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>

1 files changed, 5 insertions, 5 deletions

diff --git a/lib/genalloc.c b/lib/genalloc.c
index 144fe6b1a03e..ca06adc4f445 100644
--- a/lib/genalloc.c
+++ b/lib/genalloc.c
@@ -194,7 +194,7 @@ int gen_pool_add_virt(struct gen_pool *pool, unsigned long virt, phys_addr_t phy
         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 gen_pool *pool, size_t size,
         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, unsigned long addr, size_t size)
                         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 *pool)
 
         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;
 }