mm/memblock.c - kernel/panda - Git at Google

 /*
  * 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/memblock.h>

 #define MEMBLOCK_ALLOC_ANYWHERE	0

 struct memblock memblock;

 static int memblock_debug;

 static int __init early_memblock(char *p)
 {
 	if (p && strstr(p, "debug"))
 		memblock_debug = 1;
 	return 0;
 }
 early_param("memblock", early_memblock);

 static void memblock_dump(struct memblock_type *region, char *name)
 {
 	unsigned long long base, size;
 	int i;

 	pr_info(" %s.cnt  = 0x%lx\n", name, region->cnt);

 	for (i = 0; i < region->cnt; i++) {
 		base = region->regions[i].base;
 		size = region->regions[i].size;

 		pr_info(" %s[0x%x]\t0x%016llx - 0x%016llx, 0x%llx bytes\n",
 		    name, i, base, base + size - 1, size);
 	}
 }

 void memblock_dump_all(void)
 {
 	if (!memblock_debug)
 		return;

 	pr_info("MEMBLOCK configuration:\n");
 	pr_info(" rmo_size    = 0x%llx\n", (unsigned long long)memblock.rmo_size);
 	pr_info(" memory.size = 0x%llx\n", (unsigned long long)memblock.memory.size);

 	memblock_dump(&memblock.memory, "memory");
 	memblock_dump(&memblock.reserved, "reserved");
 }

 static unsigned long memblock_addrs_overlap(u64 base1, u64 size1, u64 base2,
 					u64 size2)
 {
 	return ((base1 < (base2 + size2)) && (base2 < (base1 + size1)));
 }

 static long memblock_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 memblock_regions_adjacent(struct memblock_type *type,
 		unsigned long r1, unsigned long r2)
 {
 	u64 base1 = type->regions[r1].base;
 	u64 size1 = type->regions[r1].size;
 	u64 base2 = type->regions[r2].base;
 	u64 size2 = type->regions[r2].size;

 	return memblock_addrs_adjacent(base1, size1, base2, size2);
 }

 static void memblock_remove_region(struct memblock_type *type, unsigned long r)
 {
 	unsigned long i;

 	for (i = r; i < type->cnt - 1; i++) {
 		type->regions[i].base = type->regions[i + 1].base;
 		type->regions[i].size = type->regions[i + 1].size;
 	}
 	type->cnt--;
 }

 /* Assumption: base addr of region 1 < base addr of region 2 */
 static void memblock_coalesce_regions(struct memblock_type *type,
 		unsigned long r1, unsigned long r2)
 {
 	type->regions[r1].size += type->regions[r2].size;
 	memblock_remove_region(type, r2);
 }

 void __init memblock_init(void)
 {
 	/* Create a dummy zero size MEMBLOCK which will get coalesced away later.
 	 * This simplifies the memblock_add() code below...
 	 */
 	memblock.memory.regions[0].base = 0;
 	memblock.memory.regions[0].size = 0;
 	memblock.memory.cnt = 1;

 	/* Ditto. */
 	memblock.reserved.regions[0].base = 0;
 	memblock.reserved.regions[0].size = 0;
 	memblock.reserved.cnt = 1;
 }

 void __init memblock_analyze(void)
 {
 	int i;

 	memblock.memory.size = 0;

 	for (i = 0; i < memblock.memory.cnt; i++)
 		memblock.memory.size += memblock.memory.regions[i].size;
 }

 static long memblock_add_region(struct memblock_type *type, u64 base, u64 size)
 {
 	unsigned long coalesced = 0;
 	long adjacent, i;

 	if ((type->cnt == 1) && (type->regions[0].size == 0)) {
 		type->regions[0].base = base;
 		type->regions[0].size = size;
 		return 0;
 	}

 	/* First try and coalesce this MEMBLOCK with another. */
 	for (i = 0; i < type->cnt; i++) {
 		u64 rgnbase = type->regions[i].base;
 		u64 rgnsize = type->regions[i].size;

 		if ((rgnbase == base) && (rgnsize == size))
 			/* Already have this region, so we're done */
 			return 0;

 		adjacent = memblock_addrs_adjacent(base, size, rgnbase, rgnsize);
 		if (adjacent > 0) {
 			type->regions[i].base -= size;
 			type->regions[i].size += size;
 			coalesced++;
 			break;
 		} else if (adjacent < 0) {
 			type->regions[i].size += size;
 			coalesced++;
 			break;
 		}
 	}

 	if ((i < type->cnt - 1) && memblock_regions_adjacent(type, i, i+1)) {
 		memblock_coalesce_regions(type, i, i+1);
 		coalesced++;
 	}

 	if (coalesced)
 		return coalesced;
 	if (type->cnt >= MAX_MEMBLOCK_REGIONS)
 		return -1;

 	/* Couldn't coalesce the MEMBLOCK, so add it to the sorted table. */
 	for (i = type->cnt - 1; i >= 0; i--) {
 		if (base < type->regions[i].base) {
 			type->regions[i+1].base = type->regions[i].base;
 			type->regions[i+1].size = type->regions[i].size;
 		} else {
 			type->regions[i+1].base = base;
 			type->regions[i+1].size = size;
 			break;
 		}
 	}

 	if (base < type->regions[0].base) {
 		type->regions[0].base = base;
 		type->regions[0].size = size;
 	}
 	type->cnt++;

 	return 0;
 }

 long memblock_add(u64 base, u64 size)
 {
 	/* On pSeries LPAR systems, the first MEMBLOCK is our RMO region. */
 	if (base == 0)
 		memblock.rmo_size = size;

 	return memblock_add_region(&memblock.memory, base, size);

 }

 static long __memblock_remove(struct memblock_type *type, u64 base, u64 size)
 {
 	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 < type->cnt; i++) {
 		rgnbegin = type->regions[i].base;
 		rgnend = rgnbegin + type->regions[i].size;

 		if ((rgnbegin <= base) && (end <= rgnend))
 			break;
 	}

 	/* Didn't find the region */
 	if (i == type->cnt)
 		return -1;

 	/* Check to see if we are removing entire region */
 	if ((rgnbegin == base) && (rgnend == end)) {
 		memblock_remove_region(type, i);
 		return 0;
 	}

 	/* Check to see if region is matching at the front */
 	if (rgnbegin == base) {
 		type->regions[i].base = end;
 		type->regions[i].size -= size;
 		return 0;
 	}

 	/* Check to see if the region is matching at the end */
 	if (rgnend == end) {
 		type->regions[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.
 	 */
 	type->regions[i].size = base - type->regions[i].base;
 	return memblock_add_region(type, end, rgnend - end);
 }

 long memblock_remove(u64 base, u64 size)
 {
 	return __memblock_remove(&memblock.memory, base, size);
 }

 long __init memblock_free(u64 base, u64 size)
 {
 	return __memblock_remove(&memblock.reserved, base, size);
 }

 long __init memblock_reserve(u64 base, u64 size)
 {
 	struct memblock_type *_rgn = &memblock.reserved;

 	BUG_ON(0 == size);

 	return memblock_add_region(_rgn, base, size);
 }

 long memblock_overlaps_region(struct memblock_type *type, u64 base, u64 size)
 {
 	unsigned long i;

 	for (i = 0; i < type->cnt; i++) {
 		u64 rgnbase = type->regions[i].base;
 		u64 rgnsize = type->regions[i].size;
 		if (memblock_addrs_overlap(base, size, rgnbase, rgnsize))
 			break;
 	}

 	return (i < type->cnt) ? i : -1;
 }

 static u64 memblock_align_down(u64 addr, u64 size)
 {
 	return addr & ~(size - 1);
 }

 static u64 memblock_align_up(u64 addr, u64 size)
 {
 	return (addr + (size - 1)) & ~(size - 1);
 }

 static u64 __init memblock_alloc_nid_unreserved(u64 start, u64 end,
 					   u64 size, u64 align)
 {
 	u64 base, res_base;
 	long j;

 	base = memblock_align_down((end - size), align);
 	while (start <= base) {
 		j = memblock_overlaps_region(&memblock.reserved, base, size);
 		if (j < 0) {
 			/* this area isn't reserved, take it */
 			if (memblock_add_region(&memblock.reserved, base, size) < 0)
 				base = ~(u64)0;
 			return base;
 		}
 		res_base = memblock.reserved.regions[j].base;
 		if (res_base < size)
 			break;
 		base = memblock_align_down(res_base - size, align);
 	}

 	return ~(u64)0;
 }

 static u64 __init memblock_alloc_nid_region(struct memblock_region *mp,
 				       u64 (*nid_range)(u64, u64, int *),
 				       u64 size, u64 align, int nid)
 {
 	u64 start, end;

 	start = mp->base;
 	end = start + mp->size;

 	start = memblock_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 = memblock_alloc_nid_unreserved(start, this_end,
 							   size, align);
 			if (ret != ~(u64)0)
 				return ret;
 		}
 		start = this_end;
 	}

 	return ~(u64)0;
 }

 u64 __init memblock_alloc_nid(u64 size, u64 align, int nid,
 			 u64 (*nid_range)(u64 start, u64 end, int *nid))
 {
 	struct memblock_type *mem = &memblock.memory;
 	int i;

 	BUG_ON(0 == size);

 	size = memblock_align_up(size, align);

 	for (i = 0; i < mem->cnt; i++) {
 		u64 ret = memblock_alloc_nid_region(&mem->regions[i],
 					       nid_range,
 					       size, align, nid);
 		if (ret != ~(u64)0)
 			return ret;
 	}

 	return memblock_alloc(size, align);
 }

 u64 __init memblock_alloc(u64 size, u64 align)
 {
 	return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ANYWHERE);
 }

 u64 __init memblock_alloc_base(u64 size, u64 align, u64 max_addr)
 {
 	u64 alloc;

 	alloc = __memblock_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 __memblock_alloc_base(u64 size, u64 align, u64 max_addr)
 {
 	long i, j;
 	u64 base = 0;
 	u64 res_base;

 	BUG_ON(0 == size);

 	size = memblock_align_up(size, align);

 	/* On some platforms, make sure we allocate lowmem */
 	/* Note that MEMBLOCK_REAL_LIMIT may be MEMBLOCK_ALLOC_ANYWHERE */
 	if (max_addr == MEMBLOCK_ALLOC_ANYWHERE)
 		max_addr = MEMBLOCK_REAL_LIMIT;

 	for (i = memblock.memory.cnt - 1; i >= 0; i--) {
 		u64 memblockbase = memblock.memory.regions[i].base;
 		u64 memblocksize = memblock.memory.regions[i].size;

 		if (memblocksize < size)
 			continue;
 		if (max_addr == MEMBLOCK_ALLOC_ANYWHERE)
 			base = memblock_align_down(memblockbase + memblocksize - size, align);
 		else if (memblockbase < max_addr) {
 			base = min(memblockbase + memblocksize, max_addr);
 			base = memblock_align_down(base - size, align);
 		} else
 			continue;

 		while (base && memblockbase <= base) {
 			j = memblock_overlaps_region(&memblock.reserved, base, size);
 			if (j < 0) {
 				/* this area isn't reserved, take it */
 				if (memblock_add_region(&memblock.reserved, base, size) < 0)
 					return 0;
 				return base;
 			}
 			res_base = memblock.reserved.regions[j].base;
 			if (res_base < size)
 				break;
 			base = memblock_align_down(res_base - size, align);
 		}
 	}
 	return 0;
 }

 /* You must call memblock_analyze() before this. */
 u64 __init memblock_phys_mem_size(void)
 {
 	return memblock.memory.size;
 }

 u64 memblock_end_of_DRAM(void)
 {
 	int idx = memblock.memory.cnt - 1;

 	return (memblock.memory.regions[idx].base + memblock.memory.regions[idx].size);
 }

 /* You must call memblock_analyze() after this. */
 void __init memblock_enforce_memory_limit(u64 memory_limit)
 {
 	unsigned long i;
 	u64 limit;
 	struct memblock_region *p;

 	if (!memory_limit)
 		return;

 	/* Truncate the memblock regions to satisfy the memory limit. */
 	limit = memory_limit;
 	for (i = 0; i < memblock.memory.cnt; i++) {
 		if (limit > memblock.memory.regions[i].size) {
 			limit -= memblock.memory.regions[i].size;
 			continue;
 		}

 		memblock.memory.regions[i].size = limit;
 		memblock.memory.cnt = i + 1;
 		break;
 	}

 	if (memblock.memory.regions[0].size < memblock.rmo_size)
 		memblock.rmo_size = memblock.memory.regions[0].size;

 	memory_limit = memblock_end_of_DRAM();

 	/* And truncate any reserves above the limit also. */
 	for (i = 0; i < memblock.reserved.cnt; i++) {
 		p = &memblock.reserved.regions[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) {
 			memblock_remove_region(&memblock.reserved, i);
 			i--;
 		}
 	}
 }

 static int memblock_search(struct memblock_type *type, u64 addr)
 {
 	unsigned int left = 0, right = type->cnt;

 	do {
 		unsigned int mid = (right + left) / 2;

 		if (addr < type->regions[mid].base)
 			right = mid;
 		else if (addr >= (type->regions[mid].base +
 				  type->regions[mid].size))
 			left = mid + 1;
 		else
 			return mid;
 	} while (left < right);
 	return -1;
 }

 int __init memblock_is_reserved(u64 addr)
 {
 	return memblock_search(&memblock.reserved, addr) != -1;
 }

 int memblock_is_memory(u64 addr)
 {
 	return memblock_search(&memblock.memory, addr) != -1;
 }

 int memblock_is_region_memory(u64 base, u64 size)
 {
 	int idx = memblock_search(&memblock.reserved, base);

 	if (idx == -1)
 		return 0;
 	return memblock.reserved.regions[idx].base <= base &&
 		(memblock.reserved.regions[idx].base +
 		 memblock.reserved.regions[idx].size) >= (base + size);
 }

 int memblock_is_region_reserved(u64 base, u64 size)
 {
 	return memblock_overlaps_region(&memblock.reserved, base, size) >= 0;
 }

 /*
  * Given a <base, len>, find which memory regions belong to this range.
  * Adjust the request and return a contiguous chunk.
  */
 int memblock_find(struct memblock_region *res)
 {
 	int i;
 	u64 rstart, rend;

 	rstart = res->base;
 	rend = rstart + res->size - 1;

 	for (i = 0; i < memblock.memory.cnt; i++) {
 		u64 start = memblock.memory.regions[i].base;
 		u64 end = start + memblock.memory.regions[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;
 }
	/*
	* 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/memblock.h>

	#define MEMBLOCK_ALLOC_ANYWHERE 0

	struct memblock memblock;

	static int memblock_debug;

	static int __init early_memblock(char *p)
	{
	if (p && strstr(p, "debug"))
	memblock_debug = 1;
	return 0;
	}
	early_param("memblock", early_memblock);

	static void memblock_dump(struct memblock_type region, char name)
	{
	unsigned long long base, size;
	int i;

	pr_info(" %s.cnt = 0x%lx\n", name, region->cnt);

	for (i = 0; i < region->cnt; i++) {
	base = region->regions[i].base;
	size = region->regions[i].size;

	pr_info(" %s[0x%x]\t0x%016llx - 0x%016llx, 0x%llx bytes\n",
	name, i, base, base + size - 1, size);
	}
	}

	void memblock_dump_all(void)
	{
	if (!memblock_debug)
	return;

	pr_info("MEMBLOCK configuration:\n");
	pr_info(" rmo_size = 0x%llx\n", (unsigned long long)memblock.rmo_size);
	pr_info(" memory.size = 0x%llx\n", (unsigned long long)memblock.memory.size);

	memblock_dump(&memblock.memory, "memory");
	memblock_dump(&memblock.reserved, "reserved");
	}

	static unsigned long memblock_addrs_overlap(u64 base1, u64 size1, u64 base2,
	u64 size2)
	{
	return ((base1 < (base2 + size2)) && (base2 < (base1 + size1)));
	}

	static long memblock_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 memblock_regions_adjacent(struct memblock_type *type,
	unsigned long r1, unsigned long r2)
	{
	u64 base1 = type->regions[r1].base;
	u64 size1 = type->regions[r1].size;
	u64 base2 = type->regions[r2].base;
	u64 size2 = type->regions[r2].size;

	return memblock_addrs_adjacent(base1, size1, base2, size2);
	}

	static void memblock_remove_region(struct memblock_type *type, unsigned long r)
	{
	unsigned long i;

	for (i = r; i < type->cnt - 1; i++) {
	type->regions[i].base = type->regions[i + 1].base;
	type->regions[i].size = type->regions[i + 1].size;
	}
	type->cnt--;
	}

	/* Assumption: base addr of region 1 < base addr of region 2 */
	static void memblock_coalesce_regions(struct memblock_type *type,
	unsigned long r1, unsigned long r2)
	{
	type->regions[r1].size += type->regions[r2].size;
	memblock_remove_region(type, r2);
	}

	void __init memblock_init(void)
	{
	/* Create a dummy zero size MEMBLOCK which will get coalesced away later.
	* This simplifies the memblock_add() code below...
	*/
	memblock.memory.regions[0].base = 0;
	memblock.memory.regions[0].size = 0;
	memblock.memory.cnt = 1;

	/* Ditto. */
	memblock.reserved.regions[0].base = 0;
	memblock.reserved.regions[0].size = 0;
	memblock.reserved.cnt = 1;
	}

	void __init memblock_analyze(void)
	{
	int i;

	memblock.memory.size = 0;

	for (i = 0; i < memblock.memory.cnt; i++)
	memblock.memory.size += memblock.memory.regions[i].size;
	}

	static long memblock_add_region(struct memblock_type *type, u64 base, u64 size)
	{
	unsigned long coalesced = 0;
	long adjacent, i;

	if ((type->cnt == 1) && (type->regions[0].size == 0)) {
	type->regions[0].base = base;
	type->regions[0].size = size;
	return 0;
	}

	/* First try and coalesce this MEMBLOCK with another. */
	for (i = 0; i < type->cnt; i++) {
	u64 rgnbase = type->regions[i].base;
	u64 rgnsize = type->regions[i].size;

	if ((rgnbase == base) && (rgnsize == size))
	/* Already have this region, so we're done */
	return 0;

	adjacent = memblock_addrs_adjacent(base, size, rgnbase, rgnsize);
	if (adjacent > 0) {
	type->regions[i].base -= size;
	type->regions[i].size += size;
	coalesced++;
	break;
	} else if (adjacent < 0) {
	type->regions[i].size += size;
	coalesced++;
	break;
	}
	}

	if ((i < type->cnt - 1) && memblock_regions_adjacent(type, i, i+1)) {
	memblock_coalesce_regions(type, i, i+1);
	coalesced++;
	}

	if (coalesced)
	return coalesced;
	if (type->cnt >= MAX_MEMBLOCK_REGIONS)
	return -1;

	/* Couldn't coalesce the MEMBLOCK, so add it to the sorted table. */
	for (i = type->cnt - 1; i >= 0; i--) {
	if (base < type->regions[i].base) {
	type->regions[i+1].base = type->regions[i].base;
	type->regions[i+1].size = type->regions[i].size;
	} else {
	type->regions[i+1].base = base;
	type->regions[i+1].size = size;
	break;
	}
	}

	if (base < type->regions[0].base) {
	type->regions[0].base = base;
	type->regions[0].size = size;
	}
	type->cnt++;

	return 0;
	}

	long memblock_add(u64 base, u64 size)
	{
	/* On pSeries LPAR systems, the first MEMBLOCK is our RMO region. */
	if (base == 0)
	memblock.rmo_size = size;

	return memblock_add_region(&memblock.memory, base, size);

	}

	static long __memblock_remove(struct memblock_type *type, u64 base, u64 size)
	{
	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 < type->cnt; i++) {
	rgnbegin = type->regions[i].base;
	rgnend = rgnbegin + type->regions[i].size;

	if ((rgnbegin <= base) && (end <= rgnend))
	break;
	}

	/* Didn't find the region */
	if (i == type->cnt)
	return -1;

	/* Check to see if we are removing entire region */
	if ((rgnbegin == base) && (rgnend == end)) {
	memblock_remove_region(type, i);
	return 0;
	}

	/* Check to see if region is matching at the front */
	if (rgnbegin == base) {
	type->regions[i].base = end;
	type->regions[i].size -= size;
	return 0;
	}

	/* Check to see if the region is matching at the end */
	if (rgnend == end) {
	type->regions[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.
	*/
	type->regions[i].size = base - type->regions[i].base;
	return memblock_add_region(type, end, rgnend - end);
	}

	long memblock_remove(u64 base, u64 size)
	{
	return __memblock_remove(&memblock.memory, base, size);
	}

	long __init memblock_free(u64 base, u64 size)
	{
	return __memblock_remove(&memblock.reserved, base, size);
	}

	long __init memblock_reserve(u64 base, u64 size)
	{
	struct memblock_type *_rgn = &memblock.reserved;

	BUG_ON(0 == size);

	return memblock_add_region(_rgn, base, size);
	}

	long memblock_overlaps_region(struct memblock_type *type, u64 base, u64 size)
	{
	unsigned long i;

	for (i = 0; i < type->cnt; i++) {
	u64 rgnbase = type->regions[i].base;
	u64 rgnsize = type->regions[i].size;
	if (memblock_addrs_overlap(base, size, rgnbase, rgnsize))
	break;
	}

	return (i < type->cnt) ? i : -1;
	}

	static u64 memblock_align_down(u64 addr, u64 size)
	{
	return addr & ~(size - 1);
	}

	static u64 memblock_align_up(u64 addr, u64 size)
	{
	return (addr + (size - 1)) & ~(size - 1);
	}

	static u64 __init memblock_alloc_nid_unreserved(u64 start, u64 end,
	u64 size, u64 align)
	{
	u64 base, res_base;
	long j;

	base = memblock_align_down((end - size), align);
	while (start <= base) {
	j = memblock_overlaps_region(&memblock.reserved, base, size);
	if (j < 0) {
	/* this area isn't reserved, take it */
	if (memblock_add_region(&memblock.reserved, base, size) < 0)
	base = ~(u64)0;
	return base;
	}
	res_base = memblock.reserved.regions[j].base;
	if (res_base < size)
	break;
	base = memblock_align_down(res_base - size, align);
	}

	return ~(u64)0;
	}

	static u64 __init memblock_alloc_nid_region(struct memblock_region *mp,
	u64 (nid_range)(u64, u64, int ),
	u64 size, u64 align, int nid)
	{
	u64 start, end;

	start = mp->base;
	end = start + mp->size;

	start = memblock_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 = memblock_alloc_nid_unreserved(start, this_end,
	size, align);
	if (ret != ~(u64)0)
	return ret;
	}
	start = this_end;
	}

	return ~(u64)0;
	}

	u64 __init memblock_alloc_nid(u64 size, u64 align, int nid,
	u64 (nid_range)(u64 start, u64 end, int nid))
	{
	struct memblock_type *mem = &memblock.memory;
	int i;

	BUG_ON(0 == size);

	size = memblock_align_up(size, align);

	for (i = 0; i < mem->cnt; i++) {
	u64 ret = memblock_alloc_nid_region(&mem->regions[i],
	nid_range,
	size, align, nid);
	if (ret != ~(u64)0)
	return ret;
	}

	return memblock_alloc(size, align);
	}

	u64 __init memblock_alloc(u64 size, u64 align)
	{
	return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ANYWHERE);
	}

	u64 __init memblock_alloc_base(u64 size, u64 align, u64 max_addr)
	{
	u64 alloc;

	alloc = __memblock_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 __memblock_alloc_base(u64 size, u64 align, u64 max_addr)
	{
	long i, j;
	u64 base = 0;
	u64 res_base;

	BUG_ON(0 == size);

	size = memblock_align_up(size, align);

	/* On some platforms, make sure we allocate lowmem */
	/* Note that MEMBLOCK_REAL_LIMIT may be MEMBLOCK_ALLOC_ANYWHERE */
	if (max_addr == MEMBLOCK_ALLOC_ANYWHERE)
	max_addr = MEMBLOCK_REAL_LIMIT;

	for (i = memblock.memory.cnt - 1; i >= 0; i--) {
	u64 memblockbase = memblock.memory.regions[i].base;
	u64 memblocksize = memblock.memory.regions[i].size;

	if (memblocksize < size)
	continue;
	if (max_addr == MEMBLOCK_ALLOC_ANYWHERE)
	base = memblock_align_down(memblockbase + memblocksize - size, align);
	else if (memblockbase < max_addr) {
	base = min(memblockbase + memblocksize, max_addr);
	base = memblock_align_down(base - size, align);
	} else
	continue;

	while (base && memblockbase <= base) {
	j = memblock_overlaps_region(&memblock.reserved, base, size);
	if (j < 0) {
	/* this area isn't reserved, take it */
	if (memblock_add_region(&memblock.reserved, base, size) < 0)
	return 0;
	return base;
	}
	res_base = memblock.reserved.regions[j].base;
	if (res_base < size)
	break;
	base = memblock_align_down(res_base - size, align);
	}
	}
	return 0;
	}

	/* You must call memblock_analyze() before this. */
	u64 __init memblock_phys_mem_size(void)
	{
	return memblock.memory.size;
	}

	u64 memblock_end_of_DRAM(void)
	{
	int idx = memblock.memory.cnt - 1;

	return (memblock.memory.regions[idx].base + memblock.memory.regions[idx].size);
	}

	/* You must call memblock_analyze() after this. */
	void __init memblock_enforce_memory_limit(u64 memory_limit)
	{
	unsigned long i;
	u64 limit;
	struct memblock_region *p;

	if (!memory_limit)
	return;

	/* Truncate the memblock regions to satisfy the memory limit. */
	limit = memory_limit;
	for (i = 0; i < memblock.memory.cnt; i++) {
	if (limit > memblock.memory.regions[i].size) {
	limit -= memblock.memory.regions[i].size;
	continue;
	}

	memblock.memory.regions[i].size = limit;
	memblock.memory.cnt = i + 1;
	break;
	}

	if (memblock.memory.regions[0].size < memblock.rmo_size)
	memblock.rmo_size = memblock.memory.regions[0].size;

	memory_limit = memblock_end_of_DRAM();

	/* And truncate any reserves above the limit also. */
	for (i = 0; i < memblock.reserved.cnt; i++) {
	p = &memblock.reserved.regions[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) {
	memblock_remove_region(&memblock.reserved, i);
	i--;
	}
	}
	}

	static int memblock_search(struct memblock_type *type, u64 addr)
	{
	unsigned int left = 0, right = type->cnt;

	do {
	unsigned int mid = (right + left) / 2;

	if (addr < type->regions[mid].base)
	right = mid;
	else if (addr >= (type->regions[mid].base +
	type->regions[mid].size))
	left = mid + 1;
	else
	return mid;
	} while (left < right);
	return -1;
	}

	int __init memblock_is_reserved(u64 addr)
	{
	return memblock_search(&memblock.reserved, addr) != -1;
	}

	int memblock_is_memory(u64 addr)
	{
	return memblock_search(&memblock.memory, addr) != -1;
	}

	int memblock_is_region_memory(u64 base, u64 size)
	{
	int idx = memblock_search(&memblock.reserved, base);

	if (idx == -1)
	return 0;
	return memblock.reserved.regions[idx].base <= base &&
	(memblock.reserved.regions[idx].base +
	memblock.reserved.regions[idx].size) >= (base + size);
	}

	int memblock_is_region_reserved(u64 base, u64 size)
	{
	return memblock_overlaps_region(&memblock.reserved, base, size) >= 0;
	}

	/*
	* Given a <base, len>, find which memory regions belong to this range.
	* Adjust the request and return a contiguous chunk.
	*/
	int memblock_find(struct memblock_region *res)
	{
	int i;
	u64 rstart, rend;

	rstart = res->base;
	rend = rstart + res->size - 1;

	for (i = 0; i < memblock.memory.cnt; i++) {
	u64 start = memblock.memory.regions[i].base;
	u64 end = start + memblock.memory.regions[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;
	}