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From: Sergei Miroshnichenko <s.miroshnichenko@yadro.com>
To: <linux-pci@vger.kernel.org>
Cc: "Bjorn Helgaas" <helgaas@kernel.org>,
	"Lukas Wunner" <lukas@wunner.de>, "Stefan Roese" <sr@denx.de>,
	"Andy Lavr" <andy.lavr@gmail.com>,
	"Christian König" <christian.koenig@amd.com>,
	"Ard Biesheuvel" <ardb@kernel.org>,
	"David Laight" <David.Laight@ACULAB.COM>,
	"Rajat Jain" <rajatja@google.com>,
	linux@yadro.com,
	"Sergei Miroshnichenko" <s.miroshnichenko@yadro.com>
Subject: [PATCH v8 18/24] PCI: hotplug: Don't disable the released bridge windows immediately
Date: Mon, 27 Apr 2020 21:23:52 +0300	[thread overview]
Message-ID: <20200427182358.2067702-19-s.miroshnichenko@yadro.com> (raw)
In-Reply-To: <20200427182358.2067702-1-s.miroshnichenko@yadro.com>

On a hotplug event with enabled BAR movement, calculating new BAR layout
and bridge windows takes some time. During this procedure, the structures
representing these windows are released - marked for recalculation.

When the new bridge window values are ready, they are written to the bridge
registers via pci_setup_bridges().

Currently, bridge's registers are updated immediately after releasing a
window to disable it. But if a driver doesn't yet support movable BARs, it
doesn't stop MEM transactions during the hotplug, so disabled bridge
windows will break them.

Let the bridge windows remain operating after releasing, as they will be
updated to the new values in the end of a hotplug event.

Signed-off-by: Sergei Miroshnichenko <s.miroshnichenko@yadro.com>
---
 drivers/pci/setup-bus.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 4cadfa1f9519..3081f2d2a48a 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1635,7 +1635,8 @@ static void pci_bridge_release_resources(struct pci_bus *bus,
 		/* Avoiding touch the one without PREF */
 		if (type & IORESOURCE_PREFETCH)
 			type = IORESOURCE_PREFETCH;
-		__pci_setup_bridge(bus, type);
+		if (!pci_can_move_bars)
+			__pci_setup_bridge(bus, type);
 		/* For next child res under same bridge */
 		r->flags = old_flags;
 	}
-- 
2.24.1


  parent reply	other threads:[~2020-04-27 18:24 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-27 18:23 [PATCH v8 00/24] PCI: Allow BAR movement during boot and hotplug Sergei Miroshnichenko
2020-04-27 18:23 ` [PATCH v8 01/24] PCI: Fix race condition in pci_enable/disable_device() Sergei Miroshnichenko
2020-04-27 18:23 ` [PATCH v8 02/24] PCI: Ensure a bridge has I/O and MEM access for hot-added devices Sergei Miroshnichenko
2020-04-29  6:30   ` kbuild test robot
2020-04-27 18:23 ` [PATCH v8 03/24] PCI: hotplug: Initial support of the movable BARs feature Sergei Miroshnichenko
2020-04-27 18:23 ` [PATCH v8 04/24] PCI: Add version of release_child_resources() aware of fixed BARs Sergei Miroshnichenko
2020-04-27 18:23 ` [PATCH v8 05/24] PCI: hotplug: Fix reassigning the released BARs Sergei Miroshnichenko
2020-04-27 18:23 ` [PATCH v8 06/24] PCI: hotplug: Recalculate every bridge window during rescan Sergei Miroshnichenko
2020-04-27 18:23 ` [PATCH v8 07/24] PCI: hotplug: Don't allow hot-added devices to steal resources Sergei Miroshnichenko
2020-04-27 18:23 ` [PATCH v8 08/24] PCI: Reassign BARs if BIOS/bootloader had assigned not all of them Sergei Miroshnichenko
2020-04-27 18:23 ` [PATCH v8 09/24] PCI: hotplug: Try to reassign movable BARs only once Sergei Miroshnichenko
2020-04-27 18:23 ` [PATCH v8 10/24] PCI: hotplug: Calculate fixed parts of bridge windows Sergei Miroshnichenko
2020-04-27 18:23 ` [PATCH v8 11/24] PCI: Include fixed BARs into the bus size calculating Sergei Miroshnichenko
2020-04-27 18:23 ` [PATCH v8 12/24] PCI: hotplug: movable BARs: Compute limits for relocated bridge windows Sergei Miroshnichenko
2020-04-27 18:23 ` [PATCH v8 13/24] PCI: Make sure bridge windows include their fixed BARs Sergei Miroshnichenko
2020-04-27 18:23 ` [PATCH v8 14/24] PCI: hotplug: Add support of fixed BARs to pci_assign_resource() Sergei Miroshnichenko
2020-04-27 18:23 ` [PATCH v8 15/24] PCI: hotplug: Sort fixed BARs before assignment Sergei Miroshnichenko
2020-04-27 18:23 ` [PATCH v8 16/24] x86/PCI/ACPI: Fix up PCIBIOS_MIN_MEM if value computed from e820 is invalid Sergei Miroshnichenko
2020-04-27 18:23 ` [PATCH v8 17/24] PCI: hotplug: Configure MPS after manual bus rescan Sergei Miroshnichenko
2020-04-27 18:23 ` Sergei Miroshnichenko [this message]
2020-04-27 18:23 ` [PATCH v8 19/24] PCI: pciehp: Trigger a domain rescan on hp events when enabled movable BARs Sergei Miroshnichenko
2020-04-27 18:23 ` [PATCH v8 20/24] PCI: Don't claim fixed BARs Sergei Miroshnichenko
2020-04-27 18:23 ` [PATCH v8 21/24] PCI: hotplug: Don't reserve bus space when enabled movable BARs Sergei Miroshnichenko
2020-04-27 18:23 ` [PATCH v8 22/24] PCI: hotplug: Enable the movable BARs feature by default Sergei Miroshnichenko
2020-04-27 18:23 ` [PATCH v8 23/24] PCI/portdrv: Declare support of movable BARs Sergei Miroshnichenko
2020-04-27 18:23 ` [PATCH v8 24/24] nvme-pci: Handle " Sergei Miroshnichenko
2020-04-28 12:59 ` [PATCH v8 00/24] PCI: Allow BAR movement during boot and hotplug Christian König
2020-05-04  9:30   ` Sergei Miroshnichenko
2020-08-10 22:21 ` Bjorn Helgaas

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