From patchwork Fri Dec 18 20:43:49 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: 11982911 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 C9086C4361B for ; Fri, 18 Dec 2020 20:45:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9409323B70 for ; Fri, 18 Dec 2020 20:45:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387675AbgLRUpI (ORCPT ); Fri, 18 Dec 2020 15:45:08 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:54790 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726145AbgLRUpI (ORCPT ); Fri, 18 Dec 2020 15:45:08 -0500 From: "Ahmed S. Darwish" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1608324265; 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=98adWOsfLr+hSn2jJKTMnAiX6dlxgrFL6Q+KkrxeV2w=; b=VUf5HJJWF0xqOXWV5WPhIPTeisRmb4goftxKvC15RIDIv/8BTrGU9YMAKgcFU8uDUjU6KZ LjMLHtLV2BlkJ2qp39VsCO0tFhwl/7fvTI3iR+wkwBJMDyLYOF5cu0DSGUJxqnLXKFmQWB ZuehE37VPrEqXcUhprflgmL15K1V3WEYDnfbt3armb15jN+gLGPsEzeXrM3EKioeo7afUr JPtVkAz/vmKjPWFptlD33aMZKTD/ZGY6ylPAvn+5G8KKhOhUuxS8I9vqNWfW3GAcdQJh+s fC59XQm/PyY7KCmflkj+Zl5mtpwS+uIL8kWNW6taUoWHOQ2x4TdgtjuKWhJ1BQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1608324265; 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=98adWOsfLr+hSn2jJKTMnAiX6dlxgrFL6Q+KkrxeV2w=; b=6wVDG2L/dANMNP6tVpXHvV5aUOdi7BdaxWwtqY0ooK5KhnkftLEuhbSmWeplN12yfUCRjN iyN3+lJvHC+HO0Ag== 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 06/11] scsi: isci: port: broadcast change: Pass gfp_t flags Date: Fri, 18 Dec 2020 21:43:49 +0100 Message-Id: <20201218204354.586951-7-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_port_event() hook is called from isci_port_bc_change_received(). Below is the context analysis for all of its call chains: host.c: sci_controller_error_handler(): atomic, irq handler (*) OR host.c: sci_controller_completion_handler(), atomic, tasklet (*) -> sci_controller_process_completions() -> sci_controller_event_completion() -> phy.c: sci_phy_event_handler() -> port.c: sci_port_broadcast_change_received() -> isci_port_bc_change_received() 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_set_phy() -> phy.c: sci_phy_set_port() -> port.c: sci_port_broadcast_change_received() -> isci_port_bc_change_received() port_config.c: apc_agent_timeout(), atomic, timer callback (*) -> sci_apc_agent_configure_ports() -> port.c: sci_port_add_phy() -> sci_port_set_phy() -> phy.c: sci_phy_set_port() -> port.c: sci_port_broadcast_change_received() -> isci_port_bc_change_received() phy.c: enter SCI state: *SCI_PHY_STOPPED* # Cont. from [1] -> 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_clear_phy() -> phy.c: sci_phy_set_port() -> port.c: sci_port_broadcast_change_received() -> isci_port_bc_change_received() phy.c: enter SCI state: *SCI_PHY_STARTING* # Cont. from [2] -> 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() -> sci_port_clear_phy() -> phy.c: sci_phy_set_port() -> port.c: sci_port_broadcast_change_received() -> isci_port_bc_change_received() [1] 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) [2] 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* # Cont. from [2A] -> 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 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() -> sci_change_state(SCI_PHY_STARTING) [2A] 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) 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 port 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 | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/isci/port.c b/drivers/scsi/isci/port.c index 69684c80c407..6244981a3ebf 100644 --- a/drivers/scsi/isci/port.c +++ b/drivers/scsi/isci/port.c @@ -164,7 +164,9 @@ static void isci_port_bc_change_received(struct isci_host *ihost, "%s: isci_phy = %p, sas_phy = %p\n", __func__, iphy, &iphy->sas_phy); - ihost->sas_ha.notify_port_event(&iphy->sas_phy, PORTE_BROADCAST_RCVD); + ihost->sas_ha.notify_port_event_gfp(&iphy->sas_phy, + PORTE_BROADCAST_RCVD, + GFP_ATOMIC); sci_port_bcn_enable(iport); }