This is done by adding a zpci_hot_reset_device() call which does a low
level reset of the PCI function without changing its higher level
function state. This way it can be used while the zPCI function is bound
to a driver and with DMA tables being controlled either through the
IOMMU or DMA APIs which is prohibited when using zpci_disable_device()
as that drop existing DMA translations.
As this reset, unlike a normal FLR, also calls zpci_clear_irq() we need
to implement arch_restore_msi_irqs() and make sure we re-enable IRQs for
the PCI function if they were previously disabled.
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Pull pci updates from Bjorn Helgaas:
"Enumeration:
- Conserve IRQs by setting up portdrv IRQs only when there are users
(Jan Kiszka)
- Rework and simplify _OSC negotiation for control of PCIe features
(Joerg Roedel)
- Remove struct pci_dev.driver pointer since it's redundant with the
struct device.driver pointer (Uwe Kleine-König)
Resource management:
- Coalesce contiguous host bridge apertures from _CRS to accommodate
BARs that cover more than one aperture (Kai-Heng Feng)
Sysfs:
- Check CAP_SYS_ADMIN before parsing user input (Krzysztof
Wilczyński)
- Return -EINVAL consistently from "store" functions (Krzysztof
Wilczyński)
- Use sysfs_emit() in endpoint "show" functions to avoid buffer
overruns (Kunihiko Hayashi)
PCIe native device hotplug:
- Ignore Link Down/Up caused by resets during error recovery so
endpoint drivers can remain bound to the device (Lukas Wunner)
Virtualization:
- Avoid bus resets on Atheros QCA6174, where they hang the device
(Ingmar Klein)
- Work around Pericom PI7C9X2G switch packet drop erratum by using
store and forward mode instead of cut-through (Nathan Rossi)
- Avoid trying to enable AtomicOps on VFs; the PF setting applies to
all VFs (Selvin Xavier)
MSI:
- Document that /sys/bus/pci/devices/.../irq contains the legacy INTx
interrupt or the IRQ of the first MSI (not MSI-X) vector (Barry
Song)
VPD:
- Add pci_read_vpd_any() and pci_write_vpd_any() to access anywhere
in the possible VPD space; use these to simplify the cxgb3 driver
(Heiner Kallweit)
Peer-to-peer DMA:
- Add (not subtract) the bus offset when calculating DMA address
(Wang Lu)
ASPM:
- Re-enable LTR at Downstream Ports so they don't report Unsupported
Requests when reset or hot-added devices send LTR messages
(Mingchuang Qiao)
Apple PCIe controller driver:
- Add driver for Apple M1 PCIe controller (Alyssa Rosenzweig, Marc
Zyngier)
Cadence PCIe controller driver:
- Return success when probe succeeds instead of falling into error
path (Li Chen)
HiSilicon Kirin PCIe controller driver:
- Reorganize PHY logic and add support for external PHY drivers
(Mauro Carvalho Chehab)
- Support PERST# GPIOs for HiKey970 external PEX 8606 bridge (Mauro
Carvalho Chehab)
- Add Kirin 970 support (Mauro Carvalho Chehab)
- Make driver removable (Mauro Carvalho Chehab)
Intel VMD host bridge driver:
- If IOMMU supports interrupt remapping, leave VMD MSI-X remapping
enabled (Adrian Huang)
- Number each controller so we can tell them apart in
/proc/interrupts (Chunguang Xu)
- Avoid building on UML because VMD depends on x86 bare metal APIs
(Johannes Berg)
Marvell Aardvark PCIe controller driver:
- Define macros for PCI_EXP_DEVCTL_PAYLOAD_* (Pali Rohár)
- Set Max Payload Size to 512 bytes per Marvell spec (Pali Rohár)
- Downgrade PIO Response Status messages to debug level (Marek Behún)
- Preserve CRS SV (Config Request Retry Software Visibility) bit in
emulated Root Control register (Pali Rohár)
- Fix issue in configuring reference clock (Pali Rohár)
- Don't clear status bits for masked interrupts (Pali Rohár)
- Don't mask unused interrupts (Pali Rohár)
- Avoid code repetition in advk_pcie_rd_conf() (Marek Behún)
- Retry config accesses on CRS response (Pali Rohár)
- Simplify emulated Root Capabilities initialization (Pali Rohár)
- Fix several link training issues (Pali Rohár)
- Fix link-up checking via LTSSM (Pali Rohár)
- Fix reporting of Data Link Layer Link Active (Pali Rohár)
- Fix emulation of W1C bits (Marek Behún)
- Fix MSI domain .alloc() method to return zero on success (Marek
Behún)
- Read entire 16-bit MSI vector in MSI handler, not just low 8 bits
(Marek Behún)
- Clear Root Port I/O Space, Memory Space, and Bus Master Enable bits
at startup; PCI core will set those as necessary (Pali Rohár)
- When operating as a Root Port, set class code to "PCI Bridge"
instead of the default "Mass Storage Controller" (Pali Rohár)
- Add emulation for PCI_BRIDGE_CTL_BUS_RESET since aardvark doesn't
implement this per spec (Pali Rohár)
- Add emulation of option ROM BAR since aardvark doesn't implement
this per spec (Pali Rohár)
MediaTek MT7621 PCIe controller driver:
- Add MediaTek MT7621 PCIe host controller driver and DT binding
(Sergio Paracuellos)
Qualcomm PCIe controller driver:
- Add SC8180x compatible string (Bjorn Andersson)
- Add endpoint controller driver and DT binding (Manivannan
Sadhasivam)
- Restructure to use of_device_get_match_data() (Prasad Malisetty)
- Add SC7280-specific pcie_1_pipe_clk_src handling (Prasad Malisetty)
Renesas R-Car PCIe controller driver:
- Remove unnecessary includes (Geert Uytterhoeven)
Rockchip DesignWare PCIe controller driver:
- Add DT binding (Simon Xue)
Socionext UniPhier Pro5 controller driver:
- Serialize INTx masking/unmasking (Kunihiko Hayashi)
Synopsys DesignWare PCIe controller driver:
- Run dwc .host_init() method before registering MSI interrupt
handler so we can deal with pending interrupts left by bootloader
(Bjorn Andersson)
- Clean up Kconfig dependencies (Andy Shevchenko)
- Export symbols to allow more modular drivers (Luca Ceresoli)
TI DRA7xx PCIe controller driver:
- Allow host and endpoint drivers to be modules (Luca Ceresoli)
- Enable external clock if present (Luca Ceresoli)
TI J721E PCIe driver:
- Disable PHY when probe fails after initializing it (Christophe
JAILLET)
MicroSemi Switchtec management driver:
- Return error to application when command execution fails because an
out-of-band reset has cleared the device BARs, Memory Space Enable,
etc (Kelvin Cao)
- Fix MRPC error status handling issue (Kelvin Cao)
- Mask out other bits when reading of management VEP instance ID
(Kelvin Cao)
- Return EOPNOTSUPP instead of ENOTSUPP from sysfs show functions
(Kelvin Cao)
- Add check of event support (Logan Gunthorpe)
Miscellaneous:
- Remove unused pci_pool wrappers, which have been replaced by
dma_pool (Cai Huoqing)
- Use 'unsigned int' instead of bare 'unsigned' (Krzysztof
Wilczyński)
- Use kstrtobool() directly, sans strtobool() wrapper (Krzysztof
Wilczyński)
- Fix some sscanf(), sprintf() format mismatches (Krzysztof
Wilczyński)
- Update PCI subsystem information in MAINTAINERS (Krzysztof
Wilczyński)
- Correct some misspellings (Krzysztof Wilczyński)"
* tag 'pci-v5.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (137 commits)
PCI: Add ACS quirk for Pericom PI7C9X2G switches
PCI: apple: Configure RID to SID mapper on device addition
iommu/dart: Exclude MSI doorbell from PCIe device IOVA range
PCI: apple: Implement MSI support
PCI: apple: Add INTx and per-port interrupt support
PCI: kirin: Allow removing the driver
PCI: kirin: De-init the dwc driver
PCI: kirin: Disable clkreq during poweroff sequence
PCI: kirin: Move the power-off code to a common routine
PCI: kirin: Add power_off support for Kirin 960 PHY
PCI: kirin: Allow building it as a module
PCI: kirin: Add MODULE_* macros
PCI: kirin: Add Kirin 970 compatible
PCI: kirin: Support PERST# GPIOs for HiKey970 external PEX 8606 bridge
PCI: apple: Set up reference clocks when probing
PCI: apple: Add initial hardware bring-up
PCI: of: Allow matching of an interrupt-map local to a PCI device
of/irq: Allow matching of an interrupt-map local to an interrupt controller
irqdomain: Make of_phandle_args_to_fwspec() generally available
PCI: Do not enable AtomicOps on VFs
...
- Tidy setup-irq.c comments (Pranay Sanghai)
- Fix misspellings (Krzysztof Wilczyński)
- Fix sprintf(), sscanf() format mismatches (Krzysztof Wilczyński)
- Tidy cpqphp code formatting (Krzysztof Wilczyński)
- Remove unused pci_pool wrappers, which have been replaced by dma_pool
(Cai Huoqing)
- Remove a redundant initialization in __pci_reset_function_locked() (Colin
Ian King)
- Use 'unsigned int' instead of 'unsigned' (Krzysztof Wilczyński)
- Update PCI subsystem information in MAINTAINERS (Krzysztof Wilczyński)
- Include generic <linux/> headers instead of <asm/> for cpqphp and vmd
(Krzysztof Wilczyński)
* pci/misc:
PCI: vmd: Drop redundant includes of <asm/device.h>, <asm/msi.h>
PCI: cpqphp: Use <linux/io.h> instead of <asm/io.h>
MAINTAINERS: Update PCI subsystem information
PCI: Prefer 'unsigned int' over bare 'unsigned'
PCI: Remove redundant 'rc' initialization
PCI: Remove unused pci_pool wrappers
PCI: cpqphp: Format if-statement code block correctly
PCI: Use unsigned to match sscanf("%x") in pci_dev_str_match_path()
PCI: hv: Remove unnecessary use of %hx
PCI: Correct misspelled and remove duplicated words
PCI: Tidy comments
Stuart Hayes reports that an error handled by DPC at a Root Port results
in pciehp gratuitously bringing down a subordinate hotplug port:
RP -- UP -- DP -- UP -- DP (hotplug) -- EP
pciehp brings the slot down because the Link to the Endpoint goes down.
That is caused by a Hot Reset being propagated as a result of DPC.
Per PCIe Base Spec 5.0, section 6.6.1 "Conventional Reset":
For a Switch, the following must cause a hot reset to be sent on all
Downstream Ports: [...]
* The Data Link Layer of the Upstream Port reporting DL_Down status.
In Switches that support Link speeds greater than 5.0 GT/s, the
Upstream Port must direct the LTSSM of each Downstream Port to the
Hot Reset state, but not hold the LTSSMs in that state. This permits
each Downstream Port to begin Link training immediately after its
hot reset completes. This behavior is recommended for all Switches.
* Receiving a hot reset on the Upstream Port.
Once DPC recovers, pcie_do_recovery() walks down the hierarchy and
invokes pcie_portdrv_slot_reset() to restore each port's config space.
At that point, a hotplug interrupt is signaled per PCIe Base Spec r5.0,
section 6.7.3.4 "Software Notification of Hot-Plug Events":
If the Port is enabled for edge-triggered interrupt signaling using
MSI or MSI-X, an interrupt message must be sent every time the logical
AND of the following conditions transitions from FALSE to TRUE: [...]
* The Hot-Plug Interrupt Enable bit in the Slot Control register is
set to 1b.
* At least one hot-plug event status bit in the Slot Status register
and its associated enable bit in the Slot Control register are both
set to 1b.
Prevent pciehp from gratuitously bringing down the slot by clearing the
error-induced Data Link Layer State Changed event before restoring
config space. Afterwards, check whether the link has unexpectedly
failed to retrain and synthesize a DLLSC event if so.
Allow each pcie_port_service_driver (one of them being pciehp) to define
a slot_reset callback and re-use the existing pm_iter() function to
iterate over the callbacks.
Thereby, the Endpoint driver remains bound throughout error recovery and
may restore the device to working state.
Surprise removal during error recovery is detected through a Presence
Detect Changed event. The hotplug port is expected to not signal that
event as a result of a Hot Reset.
The issue isn't DPC-specific, it also occurs when an error is handled by
AER through aer_root_reset(). So while the issue was noticed only now,
it's been around since 2006 when AER support was first introduced.
[bhelgaas: drop PCI_ERROR_RECOVERY Kconfig, split pm_iter() rename to
preparatory patch]
Link: https://lore.kernel.org/linux-pci/08c046b0-c9f2-3489-eeef-7e7aca435bb9@gmail.com/
Fixes: 6c2b374d74 ("PCI-Express AER implemetation: AER core and aerdriver")
Link: https://lore.kernel.org/r/251f4edcc04c14f873ff1c967bc686169cd07d2d.1627638184.git.lukas@wunner.de
Reported-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Tested-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org # v2.6.19+: ba952824e6: PCI/portdrv: Report reset for frozen channel
Cc: Keith Busch <kbusch@kernel.org>
Since commit 2a671f77ee ("s390/pci: fix use after free of zpci_dev")
the reference count of a zpci_dev is incremented between
pcibios_add_device() and pcibios_release_device() which was supposed to
prevent the zpci_dev from being freed while the common PCI code has
access to it. It was missed however that the handling of zPCI
availability events assumed that once zpci_zdev_put() was called no
later availability event would still see the device. With the previously
mentioned commit however this assumption no longer holds and we must
make sure that we only drop the initial long-lived reference the zPCI
subsystem holds exactly once.
Do so by introducing a zpci_device_reserved() function that handles when
a device is reserved. Here we make sure the zpci_dev will not be
considered for further events by removing it from the zpci_list.
This also means that the device actually stays in the
ZPCI_FN_STATE_RESERVED state between the time we know it has been
reserved and the final reference going away. We thus need to consider it
a real state instead of just a conceptual state after the removal. The
final cleanup of PCI resources, removal from zbus, and destruction of
the IOMMU stays in zpci_release_device() to make sure holders of the
reference do see valid data until the release.
Fixes: 2a671f77ee ("s390/pci: fix use after free of zpci_dev")
Cc: stable@vger.kernel.org
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
- Cache PCIe Device Capabilities register (Amey Narkhede)
- Add pcie_reset_flr() with 'probe' argument (Amey Narkhede)
- Add pdev->reset_methods[] array to track reset method ordering (Amey
Narkhede)
- Remove reset_fn field from pci_dev (Amey Narkhede)
- Add sysfs interface to query and set device reset mechanism (Amey
Narkhede)
- Add pci_set_acpi_fwnode() to set ACPI_COMPANION (Shanker Donthineni)
- Use acpi_pci_power_manageable() instead of duplicating logic (Shanker
Donthineni)
- Set ACPI fwnode early and at the same time with OF (Shanker Donthineni)
- Add support for ACPI _RST reset method (Shanker Donthineni)
- Change reset function 'probe' argument to bool (Amey Narkhede)
* pci/reset:
PCI: Change the type of probe argument in reset functions
PCI: Add support for ACPI _RST reset method
PCI: Setup ACPI fwnode early and at the same time with OF
PCI: Use acpi_pci_power_manageable()
PCI: Add pci_set_acpi_fwnode() to set ACPI_COMPANION
PCI: Allow userspace to query and set device reset mechanism
PCI: Remove reset_fn field from pci_dev
PCI: Add array to track reset method ordering
PCI: Add pcie_reset_flr() with 'probe' argument
PCI: Cache PCIe Device Capabilities register
cpci_debug is declared as a global variable in cpci_hotplug_core.c and used
in cpci_hotplug_pci.c via an "extern". Add an extern declaration in the
header file.
Resolves the following sparse warning:
drivers/pci/hotplug/cpci_hotplug_core.c:47:5: warning: symbol 'cpci_debug' was not declared. Should it be static?
Link: https://lore.kernel.org/r/20210701184306.1492003-1-kw@linux.com
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Downstream Port Containment (PCIe r5.0, sec. 6.2.10) disables the link upon
an error and attempts to re-enable it when instructed by the DPC driver.
A slot which is both DPC- and hotplug-capable is currently powered off by
pciehp once DPC is triggered (due to the link change) and powered back up
on successful recovery. That's undesirable, the slot should remain powered
so the hotplugged device remains bound to its driver. DPC notifies the
driver of the error and of successful recovery in pcie_do_recovery() and
the driver may then restore the device to working state.
Moreover, Sinan points out that turning off slot power by pciehp may foil
recovery by DPC: Power off/on is a cold reset concurrently to DPC's warm
reset. Sathyanarayanan reports extended delays or failure in link
retraining by DPC if pciehp brings down the slot.
Fix by detecting whether a Link Down event is caused by DPC and awaiting
recovery if so. On successful recovery, ignore both the Link Down and the
subsequent Link Up event.
Afterwards, check whether the link is down to detect surprise-removal or
another DPC event immediately after DPC recovery. Ensure that the
corresponding DLLSC event is not ignored by synthesizing it and invoking
irq_wake_thread() to trigger a re-run of pciehp_ist().
The IRQ threads of the hotplug and DPC drivers, pciehp_ist() and
dpc_handler(), race against each other. If pciehp is faster than DPC, it
will wait until DPC recovery completes.
Recovery consists of two steps: The first step (waiting for link
disablement) is recognizable by pciehp through a set DPC Trigger Status
bit. The second step (waiting for link retraining) is recognizable through
a newly introduced PCI_DPC_RECOVERING flag.
If DPC is faster than pciehp, neither of the two flags will be set and
pciehp may glean the recovery status from the new PCI_DPC_RECOVERED flag.
The flag is zero if DPC didn't occur at all, hence DLLSC events are not
ignored by default.
pciehp waits up to 4 seconds before assuming that DPC recovery failed and
bringing down the slot. This timeout is not taken from the spec (it
doesn't mandate one) but based on a report from Yicong Yang that DPC may
take a bit more than 3 seconds on HiSilicon's Kunpeng platform.
The timeout is necessary because the DPC Trigger Status bit may never
clear: On Root Ports which support RP Extensions for DPC, the DPC driver
polls the DPC RP Busy bit for up to 1 second before giving up on DPC
recovery. Without the timeout, pciehp would then wait indefinitely for DPC
to complete.
This commit draws inspiration from previous attempts to synchronize DPC
with pciehp:
By Sinan Kaya, August 2018:
https://lore.kernel.org/linux-pci/20180818065126.77912-1-okaya@kernel.org/
By Ethan Zhao, October 2020:
https://lore.kernel.org/linux-pci/20201007113158.48933-1-haifeng.zhao@intel.com/
By Kuppuswamy Sathyanarayanan, March 2021:
https://lore.kernel.org/linux-pci/59cb30f5e5ac6d65427ceaadf1012b2ba8dbf66c.1615606143.git.sathyanarayanan.kuppuswamy@linux.intel.com/
Link: https://lore.kernel.org/r/0be565d97438fe2a6d57354b3aa4e8626952a00b.1619857124.git.lukas@wunner.de
Reported-by: Sinan Kaya <okaya@kernel.org>
Reported-by: Ethan Zhao <haifeng.zhao@intel.com>
Reported-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Tested-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Tested-by: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Keith Busch <kbusch@kernel.org>
The sysfs_emit() and sysfs_emit_at() functions were introduced to make
it less ambiguous which function is preferred when writing to the output
buffer in a device attribute's "show" callback [1].
Convert the PCI sysfs object "show" functions from sprintf(), snprintf()
and scnprintf() to sysfs_emit() and sysfs_emit_at() accordingly, as the
latter is aware of the PAGE_SIZE buffer and correctly returns the number
of bytes written into the buffer.
No functional change intended.
[1] Documentation/filesystems/sysfs.rst
Related commit: ad025f8e46 ("PCI/sysfs: Use sysfs_emit() and
sysfs_emit_at() in "show" functions").
Link: https://lore.kernel.org/r/20210603000112.703037-2-kw@linux.com
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Pull more s390 updates from Heiko Carstens:
- add support for system call stack randomization
- handle stale PCI deconfiguration events
- couple of defconfig updates
- some fixes and cleanups
* tag 's390-5.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390: fix detection of vector enhancements facility 1 vs. vector packed decimal facility
s390/entry: add support for syscall stack randomization
s390/configs: change CONFIG_VIRTIO_CONSOLE to "m"
s390/cio: remove invalid condition on IO_SCH_UNREG
s390/cpumf: remove call to perf_event_update_userpage
s390/cpumf: move counter set size calculation to common place
s390/cpumf: beautify if-then-else indentation
s390/configs: enable CONFIG_PCI_IOV
s390/pci: handle stale deconfiguration events
s390/pci: rename zpci_configure_device()
With zpci_configure_device() now always called on a device that has
already been configured on the platform level its name has become
misleading. Rename it to zpci_scan_configured_device() to signify that
the function now only handles the correct scanning of a newly configured
PCI function taking care of the special handling necessary for function
0 and functions parked waiting for a PCI bus that can't be created
without first seeing function 0.
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Currently zpci_configure_device() can be called on a zPCI function in
two completely different states. Either the underlying zPCI function has
already been configured by the platform and we are only doing the
scanning to get it usable by Linux drivers. Or the underlying function
is in Standby and we first do an SCLP to get it configured. This makes
zpci_configure_device() harder to reason about. Since calling
zpci_configure_device() on a function in Standby only happens in
enable_slot() simply pull out the SCLP call and setting of zdev->state
and thus call zpci_configure_device() under the same circumstances as
in the event handling code.
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
