linux/lib/genalloc.c
Stephen Bates 36a3d1dd4e lib/genalloc.c: make the avail variable an atomic_long_t
If the amount of resources allocated to a gen_pool exceeds 2^32 then the
avail atomic overflows and this causes problems when clients try and
borrow resources from the pool.  This is only expected to be an issue on
64 bit systems.

Add the <linux/atomic.h> header to pull in atomic_long* operations.  So
that 32 bit systems continue to use atomic32_t but 64 bit systems can
use atomic64_t.

Link: http://lkml.kernel.org/r/1509033843-25667-1-git-send-email-sbates@raithlin.com
Signed-off-by: Stephen Bates <sbates@raithlin.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Daniel Mentz <danielmentz@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17 16:10:02 -08:00

781 lines
22 KiB
C

/*
* Basic general purpose allocator for managing special purpose
* memory, for example, memory that is not managed by the regular
* kmalloc/kfree interface. Uses for this includes on-device special
* memory, uncached memory etc.
*
* It is safe to use the allocator in NMI handlers and other special
* unblockable contexts that could otherwise deadlock on locks. This
* is implemented by using atomic operations and retries on any
* conflicts. The disadvantage is that there may be livelocks in
* extreme cases. For better scalability, one allocator can be used
* for each CPU.
*
* The lockless operation only works if there is enough memory
* available. If new memory is added to the pool a lock has to be
* still taken. So any user relying on locklessness has to ensure
* that sufficient memory is preallocated.
*
* The basic atomic operation of this allocator is cmpxchg on long.
* On architectures that don't have NMI-safe cmpxchg implementation,
* the allocator can NOT be used in NMI handler. So code uses the
* allocator in NMI handler should depend on
* CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG.
*
* Copyright 2005 (C) Jes Sorensen <jes@trained-monkey.org>
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/bitmap.h>
#include <linux/rculist.h>
#include <linux/interrupt.h>
#include <linux/genalloc.h>
#include <linux/of_device.h>
static inline size_t chunk_size(const struct gen_pool_chunk *chunk)
{
return chunk->end_addr - chunk->start_addr + 1;
}
static int set_bits_ll(unsigned long *addr, unsigned long mask_to_set)
{
unsigned long val, nval;
nval = *addr;
do {
val = nval;
if (val & mask_to_set)
return -EBUSY;
cpu_relax();
} while ((nval = cmpxchg(addr, val, val | mask_to_set)) != val);
return 0;
}
static int clear_bits_ll(unsigned long *addr, unsigned long mask_to_clear)
{
unsigned long val, nval;
nval = *addr;
do {
val = nval;
if ((val & mask_to_clear) != mask_to_clear)
return -EBUSY;
cpu_relax();
} while ((nval = cmpxchg(addr, val, val & ~mask_to_clear)) != val);
return 0;
}
/*
* bitmap_set_ll - set the specified number of bits at the specified position
* @map: pointer to a bitmap
* @start: a bit position in @map
* @nr: number of bits to set
*
* Set @nr bits start from @start in @map lock-lessly. Several users
* can set/clear the same bitmap simultaneously without lock. If two
* users set the same bit, one user will return remain bits, otherwise
* return 0.
*/
static int bitmap_set_ll(unsigned long *map, int start, int nr)
{
unsigned long *p = map + BIT_WORD(start);
const int size = start + nr;
int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
while (nr - bits_to_set >= 0) {
if (set_bits_ll(p, mask_to_set))
return nr;
nr -= bits_to_set;
bits_to_set = BITS_PER_LONG;
mask_to_set = ~0UL;
p++;
}
if (nr) {
mask_to_set &= BITMAP_LAST_WORD_MASK(size);
if (set_bits_ll(p, mask_to_set))
return nr;
}
return 0;
}
/*
* bitmap_clear_ll - clear the specified number of bits at the specified position
* @map: pointer to a bitmap
* @start: a bit position in @map
* @nr: number of bits to set
*
* Clear @nr bits start from @start in @map lock-lessly. Several users
* can set/clear the same bitmap simultaneously without lock. If two
* users clear the same bit, one user will return remain bits,
* otherwise return 0.
*/
static int bitmap_clear_ll(unsigned long *map, int start, int nr)
{
unsigned long *p = map + BIT_WORD(start);
const int size = start + nr;
int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
while (nr - bits_to_clear >= 0) {
if (clear_bits_ll(p, mask_to_clear))
return nr;
nr -= bits_to_clear;
bits_to_clear = BITS_PER_LONG;
mask_to_clear = ~0UL;
p++;
}
if (nr) {
mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
if (clear_bits_ll(p, mask_to_clear))
return nr;
}
return 0;
}
/**
* gen_pool_create - create a new special memory pool
* @min_alloc_order: log base 2 of number of bytes each bitmap bit represents
* @nid: node id of the node the pool structure should be allocated on, or -1
*
* Create a new special memory pool that can be used to manage special purpose
* memory not managed by the regular kmalloc/kfree interface.
*/
struct gen_pool *gen_pool_create(int min_alloc_order, int nid)
{
struct gen_pool *pool;
pool = kmalloc_node(sizeof(struct gen_pool), GFP_KERNEL, nid);
if (pool != NULL) {
spin_lock_init(&pool->lock);
INIT_LIST_HEAD(&pool->chunks);
pool->min_alloc_order = min_alloc_order;
pool->algo = gen_pool_first_fit;
pool->data = NULL;
pool->name = NULL;
}
return pool;
}
EXPORT_SYMBOL(gen_pool_create);
/**
* gen_pool_add_virt - add a new chunk of special memory to the pool
* @pool: pool to add new memory chunk to
* @virt: virtual starting address of memory chunk to add to pool
* @phys: physical starting address of memory chunk to add to pool
* @size: size in bytes of the memory chunk to add to pool
* @nid: node id of the node the chunk structure and bitmap should be
* allocated on, or -1
*
* Add a new chunk of special memory to the specified pool.
*
* Returns 0 on success or a -ve errno on failure.
*/
int gen_pool_add_virt(struct gen_pool *pool, unsigned long virt, phys_addr_t phys,
size_t size, int nid)
{
struct gen_pool_chunk *chunk;
int nbits = size >> pool->min_alloc_order;
int nbytes = sizeof(struct gen_pool_chunk) +
BITS_TO_LONGS(nbits) * sizeof(long);
chunk = kzalloc_node(nbytes, GFP_KERNEL, nid);
if (unlikely(chunk == NULL))
return -ENOMEM;
chunk->phys_addr = phys;
chunk->start_addr = virt;
chunk->end_addr = virt + size - 1;
atomic_long_set(&chunk->avail, size);
spin_lock(&pool->lock);
list_add_rcu(&chunk->next_chunk, &pool->chunks);
spin_unlock(&pool->lock);
return 0;
}
EXPORT_SYMBOL(gen_pool_add_virt);
/**
* gen_pool_virt_to_phys - return the physical address of memory
* @pool: pool to allocate from
* @addr: starting address of memory
*
* Returns the physical address on success, or -1 on error.
*/
phys_addr_t gen_pool_virt_to_phys(struct gen_pool *pool, unsigned long addr)
{
struct gen_pool_chunk *chunk;
phys_addr_t paddr = -1;
rcu_read_lock();
list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk) {
if (addr >= chunk->start_addr && addr <= chunk->end_addr) {
paddr = chunk->phys_addr + (addr - chunk->start_addr);
break;
}
}
rcu_read_unlock();
return paddr;
}
EXPORT_SYMBOL(gen_pool_virt_to_phys);
/**
* gen_pool_destroy - destroy a special memory pool
* @pool: pool to destroy
*
* Destroy the specified special memory pool. Verifies that there are no
* outstanding allocations.
*/
void gen_pool_destroy(struct gen_pool *pool)
{
struct list_head *_chunk, *_next_chunk;
struct gen_pool_chunk *chunk;
int order = pool->min_alloc_order;
int bit, end_bit;
list_for_each_safe(_chunk, _next_chunk, &pool->chunks) {
chunk = list_entry(_chunk, struct gen_pool_chunk, next_chunk);
list_del(&chunk->next_chunk);
end_bit = chunk_size(chunk) >> order;
bit = find_next_bit(chunk->bits, end_bit, 0);
BUG_ON(bit < end_bit);
kfree(chunk);
}
kfree_const(pool->name);
kfree(pool);
}
EXPORT_SYMBOL(gen_pool_destroy);
/**
* gen_pool_alloc - allocate special memory from the pool
* @pool: pool to allocate from
* @size: number of bytes to allocate from the pool
*
* Allocate the requested number of bytes from the specified pool.
* Uses the pool allocation function (with first-fit algorithm by default).
* Can not be used in NMI handler on architectures without
* NMI-safe cmpxchg implementation.
*/
unsigned long gen_pool_alloc(struct gen_pool *pool, size_t size)
{
return gen_pool_alloc_algo(pool, size, pool->algo, pool->data);
}
EXPORT_SYMBOL(gen_pool_alloc);
/**
* gen_pool_alloc_algo - allocate special memory from the pool
* @pool: pool to allocate from
* @size: number of bytes to allocate from the pool
* @algo: algorithm passed from caller
* @data: data passed to algorithm
*
* Allocate the requested number of bytes from the specified pool.
* Uses the pool allocation function (with first-fit algorithm by default).
* Can not be used in NMI handler on architectures without
* NMI-safe cmpxchg implementation.
*/
unsigned long gen_pool_alloc_algo(struct gen_pool *pool, size_t size,
genpool_algo_t algo, void *data)
{
struct gen_pool_chunk *chunk;
unsigned long addr = 0;
int order = pool->min_alloc_order;
int nbits, start_bit, end_bit, remain;
#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
BUG_ON(in_nmi());
#endif
if (size == 0)
return 0;
nbits = (size + (1UL << order) - 1) >> order;
rcu_read_lock();
list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk) {
if (size > atomic_long_read(&chunk->avail))
continue;
start_bit = 0;
end_bit = chunk_size(chunk) >> order;
retry:
start_bit = algo(chunk->bits, end_bit, start_bit,
nbits, data, pool);
if (start_bit >= end_bit)
continue;
remain = bitmap_set_ll(chunk->bits, start_bit, nbits);
if (remain) {
remain = bitmap_clear_ll(chunk->bits, start_bit,
nbits - remain);
BUG_ON(remain);
goto retry;
}
addr = chunk->start_addr + ((unsigned long)start_bit << order);
size = nbits << order;
atomic_long_sub(size, &chunk->avail);
break;
}
rcu_read_unlock();
return addr;
}
EXPORT_SYMBOL(gen_pool_alloc_algo);
/**
* gen_pool_dma_alloc - allocate special memory from the pool for DMA usage
* @pool: pool to allocate from
* @size: number of bytes to allocate from the pool
* @dma: dma-view physical address return value. Use NULL if unneeded.
*
* Allocate the requested number of bytes from the specified pool.
* Uses the pool allocation function (with first-fit algorithm by default).
* Can not be used in NMI handler on architectures without
* NMI-safe cmpxchg implementation.
*/
void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size, dma_addr_t *dma)
{
unsigned long vaddr;
if (!pool)
return NULL;
vaddr = gen_pool_alloc(pool, size);
if (!vaddr)
return NULL;
if (dma)
*dma = gen_pool_virt_to_phys(pool, vaddr);
return (void *)vaddr;
}
EXPORT_SYMBOL(gen_pool_dma_alloc);
/**
* gen_pool_free - free allocated special memory back to the pool
* @pool: pool to free to
* @addr: starting address of memory to free back to pool
* @size: size in bytes of memory to free
*
* Free previously allocated special memory back to the specified
* pool. Can not be used in NMI handler on architectures without
* NMI-safe cmpxchg implementation.
*/
void gen_pool_free(struct gen_pool *pool, unsigned long addr, size_t size)
{
struct gen_pool_chunk *chunk;
int order = pool->min_alloc_order;
int start_bit, nbits, remain;
#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
BUG_ON(in_nmi());
#endif
nbits = (size + (1UL << order) - 1) >> order;
rcu_read_lock();
list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk) {
if (addr >= chunk->start_addr && addr <= chunk->end_addr) {
BUG_ON(addr + size - 1 > chunk->end_addr);
start_bit = (addr - chunk->start_addr) >> order;
remain = bitmap_clear_ll(chunk->bits, start_bit, nbits);
BUG_ON(remain);
size = nbits << order;
atomic_long_add(size, &chunk->avail);
rcu_read_unlock();
return;
}
}
rcu_read_unlock();
BUG();
}
EXPORT_SYMBOL(gen_pool_free);
/**
* gen_pool_for_each_chunk - call func for every chunk of generic memory pool
* @pool: the generic memory pool
* @func: func to call
* @data: additional data used by @func
*
* Call @func for every chunk of generic memory pool. The @func is
* called with rcu_read_lock held.
*/
void gen_pool_for_each_chunk(struct gen_pool *pool,
void (*func)(struct gen_pool *pool, struct gen_pool_chunk *chunk, void *data),
void *data)
{
struct gen_pool_chunk *chunk;
rcu_read_lock();
list_for_each_entry_rcu(chunk, &(pool)->chunks, next_chunk)
func(pool, chunk, data);
rcu_read_unlock();
}
EXPORT_SYMBOL(gen_pool_for_each_chunk);
/**
* addr_in_gen_pool - checks if an address falls within the range of a pool
* @pool: the generic memory pool
* @start: start address
* @size: size of the region
*
* Check if the range of addresses falls within the specified pool. Returns
* true if the entire range is contained in the pool and false otherwise.
*/
bool addr_in_gen_pool(struct gen_pool *pool, unsigned long start,
size_t size)
{
bool found = false;
unsigned long end = start + size - 1;
struct gen_pool_chunk *chunk;
rcu_read_lock();
list_for_each_entry_rcu(chunk, &(pool)->chunks, next_chunk) {
if (start >= chunk->start_addr && start <= chunk->end_addr) {
if (end <= chunk->end_addr) {
found = true;
break;
}
}
}
rcu_read_unlock();
return found;
}
/**
* gen_pool_avail - get available free space of the pool
* @pool: pool to get available free space
*
* Return available free space of the specified pool.
*/
size_t gen_pool_avail(struct gen_pool *pool)
{
struct gen_pool_chunk *chunk;
size_t avail = 0;
rcu_read_lock();
list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk)
avail += atomic_long_read(&chunk->avail);
rcu_read_unlock();
return avail;
}
EXPORT_SYMBOL_GPL(gen_pool_avail);
/**
* gen_pool_size - get size in bytes of memory managed by the pool
* @pool: pool to get size
*
* Return size in bytes of memory managed by the pool.
*/
size_t gen_pool_size(struct gen_pool *pool)
{
struct gen_pool_chunk *chunk;
size_t size = 0;
rcu_read_lock();
list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk)
size += chunk_size(chunk);
rcu_read_unlock();
return size;
}
EXPORT_SYMBOL_GPL(gen_pool_size);
/**
* gen_pool_set_algo - set the allocation algorithm
* @pool: pool to change allocation algorithm
* @algo: custom algorithm function
* @data: additional data used by @algo
*
* Call @algo for each memory allocation in the pool.
* If @algo is NULL use gen_pool_first_fit as default
* memory allocation function.
*/
void gen_pool_set_algo(struct gen_pool *pool, genpool_algo_t algo, void *data)
{
rcu_read_lock();
pool->algo = algo;
if (!pool->algo)
pool->algo = gen_pool_first_fit;
pool->data = data;
rcu_read_unlock();
}
EXPORT_SYMBOL(gen_pool_set_algo);
/**
* gen_pool_first_fit - find the first available region
* of memory matching the size requirement (no alignment constraint)
* @map: The address to base the search on
* @size: The bitmap size in bits
* @start: The bitnumber to start searching at
* @nr: The number of zeroed bits we're looking for
* @data: additional data - unused
* @pool: pool to find the fit region memory from
*/
unsigned long gen_pool_first_fit(unsigned long *map, unsigned long size,
unsigned long start, unsigned int nr, void *data,
struct gen_pool *pool)
{
return bitmap_find_next_zero_area(map, size, start, nr, 0);
}
EXPORT_SYMBOL(gen_pool_first_fit);
/**
* gen_pool_first_fit_align - find the first available region
* of memory matching the size requirement (alignment constraint)
* @map: The address to base the search on
* @size: The bitmap size in bits
* @start: The bitnumber to start searching at
* @nr: The number of zeroed bits we're looking for
* @data: data for alignment
* @pool: pool to get order from
*/
unsigned long gen_pool_first_fit_align(unsigned long *map, unsigned long size,
unsigned long start, unsigned int nr, void *data,
struct gen_pool *pool)
{
struct genpool_data_align *alignment;
unsigned long align_mask;
int order;
alignment = data;
order = pool->min_alloc_order;
align_mask = ((alignment->align + (1UL << order) - 1) >> order) - 1;
return bitmap_find_next_zero_area(map, size, start, nr, align_mask);
}
EXPORT_SYMBOL(gen_pool_first_fit_align);
/**
* gen_pool_fixed_alloc - reserve a specific region
* @map: The address to base the search on
* @size: The bitmap size in bits
* @start: The bitnumber to start searching at
* @nr: The number of zeroed bits we're looking for
* @data: data for alignment
* @pool: pool to get order from
*/
unsigned long gen_pool_fixed_alloc(unsigned long *map, unsigned long size,
unsigned long start, unsigned int nr, void *data,
struct gen_pool *pool)
{
struct genpool_data_fixed *fixed_data;
int order;
unsigned long offset_bit;
unsigned long start_bit;
fixed_data = data;
order = pool->min_alloc_order;
offset_bit = fixed_data->offset >> order;
if (WARN_ON(fixed_data->offset & ((1UL << order) - 1)))
return size;
start_bit = bitmap_find_next_zero_area(map, size,
start + offset_bit, nr, 0);
if (start_bit != offset_bit)
start_bit = size;
return start_bit;
}
EXPORT_SYMBOL(gen_pool_fixed_alloc);
/**
* gen_pool_first_fit_order_align - find the first available region
* of memory matching the size requirement. The region will be aligned
* to the order of the size specified.
* @map: The address to base the search on
* @size: The bitmap size in bits
* @start: The bitnumber to start searching at
* @nr: The number of zeroed bits we're looking for
* @data: additional data - unused
* @pool: pool to find the fit region memory from
*/
unsigned long gen_pool_first_fit_order_align(unsigned long *map,
unsigned long size, unsigned long start,
unsigned int nr, void *data, struct gen_pool *pool)
{
unsigned long align_mask = roundup_pow_of_two(nr) - 1;
return bitmap_find_next_zero_area(map, size, start, nr, align_mask);
}
EXPORT_SYMBOL(gen_pool_first_fit_order_align);
/**
* gen_pool_best_fit - find the best fitting region of memory
* macthing the size requirement (no alignment constraint)
* @map: The address to base the search on
* @size: The bitmap size in bits
* @start: The bitnumber to start searching at
* @nr: The number of zeroed bits we're looking for
* @data: additional data - unused
* @pool: pool to find the fit region memory from
*
* Iterate over the bitmap to find the smallest free region
* which we can allocate the memory.
*/
unsigned long gen_pool_best_fit(unsigned long *map, unsigned long size,
unsigned long start, unsigned int nr, void *data,
struct gen_pool *pool)
{
unsigned long start_bit = size;
unsigned long len = size + 1;
unsigned long index;
index = bitmap_find_next_zero_area(map, size, start, nr, 0);
while (index < size) {
int next_bit = find_next_bit(map, size, index + nr);
if ((next_bit - index) < len) {
len = next_bit - index;
start_bit = index;
if (len == nr)
return start_bit;
}
index = bitmap_find_next_zero_area(map, size,
next_bit + 1, nr, 0);
}
return start_bit;
}
EXPORT_SYMBOL(gen_pool_best_fit);
static void devm_gen_pool_release(struct device *dev, void *res)
{
gen_pool_destroy(*(struct gen_pool **)res);
}
static int devm_gen_pool_match(struct device *dev, void *res, void *data)
{
struct gen_pool **p = res;
/* NULL data matches only a pool without an assigned name */
if (!data && !(*p)->name)
return 1;
if (!data || !(*p)->name)
return 0;
return !strcmp((*p)->name, data);
}
/**
* gen_pool_get - Obtain the gen_pool (if any) for a device
* @dev: device to retrieve the gen_pool from
* @name: name of a gen_pool or NULL, identifies a particular gen_pool on device
*
* Returns the gen_pool for the device if one is present, or NULL.
*/
struct gen_pool *gen_pool_get(struct device *dev, const char *name)
{
struct gen_pool **p;
p = devres_find(dev, devm_gen_pool_release, devm_gen_pool_match,
(void *)name);
if (!p)
return NULL;
return *p;
}
EXPORT_SYMBOL_GPL(gen_pool_get);
/**
* devm_gen_pool_create - managed gen_pool_create
* @dev: device that provides the gen_pool
* @min_alloc_order: log base 2 of number of bytes each bitmap bit represents
* @nid: node selector for allocated gen_pool, %NUMA_NO_NODE for all nodes
* @name: name of a gen_pool or NULL, identifies a particular gen_pool on device
*
* Create a new special memory pool that can be used to manage special purpose
* memory not managed by the regular kmalloc/kfree interface. The pool will be
* automatically destroyed by the device management code.
*/
struct gen_pool *devm_gen_pool_create(struct device *dev, int min_alloc_order,
int nid, const char *name)
{
struct gen_pool **ptr, *pool;
const char *pool_name = NULL;
/* Check that genpool to be created is uniquely addressed on device */
if (gen_pool_get(dev, name))
return ERR_PTR(-EINVAL);
if (name) {
pool_name = kstrdup_const(name, GFP_KERNEL);
if (!pool_name)
return ERR_PTR(-ENOMEM);
}
ptr = devres_alloc(devm_gen_pool_release, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
goto free_pool_name;
pool = gen_pool_create(min_alloc_order, nid);
if (!pool)
goto free_devres;
*ptr = pool;
pool->name = pool_name;
devres_add(dev, ptr);
return pool;
free_devres:
devres_free(ptr);
free_pool_name:
kfree_const(pool_name);
return ERR_PTR(-ENOMEM);
}
EXPORT_SYMBOL(devm_gen_pool_create);
#ifdef CONFIG_OF
/**
* of_gen_pool_get - find a pool by phandle property
* @np: device node
* @propname: property name containing phandle(s)
* @index: index into the phandle array
*
* Returns the pool that contains the chunk starting at the physical
* address of the device tree node pointed at by the phandle property,
* or NULL if not found.
*/
struct gen_pool *of_gen_pool_get(struct device_node *np,
const char *propname, int index)
{
struct platform_device *pdev;
struct device_node *np_pool, *parent;
const char *name = NULL;
struct gen_pool *pool = NULL;
np_pool = of_parse_phandle(np, propname, index);
if (!np_pool)
return NULL;
pdev = of_find_device_by_node(np_pool);
if (!pdev) {
/* Check if named gen_pool is created by parent node device */
parent = of_get_parent(np_pool);
pdev = of_find_device_by_node(parent);
of_node_put(parent);
of_property_read_string(np_pool, "label", &name);
if (!name)
name = np_pool->name;
}
if (pdev)
pool = gen_pool_get(&pdev->dev, name);
of_node_put(np_pool);
return pool;
}
EXPORT_SYMBOL_GPL(of_gen_pool_get);
#endif /* CONFIG_OF */