Module Name: src
Committed By: thorpej
Date: Sun May 30 04:04:27 UTC 2021
Modified Files:
src/sys/arch/alpha/alpha: pmap.c
src/sys/arch/alpha/include: pmap.h
Log Message:
Pages that are in-use as page table pages should never be part of a
UVM loan transaction, so use the vm_page::loan_count field as the PT
page reference count.
To generate a diff of this commit:
cvs rdiff -u -r1.284 -r1.285 src/sys/arch/alpha/alpha/pmap.c
cvs rdiff -u -r1.90 -r1.91 src/sys/arch/alpha/include/pmap.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/alpha/alpha/pmap.c
diff -u src/sys/arch/alpha/alpha/pmap.c:1.284 src/sys/arch/alpha/alpha/pmap.c:1.285
--- src/sys/arch/alpha/alpha/pmap.c:1.284 Sun May 30 01:41:45 2021
+++ src/sys/arch/alpha/alpha/pmap.c Sun May 30 04:04:26 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: pmap.c,v 1.284 2021/05/30 01:41:45 thorpej Exp $ */
+/* $NetBSD: pmap.c,v 1.285 2021/05/30 04:04:26 thorpej Exp $ */
/*-
* Copyright (c) 1998, 1999, 2000, 2001, 2007, 2008, 2020
@@ -135,7 +135,7 @@
#include <sys/cdefs.h> /* RCS ID & Copyright macro defns */
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.284 2021/05/30 01:41:45 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.285 2021/05/30 04:04:26 thorpej Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -3358,6 +3358,15 @@ pmap_pv_page_free(struct pool *pp, void
/******************** misc. functions ********************/
/*
+ * Pages that are in-use as page table pages should never be part
+ * of a UVM loan, so we'll use that field for our PT page reference
+ * count.
+ */
+#define PHYSPAGE_REFCNT(pg) atomic_load_relaxed(&(pg)->loan_count)
+#define PHYSPAGE_REFCNT_INC(pg) atomic_inc_uint_nv(&(pg)->loan_count)
+#define PHYSPAGE_REFCNT_DEC(pg) atomic_dec_uint_nv(&(pg)->loan_count)
+
+/*
* pmap_physpage_alloc:
*
* Allocate a single page from the VM system and return the
@@ -3376,14 +3385,7 @@ pmap_physpage_alloc(int usage)
pg = uvm_pagealloc(NULL, 0, NULL, usage == PGU_L1PT ?
UVM_PGA_USERESERVE : UVM_PGA_USERESERVE|UVM_PGA_ZERO);
if (pg != NULL) {
-#ifdef DEBUG
- struct vm_page_md * const md = VM_PAGE_TO_MD(pg);
- if (md->pvh_refcnt != 0) {
- printf("pmap_physpage_alloc: page 0x%lx has "
- "%d references\n", pa, md->pvh_refcnt);
- panic("pmap_physpage_alloc");
- }
-#endif
+ KASSERT(PHYSPAGE_REFCNT(pg) == 0);
}
return pg;
}
@@ -3401,11 +3403,7 @@ pmap_physpage_free(paddr_t pa)
if ((pg = PHYS_TO_VM_PAGE(pa)) == NULL)
panic("pmap_physpage_free: bogus physical page address");
-#ifdef DEBUG
- struct vm_page_md * const md = VM_PAGE_TO_MD(pg);
- if (md->pvh_refcnt != 0)
- panic("pmap_physpage_free: page still has references");
-#endif
+ KASSERT(PHYSPAGE_REFCNT(pg) == 0);
uvm_pagefree(pg);
}
@@ -3419,16 +3417,14 @@ static int
pmap_physpage_addref(void *kva)
{
struct vm_page *pg;
- struct vm_page_md *md;
paddr_t pa;
pa = ALPHA_K0SEG_TO_PHYS(trunc_page((vaddr_t)kva));
pg = PHYS_TO_VM_PAGE(pa);
- md = VM_PAGE_TO_MD(pg);
- KASSERT((int)md->pvh_refcnt >= 0);
+ KASSERT(PHYSPAGE_REFCNT(pg) < UINT32_MAX);
- return atomic_inc_uint_nv(&md->pvh_refcnt);
+ return PHYSPAGE_REFCNT_INC(pg);
}
/*
@@ -3440,16 +3436,14 @@ static int
pmap_physpage_delref(void *kva)
{
struct vm_page *pg;
- struct vm_page_md *md;
paddr_t pa;
pa = ALPHA_K0SEG_TO_PHYS(trunc_page((vaddr_t)kva));
pg = PHYS_TO_VM_PAGE(pa);
- md = VM_PAGE_TO_MD(pg);
- KASSERT((int)md->pvh_refcnt > 0);
+ KASSERT(PHYSPAGE_REFCNT(pg) != 0);
- return atomic_dec_uint_nv(&md->pvh_refcnt);
+ return PHYSPAGE_REFCNT_DEC(pg);
}
/******************** page table page management ********************/
@@ -3685,10 +3679,8 @@ pmap_ptpage_free(pmap_t pmap, pt_entry_t
struct vm_page * const pg = PHYS_TO_VM_PAGE(ptpa);
KASSERT(pg != NULL);
+ KASSERT(PHYSPAGE_REFCNT(pg) == 0);
#ifdef DEBUG
- struct vm_page_md * const md = VM_PAGE_TO_MD(pg);
- KDASSERT(md->pvh_refcnt == 0);
-
pmap_zero_page(ptpa);
#endif
Index: src/sys/arch/alpha/include/pmap.h
diff -u src/sys/arch/alpha/include/pmap.h:1.90 src/sys/arch/alpha/include/pmap.h:1.91
--- src/sys/arch/alpha/include/pmap.h:1.90 Sun May 30 01:41:45 2021
+++ src/sys/arch/alpha/include/pmap.h Sun May 30 04:04:26 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: pmap.h,v 1.90 2021/05/30 01:41:45 thorpej Exp $ */
+/* $NetBSD: pmap.h,v 1.91 2021/05/30 04:04:26 thorpej Exp $ */
/*-
* Copyright (c) 1998, 1999, 2000, 2001, 2007 The NetBSD Foundation, Inc.
@@ -361,13 +361,12 @@ do { \
struct vm_page_md {
struct pv_entry *pvh_list; /* pv_entry list */
int pvh_attrs; /* page attributes */
- unsigned pvh_refcnt;
};
#define VM_MDPAGE_INIT(pg) \
do { \
(pg)->mdpage.pvh_list = NULL; \
- (pg)->mdpage.pvh_refcnt = 0; \
+ (pg)->mdpage.pvh_attrs = 0; \
} while (/*CONSTCOND*/0)
#endif /* _KERNEL */
