sgl:fix large memory allocation problem in sgl

driver inclusion
category: bugfix
bugzilla: NA
CVE: NA

Currently sgl memory is allocated as block which size is
page_size *(1 << (max_order - 1)),which will be very large
when page_size and max_order are big.

This patches fix this problem by allocating sgl memory as
needed when needed memory is less than one block.

Feature or Bugfix:Bugfix
Signed-off-by: NZhou Wang <wangzhou1@hisilicon.com>
Signed-off-by: Nshenyang39 <shenyang39@huawei.com>
Reviewed-by: NLing Mingqiang <lingmingqiang@huawei.com>
Reviewed-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/crypto/hisilicon/sgl.c

@@ -58,7 +58,7 @@ struct hisi_acc_sgl_pool {
 struct hisi_acc_sgl_pool *hisi_acc_create_sgl_pool(struct device *dev,
 						   u32 count, u32 sge_nr)
 {
-	u32 sgl_size, block_size, sgl_num_per_block, block_num;
+	u32 sgl_size, block_size, sgl_num_per_block, block_num, remain_sgl = 0;
 	struct hisi_acc_sgl_pool *pool;
 	struct mem_block *block;
 	u32 i, j;
@@ -70,10 +70,11 @@ struct hisi_acc_sgl_pool *hisi_acc_create_sgl_pool(struct device *dev,
 		   sizeof(struct hisi_acc_hw_sgl);
 	block_size = PAGE_SIZE * (1 << (MAX_ORDER - 1));
 	sgl_num_per_block = block_size / sgl_size;
-	block_num = count / sgl_num_per_block +
-		    (count % sgl_num_per_block ? 1 : 0);
+	block_num = count / sgl_num_per_block;
+	remain_sgl = count % sgl_num_per_block;
 
-	if (block_num > HISI_ACC_MEM_BLOCK_NR)
+	if ((!remain_sgl && block_num > HISI_ACC_MEM_BLOCK_NR) ||
+	    (remain_sgl > 0 && block_num > HISI_ACC_MEM_BLOCK_NR - 1))
 		return ERR_PTR(-EINVAL);
 
 	pool = kzalloc(sizeof(*pool), GFP_KERNEL);
@@ -85,28 +86,38 @@ struct hisi_acc_sgl_pool *hisi_acc_create_sgl_pool(struct device *dev,
 		block[i].sgl = dma_alloc_coherent(dev, block_size,
 						  &block[i].sgl_dma,
 						  GFP_KERNEL);
-		if (!block[i].sgl) {
-			for (j = 0; j < i; j++) {
-				dma_free_coherent(dev, block_size,
-						  block[j].sgl,
-						  block[j].sgl_dma);
-				memset(block + j, 0, sizeof(*block));
-			}
-			kfree(pool);
-
-			return ERR_PTR(-ENOMEM);
-		}
+		if (!block[i].sgl)
+			goto err_free_mem;
 
 		block[i].size = block_size;
 	}
 
+	if (remain_sgl > 0) {
+		block[i].sgl = dma_alloc_coherent(dev, remain_sgl * sgl_size,
+						  &block[i].sgl_dma,
+						  GFP_KERNEL);
+		if (!block[i].sgl)
+			goto err_free_mem;
+
+		block[i].size = remain_sgl * sgl_size;
+	}
+
 	pool->sgl_num_per_block = sgl_num_per_block;
-	pool->block_num = block_num;
+	pool->block_num = remain_sgl ? block_num + 1 : block_num;
 	pool->count = count;
 	pool->sgl_size = sgl_size;
 	pool->sge_nr = sge_nr;
 
 	return pool;
+
+err_free_mem:
+	for (j = 0; j < i; j++) {
+		dma_free_coherent(dev, block_size, block[j].sgl,
+				  block[j].sgl_dma);
+		memset(block + j, 0, sizeof(*block));
+	}
+	kfree(pool);
+	return ERR_PTR(-ENOMEM);
 }
 EXPORT_SYMBOL_GPL(hisi_acc_create_sgl_pool);