nvme-pci: factor the iod mempool creation into a helper

Add a helper to create the iod mempool.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Tested-by Gerd Bayer <gbayer@linxu.ibm.com>

drivers/nvme/host/pci.c

@@ -390,14 +390,6 @@ static int nvme_pci_npages_sgl(void)
 			PAGE_SIZE);
 }
 
-static size_t nvme_pci_iod_alloc_size(void)
-{
-	size_t npages = max(nvme_pci_npages_prp(), nvme_pci_npages_sgl());
-
-	return sizeof(__le64 *) * npages +
-		sizeof(struct scatterlist) * NVME_MAX_SEGS;
-}
-
 static int nvme_admin_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
 				unsigned int hctx_idx)
 {
@@ -2762,6 +2754,22 @@ static void nvme_release_prp_pools(struct nvme_dev *dev)
 	dma_pool_destroy(dev->prp_small_pool);
 }
 
+static int nvme_pci_alloc_iod_mempool(struct nvme_dev *dev)
+{
+	size_t npages = max(nvme_pci_npages_prp(), nvme_pci_npages_sgl());
+	size_t alloc_size = sizeof(__le64 *) * npages +
+			    sizeof(struct scatterlist) * NVME_MAX_SEGS;
+
+	WARN_ON_ONCE(alloc_size > PAGE_SIZE);
+	dev->iod_mempool = mempool_create_node(1,
+			mempool_kmalloc, mempool_kfree,
+			(void *)alloc_size, GFP_KERNEL,
+			dev_to_node(dev->dev));
+	if (!dev->iod_mempool)
+		return -ENOMEM;
+	return 0;
+}
+
 static void nvme_free_tagset(struct nvme_dev *dev)
 {
 	if (dev->tagset.tags)
@@ -3087,7 +3095,6 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	int node, result = -ENOMEM;
 	struct nvme_dev *dev;
 	unsigned long quirks = id->driver_data;
-	size_t alloc_size;
 
 	node = dev_to_node(&pdev->dev);
 	if (node == NUMA_NO_NODE)
@@ -3132,21 +3139,9 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 		quirks |= NVME_QUIRK_SIMPLE_SUSPEND;
 	}
 
-	/*
-	 * Double check that our mempool alloc size will cover the biggest
-	 * command we support.
-	 */
-	alloc_size = nvme_pci_iod_alloc_size();
-	WARN_ON_ONCE(alloc_size > PAGE_SIZE);
-
-	dev->iod_mempool = mempool_create_node(1, mempool_kmalloc,
-						mempool_kfree,
-						(void *) alloc_size,
-						GFP_KERNEL, node);
-	if (!dev->iod_mempool) {
-		result = -ENOMEM;
+	result = nvme_pci_alloc_iod_mempool(dev);
+	if (result)
 		goto release_pools;
-	}
 
 	result = nvme_init_ctrl(&dev->ctrl, &pdev->dev, &nvme_pci_ctrl_ops,
 			quirks);