From patchwork Tue Aug 13 21:13:08 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mina Almasry X-Patchwork-Id: 13762551 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6E795C52D7F for ; Tue, 13 Aug 2024 21:13:35 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id DA36110E3E9; Tue, 13 Aug 2024 21:13:34 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.b="olnmFpXc"; dkim-atps=neutral Received: from mail-yw1-f202.google.com (mail-yw1-f202.google.com [209.85.128.202]) by gabe.freedesktop.org (Postfix) with ESMTPS id F3B2B10E369 for ; Tue, 13 Aug 2024 21:13:31 +0000 (UTC) Received: by mail-yw1-f202.google.com with SMTP id 00721157ae682-690404fd34eso142907607b3.1 for ; Tue, 13 Aug 2024 14:13:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1723583611; x=1724188411; darn=lists.freedesktop.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=0mCJL3RbqwHfQUta3bwCmTM+iKiOkWhDVwTWUwq4Rzo=; b=olnmFpXcYOyY2hGNYCSJgfMwXADPivjDm7xEfVgMld9KLNBMuZKpEqI85FsT/Mjx0g mmMLhZEDl7wsQNbFVdFX6M5/3Sma8KuY42pYYwoT1xQnY1utNIY9Jgu0YICVOKexV29z XRF/NaZ6gEJAOCCT5OrpMxx12brjAu15ccF8yJp+/MYA7xQBRoUGUlQUNQNwukT2t1SJ uXT23tmfvyIH6gOiNz7PQ3qq2qJAIxeX5I9oRye2Uu3MnPe3aXBNs2ixot7Rh6nOuDZK HWnnfz1eBW5/jemt8KxuD9ZJlpONSDA4+QhKjZ5r4j+OP3Cyc47+4hmM3ydoHHqGW++f r2Kw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1723583611; x=1724188411; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=0mCJL3RbqwHfQUta3bwCmTM+iKiOkWhDVwTWUwq4Rzo=; b=xPsjaPgU+PACmQqKDYYla2OvR/CN8DGRtQvawHDsQWHHNizIWqayMKlqFAxMR+9TCp MUnYMH0LpfkXSknYhWOU0eLhsP5BB32jwFS4I0NzanPjsPsIXBUrB72Lctg+XZByo7ZO DzJT1qioZ+DHRjx3pqLI0g8B3RgT2ssvocnKBWagUknZIhXBrU0ZRG8PSerFL4UMBdis lF8B81skqjd0IoF7TJsgR5BYQ/ujpxAN6AGAzBaKOOlzg6HibcxhuZAeh5Pm52/mfdHa Ti2fEwNPMIz8XtuembiKKpFl6pErJPkDjSD56tUM2sI5YxGTrutSzlFcFj5tcnxgUKn7 Y9cg== X-Forwarded-Encrypted: i=1; AJvYcCVZ/JuwciPSYfYu5RS+AGkX32i4bXyrFnu4jGbG0N511pBHxXleIJ5ze155FIo4ok88g4XeqNDL7i2MpB5xmERgwhMUgXM2ohVFrD0uda21 X-Gm-Message-State: AOJu0YysnW1yjO2UHmpMEcj7hzyXHvUR8FZiHt1d7ie2MQUevZkewpZK YBui4laNGTg7HgHzWzaG9oAteAvROl55X4LyJtTu6MvRtxdEwb8CwMSMXilxlnVNBL0AcAo7lWH DEVvqRUYcZU2TraNMIJkgRA== X-Google-Smtp-Source: AGHT+IHiPxP8A/E9YoxlvJaoAgVERYeMi+Yj3z6jWzuLSwobvImcgZOij9ODCa+RgPWAnZFn/TNmmHdAlQb76hlXGA== X-Received: from almasrymina.c.googlers.com ([fda3:e722:ac3:cc00:20:ed76:c0a8:4bc5]) (user=almasrymina job=sendgmr) by 2002:a25:c750:0:b0:e0b:ea2e:7b00 with SMTP id 3f1490d57ef6-e1155a90debmr11089276.5.1723583610828; Tue, 13 Aug 2024 14:13:30 -0700 (PDT) Date: Tue, 13 Aug 2024 21:13:08 +0000 Mime-Version: 1.0 X-Mailer: git-send-email 2.46.0.76.ge559c4bf1a-goog Message-ID: <20240813211317.3381180-7-almasrymina@google.com> Subject: [PATCH net-next v19 06/13] memory-provider: dmabuf devmem memory provider From: Mina Almasry To: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-alpha@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, sparclinux@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-kselftest@vger.kernel.org, bpf@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org Cc: Mina Almasry , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Donald Hunter , Jonathan Corbet , Richard Henderson , Ivan Kokshaysky , Matt Turner , Thomas Bogendoerfer , "James E.J. Bottomley" , Helge Deller , Andreas Larsson , Jesper Dangaard Brouer , Ilias Apalodimas , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Arnd Bergmann , Steffen Klassert , Herbert Xu , David Ahern , Willem de Bruijn , Shuah Khan , Alexei Starovoitov , Daniel Borkmann , John Fastabend , Sumit Semwal , " =?utf-8?q?Christian_K=C3=B6nig?= " , Bagas Sanjaya , Christoph Hellwig , Nikolay Aleksandrov , Taehee Yoo , Pavel Begunkov , David Wei , Jason Gunthorpe , Yunsheng Lin , Shailend Chand , Harshitha Ramamurthy , Shakeel Butt , Jeroen de Borst , Praveen Kaligineedi , Willem de Bruijn , Kaiyuan Zhang X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Implement a memory provider that allocates dmabuf devmem in the form of net_iov. The provider receives a reference to the struct netdev_dmabuf_binding via the pool->mp_priv pointer. The driver needs to set this pointer for the provider in the net_iov. The provider obtains a reference on the netdev_dmabuf_binding which guarantees the binding and the underlying mapping remains alive until the provider is destroyed. Usage of PP_FLAG_DMA_MAP is required for this memory provide such that the page_pool can provide the driver with the dma-addrs of the devmem. Support for PP_FLAG_DMA_SYNC_DEV is omitted for simplicity & p.order != 0. Signed-off-by: Willem de Bruijn Signed-off-by: Kaiyuan Zhang Signed-off-by: Mina Almasry Reviewed-by: Pavel Begunkov --- v19: - Add PP_FLAG_ALLOW_UNREADABLE_NETMEM flag. It serves 2 purposes, (a) it guards drivers that don't support unreadable netmem (net_iov backed) from accidentally getting exposed to it, and (b) drivers that wish to create header pools can unset it for that pool to force readable netmem. - Add page_pool_check_memory_provider, which verifies that the driver has created a page_pool with the expected configuration. This is used to report to the user if the mp configuration succeeded, and also verify that the driver is doing the right thing. - Don't reset niov->dma_addr on allocation/free. v17: - Use ASSERT_RTNL (Jakub) v16: - Add DEBUG_NET_WARN_ON_ONCE(!rtnl_is_locked()), to catch cases if page_pool_init without rtnl_locking when the queue is provided. In this case, the queue configuration may be changed while we're initing the page_pool, which could be a race. v13: - Return on warning (Pavel). - Fixed pool->recycle_stats not being freed on error (Pavel). - Applied reviewed-by from Pavel. v11: - Rebase to not use the ops. (Christoph) v8: - Use skb_frag_size instead of frag->bv_len to fix patch-by-patch build error v6: - refactor new memory provider functions into net/core/devmem.c (Pavel) v2: - Disable devmem for p.order != 0 v1: - static_branch check in page_is_page_pool_iov() (Willem & Paolo). - PP_DEVMEM -> PP_IOV (David). - Require PP_FLAG_DMA_MAP (Jakub). --- include/net/mp_dmabuf_devmem.h | 44 ++++++++++++++ include/net/page_pool/types.h | 16 ++++- net/core/devmem.c | 70 ++++++++++++++++++++++ net/core/page_pool.c | 103 ++++++++++++++++++++++++--------- net/core/page_pool_priv.h | 6 ++ net/core/page_pool_user.c | 26 +++++++++ 6 files changed, 237 insertions(+), 28 deletions(-) create mode 100644 include/net/mp_dmabuf_devmem.h diff --git a/include/net/mp_dmabuf_devmem.h b/include/net/mp_dmabuf_devmem.h new file mode 100644 index 000000000000..300a2356eed0 --- /dev/null +++ b/include/net/mp_dmabuf_devmem.h @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Dmabuf device memory provider. + * + * Authors: Mina Almasry + * + */ +#ifndef _NET_MP_DMABUF_DEVMEM_H +#define _NET_MP_DMABUF_DEVMEM_H + +#include + +#if defined(CONFIG_DMA_SHARED_BUFFER) && defined(CONFIG_GENERIC_ALLOCATOR) +int mp_dmabuf_devmem_init(struct page_pool *pool); + +netmem_ref mp_dmabuf_devmem_alloc_netmems(struct page_pool *pool, gfp_t gfp); + +void mp_dmabuf_devmem_destroy(struct page_pool *pool); + +bool mp_dmabuf_devmem_release_page(struct page_pool *pool, netmem_ref netmem); +#else +static inline int mp_dmabuf_devmem_init(struct page_pool *pool) +{ + return -EOPNOTSUPP; +} + +static inline netmem_ref mp_dmabuf_devmem_alloc_netmems(struct page_pool *pool, + gfp_t gfp) +{ + return 0; +} + +static inline void mp_dmabuf_devmem_destroy(struct page_pool *pool) +{ +} + +static inline bool mp_dmabuf_devmem_release_page(struct page_pool *pool, + netmem_ref netmem) +{ + return false; +} +#endif + +#endif /* _NET_MP_DMABUF_DEVMEM_H */ diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h index 4afd6dd56351..e221521cd7f3 100644 --- a/include/net/page_pool/types.h +++ b/include/net/page_pool/types.h @@ -20,8 +20,17 @@ * device driver responsibility */ #define PP_FLAG_SYSTEM_POOL BIT(2) /* Global system page_pool */ +#define PP_FLAG_ALLOW_UNREADABLE_NETMEM BIT(3) /* Allow unreadable (net_iov + * backed) netmem in this + * page_pool. Drivers setting + * this must be able to support + * unreadable netmem, where + * netmem_address() would return + * NULL. This flag should not be + * set for header page_pools. + */ #define PP_FLAG_ALL (PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV | \ - PP_FLAG_SYSTEM_POOL) + PP_FLAG_SYSTEM_POOL | PP_FLAG_ALLOW_UNREADABLE_NETMEM) /* * Fast allocation side cache array/stack @@ -52,12 +61,14 @@ struct pp_alloc_cache { * @nid: NUMA node id to allocate from pages from * @dev: device, for DMA pre-mapping purposes * @napi: NAPI which is the sole consumer of pages, otherwise NULL + * @queue: struct netdev_rx_queue this page_pool is being created for. * @dma_dir: DMA mapping direction * @max_len: max DMA sync memory size for PP_FLAG_DMA_SYNC_DEV * @offset: DMA sync address offset for PP_FLAG_DMA_SYNC_DEV * @slow: params with slowpath access only (initialization and Netlink) * @netdev: netdev this pool will serve (leave as NULL if none or multiple) - * @flags: PP_FLAG_DMA_MAP, PP_FLAG_DMA_SYNC_DEV, PP_FLAG_SYSTEM_POOL + * @flags: PP_FLAG_DMA_MAP, PP_FLAG_DMA_SYNC_DEV, PP_FLAG_SYSTEM_POOL, + * PP_FLAG_ALLOW_UNREADABLE_NETMEM. */ struct page_pool_params { struct_group_tagged(page_pool_params_fast, fast, @@ -66,6 +77,7 @@ struct page_pool_params { int nid; struct device *dev; struct napi_struct *napi; + struct netdev_rx_queue *queue; enum dma_data_direction dma_dir; unsigned int max_len; unsigned int offset; diff --git a/net/core/devmem.c b/net/core/devmem.c index 301f4250ca82..2f2a7f4dee4c 100644 --- a/net/core/devmem.c +++ b/net/core/devmem.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include "page_pool_priv.h" @@ -153,6 +154,10 @@ int net_devmem_bind_dmabuf_to_queue(struct net_device *dev, u32 rxq_idx, if (err) goto err_xa_erase; + err = page_pool_check_memory_provider(dev, rxq, binding); + if (err) + goto err_xa_erase; + return 0; err_xa_erase: @@ -305,4 +310,69 @@ void dev_dmabuf_uninstall(struct net_device *dev) xa_erase(&binding->bound_rxqs, xa_idx); } } + +/*** "Dmabuf devmem memory provider" ***/ + +int mp_dmabuf_devmem_init(struct page_pool *pool) +{ + struct net_devmem_dmabuf_binding *binding = pool->mp_priv; + + if (!binding) + return -EINVAL; + + if (!pool->dma_map) + return -EOPNOTSUPP; + + if (pool->dma_sync) + return -EOPNOTSUPP; + + if (pool->p.order != 0) + return -E2BIG; + + net_devmem_dmabuf_binding_get(binding); + return 0; +} + +netmem_ref mp_dmabuf_devmem_alloc_netmems(struct page_pool *pool, gfp_t gfp) +{ + struct net_devmem_dmabuf_binding *binding = pool->mp_priv; + netmem_ref netmem; + struct net_iov *niov; + + niov = net_devmem_alloc_dmabuf(binding); + if (!niov) + return 0; + + netmem = net_iov_to_netmem(niov); + + page_pool_set_pp_info(pool, netmem); + + pool->pages_state_hold_cnt++; + trace_page_pool_state_hold(pool, netmem, pool->pages_state_hold_cnt); + return netmem; +} + +void mp_dmabuf_devmem_destroy(struct page_pool *pool) +{ + struct net_devmem_dmabuf_binding *binding = pool->mp_priv; + + net_devmem_dmabuf_binding_put(binding); +} + +bool mp_dmabuf_devmem_release_page(struct page_pool *pool, netmem_ref netmem) +{ + if (WARN_ON_ONCE(!netmem_is_net_iov(netmem))) + return false; + + if (WARN_ON_ONCE(atomic_long_read(netmem_get_pp_ref_count_ref(netmem)) != + 1)) + return false; + + page_pool_clear_pp_info(netmem); + + net_devmem_free_dmabuf(netmem_to_net_iov(netmem)); + + /* We don't want the page pool put_page()ing our net_iovs. */ + return false; +} #endif diff --git a/net/core/page_pool.c b/net/core/page_pool.c index 13277f05aebd..25be3327561b 100644 --- a/net/core/page_pool.c +++ b/net/core/page_pool.c @@ -13,6 +13,7 @@ #include #include +#include #include #include @@ -21,6 +22,9 @@ #include #include #include +#include +#include +#include #include @@ -28,6 +32,7 @@ #include "netmem_priv.h" DEFINE_STATIC_KEY_FALSE(page_pool_mem_providers); +EXPORT_SYMBOL(page_pool_mem_providers); #define DEFER_TIME (msecs_to_jiffies(1000)) #define DEFER_WARN_INTERVAL (60 * HZ) @@ -190,6 +195,7 @@ static int page_pool_init(struct page_pool *pool, int cpuid) { unsigned int ring_qsize = 1024; /* Default */ + int err; page_pool_struct_check(); @@ -271,7 +277,36 @@ static int page_pool_init(struct page_pool *pool, if (pool->dma_map) get_device(pool->p.dev); + if (pool->p.queue && + pool->slow.flags & PP_FLAG_ALLOW_UNREADABLE_NETMEM) { + /* We rely on rtnl_lock()ing to make sure netdev_rx_queue + * configuration doesn't change while we're initializing the + * page_pool. + */ + ASSERT_RTNL(); + pool->mp_priv = pool->p.queue->mp_params.mp_priv; + } + + if (pool->mp_priv) { + err = mp_dmabuf_devmem_init(pool); + if (err) { + pr_warn("%s() mem-provider init failed %d\n", __func__, + err); + goto free_ptr_ring; + } + + static_branch_inc(&page_pool_mem_providers); + } + return 0; + +free_ptr_ring: + ptr_ring_cleanup(&pool->ring, NULL); +#ifdef CONFIG_PAGE_POOL_STATS + if (!pool->system) + free_percpu(pool->recycle_stats); +#endif + return err; } static void page_pool_uninit(struct page_pool *pool) @@ -455,28 +490,6 @@ static bool page_pool_dma_map(struct page_pool *pool, netmem_ref netmem) return false; } -static void page_pool_set_pp_info(struct page_pool *pool, netmem_ref netmem) -{ - netmem_set_pp(netmem, pool); - netmem_or_pp_magic(netmem, PP_SIGNATURE); - - /* Ensuring all pages have been split into one fragment initially: - * page_pool_set_pp_info() is only called once for every page when it - * is allocated from the page allocator and page_pool_fragment_page() - * is dirtying the same cache line as the page->pp_magic above, so - * the overhead is negligible. - */ - page_pool_fragment_netmem(netmem, 1); - if (pool->has_init_callback) - pool->slow.init_callback(netmem, pool->slow.init_arg); -} - -static void page_pool_clear_pp_info(netmem_ref netmem) -{ - netmem_clear_pp_magic(netmem); - netmem_set_pp(netmem, NULL); -} - static struct page *__page_pool_alloc_page_order(struct page_pool *pool, gfp_t gfp) { @@ -572,7 +585,10 @@ netmem_ref page_pool_alloc_netmem(struct page_pool *pool, gfp_t gfp) return netmem; /* Slow-path: cache empty, do real allocation */ - netmem = __page_pool_alloc_pages_slow(pool, gfp); + if (static_branch_unlikely(&page_pool_mem_providers) && pool->mp_priv) + netmem = mp_dmabuf_devmem_alloc_netmems(pool, gfp); + else + netmem = __page_pool_alloc_pages_slow(pool, gfp); return netmem; } EXPORT_SYMBOL(page_pool_alloc_netmem); @@ -608,6 +624,28 @@ s32 page_pool_inflight(const struct page_pool *pool, bool strict) return inflight; } +void page_pool_set_pp_info(struct page_pool *pool, netmem_ref netmem) +{ + netmem_set_pp(netmem, pool); + netmem_or_pp_magic(netmem, PP_SIGNATURE); + + /* Ensuring all pages have been split into one fragment initially: + * page_pool_set_pp_info() is only called once for every page when it + * is allocated from the page allocator and page_pool_fragment_page() + * is dirtying the same cache line as the page->pp_magic above, so + * the overhead is negligible. + */ + page_pool_fragment_netmem(netmem, 1); + if (pool->has_init_callback) + pool->slow.init_callback(netmem, pool->slow.init_arg); +} + +void page_pool_clear_pp_info(netmem_ref netmem) +{ + netmem_clear_pp_magic(netmem); + netmem_set_pp(netmem, NULL); +} + static __always_inline void __page_pool_release_page_dma(struct page_pool *pool, netmem_ref netmem) { @@ -636,8 +674,13 @@ static __always_inline void __page_pool_release_page_dma(struct page_pool *pool, void page_pool_return_page(struct page_pool *pool, netmem_ref netmem) { int count; + bool put; - __page_pool_release_page_dma(pool, netmem); + put = true; + if (static_branch_unlikely(&page_pool_mem_providers) && pool->mp_priv) + put = mp_dmabuf_devmem_release_page(pool, netmem); + else + __page_pool_release_page_dma(pool, netmem); /* This may be the last page returned, releasing the pool, so * it is not safe to reference pool afterwards. @@ -645,8 +688,10 @@ void page_pool_return_page(struct page_pool *pool, netmem_ref netmem) count = atomic_inc_return_relaxed(&pool->pages_state_release_cnt); trace_page_pool_state_release(pool, netmem, count); - page_pool_clear_pp_info(netmem); - put_page(netmem_to_page(netmem)); + if (put) { + page_pool_clear_pp_info(netmem); + put_page(netmem_to_page(netmem)); + } /* An optimization would be to call __free_pages(page, pool->p.order) * knowing page is not part of page-cache (thus avoiding a * __page_cache_release() call). @@ -965,6 +1010,12 @@ static void __page_pool_destroy(struct page_pool *pool) page_pool_unlist(pool); page_pool_uninit(pool); + + if (pool->mp_priv) { + mp_dmabuf_devmem_destroy(pool); + static_branch_dec(&page_pool_mem_providers); + } + kfree(pool); } diff --git a/net/core/page_pool_priv.h b/net/core/page_pool_priv.h index 581501b5cd8c..fcd9c1a227bc 100644 --- a/net/core/page_pool_priv.h +++ b/net/core/page_pool_priv.h @@ -33,4 +33,10 @@ static inline bool page_pool_set_dma_addr(struct page *page, dma_addr_t addr) return page_pool_set_dma_addr_netmem(page_to_netmem(page), addr); } +void page_pool_set_pp_info(struct page_pool *pool, netmem_ref netmem); +void page_pool_clear_pp_info(netmem_ref netmem); +int page_pool_check_memory_provider(struct net_device *dev, + struct netdev_rx_queue *rxq, + struct net_devmem_dmabuf_binding *binding); + #endif diff --git a/net/core/page_pool_user.c b/net/core/page_pool_user.c index 3a3277ba167b..cbc54ee4f670 100644 --- a/net/core/page_pool_user.c +++ b/net/core/page_pool_user.c @@ -344,6 +344,32 @@ void page_pool_unlist(struct page_pool *pool) mutex_unlock(&page_pools_lock); } +int page_pool_check_memory_provider(struct net_device *dev, + struct netdev_rx_queue *rxq, + struct net_devmem_dmabuf_binding *binding) +{ + struct netdev_rx_queue *binding_rxq; + struct page_pool *pool; + struct hlist_node *n; + unsigned long xa_idx; + + mutex_lock(&page_pools_lock); + hlist_for_each_entry_safe(pool, n, &dev->page_pools, user.list) { + if (pool->mp_priv != binding) + continue; + + xa_for_each(&binding->bound_rxqs, xa_idx, binding_rxq) { + if (rxq != binding_rxq) + continue; + + mutex_unlock(&page_pools_lock); + return 0; + } + } + mutex_unlock(&page_pools_lock); + return -ENODATA; +} + static void page_pool_unreg_netdev_wipe(struct net_device *netdev) { struct page_pool *pool;