Aren
/
NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

The previous microscale optimazation in pmap_asid_alloc() was 

half-baked and resulted in one superfluous ASID bump if new pmaps
are created when pmap_asid_generation > 0.   Need to initialize pmap
fields correctly.

Yet, this possibly might not be the perfect solution.  If one
process bumped pmap_asid_generation _after_ a new pmap was created
and initialized with then-current pmap_asid_generation value.  In
that case, the new pmap would have another (superfluous) ASID bump
when 2nd (not 1st) CPU tick is assigned.  I'm not sure if this case
would happen.

Have pmap_max_asid variable to hold the maximum number of ASID
(TLBpid) supported by processor anticipating the possible runtime
cost of ((CPUISMIPS3)? MIPS3_TLB_NUM_ASIDS : MIPS1_TLB_NUM_PIDS).
This commit is contained in:
nisimura 2000-03-28 01:00:00 +00:00
parent 8ae7eeef11
commit 464669d1ef
1 changed files with 18 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
sys/arch/mips/mips/pmap.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: pmap.c,v 1.84 2000/03/27 08:56:21 nisimura Exp $ */
/* $NetBSD: pmap.c,v 1.85 2000/03/28 01:00:00 nisimura Exp $ */
/*-
* Copyright (c) 1998 The NetBSD Foundation, Inc.
@ -78,7 +78,7 @@
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.84 2000/03/27 08:56:21 nisimura Exp $");
__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.85 2000/03/28 01:00:00 nisimura Exp $");
/*
* Manages physical address maps.
@ -185,8 +185,11 @@ int pv_table_npages;
struct segtab *free_segtab; /* free list kept locally */
pt_entry_t *Sysmap; /* kernel pte table */
unsigned Sysmapsize; /* number of pte's in Sysmap */
unsigned pmap_next_asid = 2; /* next available ASID */
unsigned pmap_asid_generation = 0; /* ASID generation count */
unsigned pmap_max_asid; /* max ASID supported by the system */
unsigned pmap_next_asid; /* next free ASID to use */
unsigned pmap_asid_generation; /* current ASID generation */
#define PMAP_ASID_RESERVED 0
boolean_t pmap_initialized = FALSE;
@ -308,7 +311,11 @@ pmap_bootstrap()
simple_lock_init(&pmap_kernel()->pm_lock);
pmap_kernel()->pm_count = 1;
pmap_kernel()->pm_asid = 1;
pmap_kernel()->pm_asidgen = pmap_asid_generation;
pmap_kernel()->pm_asidgen = 0;
pmap_max_asid = MIPS_TLB_NUM_PIDS;
pmap_next_asid = 2;
pmap_asid_generation = 0;
MachSetPID(1);
@ -529,8 +536,8 @@ pmap_pinit(pmap)
if (pmap->pm_segtab->seg_tab[i] != 0)
panic("pmap_pinit: pm_segtab != 0");
#endif
pmap->pm_asid = 0;
pmap->pm_asidgen = 0;
pmap->pm_asid = PMAP_ASID_RESERVED;
pmap->pm_asidgen = pmap_asid_generation;
}
/*
@ -1836,11 +1843,12 @@ pmap_alloc_asid(p)
pmap_t pmap;
pmap = p->p_vmspace->vm_map.pmap;
if (pmap->pm_asid != 0 && pmap->pm_asidgen == pmap_asid_generation)
if (pmap->pm_asid != PMAP_ASID_RESERVED
&& pmap->pm_asidgen == pmap_asid_generation)
;
else {
if (pmap_next_asid == MIPS_TLB_NUM_PIDS) {
MachTLBFlush();
if (pmap_next_asid == pmap_max_asid) {
MachTLBFlush(); /* MIPS_TBIAP */
pmap_asid_generation++; /* ok to wrap to 0 */
pmap_next_asid = 1; /* 0 means invalid */
pmap->pm_asidgen = pmap_asid_generation;