From patchwork Tue Jan 12 11:06:33 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Ahmed S. Darwish" X-Patchwork-Id: 12013227 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 C3E26C4321A for ; Tue, 12 Jan 2021 11:08:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 95B9E2310D for ; Tue, 12 Jan 2021 11:08:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730158AbhALLH5 (ORCPT ); Tue, 12 Jan 2021 06:07:57 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:45158 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726572AbhALLH4 (ORCPT ); Tue, 12 Jan 2021 06:07:56 -0500 From: "Ahmed S. Darwish" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1610449633; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=XwE3NWOoqRuJWC9QHIg8MEniBW1ChmIXc8KitBchGV0=; b=tiMCVFBrZjrzJTbvMk991vvpVJyDz+vwy6czBNOh0jTKoHLpYh6T6kKAIsdX87YA99UOgg WUbrrW1D1hvh/0aBjjkdohZ8P1wC2JC1OxzjJq8hXo6kiA1VdYRjBoKG88huXOS43WIyzX GqTdmFU7gq/V0XE+oQzqWqjaxaC85n7+H36FY5ngULZ1yyA1t/esh5jW5aVwAiZuXIONVw EF8L1nZ29Xw5infLKGX/7IA4uke0H8czRc+dUixbQIXAcDlM1CV//sMKbLaNJBiSPjskra QO4psFA3cpjkPNDKJOk464ixTyy8Y1zY/B5fgwrjxD0q2M43GH4EppwCtBu62w== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1610449633; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=XwE3NWOoqRuJWC9QHIg8MEniBW1ChmIXc8KitBchGV0=; b=Q3NNyfvJeAklW83HiScosADNvUA+LHsZ1rqZ0xyoOCxKcEnp+rVStG8s/RBk/STdFXNMpA wxrAwS3MhmDyK7Cw== To: "James E.J. Bottomley" , "Martin K. Petersen" , John Garry , Jason Yan , Daniel Wagner , Artur Paszkiewicz , Jack Wang Cc: linux-scsi@vger.kernel.org, intel-linux-scu@intel.com, LKML , Thomas Gleixner , "Sebastian A. Siewior" , "Ahmed S. Darwish" Subject: [PATCH v2 05/19] scsi: isci: port: link down: Pass gfp_t flags Date: Tue, 12 Jan 2021 12:06:33 +0100 Message-Id: <20210112110647.627783-6-a.darwish@linutronix.de> In-Reply-To: <20210112110647.627783-1-a.darwish@linutronix.de> References: <20210112110647.627783-1-a.darwish@linutronix.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Use the new libsas event notifiers API, which requires callers to explicitly pass the gfp_t memory allocation flags. sas_notify_phy_event() is exclusively called by isci_port_link_down(). Below is the context analysis for all of its call chains: port.c: port_timeout(), atomic, timer callback (*) spin_lock_irqsave(isci_host::scic_lock, ) -> port_state_machine_change(..., SCI_PORT_FAILED) -> enter SCI port state: *SCI_PORT_FAILED* -> sci_port_failed_state_enter() -> isci_port_hard_reset_complete() -> isci_port_link_down() port.c: isci_port_perform_hard_reset() spin_lock_irqsave(isci_host::scic_lock, ) -> port.c: sci_port_hard_reset(), atomic (*) -> phy.c: sci_phy_reset() -> sci_change_state(SCI_PHY_RESETTING) -> enter SCI PHY state: *SCI_PHY_RESETTING* -> sci_phy_resetting_state_enter() -> port.c: sci_port_deactivate_phy() -> isci_port_link_down() port.c: enter SCI port state: *SCI_PORT_READY* # Cont. from [1] -> sci_port_ready_state_enter() -> isci_port_hard_reset_complete() -> isci_port_link_down() phy.c: enter SCI state: *SCI_PHY_STOPPED* # Cont. from [2] -> sci_phy_stopped_state_enter() -> host.c: sci_controller_link_down() -> ->link_down_handler() == port_config.c: sci_apc_agent_link_down() -> port.c: sci_port_remove_phy() -> sci_port_deactivate_phy() -> isci_port_link_down() == port_config.c: sci_mpc_agent_link_down() -> port.c: sci_port_link_down() -> sci_port_deactivate_phy() -> isci_port_link_down() phy.c: enter SCI state: *SCI_PHY_STARTING* # Cont. from [3] -> sci_phy_starting_state_enter() -> host.c: sci_controller_link_down() -> ->link_down_handler() == port_config.c: sci_apc_agent_link_down() -> port.c: sci_port_remove_phy() -> isci_port_link_down() == port_config.c: sci_mpc_agent_link_down() -> port.c: sci_port_link_down() -> sci_port_deactivate_phy() -> isci_port_link_down() [1] Call chains for 'enter SCI port state: *SCI_PORT_READY*' ------------------------------------------------------------ host.c: isci_host_init() (@) spin_lock_irq(isci_host::scic_lock) -> sci_controller_initialize(), atomic (*) -> port_config.c: sci_port_configuration_agent_initialize() -> sci_mpc_agent_validate_phy_configuration() -> port.c: sci_port_add_phy() -> sci_port_general_link_up_handler() -> port_state_machine_change(, SCI_PORT_READY) -> enter port state *SCI_PORT_READY* host.c: isci_host_start() (@) spin_lock_irq(isci_host::scic_lock) -> host.c: sci_controller_start(), atomic (*) -> host.c: sci_port_start() -> port.c: port_state_machine_change(, SCI_PORT_READY) -> enter port state *SCI_PORT_READY* port_config.c: apc_agent_timeout(), atomic, timer callback (*) -> sci_apc_agent_configure_ports() -> port.c: sci_port_add_phy() -> sci_port_general_link_up_handler() -> port_state_machine_change(, SCI_PORT_READY) -> enter port state *SCI_PORT_READY* port_config.c: mpc_agent_timeout(), atomic, timer callback (*) spin_lock_irqsave(isci_host::scic_lock, ) -> ->link_up_handler() == port.c: sci_apc_agent_link_up() -> sci_port_general_link_up_handler() -> port_state_machine_change(, SCI_PORT_READY) -> enter port state *SCI_PORT_READY* == port.c: sci_mpc_agent_link_up() -> port.c: sci_port_link_up() -> sci_port_general_link_up_handler() -> port_state_machine_change(, SCI_PORT_READY) -> enter port state *SCI_PORT_READY* phy.c: enter SCI state: SCI_PHY_SUB_FINAL # Cont. from [1A] -> sci_phy_starting_final_substate_enter() -> sci_change_state(SCI_PHY_READY) -> enter SCI state: *SCI_PHY_READY* -> sci_phy_ready_state_enter() -> host.c: sci_controller_link_up() -> port_agent.link_up_handler() == port_config.c: sci_apc_agent_link_up() -> port.c: sci_port_link_up() -> sci_port_general_link_up_handler() -> port_state_machine_change(, SCI_PORT_READY) -> enter port state *SCI_PORT_READY* == port_config.c: sci_mpc_agent_link_up() -> port.c: sci_port_link_up() -> sci_port_general_link_up_handler() -> port_state_machine_change(, SCI_PORT_READY) -> enter port state *SCI_PORT_READY* [1A] Call chains for entering SCI state: *SCI_PHY_SUB_FINAL* ------------------------------------------------------------ host.c: power_control_timeout(), atomic, timer callback (*) spin_lock_irqsave(isci_host::scic_lock, ) -> phy.c: sci_phy_consume_power_handler() -> phy.c: sci_change_state(SCI_PHY_SUB_FINAL) host.c: sci_controller_error_handler(): atomic, irq handler (*) OR host.c: sci_controller_completion_handler(), atomic, tasklet (*) -> sci_controller_process_completions() -> sci_controller_unsolicited_frame() -> phy.c: sci_phy_frame_handler() -> sci_change_state(SCI_PHY_SUB_AWAIT_SAS_POWER) -> sci_phy_starting_await_sas_power_substate_enter() -> host.c: sci_controller_power_control_queue_insert() -> phy.c: sci_phy_consume_power_handler() -> sci_change_state(SCI_PHY_SUB_FINAL) -> sci_change_state(SCI_PHY_SUB_FINAL) -> sci_controller_event_completion() -> phy.c: sci_phy_event_handler() -> sci_phy_start_sata_link_training() -> sci_change_state(SCI_PHY_SUB_AWAIT_SATA_POWER) -> sci_phy_starting_await_sata_power_substate_enter -> host.c: sci_controller_power_control_queue_insert() -> phy.c: sci_phy_consume_power_handler() -> sci_change_state(SCI_PHY_SUB_FINAL) [2] Call chains for entering state: *SCI_PHY_STOPPED* ----------------------------------------------------- host.c: isci_host_init() (@) spin_lock_irq(isci_host::scic_lock) -> sci_controller_initialize(), atomic (*) -> phy.c: sci_phy_initialize() -> phy.c: sci_phy_link_layer_initialization() -> phy.c: sci_change_state(SCI_PHY_STOPPED) init.c: PCI ->remove() || PM_OPS ->suspend, process context (+) -> host.c: isci_host_deinit() -> sci_controller_stop_phys() -> phy.c: sci_phy_stop() -> sci_change_state(SCI_PHY_STOPPED) phy.c: isci_phy_control() spin_lock_irqsave(isci_host::scic_lock, ) -> sci_phy_stop(), atomic (*) -> sci_change_state(SCI_PHY_STOPPED) [3] Call chains for entering state: *SCI_PHY_STARTING* ------------------------------------------------------ phy.c: phy_sata_timeout(), atimer, timer callback (*) spin_lock_irqsave(isci_host::scic_lock, ) -> sci_change_state(SCI_PHY_STARTING) host.c: phy_startup_timeout(), atomic, timer callback (*) spin_lock_irqsave(isci_host::scic_lock, ) -> sci_controller_start_next_phy() -> sci_phy_start() -> sci_change_state(SCI_PHY_STARTING) host.c: isci_host_start() (@) spin_lock_irq(isci_host::scic_lock) -> sci_controller_start(), atomic (*) -> sci_controller_start_next_phy() -> sci_phy_start() -> sci_change_state(SCI_PHY_STARTING) phy.c: Enter SCI state *SCI_PHY_SUB_FINAL*, atomic, check above (*) -> sci_change_state(SCI_PHY_SUB_FINAL) -> sci_phy_starting_final_substate_enter() -> sci_change_state(SCI_PHY_READY) -> Enter SCI state: *SCI_PHY_READY* -> sci_phy_ready_state_enter() -> host.c: sci_controller_link_up() -> sci_controller_start_next_phy() -> sci_phy_start() -> sci_change_state(SCI_PHY_STARTING) phy.c: sci_phy_event_handler(), atomic, discussed earlier (*) -> sci_change_state(SCI_PHY_STARTING), 11 instances phy.c: enter SCI state: *SCI_PHY_RESETTING*, atomic, discussed (*) -> sci_phy_resetting_state_enter() -> sci_change_state(SCI_PHY_STARTING) As can be seen from the "(*)" markers above, almost all the call-chains are atomic. The only exception, marked with "(+)", is a PCI ->remove() and PM_OPS ->suspend() cold path. Thus, pass GFP_ATOMIC to the libsas phy event notifier. Note, The now-replaced libsas APIs used in_interrupt() to implicitly decide which memory allocation type to use. This was only partially correct, as it fails to choose the correct GFP flags when just preemption or interrupts are disabled. Such buggy code paths are marked with "(@)" in the call chains above. Fixes: 1c393b970e0f ("scsi: libsas: Use dynamic alloced work to avoid sas event lost") Signed-off-by: Ahmed S. Darwish Cc: Artur Paszkiewicz --- drivers/scsi/isci/port.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/isci/port.c b/drivers/scsi/isci/port.c index 8d9349738067..a3c58718c260 100644 --- a/drivers/scsi/isci/port.c +++ b/drivers/scsi/isci/port.c @@ -269,8 +269,8 @@ static void isci_port_link_down(struct isci_host *isci_host, * isci_port_deformed and isci_dev_gone functions. */ sas_phy_disconnected(&isci_phy->sas_phy); - sas_notify_phy_event(&isci_phy->sas_phy, - PHYE_LOSS_OF_SIGNAL); + sas_notify_phy_event_gfp(&isci_phy->sas_phy, + PHYE_LOSS_OF_SIGNAL, GFP_ATOMIC); dev_dbg(&isci_host->pdev->dev, "%s: isci_port = %p - Done\n", __func__, isci_port);