net/smc: cleanup function __smc_buf_create()

Split function __smc_buf_create() for better readability.

Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index ab8cdac5edb36efbb420ad24bb72f001920ead35..447bd52da0e2454948ea07c1ccf7e2d656e092c5 100644 (file)
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -487,6 +487,64 @@ static inline int smc_rmb_wnd_update_limit(int rmbe_size)
        return min_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2);
 }
 
+static struct smc_buf_desc *smc_new_buf_create(struct smc_link_group *lgr,
+                                              bool is_rmb, int bufsize)
+{
+       struct smc_buf_desc *buf_desc;
+       struct smc_link *lnk;
+       int rc;
+
+       /* try to alloc a new buffer */
+       buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
+       if (!buf_desc)
+               return ERR_PTR(-ENOMEM);
+
+       buf_desc->cpu_addr =
+               (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN |
+                                        __GFP_NOMEMALLOC |
+                                        __GFP_NORETRY | __GFP_ZERO,
+                                        get_order(bufsize));
+       if (!buf_desc->cpu_addr) {
+               kfree(buf_desc);
+               return ERR_PTR(-EAGAIN);
+       }
+       buf_desc->order = get_order(bufsize);
+
+       /* build the sg table from the pages */
+       lnk = &lgr->lnk[SMC_SINGLE_LINK];
+       rc = sg_alloc_table(&buf_desc->sgt[SMC_SINGLE_LINK], 1,
+                           GFP_KERNEL);
+       if (rc) {
+               smc_buf_free(buf_desc, lnk, is_rmb);
+               return ERR_PTR(rc);
+       }
+       sg_set_buf(buf_desc->sgt[SMC_SINGLE_LINK].sgl,
+                  buf_desc->cpu_addr, bufsize);
+
+       /* map sg table to DMA address */
+       rc = smc_ib_buf_map_sg(lnk->smcibdev, buf_desc,
+                              is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
+       /* SMC protocol depends on mapping to one DMA address only */
+       if (rc != 1)  {
+               smc_buf_free(buf_desc, lnk, is_rmb);
+               return ERR_PTR(-EAGAIN);
+       }
+
+       /* create a new memory region for the RMB */
+       if (is_rmb) {
+               rc = smc_ib_get_memory_region(lnk->roce_pd,
+                                             IB_ACCESS_REMOTE_WRITE |
+                                             IB_ACCESS_LOCAL_WRITE,
+                                             buf_desc);
+               if (rc) {
+                       smc_buf_free(buf_desc, lnk, is_rmb);
+                       return ERR_PTR(rc);
+               }
+       }
+
+       return buf_desc;
+}
+
 static int __smc_buf_create(struct smc_sock *smc, bool is_rmb)
 {
        struct smc_connection *conn = &smc->conn;
@@ -494,12 +552,9 @@ static int __smc_buf_create(struct smc_sock *smc, bool is_rmb)
        struct smc_buf_desc *buf_desc = NULL;
        struct list_head *buf_list;
        int bufsize, bufsize_short;
-       struct smc_link *lnk;
        int sk_buf_size;
        rwlock_t *lock;
-       int rc;
 
-       lnk = &lgr->lnk[SMC_SINGLE_LINK];
        if (is_rmb)
                /* use socket recv buffer size (w/o overhead) as start value */
                sk_buf_size = smc->sk.sk_rcvbuf / 2;
@@ -528,54 +583,11 @@ static int __smc_buf_create(struct smc_sock *smc, bool is_rmb)
                        break; /* found reusable slot */
                }
 
-               /* try to allocate the determined number of pages */
-               buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
-               if (!buf_desc)
-                       break; /* give up with -ENOMEM */
-
-               buf_desc->cpu_addr =
-                       (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN |
-                                                __GFP_NOMEMALLOC |
-                                                __GFP_NORETRY | __GFP_ZERO,
-                                                get_order(bufsize));
-               if (!buf_desc->cpu_addr) {
-                       kfree(buf_desc);
-                       buf_desc = NULL;
-                       continue;
-               }
-
-               rc = sg_alloc_table(&buf_desc->sgt[SMC_SINGLE_LINK], 1,
-                                   GFP_KERNEL);
-               if (rc) {
-                       smc_buf_free(buf_desc, lnk, is_rmb);
-                       buf_desc = NULL;
+               buf_desc = smc_new_buf_create(lgr, is_rmb, bufsize);
+               if (PTR_ERR(buf_desc) == -ENOMEM)
+                       break;
+               if (IS_ERR(buf_desc))
                        continue;
-               }
-               sg_set_buf(buf_desc->sgt[SMC_SINGLE_LINK].sgl,
-                          buf_desc->cpu_addr, bufsize);
-
-               /* map sg table to DMA address */
-               rc = smc_ib_buf_map_sg(lnk->smcibdev, buf_desc, is_rmb ?
-                                      DMA_FROM_DEVICE : DMA_TO_DEVICE);
-               /* SMC protocol depends on mapping to one DMA address only */
-               if (rc != 1)  {
-                       smc_buf_free(buf_desc, lnk, is_rmb);
-                       buf_desc = NULL;
-               continue; /* if mapping failed, try smaller one */
-               }
-
-               /* create a new memory region for the RMB */
-               if (is_rmb) {
-                       rc = smc_ib_get_memory_region(lnk->roce_pd,
-                                                     IB_ACCESS_REMOTE_WRITE |
-                                                     IB_ACCESS_LOCAL_WRITE,
-                                                     buf_desc);
-                       if (rc) {
-                               smc_buf_free(buf_desc, lnk, is_rmb);
-                               buf_desc = NULL;
-                               continue;
-                       }
-               }
 
                buf_desc->used = 1;
                write_lock_bh(lock);
@@ -584,7 +596,7 @@ static int __smc_buf_create(struct smc_sock *smc, bool is_rmb)
                break; /* found */
        }
 
-       if (!buf_desc || !buf_desc->cpu_addr)
+       if (IS_ERR(buf_desc))
                return -ENOMEM;
 
        if (is_rmb) {