From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 2569A200AE for ; Thu, 12 Oct 2023 17:03:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ugzDwh8U" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 88563C433C7; Thu, 12 Oct 2023 17:03:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1697130222; bh=0Y/nIS+JSufroA30qp7iEka7S/VoswZPUe/5whv+S3M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ugzDwh8UUd/SXCo8wFfUD+OMyGlcRDMe82MzPWysUll2SGi5R7puljV7H93tXFNn0 ZN0tJj/Cm9qN/tL6GbHNu6bDfI4+Zd0Vwa0YWQdR786Nm013b2V65UqQTt9WTY3zpi +cTFDiSDEScsWBm+/T/jKc6/FF/clAmV4G2Onantzp6QJTfOtkvNPJOC+ukic4DqUU RupLY7vi0DVOq7AEhHc8NCt49w+T+qN7UVSoAe8NaZsewKE3Pvo3bapANUBgDU+/sj yfH8fNe1tqopDy0TbIs8VKKoC2hghPtzM+ezxjqYuK8BZrZJHXKuakdrzbzFwNkdZ/ nBdKX8Er+L0qQ== Date: Thu, 12 Oct 2023 10:03:41 -0700 From: Saeed Mahameed To: Niklas Schnelle Cc: "David S. Miller" , Jakub Kicinski , Paolo Abeni , Eric Dumazet , Saeed Mahameed , netdev@vger.kernel.org, Tariq Toukan , Shay Drory , Moshe Shemesh , Leon Romanovsky Subject: Re: [RFC PATCH net] net/mlx5: Perform DMA operations cleanup before pci_disable_device() Message-ID: References: <20231011184511.19818-1-saeed@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: On 12 Oct 13:51, Niklas Schnelle wrote: >On Wed, 2023-10-11 at 11:45 -0700, Saeed Mahameed wrote: >> From: Shay Drory >> >> The cited patch change mlx5 driver so that during probe, DMA >> operations were performed before pci_enable_device() and during >> teardown, DMA operations were performed after pci_disable_device(). >> DMA operations require PCI to be enabled. Hence, The above leads to >> the following oops in PPC systems[2]. >> >> Fix it by performing the DMA operations during probe, after >> pci_enable_device() and during teardown, before pci_disable_device(). >> >> This also fixes a problem reported by Niklas Schnelle [1] >> >> [1] https://lore.kernel.org/lkml/20231011-mlx5_init_fix-v3-1-787ffb9183c6@linux.ibm.com/ >> >> [2] >> Oops: Kernel access of bad area, sig: 11 [#1] >> LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries >> Modules linked in: xt_MASQUERADE nf_conntrack_netlink >> nfnetlink xfrm_user iptable_nat xt_addrtype xt_conntrack nf_nat >> nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 netconsole rpcsec_gss_krb5 >> auth_rpcgss oid_registry overlay rpcrdma rdma_ucm ib_iser ib_umad >> rdma_cm ib_ipoib iw_cm libiscsi scsi_transport_iscsi ib_cm ib_uverbs >> ib_core mlx5_core(-) ptp pps_core fuse vmx_crypto crc32c_vpmsum [last >> unloaded: mlx5_ib] >> CPU: 1 PID: 8937 Comm: modprobe Not tainted 6.5.0-rc3_for_upstream_min_debug_2023_07_31_16_02 #1 >> Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries >> NIP: c000000000423388 LR: c0000000001e733c CTR: c0000000001e4720 >> REGS: c0000000055636d0 TRAP: 0380 Not tainted (6.5.0-rc3_for_upstream_min_debug_2023_07_31_16_02) >> MSR: 8000000000009033 CR: 24008884 XER: 20040000 >> CFAR: c0000000001e7338 IRQMASK: 0 >> NIP [c000000000423388] __free_pages+0x28/0x160 >> LR [c0000000001e733c] dma_direct_free+0xac/0x190 >> Call Trace: >> [c000000005563970] [5deadbeef0000100] 0x5deadbeef0000100 (unreliable) >> [c0000000055639b0] [c0000000003d46cc] kfree+0x7c/0x150 >> [c000000005563a40] [c0000000001e47c8] dma_free_attrs+0xa8/0x1a0 >> [c000000005563aa0] [c008000000d0064c] mlx5_cmd_cleanup+0xa4/0x100 [mlx5_core] >> [c000000005563ad0] [c008000000cf629c] mlx5_mdev_uninit+0xf4/0x140 [mlx5_core] >> [c000000005563b00] [c008000000cf6448] remove_one+0x160/0x1d0 [mlx5_core] >> [c000000005563b40] [c000000000958540] pci_device_remove+0x60/0x110 >> [c000000005563b80] [c000000000a35e80] device_remove+0x70/0xd0 >> [c000000005563bb0] [c000000000a37a38] device_release_driver_internal+0x2a8/0x330 >> [c000000005563c00] [c000000000a37b8c] driver_detach+0x8c/0x160 >> [c000000005563c40] [c000000000a35350] bus_remove_driver+0x90/0x110 >> [c000000005563c80] [c000000000a38948] driver_unregister+0x48/0x90 >> [c000000005563cf0] [c000000000957e38] pci_unregister_driver+0x38/0x150 >> [c000000005563d40] [c008000000eb6140] mlx5_cleanup+0x38/0x90 [mlx5_core] >> >> Fixes: 06cd555f73ca ("net/mlx5: split mlx5_cmd_init() to probe and reload routines") >> Signed-off-by: Shay Drory >> Reviewed-by: Moshe Shemesh >> Reviewed-by: Tariq Toukan >> Signed-off-by: Saeed Mahameed >> CC: Leon Romanovsky >> CC: Niklas Schnelle >> >> --- >> drivers/net/ethernet/mellanox/mlx5/core/cmd.c | 62 ++++++++----------- >> 1 file changed, 27 insertions(+), 35 deletions(-) > > >I can confirm that this indeed fixes the problem I was seeing. I also >tested hot unplug and re-plug as well as some smoke tests with the >devices at hand across multiple ConnectX generations. >So feel free to add my: > >Tested-by: Niklas Schnelle > >> >> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c >> index afb348579577..dd36d9cba62f 100644 >> --- a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c >> +++ b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c >> @@ -2186,52 +2186,23 @@ static u16 cmdif_rev(struct mlx5_core_dev *dev) >> >> int mlx5_cmd_init(struct mlx5_core_dev *dev) >> { >> - int size = sizeof(struct mlx5_cmd_prot_block); >> - int align = roundup_pow_of_two(size); >> struct mlx5_cmd *cmd = &dev->cmd; >> - u32 cmd_l; >> - int err; >> - >> - cmd->pool = dma_pool_create("mlx5_cmd", mlx5_core_dma_dev(dev), size, align, 0); >> - if (!cmd->pool) >> - return -ENOMEM; >> >> - err = alloc_cmd_page(dev, cmd); >> - if (err) >> - goto err_free_pool; >> - >> - cmd_l = (u32)(cmd->dma); >> - if (cmd_l & 0xfff) { >> - mlx5_core_err(dev, "invalid command queue address\n"); >> - err = -ENOMEM; >> - goto err_cmd_page; >> - } >> cmd->checksum_disabled = 1; >> >> spin_lock_init(&cmd->alloc_lock); >> spin_lock_init(&cmd->token_lock); >> >> - create_msg_cache(dev); >> - >> set_wqname(dev); >> cmd->wq = create_singlethread_workqueue(cmd->wq_name); >> if (!cmd->wq) { >> mlx5_core_err(dev, "failed to create command workqueue\n"); >> - err = -ENOMEM; >> - goto err_cache; >> + return -ENOMEM; >> } >> >> mlx5_cmdif_debugfs_init(dev); >> >> return 0; >> - >> -err_cache: >> - destroy_msg_cache(dev); >> -err_cmd_page: >> - free_cmd_page(dev, cmd); >> -err_free_pool: >> - dma_pool_destroy(cmd->pool); >> - return err; >> } > >I like that this leaves mlx5_cmd_init() simpler. > >> >> void mlx5_cmd_cleanup(struct mlx5_core_dev *dev) >> @@ -2240,15 +2211,15 @@ void mlx5_cmd_cleanup(struct mlx5_core_dev *dev) >> >> mlx5_cmdif_debugfs_cleanup(dev); >> destroy_workqueue(cmd->wq); >> - destroy_msg_cache(dev); >> - free_cmd_page(dev, cmd); >> - dma_pool_destroy(cmd->pool); >> } >> >> int mlx5_cmd_enable(struct mlx5_core_dev *dev) >> { >> + int size = sizeof(struct mlx5_cmd_prot_block); >> + int align = roundup_pow_of_two(size); >> struct mlx5_cmd *cmd = &dev->cmd; >> u32 cmd_h, cmd_l; >> + int err; >> >> memset(&cmd->vars, 0, sizeof(cmd->vars)); >> cmd->vars.cmdif_rev = cmdif_rev(dev); >> @@ -2281,10 +2252,21 @@ int mlx5_cmd_enable(struct mlx5_core_dev *dev) >> sema_init(&cmd->vars.pages_sem, 1); >> sema_init(&cmd->vars.throttle_sem, DIV_ROUND_UP(cmd->vars.max_reg_cmds, 2)); >> >> + cmd->pool = dma_pool_create("mlx5_cmd", mlx5_core_dma_dev(dev), size, align, 0); >> + if (!cmd->pool) >> + return -ENOMEM; >> + >> + err = alloc_cmd_page(dev, cmd); >> + if (err) >> + goto err_free_pool; >> + >> cmd_h = (u32)((u64)(cmd->dma) >> 32); >> cmd_l = (u32)(cmd->dma); >> - if (WARN_ON(cmd_l & 0xfff)) >> - return -EINVAL; >> + if (cmd_l & 0xfff) { >> + mlx5_core_err(dev, "invalid command queue address\n"); >> + err = -ENOMEM; >> + goto err_cmd_page; >> + } >> >> iowrite32be(cmd_h, &dev->iseg->cmdq_addr_h); >> iowrite32be(cmd_l, &dev->iseg->cmdq_addr_l_sz); >> @@ -2297,16 +2279,26 @@ int mlx5_cmd_enable(struct mlx5_core_dev *dev) >> cmd->mode = CMD_MODE_POLLING; >> cmd->allowed_opcode = CMD_ALLOWED_OPCODE_ALL; >> >> + create_msg_cache(dev); >> create_debugfs_files(dev); >> >> return 0; >> + >> +err_cmd_page: >> + free_cmd_page(dev, cmd); >> +err_free_pool: >> + dma_pool_destroy(cmd->pool); >> + return err; >> } >> >> void mlx5_cmd_disable(struct mlx5_core_dev *dev) >> { >> struct mlx5_cmd *cmd = &dev->cmd; >> >> + destroy_msg_cache(dev); >> clean_debug_files(dev); >> + free_cmd_page(dev, cmd); >> + dma_pool_destroy(cmd->pool); >> flush_workqueue(cmd->wq); >> } > >I do like that this tears down the DMA stuff before >pci_disable_device() I don't think this fixes a problem on s390x but to >me it's the more natural order. That said, are we sure that the >flush_workqueue() won't still need DMA and cmd page? > Agreed, tt is safer to flush_workqueue first thing in the function. >> >> -- >> 2.41.0 >> >