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Renamed a temporary variable in pmap_enter() that conflicted with the

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name of the new 'flags' argument, added as part of the new pmap_enter() API.
Added a comment which explains why there are still sun3x-specific flags
being passed in the unused bits of the physical address, and how these flags
are independent of the new 'flags' argument.
This commit is contained in:
jeremy 1999-12-17 08:10:59 +00:00
parent 4990e1cf94
commit a1c67d1d61
1 changed files with 30 additions and 7 deletions
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37
sys/arch/sun3/sun3x/pmap.c
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@ -1,4 +1,4 @@
/* $NetBSD: pmap.c,v 1.51 1999/11/13 00:32:19 thorpej Exp $ */
/* $NetBSD: pmap.c,v 1.52 1999/12/17 08:10:59 jeremy Exp $ */
/*-
* Copyright (c) 1996, 1997 The NetBSD Foundation, Inc.
@ -1682,7 +1682,7 @@ pmap_enter(pmap, va, pa, prot, flags)
boolean_t insert, managed; /* Marks the need for PV insertion.*/
u_short nidx; /* PV list index */
int s; /* Used for splimp()/splx() */
int flags; /* Mapping flags. eg. Cache inhibit */
int mapflags; /* Flags for the mapping (see NOTE1) */
u_int a_idx, b_idx, pte_idx; /* table indices */
a_tmgr_t *a_tbl; /* A: long descriptor table manager */
b_tmgr_t *b_tbl; /* B: short descriptor table manager */
@ -1691,7 +1691,7 @@ pmap_enter(pmap, va, pa, prot, flags)
mmu_short_dte_t *b_dte; /* B: short descriptor table */
mmu_short_pte_t *c_pte; /* C: short page descriptor table */
pv_t *pv; /* pv list head */
boolean_t wired = (flags & PMAP_WIRED) != 0;
boolean_t wired; /* is the mapping to be wired? */
enum {NONE, NEWA, NEWB, NEWC} llevel; /* used at end */
if (pmap == NULL)
@ -1701,8 +1701,31 @@ pmap_enter(pmap, va, pa, prot, flags)
return (KERN_SUCCESS);
}
flags = (pa & ~MMU_PAGE_MASK);
pa &= MMU_PAGE_MASK;
/*
* Determine if the mapping should be wired.
*/
wired = ((flags & PMAP_WIRED) != 0);
/*
* NOTE1:
*
* On November 13, 1999, someone changed the pmap_enter() API such
* that it now accepts a 'flags' argument. This new argument
* contains bit-flags for the architecture-independent (UVM) system to
* use in signalling certain mapping requirements to the architecture-
* dependent (pmap) system. The argument it replaces, 'wired', is now
* one of the flags within it.
*
* In addition to flags signaled by the architecture-independent
* system, parts of the architecture-dependent section of the sun3x
* kernel pass their own flags in the lower, unused bits of the
* physical address supplied to this function. These flags are
* extracted and stored in the temporary variable 'mapflags'.
*
* Extract sun3x specific flags from the physical address.
*/
mapflags = (pa & ~MMU_PAGE_MASK);
pa &= MMU_PAGE_MASK;
/*
* Determine if the physical address being mapped is on-board RAM.
@ -1710,7 +1733,7 @@ pmap_enter(pmap, va, pa, prot, flags)
* device and hence it would be disasterous to cache its contents.
*/
if ((managed = is_managed(pa)) == FALSE)
flags |= PMAP_NC;
mapflags |= PMAP_NC;
/*
* For user mappings we walk along the MMU tables of the given
@ -2000,7 +2023,7 @@ pmap_enter(pmap, va, pa, prot, flags)
* bits found on the lower order of the physical address.)
* mark the PTE as a cache inhibited page.
*/
if (flags & PMAP_NC)
if (mapflags & PMAP_NC)
c_pte->attr.raw |= MMU_SHORT_PTE_CI;
/*