+ genalloc-make-the-avail-variable-an-atomic_long_t.patch added to -mm tree

+ genalloc-make-the-avail-variable-an-atomic_long_t.patch added to -mm tree

[akpm]

The patch titled
     Subject: lib/genalloc.c: make the avail variable an atomic_long_t
has been added to the -mm tree.  Its filename is
     genalloc-make-the-avail-variable-an-atomic_long_t.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/genalloc-make-the-avail-variable-an-atomic_long_t.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/genalloc-make-the-avail-variable-an-atomic_long_t.patch

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------------------------------------------------------
From: Stephen Bates <sbates@raithlin.com>
Subject: 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>
---

 include/linux/genalloc.h |    3 ++-
 lib/genalloc.c           |   10 +++++-----
 2 files changed, 7 insertions(+), 6 deletions(-)

diff -puN include/linux/genalloc.h~genalloc-make-the-avail-variable-an-atomic_long_t include/linux/genalloc.h
--- a/include/linux/genalloc.h~genalloc-make-the-avail-variable-an-atomic_long_t
+++ a/include/linux/genalloc.h
@@ -32,6 +32,7 @@
 
 #include <linux/types.h>
 #include <linux/spinlock_types.h>
+#include <linux/atomic.h>
 
 struct device;
 struct device_node;
@@ -71,7 +72,7 @@ struct gen_pool {
  */
 struct gen_pool_chunk {
 	struct list_head next_chunk;	/* next chunk in pool */
-	atomic_t avail;
+	atomic_long_t avail;
 	phys_addr_t phys_addr;		/* physical starting address of memory chunk */
 	unsigned long start_addr;	/* start address of memory chunk */
 	unsigned long end_addr;		/* end address of memory chunk (inclusive) */
diff -puN lib/genalloc.c~genalloc-make-the-avail-variable-an-atomic_long_t lib/genalloc.c
--- a/lib/genalloc.c~genalloc-make-the-avail-variable-an-atomic_long_t
+++ a/lib/genalloc.c
@@ -194,7 +194,7 @@ int gen_pool_add_virt(struct gen_pool *p
 	chunk->phys_addr = phys;
 	chunk->start_addr = virt;
 	chunk->end_addr = virt + size - 1;
-	atomic_set(&chunk->avail, size);
+	atomic_long_set(&chunk->avail, size);
 
 	spin_lock(&pool->lock);
 	list_add_rcu(&chunk->next_chunk, &pool->chunks);
@@ -304,7 +304,7 @@ unsigned long gen_pool_alloc_algo(struct
 	nbits = (size + (1UL << order) - 1) >> order;
 	rcu_read_lock();
 	list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk) {
-		if (size > atomic_read(&chunk->avail))
+		if (size > atomic_long_read(&chunk->avail))
 			continue;
 
 		start_bit = 0;
@@ -324,7 +324,7 @@ retry:
 
 		addr = chunk->start_addr + ((unsigned long)start_bit << order);
 		size = nbits << order;
-		atomic_sub(size, &chunk->avail);
+		atomic_long_sub(size, &chunk->avail);
 		break;
 	}
 	rcu_read_unlock();
@@ -390,7 +390,7 @@ void gen_pool_free(struct gen_pool *pool
 			remain = bitmap_clear_ll(chunk->bits, start_bit, nbits);
 			BUG_ON(remain);
 			size = nbits << order;
-			atomic_add(size, &chunk->avail);
+			atomic_long_add(size, &chunk->avail);
 			rcu_read_unlock();
 			return;
 		}
@@ -464,7 +464,7 @@ size_t gen_pool_avail(struct gen_pool *p
 
 	rcu_read_lock();
 	list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk)
-		avail += atomic_read(&chunk->avail);
+		avail += atomic_long_read(&chunk->avail);
 	rcu_read_unlock();
 	return avail;
 }
_

Patches currently in -mm which might be from sbates@raithlin.com are

genalloc-make-the-avail-variable-an-atomic_long_t.patch