From patchwork Fri Dec 18 20:43:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Ahmed S. Darwish" X-Patchwork-Id: 11982905 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=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 82DE1C3526B for ; Fri, 18 Dec 2020 20:45:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4B1C223B74 for ; Fri, 18 Dec 2020 20:45:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387642AbgLRUo7 (ORCPT ); Fri, 18 Dec 2020 15:44:59 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:54760 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725870AbgLRUo7 (ORCPT ); Fri, 18 Dec 2020 15:44:59 -0500 From: "Ahmed S. Darwish" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1608324255; 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=evXtZ/LWFHkem3A8otQhSiq2uaR1XqZP0VRcfd96Dwk=; b=L03AEOwfh4wae846XF7hKIQSYaiLVzWtFUPMrs2zUV0bi8OrhrwS47ZbYo9t8/HJK9nUtQ sQZiiDvJx8p61Tkol613kqQQcwqRpQR0cFXHJLZKsoeCwq9qF9CkVQ+LjiDsX+QQj5A/Xp kVG+TIzpmERkXJKyaMj3Jy6wn1XbVePL8VCUKX6mV1V9Z0RcHTP/6u9meOoWz4mvOskWmE W4c8UcCwYpscCpeqUrjGRaxnen20bDGno70AqU3nxLHvU+WqwUam5tJsqA9nU8EQszmIDi Wjb7hvA2MhF0VYDFQpILDMlCd7CaufH07Wan7SzMDRhaugWSeA2HXulteaPYtw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1608324255; 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=evXtZ/LWFHkem3A8otQhSiq2uaR1XqZP0VRcfd96Dwk=; b=PEDfG77SLk1Y7GGUwX6EBJyQQN/izqqMqkJrfZetmQkzxokdiNybGrN3r3XCWLieipPfUz e0Tu6SHEPPUrMICw== To: "James E.J. Bottomley" , "Martin K. Petersen" , Daniel Wagner , Jason Yan , John Garry , Artur Paszkiewicz , Jack Wang Cc: linux-scsi@vger.kernel.org, LKML , Thomas Gleixner , "Sebastian A. Siewior" , "Ahmed S. Darwish" Subject: [PATCH 04/11] scsi: isci: port: link down: Pass gfp_t flags Date: Fri, 18 Dec 2020 21:43:47 +0100 Message-Id: <20201218204354.586951-5-a.darwish@linutronix.de> In-Reply-To: <20201218204354.586951-1-a.darwish@linutronix.de> References: <20201218204354.586951-1-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. The libsas ->notify_phy_event() hook is exclusively called from 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: [->link_up_handler = sci_apc_agent_link_up] 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: [->link_up_handler = sci_mpc_agent_link_up] 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. Signed-off-by: Ahmed S. Darwish Cc: stable@vger.kernel.org Cc: Artur Paszkiewicz --- drivers/scsi/isci/port.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/isci/port.c b/drivers/scsi/isci/port.c index 1df45f028ea7..c3a8c84b19a2 100644 --- a/drivers/scsi/isci/port.c +++ b/drivers/scsi/isci/port.c @@ -270,8 +270,9 @@ 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); - isci_host->sas_ha.notify_phy_event(&isci_phy->sas_phy, - PHYE_LOSS_OF_SIGNAL); + isci_host->sas_ha.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);