From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx3-rdu2.redhat.com ([66.187.233.73]:45174 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751791AbeCIU4G (ORCPT ); Fri, 9 Mar 2018 15:56:06 -0500 Subject: [bpf-next V3 PATCH 12/15] xdp: allow page_pool as an allocator type in xdp_return_frame From: Jesper Dangaard Brouer To: netdev@vger.kernel.org, =?utf-8?b?QmrDtnJu?= =?utf-8?b?VMO2cGVs?= , magnus.karlsson@intel.com Cc: eugenia@mellanox.com, Jason Wang , John Fastabend , Eran Ben Elisha , Saeed Mahameed , galp@mellanox.com, Jesper Dangaard Brouer , Daniel Borkmann , Alexei Starovoitov , Tariq Toukan Date: Fri, 09 Mar 2018 21:56:02 +0100 Message-ID: <152062896273.27458.9739137295895929303.stgit@firesoul> In-Reply-To: <152062887576.27458.8590966896888512270.stgit@firesoul> References: <152062887576.27458.8590966896888512270.stgit@firesoul> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org List-ID: New allocator type MEM_TYPE_PAGE_POOL for page_pool usage. The registered allocator page_pool pointer is not available directly from xdp_rxq_info, but it could be (if needed). For now, the driver should keep separate track of the page_pool pointer, which it should use for RX-ring page allocation. As suggested by Saeed, to maintain a symmetric API it is the drivers responsibility to allocate/create and free/destroy the page_pool. Thus, after the driver have called xdp_rxq_info_unreg(), it is drivers responsibility to free the page_pool, but with a RCU free call. This is done easily via the page_pool helper page_pool_destroy_rcu() (which avoids touching any driver code during the RCU callback, which could happen after the driver have been unloaded). Signed-off-by: Jesper Dangaard Brouer --- include/net/xdp.h | 3 +++ net/core/xdp.c | 23 ++++++++++++++++++++--- 2 files changed, 23 insertions(+), 3 deletions(-) diff --git a/include/net/xdp.h b/include/net/xdp.h index 859aa9b737fe..98b55eaf8fd7 100644 --- a/include/net/xdp.h +++ b/include/net/xdp.h @@ -36,6 +36,7 @@ enum mem_type { MEM_TYPE_PAGE_SHARED = 0, /* Split-page refcnt based model */ MEM_TYPE_PAGE_ORDER0, /* Orig XDP full page model */ + MEM_TYPE_PAGE_POOL, MEM_TYPE_MAX, }; @@ -44,6 +45,8 @@ struct xdp_mem_info { u32 id; }; +struct page_pool; + struct xdp_rxq_info { struct net_device *dev; u32 queue_index; diff --git a/net/core/xdp.c b/net/core/xdp.c index 06a5b39491ad..fe8e87abc266 100644 --- a/net/core/xdp.c +++ b/net/core/xdp.c @@ -8,6 +8,7 @@ #include #include #include +#include #include @@ -27,7 +28,10 @@ static struct rhashtable *mem_id_ht; struct xdp_mem_allocator { struct xdp_mem_info mem; - void *allocator; + union { + void *allocator; + struct page_pool *page_pool; + }; struct rhash_head node; struct rcu_head rcu; }; @@ -74,7 +78,9 @@ void __xdp_mem_allocator_rcu_free(struct rcu_head *rcu) /* Allow this ID to be reused */ ida_simple_remove(&mem_id_pool, xa->mem.id); - /* TODO: Depending on allocator type/pointer free resources */ + /* Notice, driver is expected to free the *allocator, + * e.g. page_pool, and MUST also use RCU free. + */ /* Poison memory */ xa->mem.id = 0xFFFF; @@ -290,11 +296,21 @@ EXPORT_SYMBOL_GPL(xdp_rxq_info_reg_mem_model); void xdp_return_frame(void *data, struct xdp_mem_info *mem) { - struct xdp_mem_allocator *xa; + struct xdp_mem_allocator *xa = NULL; rcu_read_lock(); if (mem->id) xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params); + + if (mem->type == MEM_TYPE_PAGE_POOL) { + struct page *page = virt_to_head_page(data); + + if (xa) + page_pool_put_page(xa->page_pool, page); + else + put_page(page); + return; + } rcu_read_unlock(); if (mem->type == MEM_TYPE_PAGE_SHARED) { @@ -306,6 +322,7 @@ void xdp_return_frame(void *data, struct xdp_mem_info *mem) struct page *page = virt_to_page(data); /* Assumes order0 page*/ put_page(page); + return; } } EXPORT_SYMBOL_GPL(xdp_return_frame);