dmapool: cleanup integer types

To represent the size of a single allocation, dmapool currently uses
'unsigned int' in some places and 'size_t' in other places.  Standardize
on 'unsigned int' to reduce overhead, but use 'size_t' when counting all
the blocks in the entire pool.

Link: https://lkml.kernel.org/r/20230126215125.4069751-5-kbusch@meta.com
Fixes: 2d55c16c ("dmapool: create/destroy cleanup")
Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/dmapool.c

@@ -43,10 +43,10 @@
 struct dma_pool {		/* the pool */
 	struct list_head page_list;
 	spinlock_t lock;
-	size_t size;
 	struct device *dev;
-	size_t allocation;
-	size_t boundary;
+	unsigned int size;
+	unsigned int allocation;
+	unsigned int boundary;
 	char name[32];
 	struct list_head pools;
 };
@@ -73,7 +73,7 @@ static ssize_t pools_show(struct device *dev, struct device_attribute *attr, cha
 	mutex_lock(&pools_lock);
 	list_for_each_entry(pool, &dev->dma_pools, pools) {
 		unsigned pages = 0;
-		unsigned blocks = 0;
+		size_t blocks = 0;
 
 		spin_lock_irq(&pool->lock);
 		list_for_each_entry(page, &pool->page_list, page_list) {
@@ -83,9 +83,10 @@ static ssize_t pools_show(struct device *dev, struct device_attribute *attr, cha
 		spin_unlock_irq(&pool->lock);
 
 		/* per-pool info, no real statistics yet */
-		size += sysfs_emit_at(buf, size, "%-16s %4u %4zu %4zu %2u\n",
+		size += sysfs_emit_at(buf, size, "%-16s %4zu %4zu %4u %2u\n",
 				      pool->name, blocks,
-				      pages * (pool->allocation / pool->size),
+				      (size_t) pages *
+				      (pool->allocation / pool->size),
 				      pool->size, pages);
 	}
 	mutex_unlock(&pools_lock);
@@ -133,7 +134,7 @@ struct dma_pool *dma_pool_create(const char *name, struct device *dev,
 	else if (align & (align - 1))
 		return NULL;
 
-	if (size == 0)
+	if (size == 0 || size > INT_MAX)
 		return NULL;
 	else if (size < 4)
 		size = 4;
@@ -146,6 +147,8 @@ struct dma_pool *dma_pool_create(const char *name, struct device *dev,
 	else if ((boundary < size) || (boundary & (boundary - 1)))
 		return NULL;
 
+	boundary = min(boundary, allocation);
+
 	retval = kmalloc(sizeof(*retval), GFP_KERNEL);
 	if (!retval)
 		return retval;
@@ -306,7 +309,7 @@ void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags,
 {
 	unsigned long flags;
 	struct dma_page *page;
-	size_t offset;
+	unsigned int offset;
 	void *retval;
 
 	might_alloc(mem_flags);