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linux/lib/lmb.c
David S. Miller ebb1951d36 lmb: Fix reserved region handling in lmb_enforce_memory_limit(). 
The idea of the implementation of this fix is from Michael Ellerman.

This function has two loops, but they each interpret the memory_limit
value differently.  The first loop interprets it as a "size limit"
whereas the second loop interprets it as an "address limit".

Before the second loop runs, reset memory_limit to lmb_end_of_DRAM()
so that it all works out.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Michael Ellerman <michael@ellerman.id.au>
2008-08-15 19:57:57 -07:00

528 lines
12 KiB
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/*
* 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>
#define LMB_ALLOC_ANYWHERE 0
struct lmb lmb;
static int lmb_debug;
static int __init early_lmb(char *p)
{
if (p && strstr(p, "debug"))
lmb_debug = 1;
return 0;
}
early_param("lmb", early_lmb);
void lmb_dump_all(void)
{
unsigned long i;
if (!lmb_debug)
return;
pr_info("lmb_dump_all:\n");
pr_info(" memory.cnt = 0x%lx\n", lmb.memory.cnt);
pr_info(" memory.size = 0x%llx\n",
(unsigned long long)lmb.memory.size);
for (i=0; i < lmb.memory.cnt ;i++) {
pr_info(" memory.region[0x%lx].base = 0x%llx\n",
i, (unsigned long long)lmb.memory.region[i].base);
pr_info(" .size = 0x%llx\n",
(unsigned long long)lmb.memory.region[i].size);
}
pr_info(" reserved.cnt = 0x%lx\n", lmb.reserved.cnt);
pr_info(" reserved.size = 0x%llx\n",
(unsigned long long)lmb.memory.size);
for (i=0; i < lmb.reserved.cnt ;i++) {
pr_info(" reserved.region[0x%lx].base = 0x%llx\n",
i, (unsigned long long)lmb.reserved.region[i].base);
pr_info(" .size = 0x%llx\n",
(unsigned long long)lmb.reserved.region[i].size);
}
}
static unsigned long lmb_addrs_overlap(u64 base1, u64 size1, u64 base2,
u64 size2)
{
return ((base1 < (base2 + size2)) && (base2 < (base1 + size1)));
}
static long 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 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 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 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);
}
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;
}
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;
}
static long 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;
}
long 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 lmb_remove(u64 base, u64 size)
{
struct lmb_region *rgn = &(lmb.memory);
u64 rgnbegin, rgnend;
u64 end = base + size;
int i;
rgnbegin = rgnend = 0; /* supress gcc warnings */
/* Find the region where (base, size) belongs to */
for (i=0; i < rgn->cnt; i++) {
rgnbegin = rgn->region[i].base;
rgnend = rgnbegin + rgn->region[i].size;
if ((rgnbegin <= base) && (end <= rgnend))
break;
}
/* Didn't find the region */
if (i == rgn->cnt)
return -1;
/* Check to see if we are removing entire region */
if ((rgnbegin == base) && (rgnend == end)) {
lmb_remove_region(rgn, i);
return 0;
}
/* Check to see if region is matching at the front */
if (rgnbegin == base) {
rgn->region[i].base = end;
rgn->region[i].size -= size;
return 0;
}
/* Check to see if the region is matching at the end */
if (rgnend == end) {
rgn->region[i].size -= size;
return 0;
}
/*
* We need to split the entry - adjust the current one to the
* beginging of the hole and add the region after hole.
*/
rgn->region[i].size = base - rgn->region[i].base;
return lmb_add_region(rgn, end, rgnend - end);
}
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;
}
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);
}
static u64 __init lmb_alloc_nid_unreserved(u64 start, u64 end,
u64 size, u64 align)
{
u64 base, res_base;
long j;
base = lmb_align_down((end - size), align);
while (start <= base) {
j = lmb_overlaps_region(&lmb.reserved, base, size);
if (j < 0) {
/* this area isn't reserved, take it */
if (lmb_add_region(&lmb.reserved, base, size) < 0)
base = ~(u64)0;
return base;
}
res_base = lmb.reserved.region[j].base;
if (res_base < size)
break;
base = lmb_align_down(res_base - size, align);
}
return ~(u64)0;
}
static u64 __init lmb_alloc_nid_region(struct lmb_property *mp,
u64 (*nid_range)(u64, u64, int *),
u64 size, u64 align, int nid)
{
u64 start, end;
start = mp->base;
end = start + mp->size;
start = lmb_align_up(start, align);
while (start < end) {
u64 this_end;
int this_nid;
this_end = nid_range(start, end, &this_nid);
if (this_nid == nid) {
u64 ret = lmb_alloc_nid_unreserved(start, this_end,
size, align);
if (ret != ~(u64)0)
return ret;
}
start = this_end;
}
return ~(u64)0;
}
u64 __init lmb_alloc_nid(u64 size, u64 align, int nid,
u64 (*nid_range)(u64 start, u64 end, int *nid))
{
struct lmb_region *mem = &lmb.memory;
int i;
BUG_ON(0 == size);
size = lmb_align_up(size, align);
for (i = 0; i < mem->cnt; i++) {
u64 ret = lmb_alloc_nid_region(&mem->region[i],
nid_range,
size, align, nid);
if (ret != ~(u64)0)
return ret;
}
return lmb_alloc(size, align);
}
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;
}
u64 __init __lmb_alloc_base(u64 size, u64 align, u64 max_addr)
{
long i, j;
u64 base = 0;
u64 res_base;
BUG_ON(0 == size);
size = lmb_align_up(size, align);
/* On some platforms, make sure we allocate lowmem */
/* Note that LMB_REAL_LIMIT may be LMB_ALLOC_ANYWHERE */
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 (lmbsize < size)
continue;
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 (base && lmbbase <= base) {
j = lmb_overlaps_region(&lmb.reserved, base, size);
if (j < 0) {
/* this area isn't reserved, take it */
if (lmb_add_region(&lmb.reserved, base, size) < 0)
return 0;
return base;
}
res_base = lmb.reserved.region[j].base;
if (res_base < size)
break;
base = lmb_align_down(res_base - size, align);
}
}
return 0;
}
/* 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;
memory_limit = lmb_end_of_DRAM();
/* 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;
}
/*
* Given a <base, len>, find which memory regions belong to this range.
* Adjust the request and return a contiguous chunk.
*/
int lmb_find(struct lmb_property *res)
{
int i;
u64 rstart, rend;
rstart = res->base;
rend = rstart + res->size - 1;
for (i = 0; i < lmb.memory.cnt; i++) {
u64 start = lmb.memory.region[i].base;
u64 end = start + lmb.memory.region[i].size - 1;
if (start > rend)
return -1;
if ((end >= rstart) && (start < rend)) {
/* adjust the request */
if (rstart < start)
rstart = start;
if (rend > end)
rend = end;
res->base = rstart;
res->size = rend - rstart + 1;
return 0;
}
}
return -1;
}
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