Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 912 insertions, 0 deletions

diff --git a/lib/genalloc.c b/lib/genalloc.c
new file mode 100644
index 000000000..841f29783
--- /dev/null
+++ b/lib/genalloc.c
@@ -0,0 +1,912 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 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>
+ */
+
+#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.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/vmalloc.h>
+
+static inline size_t chunk_size(const struct gen_pool_chunk *chunk)
+{
+	return chunk->end_addr - chunk->start_addr + 1;
+}
+
+static inline int
+set_bits_ll(unsigned long *addr, unsigned long mask_to_set)
+{
+	unsigned long val = READ_ONCE(*addr);
+
+	do {
+		if (val & mask_to_set)
+			return -EBUSY;
+		cpu_relax();
+	} while (!try_cmpxchg(addr, &val, val | mask_to_set));
+
+	return 0;
+}
+
+static inline int
+clear_bits_ll(unsigned long *addr, unsigned long mask_to_clear)
+{
+	unsigned long val = READ_ONCE(*addr);
+
+	do {
+		if ((val & mask_to_clear) != mask_to_clear)
+			return -EBUSY;
+		cpu_relax();
+	} while (!try_cmpxchg(addr, &val, val & ~mask_to_clear));
+
+	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 unsigned long
+bitmap_set_ll(unsigned long *map, unsigned long start, unsigned long nr)
+{
+	unsigned long *p = map + BIT_WORD(start);
+	const unsigned long 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) {
+		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 unsigned long
+bitmap_clear_ll(unsigned long *map, unsigned long start, unsigned long nr)
+{
+	unsigned long *p = map + BIT_WORD(start);
+	const unsigned long 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) {
+		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_owner- 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
+ * @owner: private data the publisher would like to recall at alloc time
+ *
+ * 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_owner(struct gen_pool *pool, unsigned long virt, phys_addr_t phys,
+		 size_t size, int nid, void *owner)
+{
+	struct gen_pool_chunk *chunk;
+	unsigned long nbits = size >> pool->min_alloc_order;
+	unsigned long nbytes = sizeof(struct gen_pool_chunk) +
+				BITS_TO_LONGS(nbits) * sizeof(long);
+
+	chunk = vzalloc_node(nbytes, nid);
+	if (unlikely(chunk == NULL))
+		return -ENOMEM;
+
+	chunk->phys_addr = phys;
+	chunk->start_addr = virt;
+	chunk->end_addr = virt + size - 1;
+	chunk->owner = owner;
+	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_owner);
+
+/**
+ * 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;
+	unsigned long 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_first_bit(chunk->bits, end_bit);
+		BUG_ON(bit < end_bit);
+
+		vfree(chunk);
+	}
+	kfree_const(pool->name);
+	kfree(pool);
+}
+EXPORT_SYMBOL(gen_pool_destroy);
+
+/**
+ * gen_pool_alloc_algo_owner - 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
+ * @owner: optionally retrieve the chunk owner
+ *
+ * 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_owner(struct gen_pool *pool, size_t size,
+		genpool_algo_t algo, void *data, void **owner)
+{
+	struct gen_pool_chunk *chunk;
+	unsigned long addr = 0;
+	int order = pool->min_alloc_order;
+	unsigned long nbits, start_bit, end_bit, remain;
+
+#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
+	BUG_ON(in_nmi());
+#endif
+
+	if (owner)
+		*owner = NULL;
+
+	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, chunk->start_addr);
+		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);
+		if (owner)
+			*owner = chunk->owner;
+		break;
+	}
+	rcu_read_unlock();
+	return addr;
+}
+EXPORT_SYMBOL(gen_pool_alloc_algo_owner);
+
+/**
+ * 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.
+ *
+ * Return: virtual address of the allocated memory, or %NULL on failure
+ */
+void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size, dma_addr_t *dma)
+{
+	return gen_pool_dma_alloc_algo(pool, size, dma, pool->algo, pool->data);
+}
+EXPORT_SYMBOL(gen_pool_dma_alloc);
+
+/**
+ * gen_pool_dma_alloc_algo - allocate special memory from the pool for DMA
+ * usage with the given pool algorithm
+ * @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.
+ * @algo: algorithm passed from caller
+ * @data: data passed to algorithm
+ *
+ * Allocate the requested number of bytes from the specified pool. Uses the
+ * given pool allocation function. Can not be used in NMI handler on
+ * architectures without NMI-safe cmpxchg implementation.
+ *
+ * Return: virtual address of the allocated memory, or %NULL on failure
+ */
+void *gen_pool_dma_alloc_algo(struct gen_pool *pool, size_t size,
+		dma_addr_t *dma, genpool_algo_t algo, void *data)
+{
+	unsigned long vaddr;
+
+	if (!pool)
+		return NULL;
+
+	vaddr = gen_pool_alloc_algo(pool, size, algo, data);
+	if (!vaddr)
+		return NULL;
+
+	if (dma)
+		*dma = gen_pool_virt_to_phys(pool, vaddr);
+
+	return (void *)vaddr;
+}
+EXPORT_SYMBOL(gen_pool_dma_alloc_algo);
+
+/**
+ * gen_pool_dma_alloc_align - allocate special memory from the pool for DMA
+ * usage with the given alignment
+ * @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.
+ * @align: alignment in bytes for starting address
+ *
+ * Allocate the requested number bytes from the specified pool, with the given
+ * alignment restriction. Can not be used in NMI handler on architectures
+ * without NMI-safe cmpxchg implementation.
+ *
+ * Return: virtual address of the allocated memory, or %NULL on failure
+ */
+void *gen_pool_dma_alloc_align(struct gen_pool *pool, size_t size,
+		dma_addr_t *dma, int align)
+{
+	struct genpool_data_align data = { .align = align };
+
+	return gen_pool_dma_alloc_algo(pool, size, dma,
+			gen_pool_first_fit_align, &data);
+}
+EXPORT_SYMBOL(gen_pool_dma_alloc_align);
+
+/**
+ * gen_pool_dma_zalloc - allocate special zeroed 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 zeroed 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.
+ *
+ * Return: virtual address of the allocated zeroed memory, or %NULL on failure
+ */
+void *gen_pool_dma_zalloc(struct gen_pool *pool, size_t size, dma_addr_t *dma)
+{
+	return gen_pool_dma_zalloc_algo(pool, size, dma, pool->algo, pool->data);
+}
+EXPORT_SYMBOL(gen_pool_dma_zalloc);
+
+/**
+ * gen_pool_dma_zalloc_algo - allocate special zeroed memory from the pool for
+ * DMA usage with the given pool algorithm
+ * @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.
+ * @algo: algorithm passed from caller
+ * @data: data passed to algorithm
+ *
+ * Allocate the requested number of zeroed bytes from the specified pool. Uses
+ * the given pool allocation function. Can not be used in NMI handler on
+ * architectures without NMI-safe cmpxchg implementation.
+ *
+ * Return: virtual address of the allocated zeroed memory, or %NULL on failure
+ */
+void *gen_pool_dma_zalloc_algo(struct gen_pool *pool, size_t size,
+		dma_addr_t *dma, genpool_algo_t algo, void *data)
+{
+	void *vaddr = gen_pool_dma_alloc_algo(pool, size, dma, algo, data);
+
+	if (vaddr)
+		memset(vaddr, 0, size);
+
+	return vaddr;
+}
+EXPORT_SYMBOL(gen_pool_dma_zalloc_algo);
+
+/**
+ * gen_pool_dma_zalloc_align - allocate special zeroed memory from the pool for
+ * DMA usage with the given alignment
+ * @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.
+ * @align: alignment in bytes for starting address
+ *
+ * Allocate the requested number of zeroed bytes from the specified pool,
+ * with the given alignment restriction. Can not be used in NMI handler on
+ * architectures without NMI-safe cmpxchg implementation.
+ *
+ * Return: virtual address of the allocated zeroed memory, or %NULL on failure
+ */
+void *gen_pool_dma_zalloc_align(struct gen_pool *pool, size_t size,
+		dma_addr_t *dma, int align)
+{
+	struct genpool_data_align data = { .align = align };
+
+	return gen_pool_dma_zalloc_algo(pool, size, dma,
+			gen_pool_first_fit_align, &data);
+}
+EXPORT_SYMBOL(gen_pool_dma_zalloc_align);
+
+/**
+ * gen_pool_free_owner - 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
+ * @owner: private data stashed at gen_pool_add() time
+ *
+ * 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_owner(struct gen_pool *pool, unsigned long addr, size_t size,
+		void **owner)
+{
+	struct gen_pool_chunk *chunk;
+	int order = pool->min_alloc_order;
+	unsigned long start_bit, nbits, remain;
+
+#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
+	BUG_ON(in_nmi());
+#endif
+
+	if (owner)
+		*owner = NULL;
+
+	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);
+			if (owner)
+				*owner = chunk->owner;
+			rcu_read_unlock();
+			return;
+		}
+	}
+	rcu_read_unlock();
+	BUG();
+}
+EXPORT_SYMBOL(gen_pool_free_owner);
+
+/**
+ * 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);
+
+/**
+ * gen_pool_has_addr - 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 gen_pool_has_addr(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;
+}
+EXPORT_SYMBOL(gen_pool_has_addr);
+
+/**
+ * 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
+ * @start_addr: not used in this function
+ */
+unsigned long gen_pool_first_fit(unsigned long *map, unsigned long size,
+		unsigned long start, unsigned int nr, void *data,
+		struct gen_pool *pool, unsigned long start_addr)
+{
+	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
+ * @start_addr: start addr of alloction chunk
+ */
+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, unsigned long start_addr)
+{
+	struct genpool_data_align *alignment;
+	unsigned long align_mask, align_off;
+	int order;
+
+	alignment = data;
+	order = pool->min_alloc_order;
+	align_mask = ((alignment->align + (1UL << order) - 1) >> order) - 1;
+	align_off = (start_addr & (alignment->align - 1)) >> order;
+
+	return bitmap_find_next_zero_area_off(map, size, start, nr,
+					      align_mask, align_off);
+}
+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
+ * @start_addr: not used in this function
+ */
+unsigned long gen_pool_fixed_alloc(unsigned long *map, unsigned long size,
+		unsigned long start, unsigned int nr, void *data,
+		struct gen_pool *pool, unsigned long start_addr)
+{
+	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
+ * @start_addr: not used in this function
+ */
+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 start_addr)
+{
+	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
+ * 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
+ * @start_addr: not used in this function
+ *
+ * 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_addr)
+{
+	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) {
+		unsigned long 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 = of_node_full_name(np_pool);
+	}
+	if (pdev) {
+		pool = gen_pool_get(&pdev->dev, name);
+		put_device(&pdev->dev);
+	}
+
+	of_node_put(np_pool);
+
+	return pool;
+}
+EXPORT_SYMBOL_GPL(of_gen_pool_get);
+#endif /* CONFIG_OF */