When a PCIe card is hot-removed, the Presence Detect State and Data Link
Layer Link Active bits often do not clear simultaneously. I've seen delays
of up to 244 msec between the two events with Thunderbolt.
After pciehp has brought down the slot in response to the first event, the
other bit may still be set. It's not discernible whether it's set because
a new card is already in the slot or if it will soon clear. So pciehp
tries to bring up the slot and in the latter case fails with a bunch of
messages, some of them at KERN_ERR severity. If the slot is no longer
occupied, the messages are false positives and annoy users.
Stuart Hayes reports the following splat on hot removal:
KERN_INFO pcieport 0000:3c:06.0: pciehp: Slot(180): Link Up
KERN_INFO pcieport 0000:3c:06.0: pciehp: Timeout waiting for Presence Detect
KERN_ERR pcieport 0000:3c:06.0: pciehp: link training error: status 0x0001
KERN_ERR pcieport 0000:3c:06.0: pciehp: Failed to check link status
Dongdong Liu complains about a similar splat:
KERN_INFO pciehp 0000:80:10.0:pcie004: Slot(36): Link Down
KERN_INFO iommu: Removing device 0000:87:00.0 from group 12
KERN_INFO pciehp 0000:80:10.0:pcie004: Slot(36): Card present
KERN_INFO pcieport 0000:80:10.0: Data Link Layer Link Active not set in 1000 msec
KERN_ERR pciehp 0000:80:10.0:pcie004: Failed to check link status
Users are particularly irritated to see a bringup attempt even though the
slot was explicitly brought down via sysfs. In a perfect world, we could
avoid this by setting Link Disable on slot bringdown and re-enabling it
upon a Presence Detect State change. In reality however, there are broken
hotplug ports which hardwire Presence Detect to zero, see 80696f9914
("PCI: pciehp: Tolerate Presence Detect hardwired to zero"). Conversely,
PCIe r1.0 hotplug ports hardwire Link Active to zero because Link Active
Reporting wasn't specified before PCIe r1.1. On unplug, some ports first
clear Presence then Link (see Stuart Hayes' splat) whereas others use the
inverse order (see Dongdong Liu's splat). To top it off, there are hotplug
ports which flap the Presence and Link bits on slot bringup, see
6c35a1ac3d ("PCI: pciehp: Tolerate initially unstable link").
pciehp is designed to work with all of these variants. Surplus attempts at
slot bringup are a lesser evil than not being able to bring up slots at
all. Although we could try to perfect the behavior for specific hotplug
controllers, we'd risk breaking others or increasing code complexity.
But we can certainly minimize annoyance by emitting only a single message
with KERN_INFO severity if bringup is unsuccessful:
* Drop the "Timeout waiting for Presence Detect" message in
pcie_wait_for_presence(). The sole caller of that function,
pciehp_check_link_status(), ignores the timeout and carries on. It emits
error messages of its own and I don't think this particular message adds
much value.
* There's a single error condition in pciehp_check_link_status() which
does not emit a message. Adding one allows dropping the "Failed to check
link status" message emitted by board_added() if
pciehp_check_link_status() returns a non-zero integer.
* Tone down all messages in pciehp_check_link_status() to KERN_INFO
severity and rephrase them to look as innocuous as possible. To this
end, move the message emitted by pcie_wait_for_link_delay() to its
callers.
As a result, Stuart Hayes' splat becomes:
KERN_INFO pcieport 0000:3c:06.0: pciehp: Slot(180): Link Up
KERN_INFO pcieport 0000:3c:06.0: pciehp: Slot(180): Cannot train link: status 0x0001
Dongdong Liu's splat becomes:
KERN_INFO pciehp 0000:80:10.0:pcie004: Slot(36): Card present
KERN_INFO pciehp 0000:80:10.0:pcie004: Slot(36): No link
The messages now merely serve as information that presence or link bits
were set a little longer than expected. Bringup failures which are not
false positives are still reported, albeit no longer at KERN_ERR severity.
Link: https://lore.kernel.org/linux-pci/20200310182100.102987-1-stuart.w.hayes@gmail.com/
Link: https://lore.kernel.org/linux-pci/1547649064-19019-1-git-send-email-liudongdong3@huawei.com/
Link: https://lore.kernel.org/r/b45e46fd8a6aa6930aaac9d7718c2e4b787a4e5e.1595935071.git.lukas@wunner.de
Reported-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Reported-by: Dongdong Liu <liudongdong3@huawei.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
f719582435 ("PCI: Add pci_mmap_resource_range() and use it for ARM64")
changed the #ifdef condition around pci_create_resource_files(),
pci_remove_resource_files(), and related functions, but did not update
comments at the #else and #ifdef.
Update the comments to match the #ifdef.
[bhelgaas: commit log, drop #endif comment since it's close to the #else]
Link: https://lore.kernel.org/r/20200821155121.nzxjeeoze4h5pone@amazon.com
Signed-off-by: Clint Sbisa <csbisa@amazon.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The PERST# bit was moved to a different register in 7278-type STB chips.
In addition, the polarity of the bit was also changed; for other chips
writing a 1 specified assert; for 7278-type chips, writing a 0 specifies
assert. Of course, PERST# is a PCIe asserted-low signal.
While we are here, also change the bridge_sw_init_set() functions so like
the perst_set() functions they are chip specific and we no longer rely on
data wrt chip specific field mask and shift values.
Link: https://lore.kernel.org/r/20200911175232.19016-6-james.quinlan@broadcom.com
Signed-off-by: Jim Quinlan <jquinlan@broadcom.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Add in compatibility strings and code for three Broadcom STB chips. Some
of the register locations, shifts, and masks are different for certain
chips, requiring the use of different constants based on of_id.
We would like to add the following at this time to the match list but we
need to wait until the end of this patchset so that everything works.
{ .compatible = "brcm,bcm7211-pcie", .data = &generic_cfg },
{ .compatible = "brcm,bcm7278-pcie", .data = &bcm7278_cfg },
{ .compatible = "brcm,bcm7216-pcie", .data = &bcm7278_cfg },
{ .compatible = "brcm,bcm7445-pcie", .data = &generic_cfg },
Link: https://lore.kernel.org/r/20200911175232.19016-4-james.quinlan@broadcom.com
Signed-off-by: Jim Quinlan <jquinlan@broadcom.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Translation Blocking is a required feature for Downstream Ports (Root
Ports or Switch Downstream Ports) that implement ACS. When enabled, the
Port checks the Address Type (AT) of each upstream Memory Request it
receives.
The default AT (00b) means "untranslated" and the IOMMU can decide whether
to treat the address as I/O virtual or physical.
If AT is not the default, i.e., if the Memory Request contains an
already-translated (physical) address, the Port blocks the request and
reports an ACS error.
When enabling ACS, enable Translation Blocking for external-facing ports
and untrusted (external) devices. This is to help prevent attacks from
external devices that initiate DMA with physical addresses that bypass the
IOMMU.
[bhelgaas: commit log, simplify setting bit and drop warning; TB is
required for Downstream Ports with ACS, so we should never see the warning]
Link: https://lore.kernel.org/r/20200707224604.3737893-4-rajatja@google.com
Signed-off-by: Rajat Jain <rajatja@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The arch_.*_msi_irq[s] fallbacks are compiled in whether an architecture
requires them or not. Architectures which are fully utilizing hierarchical
irq domains should never call into that code.
It's not only architectures which depend on that by implementing one or
more of the weak functions, there is also a bunch of drivers which relies
on the weak functions which invoke msi_controller::setup_irq[s] and
msi_controller::teardown_irq.
Make the architectures and drivers which rely on them select them in Kconfig
and if not selected replace them by stub functions which emit a warning and
fail the PCI/MSI interrupt allocation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200826112333.992429909@linutronix.de
Provide a helper function to check whether a PCI device is handled by a
non-standard PCI/MSI domain. This will be used to exclude such devices
which hang of a special bus, e.g. VMD, to be excluded from the irq domain
override in irq remapping.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20200826112333.139387358@linutronix.de
pci_msi_get_hwirq() and pci_msi_set_desc are not longer special. Enable the
generic MSI domain ops in the core and PCI MSI code unconditionally and get
rid of the x86 specific implementations in the X86 MSI code and in the
hyperv PCI driver.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200826112332.564274859@linutronix.de
VMD has it's own PCI/MSI interrupt domain which is not in any way depending
on the x86 vector domain. PCI devices behind VMD share the VMD MSIX vector
entries via a VMD specific message translation to the actual VMD MSIX
vector. The VMD device interrupt handler for the VMD MSIX vectors invokes
all interrupt handlers of the devices which share a vector.
Making the x86 vector domain the actual parent of the VMD irq domain is
pointless and actually counterproductive. When a device interrupt is
requested then it will activate the interrupt which traverses down the
hierarchy and consumes an interrupt vector in the vector domain which is
never used.
The domain is self contained and has no parent dependencies, so just hand
in NULL for the parent and be done with it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200826112330.928952181@linutronix.de
The HiSilicon HIP PCIe controller is capable of handling errors
on root port and performing port reset separately at each root port.
Add error handling driver for HIP PCIe controller to log
and report recoverable errors. Perform root port reset and restore
link status after the recovery.
Following are some of the PCIe controller's recoverable errors
1. completion transmission timeout error.
2. CRS retry counter over the threshold error.
3. ECC 2 bit errors
4. AXI bresponse/rresponse errors etc.
The driver placed in the drivers/pci/controller/ because the
HIP PCIe controller does not use DWC IP.
Link: https://lore.kernel.org/r/20200903123456.1823-3-shiju.jose@huawei.com
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Shiju Jose <shiju.jose@huawei.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
The root bus checks rework in d84c572de1 ("PCI: rockchip: Use
pci_is_root_bus() to check if bus is root bus") caused a regression whereby
in rockchip_pcie_valid_device() if the bus parameter is the root bus and
the dev value == 0, the function should return 1 (ie true) without checking
if the bus->parent pointer is a root bus because that triggers a NULL
pointer dereference.
Fix this by streamlining the root bus detection.
Fixes: d84c572de1 ("PCI: rockchip: Use pci_is_root_bus() to check if bus is root bus")
Link: https://lore.kernel.org/r/20200904140904.944-1-lorenzo.pieralisi@arm.com
Reported-by: Samuel Dionne-Riel <samuel@dionne-riel.com>
Tested-by: Samuel Dionne-Riel <samuel@dionne-riel.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Cc: Shawn Lin <shawn.lin@rock-chips.com>
