From patchwork Mon Jan 18 10:09:41 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: 12028303 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,URIBL_BLOCKED autolearn=ham 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 51389C433DB for ; Mon, 18 Jan 2021 21:27:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 12FBF22D6F for ; Mon, 18 Jan 2021 21:27:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2394655AbhARV1B (ORCPT ); Mon, 18 Jan 2021 16:27:01 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:54966 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389621AbhARKLL (ORCPT ); Mon, 18 Jan 2021 05:11:11 -0500 From: "Ahmed S. Darwish" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1610964625; 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=SqeRulDhHNHgL6fy8LbaFwThp5hQYIRRAVQEh8ugmNg=; b=ntnlxHd7IuHcgbEk0ZOKpUm9vd+xZnLDVgXvuho+1zC+/NPMGSii0wc39ObkOAtY1tTzYa WdrxQJhdkuFV4PPSmaQamIUEijaufnr7B6BChBmey10HJFTwLdOuGAcpx2apENRiZ7oXzP Hbo0pn/oWJPQLJ+NLnBHs+jCs4kt8wNdkv/UuCtqpwNjUvtbHUnPpI4pGSEFuAcct+O7fh lNMWV7cfMm9+pOFFa2TOi4CDYAh8HsW6HQ5eK1a7zwR3P81A4sUAKEA4612w7mGx212Ves NfDKwMsamb3/dYcJXOo0CgpDWDWq3y/i/c1kM4WsgzfKGl4syY9Uv+Cm3cfYNw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1610964625; 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=SqeRulDhHNHgL6fy8LbaFwThp5hQYIRRAVQEh8ugmNg=; b=kcwnSThXdgqdPmMpuJcSMgWMmx4FqCXJRH2KousTyv2QEW5oeWom7TKKDF3VCZLtWDYh1/ XHJJFC56Jt32FRBQ== To: "James E.J. Bottomley" , "Martin K. Petersen" , Christoph Hellwig , John Garry , Jason Yan , Daniel Wagner , Artur Paszkiewicz , Jack Wang Cc: linux-scsi@vger.kernel.org, LKML , Thomas Gleixner , "Sebastian A. Siewior" , "Ahmed S. Darwish" Subject: [PATCH v3 05/19] scsi: isci: port: link down: Pass gfp_t flags Date: Mon, 18 Jan 2021 11:09:41 +0100 Message-Id: <20210118100955.1761652-6-a.darwish@linutronix.de> In-Reply-To: <20210118100955.1761652-1-a.darwish@linutronix.de> References: <20210118100955.1761652-1-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 Reviewed-by: John Garry 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);