From 78a0f703ea6c4de2a88965a184026be503644c01 Mon Sep 17 00:00:00 2001
From: Magnus Karlsson <magnus.karlsson@intel.com>
Date: Fri, 28 Aug 2020 10:26:21 +0200
Subject: [PATCH] xsk: Move addrs from buffer pool to umem
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Replicate the addrs pointer in the buffer pool to the umem. This mapping
will be the same for all buffer pools sharing the same umem. In the
buffer pool we leave the addrs pointer for performance reasons.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Link: https://lore.kernel.org/bpf/1598603189-32145-8-git-send-email-magnus.karlsson@intel.com
---
 include/net/xdp_sock.h  |  1 +
 net/xdp/xdp_umem.c      | 22 ++++++++++++++++++++++
 net/xdp/xsk_buff_pool.c | 21 ++-------------------
 3 files changed, 25 insertions(+), 19 deletions(-)

diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h
index 9a61d05ec1326..126d24364b5a2 100644
--- a/include/net/xdp_sock.h
+++ b/include/net/xdp_sock.h
@@ -18,6 +18,7 @@ struct xsk_queue;
 struct xdp_buff;
 
 struct xdp_umem {
+	void *addrs;
 	u64 size;
 	u32 headroom;
 	u32 chunk_size;
diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c
index 77515925f3c51..77604c30aa0f8 100644
--- a/net/xdp/xdp_umem.c
+++ b/net/xdp/xdp_umem.c
@@ -39,11 +39,27 @@ static void xdp_umem_unaccount_pages(struct xdp_umem *umem)
 	}
 }
 
+static void xdp_umem_addr_unmap(struct xdp_umem *umem)
+{
+	vunmap(umem->addrs);
+	umem->addrs = NULL;
+}
+
+static int xdp_umem_addr_map(struct xdp_umem *umem, struct page **pages,
+			     u32 nr_pages)
+{
+	umem->addrs = vmap(pages, nr_pages, VM_MAP, PAGE_KERNEL);
+	if (!umem->addrs)
+		return -ENOMEM;
+	return 0;
+}
+
 static void xdp_umem_release(struct xdp_umem *umem)
 {
 	umem->zc = false;
 	ida_simple_remove(&umem_ida, umem->id);
 
+	xdp_umem_addr_unmap(umem);
 	xdp_umem_unpin_pages(umem);
 
 	xdp_umem_unaccount_pages(umem);
@@ -192,8 +208,14 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
 	if (err)
 		goto out_account;
 
+	err = xdp_umem_addr_map(umem, umem->pgs, umem->npgs);
+	if (err)
+		goto out_unpin;
+
 	return 0;
 
+out_unpin:
+	xdp_umem_unpin_pages(umem);
 out_account:
 	xdp_umem_unaccount_pages(umem);
 	return err;
diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
index dbd913ef49286..c56387439f679 100644
--- a/net/xdp/xsk_buff_pool.c
+++ b/net/xdp/xsk_buff_pool.c
@@ -35,26 +35,11 @@ void xp_del_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs)
 	spin_unlock_irqrestore(&pool->xsk_tx_list_lock, flags);
 }
 
-static void xp_addr_unmap(struct xsk_buff_pool *pool)
-{
-	vunmap(pool->addrs);
-}
-
-static int xp_addr_map(struct xsk_buff_pool *pool,
-		       struct page **pages, u32 nr_pages)
-{
-	pool->addrs = vmap(pages, nr_pages, VM_MAP, PAGE_KERNEL);
-	if (!pool->addrs)
-		return -ENOMEM;
-	return 0;
-}
-
 void xp_destroy(struct xsk_buff_pool *pool)
 {
 	if (!pool)
 		return;
 
-	xp_addr_unmap(pool);
 	kvfree(pool->heads);
 	kvfree(pool);
 }
@@ -64,7 +49,6 @@ struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
 {
 	struct xsk_buff_pool *pool;
 	struct xdp_buff_xsk *xskb;
-	int err;
 	u32 i;
 
 	pool = kvzalloc(struct_size(pool, free_heads, umem->chunks),
@@ -86,6 +70,7 @@ struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
 	pool->frame_len = umem->chunk_size - umem->headroom -
 		XDP_PACKET_HEADROOM;
 	pool->umem = umem;
+	pool->addrs = umem->addrs;
 	INIT_LIST_HEAD(&pool->free_list);
 	INIT_LIST_HEAD(&pool->xsk_tx_list);
 	spin_lock_init(&pool->xsk_tx_list_lock);
@@ -103,9 +88,7 @@ struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
 		pool->free_heads[i] = xskb;
 	}
 
-	err = xp_addr_map(pool, umem->pgs, umem->npgs);
-	if (!err)
-		return pool;
+	return pool;
 
 out:
 	xp_destroy(pool);
-- 
2.39.5