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/*
* Copyright (c) 1996 Paul Mackerras <paulus@cs.anu.edu.au>
* Changes to accommodate Power Macintoshes.
* Cort Dougan <cort@cs.nmt.edu>
* Rewrites.
* Grant Erickson <grant@lcse.umn.edu>
* General rework and split from mm/init.c.
*
* Module name: mem_pieces.c
*
* Description:
* Routines and data structures for manipulating and representing
* phyiscal memory extents (i.e. address/length pairs).
*
*/
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/stddef.h>
#include <linux/init.h>
#include <asm/page.h>
#include "mem_pieces.h"
extern struct mem_pieces phys_avail;
static void mem_pieces_print(struct mem_pieces *);
/*
* Scan a region for a piece of a given size with the required alignment.
*/
void __init *
mem_pieces_find(unsigned int size, unsigned int align)
{
int i;
unsigned a, e;
struct mem_pieces *mp = &phys_avail;
for (i = 0; i < mp->n_regions; ++i) {
a = mp->regions[i].address;
e = a + mp->regions[i].size;
a = (a + align - 1) & -align;
if (a + size <= e) {
mem_pieces_remove(mp, a, size, 1);
return (void *) __va(a);
}
}
panic("Couldn't find %u bytes at %u alignment\n", size, align);
return NULL;
}
/*
* Remove some memory from an array of pieces
*/
void __init
mem_pieces_remove(struct mem_pieces *mp, unsigned int start, unsigned int size,
int must_exist)
{
int i, j;
unsigned int end, rs, re;
struct reg_property *rp;
end = start + size;
for (i = 0, rp = mp->regions; i < mp->n_regions; ++i, ++rp) {
if (end > rp->address && start < rp->address + rp->size)
break;
}
if (i >= mp->n_regions) {
if (must_exist)
printk("mem_pieces_remove: [%x,%x) not in any region\n",
start, end);
return;
}
for (; i < mp->n_regions && end > rp->address; ++i, ++rp) {
rs = rp->address;
re = rs + rp->size;
if (must_exist && (start < rs || end > re)) {
printk("mem_pieces_remove: bad overlap [%x,%x) with",
start, end);
mem_pieces_print(mp);
must_exist = 0;
}
if (start > rs) {
rp->size = start - rs;
if (end < re) {
/* need to split this entry */
if (mp->n_regions >= MEM_PIECES_MAX)
panic("eek... mem_pieces overflow");
for (j = mp->n_regions; j > i + 1; --j)
mp->regions[j] = mp->regions[j-1];
++mp->n_regions;
rp[1].address = end;
rp[1].size = re - end;
}
} else {
if (end < re) {
rp->address = end;
rp->size = re - end;
} else {
/* need to delete this entry */
for (j = i; j < mp->n_regions - 1; ++j)
mp->regions[j] = mp->regions[j+1];
--mp->n_regions;
--i;
--rp;
}
}
}
}
static void __init
mem_pieces_print(struct mem_pieces *mp)
{
int i;
for (i = 0; i < mp->n_regions; ++i)
printk(" [%x, %x)", mp->regions[i].address,
mp->regions[i].address + mp->regions[i].size);
printk("\n");
}
void __init
mem_pieces_sort(struct mem_pieces *mp)
{
unsigned long a, s;
int i, j;
for (i = 1; i < mp->n_regions; ++i) {
a = mp->regions[i].address;
s = mp->regions[i].size;
for (j = i - 1; j >= 0; --j) {
if (a >= mp->regions[j].address)
break;
mp->regions[j+1] = mp->regions[j];
}
mp->regions[j+1].address = a;
mp->regions[j+1].size = s;
}
}
void __init
mem_pieces_coalesce(struct mem_pieces *mp)
{
unsigned long a, s, ns;
int i, j, d;
d = 0;
for (i = 0; i < mp->n_regions; i = j) {
a = mp->regions[i].address;
s = mp->regions[i].size;
for (j = i + 1; j < mp->n_regions
&& mp->regions[j].address - a <= s; ++j) {
ns = mp->regions[j].address + mp->regions[j].size - a;
if (ns > s)
s = ns;
}
mp->regions[d].address = a;
mp->regions[d].size = s;
++d;
}
mp->n_regions = d;
}
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