LKML Archive on lore.kernel.org
help / color / mirror / 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>,
	Christoph Hellwig <hch@infradead.org>,
	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, 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 v3 06/19] scsi: isci: port: link up: Pass gfp_t flags
Date: Mon, 18 Jan 2021 11:09:42 +0100	[thread overview]
Message-ID: <20210118100955.1761652-7-a.darwish@linutronix.de> (raw)
In-Reply-To: <20210118100955.1761652-1-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>
Reviewed-by: John Garry <john.garry@huawei.com>
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	other threads:[~2021-01-18 21:24 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-18 10:09 [PATCH v3 00/19] scsi: libsas: Remove in_interrupt() check Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 01/19] Documentation: scsi: libsas: Remove notify_ha_event() Ahmed S. Darwish
2021-01-18 10:22   ` Jinpu Wang
2021-01-18 10:09 ` [PATCH v3 02/19] scsi: libsas and users: Remove notifier indirection Ahmed S. Darwish
2021-01-18 10:26   ` Jinpu Wang
2021-01-18 10:09 ` [PATCH v3 03/19] scsi: libsas: Introduce a _gfp() variant of event notifiers Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 04/19] scsi: mvsas: Pass gfp_t flags to libsas " Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 05/19] scsi: isci: port: link down: Pass gfp_t flags Ahmed S. Darwish
2021-01-18 10:09 ` Ahmed S. Darwish [this message]
2021-01-18 10:09 ` [PATCH v3 07/19] scsi: isci: port: broadcast change: " Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 08/19] scsi: libsas: Pass gfp_t flags to event notifiers Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 09/19] scsi: pm80xx: Pass gfp_t flags to libsas " Ahmed S. Darwish
2021-01-18 10:26   ` Jinpu Wang
2021-01-18 10:09 ` [PATCH v3 10/19] scsi: aic94xx: " Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 11/19] scsi: hisi_sas: " Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 12/19] scsi: libsas: event notifiers API: Add gfp_t flags parameter Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 13/19] scsi: hisi_sas: Switch back to original libsas event notifiers Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 14/19] scsi: aic94xx: " Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 15/19] scsi: pm80xx: " Ahmed S. Darwish
2021-01-18 10:27   ` Jinpu Wang
2021-01-18 10:09 ` [PATCH v3 16/19] scsi: libsas: Switch back to original event notifiers API Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 17/19] scsi: isci: Switch back to original libsas event notifiers Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 18/19] scsi: mvsas: " Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 19/19] scsi: libsas: Remove temporarily-added _gfp() API variants Ahmed S. Darwish
2021-01-23  2:32 ` [PATCH v3 00/19] scsi: libsas: Remove in_interrupt() check Martin K. Petersen
2021-01-27  4:54 ` Martin K. Petersen

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=20210118100955.1761652-7-a.darwish@linutronix.de \
    --to=a.darwish@linutronix.de \
    --cc=artur.paszkiewicz@intel.com \
    --cc=bigeasy@linutronix.de \
    --cc=dwagner@suse.de \
    --cc=hch@infradead.org \
    --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 \
    --subject='Re: [PATCH v3 06/19] scsi: isci: port: link up: Pass gfp_t flags' \
    /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

This is a public inbox, see mirroring instructions
on how to clone and mirror all data and code used for this inbox