From patchwork Mon Nov 6 02:44:05 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mina Almasry X-Patchwork-Id: 13446222 X-Patchwork-Delegate: kuba@kernel.org Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DA3881843 for ; Mon, 6 Nov 2023 02:44:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="kPU0CZN9" Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D34541BF for ; Sun, 5 Nov 2023 18:44:32 -0800 (PST) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-5af9ad9341fso55030187b3.2 for ; Sun, 05 Nov 2023 18:44:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1699238672; x=1699843472; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=9xKJa4I8M00nBYKJxGW44sf+c8CRhaACyIJxG3DJfPA=; b=kPU0CZN9YttlE3LT7KY9sbebcPDKJagb8NoBLKYEmq1Q8hcYA7FwdNfhmolbqz6x90 OFKb+ubxZ0h0pVp5SQKigLP0EZB1fv6Uvcdt6b1bR39oH1/5VhOp5oUKJBz9KgYHPbDq mZsz6oTSAkvgH1+JZYgRx/aQxrZhxqWVK1H472uG8gAP4Ev1v5c6u/GgWaBZ/XO82G+e +DVausM/OLLfTmAI2Ia/8L6sWmeWzOhH7Tnq07ZZAjCZWzHNSxnOPUUZh9nUXHm7FG8B R5AHvHMgv3W1zOE92a/unhROT17QDEJ6AwBvY9jTvyCfSJUzbe3cMhiNf5Ul76RIIE/h Lp9w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699238672; x=1699843472; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=9xKJa4I8M00nBYKJxGW44sf+c8CRhaACyIJxG3DJfPA=; b=LLFd9WFo60iT0WeEDl7fLd+mZ9uuTu5zLhHo9ZAl0MxHEnrMTeqQrommmaYqIcwnA0 TzhFjoDeGfdzXaLCE39yG7lFyDv81HUn7FNBq0lHMT+kroI1Ct2l/FNM+o/9hHpAHac8 cqSDp7QZM0WxjW+NF7mZKnwwvO3y3a1XChTpE4FBF2dMb+r4QEKIc5yISIKsjh8BVmmX MkQ9hlIHylWz4Q/nyM/i73XEsqaNdl7HV+LsQ15Gx+8S5IEsE5XTBJDxVFlLqOxBzII7 U2maABbZjIrUmiQYsJMI03HHCkceITJyBpjJheZUHj1Z40hSiDxKjRaNQMW46/K/TpJr lllQ== X-Gm-Message-State: AOJu0Yw8d5X7elBOeRsO9/Z1fJt4uoTZp+zC069uiV6+pAEET2XPajdx 2eGGYhy/nnWrhzgbkWNg+Eky01qjm0d7d2KAtDRFolZ7vVchrLQyQn2tl/t72i/aCV/949YJ8hz IzsoaPkiYPfMaXANy6rBDOfj9XNAtiLOragdCVUXRyjISoxadHXnEvtZuiCJjU/izBiv005ZpG7 8= X-Google-Smtp-Source: AGHT+IHQZek7gksg2/4l9r8mKorM1hefc52r/xXnPMd1/CJoSrUbDmmvNsfJ2kDrXMdiPilQpsmvFoDWEPDC3BTnqw== X-Received: from almasrymina.svl.corp.google.com ([2620:15c:2c4:200:35de:fff:97b7:db3e]) (user=almasrymina job=sendgmr) by 2002:a81:914a:0:b0:5a8:2fb9:aeab with SMTP id i71-20020a81914a000000b005a82fb9aeabmr164143ywg.3.1699238671757; Sun, 05 Nov 2023 18:44:31 -0800 (PST) Date: Sun, 5 Nov 2023 18:44:05 -0800 In-Reply-To: <20231106024413.2801438-1-almasrymina@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20231106024413.2801438-1-almasrymina@google.com> X-Mailer: git-send-email 2.42.0.869.gea05f2083d-goog Message-ID: <20231106024413.2801438-7-almasrymina@google.com> Subject: [RFC PATCH v3 06/12] memory-provider: dmabuf devmem memory provider From: Mina Almasry To: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org Cc: Mina Almasry , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Jesper Dangaard Brouer , Ilias Apalodimas , Arnd Bergmann , David Ahern , Willem de Bruijn , Shuah Khan , Sumit Semwal , " =?utf-8?q?Christian_K=C3=B6nig?= " , Shakeel Butt , Jeroen de Borst , Praveen Kaligineedi , Willem de Bruijn , Kaiyuan Zhang X-Patchwork-Delegate: kuba@kernel.org X-Patchwork-State: RFC Implement a memory provider that allocates dmabuf devmem page_pool_iovs. Support of PP_FLAG_DMA_MAP and PP_FLAG_DMA_SYNC_DEV is omitted for simplicity. 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 page_pool_params. 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. Signed-off-by: Willem de Bruijn Signed-off-by: Kaiyuan Zhang Signed-off-by: Mina Almasry --- include/net/page_pool/helpers.h | 40 +++++++++++++++++ include/net/page_pool/types.h | 10 +++++ net/core/page_pool.c | 76 +++++++++++++++++++++++++++++++++ 3 files changed, 126 insertions(+) diff --git a/include/net/page_pool/helpers.h b/include/net/page_pool/helpers.h index 78cbb040af94..b93243c2a640 100644 --- a/include/net/page_pool/helpers.h +++ b/include/net/page_pool/helpers.h @@ -53,6 +53,7 @@ #define _NET_PAGE_POOL_HELPERS_H #include +#include #ifdef CONFIG_PAGE_POOL_STATS int page_pool_ethtool_stats_get_count(void); @@ -111,6 +112,45 @@ page_pool_iov_binding(const struct page_pool_iov *ppiov) return page_pool_iov_owner(ppiov)->binding; } +static inline int page_pool_iov_refcount(const struct page_pool_iov *ppiov) +{ + return refcount_read(&ppiov->refcount); +} + +static inline void page_pool_iov_get_many(struct page_pool_iov *ppiov, + unsigned int count) +{ + refcount_add(count, &ppiov->refcount); +} + +void __page_pool_iov_free(struct page_pool_iov *ppiov); + +static inline void page_pool_iov_put_many(struct page_pool_iov *ppiov, + unsigned int count) +{ + if (!refcount_sub_and_test(count, &ppiov->refcount)) + return; + + __page_pool_iov_free(ppiov); +} + +/* page pool mm helpers */ + +static inline bool page_is_page_pool_iov(const struct page *page) +{ + return (unsigned long)page & PP_DEVMEM; +} + +static inline struct page_pool_iov *page_to_page_pool_iov(struct page *page) +{ + if (page_is_page_pool_iov(page)) + return (struct page_pool_iov *)((unsigned long)page & + ~PP_DEVMEM); + + DEBUG_NET_WARN_ON_ONCE(true); + return NULL; +} + /** * page_pool_dev_alloc_pages() - allocate a page. * @pool: pool from which to allocate diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h index 64386325d965..1e67f9466250 100644 --- a/include/net/page_pool/types.h +++ b/include/net/page_pool/types.h @@ -124,6 +124,7 @@ struct mem_provider; enum pp_memory_provider_type { __PP_MP_NONE, /* Use system allocator directly */ + PP_MP_DMABUF_DEVMEM, /* dmabuf devmem provider */ }; struct pp_memory_provider_ops { @@ -133,8 +134,15 @@ struct pp_memory_provider_ops { bool (*release_page)(struct page_pool *pool, struct page *page); }; +extern const struct pp_memory_provider_ops dmabuf_devmem_ops; + /* page_pool_iov support */ +/* We overload the LSB of the struct page pointer to indicate whether it's + * a page or page_pool_iov. + */ +#define PP_DEVMEM 0x01UL + /* Owner of the dma-buf chunks inserted into the gen pool. Each scatterlist * entry from the dmabuf is inserted into the genpool as a chunk, and needs * this owner struct to keep track of some metadata necessary to create @@ -158,6 +166,8 @@ struct page_pool_iov { struct dmabuf_genpool_chunk_owner *owner; refcount_t refcount; + + struct page_pool *pp; }; struct page_pool { diff --git a/net/core/page_pool.c b/net/core/page_pool.c index 7ea1f4682479..138ddea0b28f 100644 --- a/net/core/page_pool.c +++ b/net/core/page_pool.c @@ -20,6 +20,7 @@ #include #include #include +#include #include @@ -231,6 +232,9 @@ static int page_pool_init(struct page_pool *pool, switch (pool->p.memory_provider) { case __PP_MP_NONE: break; + case PP_MP_DMABUF_DEVMEM: + pool->mp_ops = &dmabuf_devmem_ops; + break; default: err = -EINVAL; goto free_ptr_ring; @@ -996,3 +1000,75 @@ void page_pool_update_nid(struct page_pool *pool, int new_nid) } } EXPORT_SYMBOL(page_pool_update_nid); + +void __page_pool_iov_free(struct page_pool_iov *ppiov) +{ + if (ppiov->pp->mp_ops != &dmabuf_devmem_ops) + return; + + netdev_free_devmem(ppiov); +} +EXPORT_SYMBOL_GPL(__page_pool_iov_free); + +/*** "Dmabuf devmem memory provider" ***/ + +static int mp_dmabuf_devmem_init(struct page_pool *pool) +{ + struct netdev_dmabuf_binding *binding = pool->mp_priv; + + if (!binding) + return -EINVAL; + + if (pool->p.flags & PP_FLAG_DMA_MAP || + pool->p.flags & PP_FLAG_DMA_SYNC_DEV) + return -EOPNOTSUPP; + + netdev_devmem_binding_get(binding); + return 0; +} + +static struct page *mp_dmabuf_devmem_alloc_pages(struct page_pool *pool, + gfp_t gfp) +{ + struct netdev_dmabuf_binding *binding = pool->mp_priv; + struct page_pool_iov *ppiov; + + ppiov = netdev_alloc_devmem(binding); + if (!ppiov) + return NULL; + + ppiov->pp = pool; + pool->pages_state_hold_cnt++; + trace_page_pool_state_hold(pool, (struct page *)ppiov, + pool->pages_state_hold_cnt); + return (struct page *)((unsigned long)ppiov | PP_DEVMEM); +} + +static void mp_dmabuf_devmem_destroy(struct page_pool *pool) +{ + struct netdev_dmabuf_binding *binding = pool->mp_priv; + + netdev_devmem_binding_put(binding); +} + +static bool mp_dmabuf_devmem_release_page(struct page_pool *pool, + struct page *page) +{ + struct page_pool_iov *ppiov; + + if (WARN_ON_ONCE(!page_is_page_pool_iov(page))) + return false; + + ppiov = page_to_page_pool_iov(page); + page_pool_iov_put_many(ppiov, 1); + /* We don't want the page pool put_page()ing our page_pool_iovs. */ + return false; +} + +const struct pp_memory_provider_ops dmabuf_devmem_ops = { + .init = mp_dmabuf_devmem_init, + .destroy = mp_dmabuf_devmem_destroy, + .alloc_pages = mp_dmabuf_devmem_alloc_pages, + .release_page = mp_dmabuf_devmem_release_page, +}; +EXPORT_SYMBOL(dmabuf_devmem_ops);