LKML Archive on lore.kernel.org
 help / color / Atom feed
From: "Ahmed S. Darwish" <a.darwish@linutronix.de>
To: "James E.J. Bottomley" <jejb@linux.ibm.com>,
	"Martin K. Petersen" <martin.petersen@oracle.com>,
	John Garry <john.garry@huawei.com>,
	Jason Yan <yanaijie@huawei.com>, Daniel Wagner <dwagner@suse.de>,
	Artur Paszkiewicz <artur.paszkiewicz@intel.com>,
	Jack Wang <jinpu.wang@cloud.ionos.com>
Cc: linux-scsi@vger.kernel.org, intel-linux-scu@intel.com,
	LKML <linux-kernel@vger.kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	"Sebastian A. Siewior" <bigeasy@linutronix.de>,
	"Ahmed S. Darwish" <a.darwish@linutronix.de>
Subject: [PATCH v2 06/19] scsi: isci: port: link up: Pass gfp_t flags
Date: Tue, 12 Jan 2021 12:06:34 +0100
Message-ID: <20210112110647.627783-7-a.darwish@linutronix.de> (raw)
In-Reply-To: <20210112110647.627783-1-a.darwish@linutronix.de>

Use the new libsas event notifiers API, which requires callers to
explicitly pass the gfp_t memory allocation flags.

libsas sas_notify_port_event() is called from isci_port_link_up().
Below is the context analysis for all of its call chains:

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()
            -> sci_port_activate_phy()
              -> isci_port_link_up()

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()
        -> sci_port_activate_phy()
          -> isci_port_link_up()

phy.c: enter SCI state: *SCI_PHY_SUB_FINAL*                     # Cont. from [1]
  -> phy.c: sci_phy_starting_final_substate_enter()
    -> phy.c: sci_change_state(SCI_PHY_READY)
      -> enter SCI state: *SCI_PHY_READY*
        -> phy.c: sci_phy_ready_state_enter()
          -> host.c: sci_controller_link_up()
            -> .link_up_handler()
            == port_config.c: sci_apc_agent_link_up()
              -> port.c: sci_port_link_up()
                -> (continue at [A])
            == port_config.c: sci_mpc_agent_link_up()
	      -> port.c: sci_port_link_up()
                -> (continue at [A])

port_config.c: mpc_agent_timeout(), atomic, timer callback      (*)
spin_lock_irqsave(isci_host::scic_lock, )
  -> ->link_up_handler()
  == port_config.c: sci_apc_agent_link_up()
    -> port.c: sci_port_link_up()
      -> (continue at [A])
  == port_config.c: sci_mpc_agent_link_up()
    -> port.c: sci_port_link_up()
      -> (continue at [A])

[A] port.c: sci_port_link_up()
  -> sci_port_activate_phy()
    -> isci_port_link_up()
  -> sci_port_general_link_up_handler()
    -> sci_port_activate_phy()
      -> isci_port_link_up()

[1] 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, all the call-chains are
atomic.  Pass GFP_ATOMIC to 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.

Fixes: 1c393b970e0f ("scsi: libsas: Use dynamic alloced work to avoid sas event lost")
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Cc: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
---
 drivers/scsi/isci/port.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/isci/port.c b/drivers/scsi/isci/port.c
index a3c58718c260..10136ae466e2 100644
--- a/drivers/scsi/isci/port.c
+++ b/drivers/scsi/isci/port.c
@@ -223,7 +223,8 @@ static void isci_port_link_up(struct isci_host *isci_host,
 	/* Notify libsas that we have an address frame, if indeed
 	 * we've found an SSP, SMP, or STP target */
 	if (success)
-		sas_notify_port_event(&iphy->sas_phy, PORTE_BYTES_DMAED);
+		sas_notify_port_event_gfp(&iphy->sas_phy,
+					  PORTE_BYTES_DMAED, GFP_ATOMIC);
 }
 
 
-- 
2.30.0


  parent reply index

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-12 11:06 [PATCH v2 00/19] scsi: libsas: Remove in_interrupt() check Ahmed S. Darwish
2021-01-12 11:06 ` [PATCH v2 01/19] Documentation: scsi: libsas: Remove notify_ha_event() Ahmed S. Darwish
2021-01-12 11:06 ` [PATCH v2 02/19] scsi: libsas and users: Remove notifier indirection Ahmed S. Darwish
2021-01-12 11:36   ` John Garry
2021-01-12 12:09     ` Ahmed S. Darwish
2021-01-12 13:07     ` [PATCH v3 " Ahmed S. Darwish
2021-01-12 15:43       ` Christoph Hellwig
2021-01-12 11:06 ` [PATCH v2 03/19] scsi: libsas: Introduce a _gfp() variant of event notifiers Ahmed S. Darwish
2021-01-12 15:45   ` Christoph Hellwig
2021-01-12 17:12     ` Sebastian A. Siewior
2021-01-12 11:06 ` [PATCH v2 04/19] scsi: mvsas: Pass gfp_t flags to libsas " Ahmed S. Darwish
2021-01-12 15:46   ` Christoph Hellwig
2021-01-12 17:03     ` Ahmed S. Darwish
2021-01-12 11:06 ` [PATCH v2 05/19] scsi: isci: port: link down: Pass gfp_t flags Ahmed S. Darwish
2021-01-12 11:06 ` Ahmed S. Darwish [this message]
2021-01-12 11:06 ` [PATCH v2 07/19] scsi: isci: port: broadcast change: " Ahmed S. Darwish
2021-01-12 11:06 ` [PATCH v2 08/19] scsi: libsas: Pass gfp_t flags to event notifiers Ahmed S. Darwish
2021-01-12 11:06 ` [PATCH v2 09/19] scsi: pm80xx: Pass gfp_t flags to libsas " Ahmed S. Darwish
2021-01-12 11:06 ` [PATCH v2 10/19] scsi: aic94xx: " Ahmed S. Darwish
2021-01-12 11:06 ` [PATCH v2 11/19] scsi: hisi_sas: " Ahmed S. Darwish
2021-01-12 11:06 ` [PATCH v2 12/19] scsi: libsas: event notifiers API: Add gfp_t flags parameter Ahmed S. Darwish
2021-01-12 11:06 ` [PATCH v2 13/19] scsi: hisi_sas: Switch back to original libsas event notifiers Ahmed S. Darwish
2021-01-12 11:06 ` [PATCH v2 14/19] scsi: aic94xx: " Ahmed S. Darwish
2021-01-12 11:06 ` [PATCH v2 15/19] scsi: pm80xx: " Ahmed S. Darwish
2021-01-12 11:06 ` [PATCH v2 16/19] scsi: libsas: Switch back to original event notifiers API Ahmed S. Darwish
2021-01-12 14:42   ` John Garry
2021-01-12 11:06 ` [PATCH v2 17/19] scsi: isci: Switch back to original libsas event notifiers Ahmed S. Darwish
2021-01-12 11:06 ` [PATCH v2 18/19] scsi: mvsas: " Ahmed S. Darwish
2021-01-12 11:06 ` [PATCH v2 19/19] scsi: libsas: Remove temporarily-added _gfp() API variants Ahmed S. Darwish
2021-01-12 11:53 ` [PATCH v2 00/19] scsi: libsas: Remove in_interrupt() check John Garry
2021-01-12 13:19   ` Ahmed S. Darwish
2021-01-12 16:00     ` John Garry
2021-01-12 17:33       ` Ahmed S. Darwish
2021-01-14  9:51         ` John Garry
2021-01-15 16:27           ` Ahmed S. Darwish
2021-01-15 16:29             ` John Garry
2021-01-15 16:41               ` Ahmed S. Darwish

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210112110647.627783-7-a.darwish@linutronix.de \
    --to=a.darwish@linutronix.de \
    --cc=artur.paszkiewicz@intel.com \
    --cc=bigeasy@linutronix.de \
    --cc=dwagner@suse.de \
    --cc=intel-linux-scu@intel.com \
    --cc=jejb@linux.ibm.com \
    --cc=jinpu.wang@cloud.ionos.com \
    --cc=john.garry@huawei.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-scsi@vger.kernel.org \
    --cc=martin.petersen@oracle.com \
    --cc=tglx@linutronix.de \
    --cc=yanaijie@huawei.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lkml.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lkml.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lkml.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lkml.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lkml.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lkml.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lkml.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lkml.kernel.org/lkml/7 lkml/git/7.git
	git clone --mirror https://lkml.kernel.org/lkml/8 lkml/git/8.git
	git clone --mirror https://lkml.kernel.org/lkml/9 lkml/git/9.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lkml.kernel.org/lkml \
		linux-kernel@vger.kernel.org
	public-inbox-index lkml

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git