From patchwork Wed Sep 22 10:38:54 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leon Romanovsky X-Patchwork-Id: 12510149 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-20.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EAA92C433F5 for ; Wed, 22 Sep 2021 10:39:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CA36B61351 for ; Wed, 22 Sep 2021 10:39:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235149AbhIVKk5 (ORCPT ); Wed, 22 Sep 2021 06:40:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:48978 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235122AbhIVKkp (ORCPT ); Wed, 22 Sep 2021 06:40:45 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8BAD861267; Wed, 22 Sep 2021 10:39:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1632307155; bh=1qzyHXULrGHTwODUKDiWXKGr1uQ4+mGgIlC+7I0WkZo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dtgZQCZ1fSQg9R/3fhVf72zdgoHr/LyJzOvOjgYivRPWggxSsxp1SZfmTDdXXzvY2 Wqqnf/nHCGoJRzYKFQAmaGJOn8cY8U4Z0qMuXcdO+YRXwl4mMT+AWGnqk/3id8mT70 UFcdTPRcaFqAeBUAa/4a+g5Gdf67eerRwN0AVTYwzHFHfNsETNbjBwtVSg6K3NSFEc MvytLUBiggfx1/WbmiAdS3ZLSpII4T6V4b7oZVng1sijHi5qG9/dlpZMiqcALe4nis kbQXr4xdJUKjsGRxC2sCbACYhQRuoPCGjDHReq1iYSuYAaBXf2gYej9U6mLE/BjmAo m5G4izsSg7MgA== From: Leon Romanovsky To: Doug Ledford , Jason Gunthorpe Cc: Yishai Hadas , Alex Williamson , Bjorn Helgaas , Jakub Kicinski , Kirti Wankhede , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-rdma@vger.kernel.org, netdev@vger.kernel.org, Saeed Mahameed Subject: [PATCH mlx5-next 5/7] net/mlx5: Expose APIs to get/put the mlx5 core device Date: Wed, 22 Sep 2021 13:38:54 +0300 Message-Id: <25d023ef23ef78fcf9b99bf428244149e1f78e95.1632305919.git.leonro@nvidia.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Yishai Hadas Expose an API to get the mlx5 core device from a given PCI device if mlx5_core is its driver. Upon the get API we stay with the intf_state_mutex locked to make sure that the device can't be gone/unloaded till the caller will complete its job over the device, this expects to be for a short period of time for any flow that the lock is taken. Upon the put API we unlock the intf_state_mutex. The use case for those APIs is the migration flow of a VF over VFIO PCI. In that case the VF doesn't ride on mlx5_core, because the device is driving *two* different PCI devices, the PF owned by mlx5_core and the VF owned by the vfio driver. The mlx5_core of the PF is accessed only during the narrow window of the VF's ioctl that requires its services. This allows the PF driver to be more independent of the VF driver, so long as it doesn't reset the FW. Signed-off-by: Yishai Hadas Signed-off-by: Leon Romanovsky --- .../net/ethernet/mellanox/mlx5/core/main.c | 43 +++++++++++++++++++ include/linux/mlx5/driver.h | 3 ++ 2 files changed, 46 insertions(+) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/main.c b/drivers/net/ethernet/mellanox/mlx5/core/main.c index 79482824c64f..fcc8b7830421 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/main.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/main.c @@ -1795,6 +1795,49 @@ static struct pci_driver mlx5_core_driver = { .sriov_set_msix_vec_count = mlx5_core_sriov_set_msix_vec_count, }; +/** + * mlx5_get_core_dev - Get the mlx5 core device from a given PCI device if + * mlx5_core is its driver. + * @pdev: The associated PCI device. + * + * Upon return the interface state lock stay held to let caller uses it safely. + * Caller must ensure to use the returned mlx5 device for a narrow window + * and put it back with mlx5_put_core_dev() immediately once usage was over. + * + * Return: Pointer to the associated mlx5_core_dev or NULL. + */ +struct mlx5_core_dev *mlx5_get_core_dev(struct pci_dev *pdev) + __acquires(&mdev->intf_state_mutex) +{ + struct mlx5_core_dev *mdev; + + device_lock(&pdev->dev); + if (pdev->driver != &mlx5_core_driver) { + device_unlock(&pdev->dev); + return NULL; + } + + mdev = pci_get_drvdata(pdev); + mutex_lock(&mdev->intf_state_mutex); + device_unlock(&pdev->dev); + + return mdev; +} +EXPORT_SYMBOL(mlx5_get_core_dev); + +/** + * mlx5_put_core_dev - Put the mlx5 core device back. + * @mdev: The mlx5 core device. + * + * Upon return the interface state lock is unlocked and caller should not + * access the mdev any more. + */ +void mlx5_put_core_dev(struct mlx5_core_dev *mdev) +{ + mutex_unlock(&mdev->intf_state_mutex); +} +EXPORT_SYMBOL(mlx5_put_core_dev); + static void mlx5_core_verify_params(void) { if (prof_sel >= ARRAY_SIZE(profile)) { diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h index 1b8bae246b28..e9a96904d6f1 100644 --- a/include/linux/mlx5/driver.h +++ b/include/linux/mlx5/driver.h @@ -1156,6 +1156,9 @@ int mlx5_dm_sw_icm_alloc(struct mlx5_core_dev *dev, enum mlx5_sw_icm_type type, int mlx5_dm_sw_icm_dealloc(struct mlx5_core_dev *dev, enum mlx5_sw_icm_type type, u64 length, u16 uid, phys_addr_t addr, u32 obj_id); +struct mlx5_core_dev *mlx5_get_core_dev(struct pci_dev *pdev); +void mlx5_put_core_dev(struct mlx5_core_dev *mdev); + #ifdef CONFIG_MLX5_CORE_IPOIB struct net_device *mlx5_rdma_netdev_alloc(struct mlx5_core_dev *mdev, struct ib_device *ibdev,