0, "$NetBSD: x86_xpmap.c,v 1.37 2012/01/09 13:04:13 cherry Exp $");
 
 #include "opt_xen.h"
 #include "opt_ddb.h"
@@ -117,6 +117,7 @@
 /* Xen requires the start_info struct to be page aligned */
 union start_info_union start_info_union __aligned(PAGE_SIZE);
 unsigned long *xpmap_phys_to_machine_mapping;
+kmutex_t pte_lock;
 
 void xen_failsafe_handler(void);
 
@@ -652,6 +653,8 @@
        /* Finally, flush TLB. */
        xpq_queue_tlb_flush();
 
+       mutex_init(&pte_lock, MUTEX_DEFAULT, IPL_VM);
+       
        return (init_tables + ((count + l2_4_count) * PAGE_SIZE));
 }