From patchwork Wed Mar 9 16:52:15 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "T.J. Mercier" X-Patchwork-Id: 550217 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7A924C433FE for ; Wed, 9 Mar 2022 17:04:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237449AbiCIRFg (ORCPT ); Wed, 9 Mar 2022 12:05:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53834 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238954AbiCIREO (ORCPT ); Wed, 9 Mar 2022 12:04:14 -0500 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AF41C19E0B6 for ; Wed, 9 Mar 2022 08:53:01 -0800 (PST) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-2dc44b6dc9dso18781897b3.23 for ; Wed, 09 Mar 2022 08:53:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc:content-transfer-encoding; bh=V8vMjTnKNpMlnc7JqoQhhcwCYCICGfVTjA11ueJBqJY=; b=HPhBJpTBiJVYDhNj0DZQIrh2V35TDbkma5Iio+WXF/hcMekPxUMRND2g0CCX8In7eA LEUpnnJ+An6CQt91VMdWJ16FK8gQvFAyqTsa5rlG5AWdns4o+hy7+0OojxnhgPcTuenF BMnLv3wL46KC+ysjzZ76R5d/tGOpuWkWCWCPvMAfXwR0a5KK3XjpjLwL9pQFigkgD89h UfwDU4EeBZ+AuUjNHIDB5TQ3ZOrtGFi86NY5EeNgywb7PE5VH443fnkWqKIiup1Y0udy R7MVYYHFJitKmNj3Z9u+ZFiGhMd6bk7xZU88I9EiTT+qF25ldxx/Q3auo1GI4V9pSZKP UyXw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc:content-transfer-encoding; bh=V8vMjTnKNpMlnc7JqoQhhcwCYCICGfVTjA11ueJBqJY=; b=mTVQvJZdBon8jSdomMrSnfmtaEXPDikmj6Edsb2lIVU40/FSJxR1VEUDHwQkkYb+6U mu8ETPK7qKsFFlDQtKHkFV0BWHPnVv7eDNawNbdAra/fVednl7nJ9lwosWwvTlcvEGpa 221j3DZR+TzJikB5hOA7eROHvPDy9mzRoNQtGxGQrgQem0fpWSU3RsbGDpMNuvYyH/Jn xc1vJ2ZP5ZPgji7/vHJ9CrAw0t70PIXSNW2oN/gfW0O3R3EHs+2eM3txi4dmCqzFVMLy bAmziVDi34qlPsHt1hLDFFY6IVOh4NhJfjNeVYAATjEr/AfA0vZIm5hvxGFp5rdo2vii F09w== X-Gm-Message-State: AOAM531TVrfWhdc0n8e1KFNA5NCUxEyiGkv4Fuo/Gh8dWKkOtWKXvTtK abAF6M4DTkNoTLoQd9HF5kKNz1jRyDgNtIg= X-Google-Smtp-Source: ABdhPJz9YUAclnREKPfkUSw/YVlrcGlYfdaexMLMRAzjJT1CtoYDbmyjdA8pza54fHB/e3zequa24JlX1KWu3NI= X-Received: from tj2.c.googlers.com ([fda3:e722:ac3:cc00:20:ed76:c0a8:187]) (user=tjmercier job=sendgmr) by 2002:a81:38c6:0:b0:2d7:ee4f:797b with SMTP id f189-20020a8138c6000000b002d7ee4f797bmr650786ywa.14.1646844768454; Wed, 09 Mar 2022 08:52:48 -0800 (PST) Date: Wed, 9 Mar 2022 16:52:15 +0000 In-Reply-To: <20220309165222.2843651-1-tjmercier@google.com> Message-Id: <20220309165222.2843651-6-tjmercier@google.com> Mime-Version: 1.0 References: <20220309165222.2843651-1-tjmercier@google.com> X-Mailer: git-send-email 2.35.1.616.g0bdcbb4464-goog Subject: [RFC v3 5/8] dmabuf: Add gpu cgroup charge transfer function From: "T.J. Mercier" To: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , Jonathan Corbet , Greg Kroah-Hartman , " =?utf-8?q?Arve_Hj=C3=B8n?= =?utf-8?q?nev=C3=A5g?= " , Todd Kjos , Martijn Coenen , Joel Fernandes , Christian Brauner , Hridya Valsaraju , Suren Baghdasaryan , Sumit Semwal , " =?utf-8?q?Christian_K=C3=B6nig?= " , Benjamin Gaignard , Liam Mark , Laura Abbott , Brian Starkey , John Stultz , Tejun Heo , Zefan Li , Johannes Weiner , Shuah Khan Cc: kaleshsingh@google.com, Kenny.Ho@amd.com, "T.J. Mercier" , dri-devel@lists.freedesktop.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, cgroups@vger.kernel.org, linux-kselftest@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Hridya Valsaraju The dma_buf_charge_transfer function provides a way for processes to transfer charge of a buffer to a different process. This is essential for the cases where a central allocator process does allocations for various subsystems, hands over the fd to the client who requested the memory and drops all references to the allocated memory. Signed-off-by: Hridya Valsaraju Signed-off-by: T.J. Mercier --- v3 changes Use more common dual author commit message format per John Stultz. v2 changes Move dma-buf cgroup charge transfer from a dma_buf_op defined by every heap to a single dma-buf function for all heaps per Daniel Vetter and Christian König. --- drivers/dma-buf/dma-buf.c | 48 +++++++++++++++++++++++++++++++++++++++ include/linux/dma-buf.h | 2 ++ 2 files changed, 50 insertions(+) diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 83d0d1b91547..55e1b982f840 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -1374,6 +1374,54 @@ void dma_buf_vunmap(struct dma_buf *dmabuf, struct dma_buf_map *map) } EXPORT_SYMBOL_NS_GPL(dma_buf_vunmap, DMA_BUF); +/** + * dma_buf_charge_transfer - Change the GPU cgroup to which the provided dma_buf + * is charged. + * @dmabuf: [in] buffer whose charge will be migrated to a different GPU + * cgroup + * @gpucg: [in] the destination GPU cgroup for dmabuf's charge + * + * Only tasks that belong to the same cgroup the buffer is currently charged to + * may call this function, otherwise it will return -EPERM. + * + * Returns 0 on success, or a negative errno code otherwise. + */ +int dma_buf_charge_transfer(struct dma_buf *dmabuf, struct gpucg *gpucg) +{ +#ifdef CONFIG_CGROUP_GPU + struct gpucg *current_gpucg; + int ret = 0; + + /* + * Verify that the cgroup of the process requesting the transfer is the + * same as the one the buffer is currently charged to. + */ + current_gpucg = gpucg_get(current); + mutex_lock(&dmabuf->lock); + if (current_gpucg != dmabuf->gpucg) { + ret = -EPERM; + goto err; + } + + ret = gpucg_try_charge(gpucg, dmabuf->gpucg_dev, dmabuf->size); + if (ret) + goto err; + + dmabuf->gpucg = gpucg; + + /* uncharge the buffer from the cgroup it's currently charged to. */ + gpucg_uncharge(current_gpucg, dmabuf->gpucg_dev, dmabuf->size); + +err: + mutex_unlock(&dmabuf->lock); + gpucg_put(current_gpucg); + return ret; +#else + return 0; +#endif /* CONFIG_CGROUP_GPU */ +} +EXPORT_SYMBOL_NS_GPL(dma_buf_charge_transfer, DMA_BUF); + #ifdef CONFIG_DEBUG_FS static int dma_buf_debug_show(struct seq_file *s, void *unused) { diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index 742f29c3daaf..85c940c08867 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -646,4 +646,6 @@ int dma_buf_mmap(struct dma_buf *, struct vm_area_struct *, unsigned long); int dma_buf_vmap(struct dma_buf *dmabuf, struct dma_buf_map *map); void dma_buf_vunmap(struct dma_buf *dmabuf, struct dma_buf_map *map); + +int dma_buf_charge_transfer(struct dma_buf *dmabuf, struct gpucg *gpucg); #endif /* __DMA_BUF_H__ */