net: page_pool: id the page pools

To give ourselves the flexibility of creating netlink commands
and ability to refer to page pool instances in uAPIs create
IDs for page pools.

Reviewed-by: Ilias Apalodimas <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Acked-by: Jesper Dangaard Brouer <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

1 files changed, 36 insertions, 0 deletions

diff --git a/net/core/page_pool_user.c b/net/core/page_pool_user.c
new file mode 100644
index 000000000000..630d1eeecf2a
--- /dev/null
+++ b/net/core/page_pool_user.c
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/mutex.h>
+#include <linux/xarray.h>
+#include <net/page_pool/types.h>
+
+#include "page_pool_priv.h"
+
+static DEFINE_XARRAY_FLAGS(page_pools, XA_FLAGS_ALLOC1);
+static DEFINE_MUTEX(page_pools_lock);
+
+int page_pool_list(struct page_pool *pool)
+{
+	static u32 id_alloc_next;
+	int err;
+
+	mutex_lock(&page_pools_lock);
+	err = xa_alloc_cyclic(&page_pools, &pool->user.id, pool, xa_limit_32b,
+			      &id_alloc_next, GFP_KERNEL);
+	if (err < 0)
+		goto err_unlock;
+
+	mutex_unlock(&page_pools_lock);
+	return 0;
+
+err_unlock:
+	mutex_unlock(&page_pools_lock);
+	return err;
+}
+
+void page_pool_unlist(struct page_pool *pool)
+{
+	mutex_lock(&page_pools_lock);
+	xa_erase(&page_pools, pool->user.id);
+	mutex_unlock(&page_pools_lock);
+}