linux/lib/lmb.c
Kumar Gala 74b20dad1c [LMB]: Fix lmb_add_region if region should be added at the head
We introduced a bug in fixing lmb_add_region to handle an initial
region being non-zero.  Before that fix it was impossible to insert a
region at the head of the list since the first region always started
at zero.

Now that its possible for the first region to be non-zero we need to
check to see if the new region should be added at the head and if so
actually add it.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-02-19 21:28:18 -08:00

371 lines
8.4 KiB
C

/*
* Procedures for maintaining information about logical memory blocks.
*
* Peter Bergner, IBM Corp. June 2001.
* Copyright (C) 2001 Peter Bergner.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <linux/lmb.h>
#undef DEBUG
#ifdef DEBUG
#define DBG(fmt...) LMB_DBG(fmt)
#else
#define DBG(fmt...)
#endif
#define LMB_ALLOC_ANYWHERE 0
struct lmb lmb;
void lmb_dump_all(void)
{
#ifdef DEBUG
unsigned long i;
DBG("lmb_dump_all:\n");
DBG(" memory.cnt = 0x%lx\n", lmb.memory.cnt);
DBG(" memory.size = 0x%llx\n",
(unsigned long long)lmb.memory.size);
for (i=0; i < lmb.memory.cnt ;i++) {
DBG(" memory.region[0x%x].base = 0x%llx\n",
i, (unsigned long long)lmb.memory.region[i].base);
DBG(" .size = 0x%llx\n",
(unsigned long long)lmb.memory.region[i].size);
}
DBG("\n reserved.cnt = 0x%lx\n", lmb.reserved.cnt);
DBG(" reserved.size = 0x%lx\n", lmb.reserved.size);
for (i=0; i < lmb.reserved.cnt ;i++) {
DBG(" reserved.region[0x%x].base = 0x%llx\n",
i, (unsigned long long)lmb.reserved.region[i].base);
DBG(" .size = 0x%llx\n",
(unsigned long long)lmb.reserved.region[i].size);
}
#endif /* DEBUG */
}
static unsigned long __init lmb_addrs_overlap(u64 base1,
u64 size1, u64 base2, u64 size2)
{
return ((base1 < (base2+size2)) && (base2 < (base1+size1)));
}
static long __init lmb_addrs_adjacent(u64 base1, u64 size1,
u64 base2, u64 size2)
{
if (base2 == base1 + size1)
return 1;
else if (base1 == base2 + size2)
return -1;
return 0;
}
static long __init lmb_regions_adjacent(struct lmb_region *rgn,
unsigned long r1, unsigned long r2)
{
u64 base1 = rgn->region[r1].base;
u64 size1 = rgn->region[r1].size;
u64 base2 = rgn->region[r2].base;
u64 size2 = rgn->region[r2].size;
return lmb_addrs_adjacent(base1, size1, base2, size2);
}
static void __init lmb_remove_region(struct lmb_region *rgn, unsigned long r)
{
unsigned long i;
for (i = r; i < rgn->cnt - 1; i++) {
rgn->region[i].base = rgn->region[i + 1].base;
rgn->region[i].size = rgn->region[i + 1].size;
}
rgn->cnt--;
}
/* Assumption: base addr of region 1 < base addr of region 2 */
static void __init lmb_coalesce_regions(struct lmb_region *rgn,
unsigned long r1, unsigned long r2)
{
rgn->region[r1].size += rgn->region[r2].size;
lmb_remove_region(rgn, r2);
}
/* This routine called with relocation disabled. */
void __init lmb_init(void)
{
/* Create a dummy zero size LMB which will get coalesced away later.
* This simplifies the lmb_add() code below...
*/
lmb.memory.region[0].base = 0;
lmb.memory.region[0].size = 0;
lmb.memory.cnt = 1;
/* Ditto. */
lmb.reserved.region[0].base = 0;
lmb.reserved.region[0].size = 0;
lmb.reserved.cnt = 1;
}
/* This routine may be called with relocation disabled. */
void __init lmb_analyze(void)
{
int i;
lmb.memory.size = 0;
for (i = 0; i < lmb.memory.cnt; i++)
lmb.memory.size += lmb.memory.region[i].size;
}
/* This routine called with relocation disabled. */
static long __init lmb_add_region(struct lmb_region *rgn, u64 base, u64 size)
{
unsigned long coalesced = 0;
long adjacent, i;
if ((rgn->cnt == 1) && (rgn->region[0].size == 0)) {
rgn->region[0].base = base;
rgn->region[0].size = size;
return 0;
}
/* First try and coalesce this LMB with another. */
for (i=0; i < rgn->cnt; i++) {
u64 rgnbase = rgn->region[i].base;
u64 rgnsize = rgn->region[i].size;
if ((rgnbase == base) && (rgnsize == size))
/* Already have this region, so we're done */
return 0;
adjacent = lmb_addrs_adjacent(base,size,rgnbase,rgnsize);
if ( adjacent > 0 ) {
rgn->region[i].base -= size;
rgn->region[i].size += size;
coalesced++;
break;
}
else if ( adjacent < 0 ) {
rgn->region[i].size += size;
coalesced++;
break;
}
}
if ((i < rgn->cnt-1) && lmb_regions_adjacent(rgn, i, i+1) ) {
lmb_coalesce_regions(rgn, i, i+1);
coalesced++;
}
if (coalesced)
return coalesced;
if (rgn->cnt >= MAX_LMB_REGIONS)
return -1;
/* Couldn't coalesce the LMB, so add it to the sorted table. */
for (i = rgn->cnt-1; i >= 0; i--) {
if (base < rgn->region[i].base) {
rgn->region[i+1].base = rgn->region[i].base;
rgn->region[i+1].size = rgn->region[i].size;
} else {
rgn->region[i+1].base = base;
rgn->region[i+1].size = size;
break;
}
}
if (base < rgn->region[0].base) {
rgn->region[0].base = base;
rgn->region[0].size = size;
}
rgn->cnt++;
return 0;
}
/* This routine may be called with relocation disabled. */
long __init lmb_add(u64 base, u64 size)
{
struct lmb_region *_rgn = &(lmb.memory);
/* On pSeries LPAR systems, the first LMB is our RMO region. */
if (base == 0)
lmb.rmo_size = size;
return lmb_add_region(_rgn, base, size);
}
long __init lmb_reserve(u64 base, u64 size)
{
struct lmb_region *_rgn = &(lmb.reserved);
BUG_ON(0 == size);
return lmb_add_region(_rgn, base, size);
}
long __init lmb_overlaps_region(struct lmb_region *rgn, u64 base,
u64 size)
{
unsigned long i;
for (i=0; i < rgn->cnt; i++) {
u64 rgnbase = rgn->region[i].base;
u64 rgnsize = rgn->region[i].size;
if ( lmb_addrs_overlap(base,size,rgnbase,rgnsize) ) {
break;
}
}
return (i < rgn->cnt) ? i : -1;
}
u64 __init lmb_alloc(u64 size, u64 align)
{
return lmb_alloc_base(size, align, LMB_ALLOC_ANYWHERE);
}
u64 __init lmb_alloc_base(u64 size, u64 align, u64 max_addr)
{
u64 alloc;
alloc = __lmb_alloc_base(size, align, max_addr);
if (alloc == 0)
panic("ERROR: Failed to allocate 0x%llx bytes below 0x%llx.\n",
(unsigned long long) size, (unsigned long long) max_addr);
return alloc;
}
static u64 lmb_align_down(u64 addr, u64 size)
{
return addr & ~(size - 1);
}
static u64 lmb_align_up(u64 addr, u64 size)
{
return (addr + (size - 1)) & ~(size - 1);
}
u64 __init __lmb_alloc_base(u64 size, u64 align, u64 max_addr)
{
long i, j;
u64 base = 0;
BUG_ON(0 == size);
/* On some platforms, make sure we allocate lowmem */
if (max_addr == LMB_ALLOC_ANYWHERE)
max_addr = LMB_REAL_LIMIT;
for (i = lmb.memory.cnt-1; i >= 0; i--) {
u64 lmbbase = lmb.memory.region[i].base;
u64 lmbsize = lmb.memory.region[i].size;
if (max_addr == LMB_ALLOC_ANYWHERE)
base = lmb_align_down(lmbbase + lmbsize - size, align);
else if (lmbbase < max_addr) {
base = min(lmbbase + lmbsize, max_addr);
base = lmb_align_down(base - size, align);
} else
continue;
while ((lmbbase <= base) &&
((j = lmb_overlaps_region(&lmb.reserved, base, size)) >= 0) )
base = lmb_align_down(lmb.reserved.region[j].base - size,
align);
if ((base != 0) && (lmbbase <= base))
break;
}
if (i < 0)
return 0;
if (lmb_add_region(&lmb.reserved, base, lmb_align_up(size, align)) < 0)
return 0;
return base;
}
/* You must call lmb_analyze() before this. */
u64 __init lmb_phys_mem_size(void)
{
return lmb.memory.size;
}
u64 __init lmb_end_of_DRAM(void)
{
int idx = lmb.memory.cnt - 1;
return (lmb.memory.region[idx].base + lmb.memory.region[idx].size);
}
/* You must call lmb_analyze() after this. */
void __init lmb_enforce_memory_limit(u64 memory_limit)
{
unsigned long i;
u64 limit;
struct lmb_property *p;
if (! memory_limit)
return;
/* Truncate the lmb regions to satisfy the memory limit. */
limit = memory_limit;
for (i = 0; i < lmb.memory.cnt; i++) {
if (limit > lmb.memory.region[i].size) {
limit -= lmb.memory.region[i].size;
continue;
}
lmb.memory.region[i].size = limit;
lmb.memory.cnt = i + 1;
break;
}
if (lmb.memory.region[0].size < lmb.rmo_size)
lmb.rmo_size = lmb.memory.region[0].size;
/* And truncate any reserves above the limit also. */
for (i = 0; i < lmb.reserved.cnt; i++) {
p = &lmb.reserved.region[i];
if (p->base > memory_limit)
p->size = 0;
else if ((p->base + p->size) > memory_limit)
p->size = memory_limit - p->base;
if (p->size == 0) {
lmb_remove_region(&lmb.reserved, i);
i--;
}
}
}
int __init lmb_is_reserved(u64 addr)
{
int i;
for (i = 0; i < lmb.reserved.cnt; i++) {
u64 upper = lmb.reserved.region[i].base +
lmb.reserved.region[i].size - 1;
if ((addr >= lmb.reserved.region[i].base) && (addr <= upper))
return 1;
}
return 0;
}