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Added a `boundary' arg to vm_alloc_page_contig(). Previously the only

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way to avoid crossing a 64K DMA boundary was to specify an alignment
greater than the size even when the alignment didn't matter, and for
sizes larger than a page, this reduced the chance of finding enough
contiguous pages.  E.g., allocations of 8K not crossing a 64K boundary
previously had to be allocated on 8K boundaries; now they can be
allocated on any 4K boundary except (64 * n + 60)K.

Fixed bugs in vm_alloc_page_contig():
- the last page wasn't allocated for sizes smaller than a page.
- failures of kmem_alloc_pageable() weren't handled.

Mutated vm_page_alloc_contig() to create a more convenient interface
named contigmalloc().  This is the same as the one in 1.1.5 except
it has `low' and `high' args, and the `alignment' and `boundary'
args are multipliers instead of masks.
This commit is contained in:
Bruce Evans 1996-01-27 00:13:33 +00:00
parent 7c399a896a
commit 324e9ed2a4
2 changed files with 50 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
sys/sys/malloc.h
View File

@ -31,7 +31,7 @@
* SUCH DAMAGE.
*
* @(#)malloc.h 8.3 (Berkeley) 1/12/94
* $Id: malloc.h,v 1.9 1995/09/14 16:25:06 wollman Exp $
* $Id: malloc.h,v 1.10 1995/12/02 20:40:12 phk Exp $
*/
#ifndef _SYS_MALLOC_H_
@ -328,7 +328,12 @@ extern struct kmemstats kmemstats[];
extern struct kmemusage *kmemusage;
extern char *kmembase;
extern struct kmembuckets bucket[];
extern void *malloc __P((unsigned long size, int type, int flags));
extern void free __P((void *addr, int type));
void *contigmalloc __P((unsigned long size, int type, int flags,
unsigned long low, unsigned long high,
unsigned long alignment, unsigned long boundary));
void free __P((void *addr, int type));
void *malloc __P((unsigned long size, int type, int flags));
#endif /* KERNEL */
#endif /* !_SYS_MALLOC_H_ */

52
sys/vm/vm_page.c
View File

@ -34,7 +34,7 @@
* SUCH DAMAGE.
*
* from: @(#)vm_page.c 7.4 (Berkeley) 5/7/91
* $Id: vm_page.c,v 1.45 1996/01/04 21:13:23 wollman Exp $
* $Id: vm_page.c,v 1.46 1996/01/19 04:00:10 dyson Exp $
*/
/*
@ -71,6 +71,7 @@
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <sys/vmmeter.h>
@ -686,31 +687,47 @@ vm_page_alloc(object, pindex, page_req)
return (m);
}
vm_offset_t
vm_page_alloc_contig(size, low, high, alignment)
vm_offset_t size;
vm_offset_t low;
vm_offset_t high;
vm_offset_t alignment;
/*
* This interface is for merging with malloc() someday.
* Even if we never implement compaction so that contiguous allocation
* works after initialization time, malloc()'s data structures are good
* for statistics and for allocations of less than a page.
*/
void *
contigmalloc(size, type, flags, low, high, alignment, boundary)
unsigned long size; /* should be size_t here and for malloc() */
int type;
int flags;
unsigned long low;
unsigned long high;
unsigned long alignment;
unsigned long boundary;
{
int i, s, start;
vm_offset_t addr, phys, tmp_addr;
vm_page_t pga = vm_page_array;
size = round_page(size);
if (size == 0)
panic("vm_page_alloc_contig: size must not be 0");
if ((alignment & (alignment - 1)) != 0)
panic("vm_page_alloc_contig: alignment must be a power of 2");
if ((boundary & (boundary - 1)) != 0)
panic("vm_page_alloc_contig: boundary must be a power of 2");
start = 0;
s = splhigh();
again:
/*
* Find first page in array that is free, within range, and aligned.
* Find first page in array that is free, within range, aligned, and
* such that the boundary won't be crossed.
*/
for (i = start; i < cnt.v_page_count; i++) {
phys = VM_PAGE_TO_PHYS(&pga[i]);
if ((pga[i].queue == PQ_FREE) &&
(phys >= low) && (phys < high) &&
((phys & (alignment - 1)) == 0))
((phys & (alignment - 1)) == 0) &&
(((phys ^ (phys + size - 1)) & ~(boundary - 1)) == 0))
break;
}
@ -742,6 +759,10 @@ vm_page_alloc_contig(size, low, high, alignment)
* return kernel VM pointer.
*/
tmp_addr = addr = kmem_alloc_pageable(kernel_map, size);
if (addr == 0) {
splx(s);
return (NULL);
}
for (i = start; i < (start + size / PAGE_SIZE); i++) {
vm_page_t m = &pga[i];
@ -763,7 +784,18 @@ vm_page_alloc_contig(size, low, high, alignment)
}
splx(s);
return (addr);
return ((void *)addr);
}
vm_offset_t
vm_page_alloc_contig(size, low, high, alignment)
vm_offset_t size;
vm_offset_t low;
vm_offset_t high;
vm_offset_t alignment;
{
return ((vm_offset_t)contigmalloc(size, M_DEVBUF, M_NOWAIT, low, high,
alignment, 0ul));
}
/*