smc: allocate RMBs as compound pages

Preparatory work for splice() support.
Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com><
Signed-off-by: David S. Miller <davem@davemloft.net>

net/smc/smc_core.c

@@ -290,8 +290,8 @@ static void smc_buf_free(struct smc_buf_desc *buf_desc, struct smc_link *lnk,
 				    DMA_TO_DEVICE);
 	}
 	sg_free_table(&buf_desc->sgt[SMC_SINGLE_LINK]);
-	if (buf_desc->cpu_addr)
-		free_pages((unsigned long)buf_desc->cpu_addr, buf_desc->order);
+	if (buf_desc->pages)
+		__free_pages(buf_desc->pages, buf_desc->order);
 	kfree(buf_desc);
 }
 
@@ -566,16 +566,16 @@ static struct smc_buf_desc *smc_new_buf_create(struct smc_link_group *lgr,
 	if (!buf_desc)
 		return ERR_PTR(-ENOMEM);
 
-	buf_desc->cpu_addr =
-		(void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN |
-					 __GFP_NOMEMALLOC |
+	buf_desc->order = get_order(bufsize);
+	buf_desc->pages = alloc_pages(GFP_KERNEL | __GFP_NOWARN |
+				      __GFP_NOMEMALLOC | __GFP_COMP |
 				      __GFP_NORETRY | __GFP_ZERO,
-					 get_order(bufsize));
-	if (!buf_desc->cpu_addr) {
+				      buf_desc->order);
+	if (!buf_desc->pages) {
 		kfree(buf_desc);
 		return ERR_PTR(-EAGAIN);
 	}
-	buf_desc->order = get_order(bufsize);
+	buf_desc->cpu_addr = (void *)page_address(buf_desc->pages);
 
 	/* build the sg table from the pages */
 	lnk = &lgr->lnk[SMC_SINGLE_LINK];

net/smc/smc_core.h

@@ -120,6 +120,7 @@ struct smc_link {
 struct smc_buf_desc {
 	struct list_head	list;
 	void			*cpu_addr;	/* virtual address of buffer */
+	struct page		*pages;
 	struct sg_table		sgt[SMC_LINKS_PER_LGR_MAX];/* virtual buffer */
 	struct ib_mr		*mr_rx[SMC_LINKS_PER_LGR_MAX];
 						/* for rmb only: memory region