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>,
linux-nvme@lists.infradead.org, "Christoph Hellwig" <hch@lst.de>
Subject: [PATCH v8 24/24] nvme-pci: Handle movable BARs
Date: Mon, 27 Apr 2020 21:23:58 +0300 [thread overview]
Message-ID: <20200427182358.2067702-25-s.miroshnichenko@yadro.com> (raw)
In-Reply-To: <20200427182358.2067702-1-s.miroshnichenko@yadro.com>
Hot-added devices can affect the existing ones by moving their BARs. The
PCI subsystem will inform the NVME driver about this by invoking the
.rescan_prepare() and .rescan_done() hooks, so the BARs can by re-mapped.
Tested under the "randrw" mode of the fio tool, and when using an NVME
drive as a root filesystem storage. Before the hot-adding:
% sudo cat /proc/iomem
...
3fe800000000-3fe8007fffff : PCI Bus 0020:0b
3fe800000000-3fe8007fffff : PCI Bus 0020:18
3fe800000000-3fe8000fffff : 0020:18:00.0
3fe800000000-3fe8000fffff : nvme
^^^^^^^^^^^^^^^^^^^^^^^^^
3fe800100000-3fe80017ffff : 0020:18:00.0
...
Then another NVME drive was hot-added, so BARs of the 0020:18:00.0 are
moved:
% sudo cat /proc/iomem
...
3fe800000000-3fe800ffffff : PCI Bus 0020:0b
3fe800000000-3fe8007fffff : PCI Bus 0020:10
3fe800000000-3fe800003fff : 0020:10:00.0
3fe800000000-3fe800003fff : nvme
3fe800010000-3fe80001ffff : 0020:10:00.0
3fe800800000-3fe800ffffff : PCI Bus 0020:18
3fe800800000-3fe8008fffff : 0020:18:00.0
3fe800800000-3fe8008fffff : nvme
^^^^^^^^^^^^^^^^^^^^^^^^^
3fe800900000-3fe80097ffff : 0020:18:00.0
...
During the rescanning, both READ and WRITE speeds drop to zero for a while
due to driver's pause, then restore.
Cc: linux-nvme@lists.infradead.org
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sergei Miroshnichenko <s.miroshnichenko@yadro.com>
---
drivers/nvme/host/pci.c | 21 ++++++++++++++++++++-
1 file changed, 20 insertions(+), 1 deletion(-)
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 4e79e412b276..677ded2d4dd4 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1621,7 +1621,7 @@ static int nvme_remap_bar(struct nvme_dev *dev, unsigned long size)
{
struct pci_dev *pdev = to_pci_dev(dev->dev);
- if (size <= dev->bar_mapped_size)
+ if (dev->bar && size <= dev->bar_mapped_size)
return 0;
if (size > pci_resource_len(pdev, 0))
return -ENOMEM;
@@ -3032,6 +3032,23 @@ static void nvme_error_resume(struct pci_dev *pdev)
flush_work(&dev->ctrl.reset_work);
}
+static void nvme_rescan_prepare(struct pci_dev *pdev)
+{
+ struct nvme_dev *dev = pci_get_drvdata(pdev);
+
+ nvme_dev_disable(dev, false);
+ nvme_dev_unmap(dev);
+ dev->bar = NULL;
+}
+
+static void nvme_rescan_done(struct pci_dev *pdev)
+{
+ struct nvme_dev *dev = pci_get_drvdata(pdev);
+
+ nvme_dev_map(dev);
+ nvme_reset_ctrl_sync(&dev->ctrl);
+}
+
static const struct pci_error_handlers nvme_err_handler = {
.error_detected = nvme_error_detected,
.slot_reset = nvme_slot_reset,
@@ -3110,6 +3127,8 @@ static struct pci_driver nvme_driver = {
#endif
.sriov_configure = pci_sriov_configure_simple,
.err_handler = &nvme_err_handler,
+ .rescan_prepare = nvme_rescan_prepare,
+ .rescan_done = nvme_rescan_done,
};
static int __init nvme_init(void)
--
2.24.1
next prev 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 ` [PATCH v8 18/24] PCI: hotplug: Don't disable the released bridge windows immediately Sergei Miroshnichenko
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 ` Sergei Miroshnichenko [this message]
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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