nvme-pci: add a symolic name for the small pool size

Open coding magic numbers in multiple places is never a good idea.

Signed-off-by: Leon Romanovsky <leon@kernel.org>
[hch: split from a larger patch]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 5017d6c565196070dc4b1bd7a6a9d1a6683a9958..2dbe6757e1a346e6335f9f17d339c87a94120ef9 100644 (file)
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -37,6 +37,9 @@
 
 #define SGES_PER_PAGE  (NVME_CTRL_PAGE_SIZE / sizeof(struct nvme_sgl_desc))
 
+/* Optimisation for I/Os between 4k and 128k */
+#define NVME_SMALL_POOL_SIZE   256
+
 /*
  * These can be higher, but we need to ensure that any command doesn't
  * require an sg allocation that needs more than a page of data.
@@ -407,7 +410,7 @@ static struct nvme_descriptor_pools *
 nvme_setup_descriptor_pools(struct nvme_dev *dev, unsigned numa_node)
 {
        struct nvme_descriptor_pools *pools = &dev->descriptor_pools[numa_node];
-       size_t small_align = 256;
+       size_t small_align = NVME_SMALL_POOL_SIZE;
 
        if (pools->small)
                return pools; /* already initialized */
@@ -420,9 +423,8 @@ nvme_setup_descriptor_pools(struct nvme_dev *dev, unsigned numa_node)
        if (dev->ctrl.quirks & NVME_QUIRK_DMAPOOL_ALIGN_512)
                small_align = 512;
 
-       /* Optimisation for I/Os between 4k and 128k */
-       pools->small = dma_pool_create_node("nvme descriptor 256", dev->dev,
-                       256, small_align, 0, numa_node);
+       pools->small = dma_pool_create_node("nvme descriptor small", dev->dev,
+                       NVME_SMALL_POOL_SIZE, small_align, 0, numa_node);
        if (!pools->small) {
                dma_pool_destroy(pools->large);
                pools->large = NULL;
@@ -689,7 +691,7 @@ static blk_status_t nvme_pci_setup_prps(struct nvme_queue *nvmeq,
        }
 
        if (DIV_ROUND_UP(length, NVME_CTRL_PAGE_SIZE) <=
-           256 / sizeof(__le64))
+           NVME_SMALL_POOL_SIZE / sizeof(__le64))
                iod->flags |= IOD_SMALL_DESCRIPTOR;
 
        prp_list = dma_pool_alloc(nvme_dma_pool(nvmeq, iod), GFP_ATOMIC,
@@ -774,7 +776,7 @@ static blk_status_t nvme_pci_setup_sgls(struct nvme_queue *nvmeq,
                return BLK_STS_OK;
        }
 
-       if (entries <= 256 / sizeof(*sg_list))
+       if (entries <= NVME_SMALL_POOL_SIZE / sizeof(*sg_list))
                iod->flags |= IOD_SMALL_DESCRIPTOR;
 
        sg_list = dma_pool_alloc(nvme_dma_pool(nvmeq, iod), GFP_ATOMIC,