Pull powerpc fixes from Michael Ellerman:

 - Fix a possible stack corruption and subsequent DLPAR failure in the
   rpadlpar_io PCI hotplug driver

 - Two build fixes for uncommon configurations

Thanks to Christophe Leroy and Tyrel Datwyler.

* tag 'powerpc-5.12-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  PCI: rpadlpar: Fix potential drc_name corruption in store functions
  powerpc: Force inlining of cpu_has_feature() to avoid build failure
  powerpc/vdso32: Add missing _restgpr_31_x to fix build failure

Both add_slot_store() and remove_slot_store() try to fix up the
drc_name copied from the store buffer by placing a NUL terminator at
nbyte + 1 or in place of a '\n' if present. However, the static buffer
that we copy the drc_name data into is not zeroed and can contain
anything past the n-th byte.

This is problematic if a '\n' byte appears in that buffer after nbytes
and the string copied into the store buffer was not NUL terminated to
start with as the strchr() search for a '\n' byte will mark this
incorrectly as the end of the drc_name string resulting in a drc_name
string that contains garbage data after the n-th byte.

Additionally it will cause us to overwrite that '\n' byte on the stack
with NUL, potentially corrupting data on the stack.

The following debugging shows an example of the drmgr utility writing
"PHB 4543" to the add_slot sysfs attribute, but add_slot_store()
logging a corrupted string value.

  drmgr: drmgr: -c phb -a -s PHB 4543 -d 1
  add_slot_store: drc_name = PHB 4543°|<82>!, rc = -19

Fix this by using strscpy() instead of memcpy() to ensure the string
is NUL terminated when copied into the static drc_name buffer.
Further, since the string is now NUL terminated the code only needs to
change '\n' to '\0' when present.

Cc: stable@vger.kernel.org
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
[mpe: Reformat change log and add mention of possible stack corruption]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210315214821.452959-1-tyreld@linux.ibm.com

In commit 05bc1be6db4b2 ("s390/pci: create zPCI bus") we removed the
pci_dev_put() call matching the earlier pci_get_slot() done as part of
__zpci_event_availability(). This was based on the wrong understanding
that the device_put() done as part of pci_destroy_device() would counter
the pci_get_slot() when it only counters the initial reference. This
same understanding and existing bad example also lead to not doing
a pci_dev_put() in zpci_remove_device().

Since releasing the PCI devices, unlike releasing the PCI slot, does not
print any debug message for testing I added one in pci_release_dev().
This revealed that we are indeed leaking the PCI device on PCI
hotunplug. Further testing also revealed another missing pci_dev_put() in
disable_slot().

Fix this by adding the missing pci_dev_put() in disable_slot() and fix
zpci_remove_device() with the correct pci_dev_put() calls. Also instead
of calling pci_get_slot() in __zpci_event_availability() to determine if
a PCI device is registered and then doing the same again in
zpci_remove_device() do this once in zpci_remove_device() which makes
sure that the pdev in __zpci_event_availability() is only used for the
result of pci_scan_single_device() which does not need a reference count
decremnt as its ownership goes to the PCI bus.

Also move the check if zdev->zbus->bus is set into zpci_remove_device()
since it may be that we're removing a device with devfn != 0 which never
had a PCI bus. So we can still set the pdev->error_state to indicate
that the device is not usable anymore, add a flag to set the error state.

Fixes: 05bc1be6db4b2 ("s390/pci: create zPCI bus")
Cc: <stable@vger.kernel.org> # 5.8+: e1bff843cde6 s390/pci: remove superfluous zdev->zbus check
Cc: <stable@vger.kernel.org> # 5.8+: ba764dd703fe s390/pci: refactor zpci_create_device()
Cc: <stable@vger.kernel.org> # 5.8+
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

Remove the 'acpiphp_callback' typedef as it is not used.

Link: https://lore.kernel.org/r/1613443120-4279-1-git-send-email-chen45464546@163.com
Signed-off-by: Chen Lin <chen.lin5@zte.com.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Krzysztof Wilczyński <kw@linux.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

A break is not needed if it is preceded by a return.

Based on Tom Rix's treewide patch; this instance extracted from Joe
Perches' list.

Link: https://lore.kernel.org/r/20201017160928.12698-1-trix@redhat.com
Link: https://lore.kernel.org/r/f530b7aeecbbf9654b4540cfa20023a4c2a11889.camel@perches
.com
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Tom Rix <trix@redhat.com>
Cc: Joe Perches <joe@perches.com>

Pull PCI updates from Bjorn Helgaas:
 "Enumeration:
   - Print IRQ number used by PCIe Link Bandwidth Notification (Dongdong
     Liu)
   - Add schedule point in pci_read_config() to reduce max latency
     (Jiang Biao)
   - Add Kconfig options for MPS/MRRS strategy (Jim Quinlan)

  Resource management:
   - Fix pci_iounmap() memory leak when !CONFIG_GENERIC_IOMAP (Lorenzo
     Pieralisi)

  PCIe native device hotplug:
   - Reduce noisiness on hot removal (Lukas Wunner)

  Power management:
   - Revert "PCI/PM: Apply D2 delay as milliseconds, not microseconds"
     that was done on the basis of spec typo (Bjorn Helgaas)
   - Rename pci_dev.d3_delay to d3hot_delay to remove D3hot/D3cold
     ambiguity (Krzysztof Wilczyński)
   - Remove unused pcibios_pm_ops (Vaibhav Gupta)

  IOMMU:
   - Enable Translation Blocking for external devices to harden against
     DMA attacks (Rajat Jain)

  Error handling:
   - Add an ACPI APEI notifier chain for vendor CPER records to enable
     device-specific error handling (Shiju Jose)

  ASPM:
   - Remove struct aspm_register_info to simplify code (Saheed O.
     Bolarinwa)

  Amlogic Meson PCIe controller driver:
   - Build as module by default (Kevin Hilman)

  Ampere Altra PCIe controller driver:
   - Add MCFG quirk to work around non-standard ECAM implementation
     (Tuan Phan)

  Broadcom iProc PCIe controller driver:
   - Set affinity mask on MSI interrupts (Mark Tomlinson)

  Broadcom STB PCIe controller driver:
   - Make PCIE_BRCMSTB depend on ARCH_BRCMSTB (Jim Quinlan)
   - Add DT bindings for more Brcmstb chips (Jim Quinlan)
   - Add bcm7278 register info (Jim Quinlan)
   - Add bcm7278 PERST# support (Jim Quinlan)
   - Add suspend and resume pm_ops (Jim Quinlan)
   - Add control of rescal reset (Jim Quinlan)
   - Set additional internal memory DMA viewport sizes (Jim Quinlan)
   - Accommodate MSI for older chips (Jim Quinlan)
   - Set bus max burst size by chip type (Jim Quinlan)
   - Add support for bcm7211, bcm7216, bcm7445, bcm7278 (Jim Quinlan)

  Freescale i.MX6 PCIe controller driver:
   - Use dev_err_probe() to reduce redundant messages (Anson Huang)

  Freescale Layerscape PCIe controller driver:
   - Enforce 4K DMA buffer alignment in endpoint test (Hou Zhiqiang)
   - Add DT compatible strings for ls1088a, ls2088a (Xiaowei Bao)
   - Add endpoint support for ls1088a, ls2088a (Xiaowei Bao)
   - Add endpoint test support for lS1088a (Xiaowei Bao)
   - Add MSI-X support for ls1088a (Xiaowei Bao)

  HiSilicon HIP PCIe controller driver:
   - Handle HIP-specific errors via ACPI APEI (Yicong Yang)

  HiSilicon Kirin PCIe controller driver:
   - Return -EPROBE_DEFER if the GPIO isn't ready (Bean Huo)

  Intel VMD host bridge driver:
   - Factor out physical offset, bus offset, IRQ domain, IRQ allocation
     (Jon Derrick)
   - Use generic PCI PM correctly (Jon Derrick)

  Marvell Aardvark PCIe controller driver:
   - Fix compilation on s390 (Pali Rohár)
   - Implement driver 'remove' function and allow to build it as module
     (Pali Rohár)
   - Move PCIe reset card code to advk_pcie_train_link() (Pali Rohár)
   - Convert mvebu a3700 internal SMCC firmware return codes to errno
     (Pali Rohár)
   - Fix initialization with old Marvell's Arm Trusted Firmware (Pali
     Rohár)

  Microsoft Hyper-V host bridge driver:
   - Fix hibernation in case interrupts are not re-created (Dexuan Cui)

  NVIDIA Tegra PCIe controller driver:
   - Stop checking return value of debugfs_create() functions (Greg
     Kroah-Hartman)
   - Convert to use DEFINE_SEQ_ATTRIBUTE macro (Liu Shixin)

  Qualcomm PCIe controller driver:
   - Reset PCIe to work around Qsdk U-Boot issue (Ansuel Smith)

  Renesas R-Car PCIe controller driver:
   - Add DT documentation for r8a774a1, r8a774b1, r8a774e1 endpoints
     (Lad Prabhakar)
   - Add RZ/G2M, RZ/G2N, RZ/G2H IDs to endpoint test (Lad Prabhakar)
   - Add DT support for r8a7742 (Lad Prabhakar)

  Socionext UniPhier Pro5 controller driver:
   - Add DT descriptions of iATU register (host and endpoint) (Kunihiko
     Hayashi)

  Synopsys DesignWare PCIe controller driver:
   - Add link up check in dw_child_pcie_ops.map_bus() (racy, but seems
     unavoidable) (Hou Zhiqiang)
   - Fix endpoint Header Type check so multi-function devices work (Hou
     Zhiqiang)
   - Skip PCIE_MSI_INTR0* programming if MSI is disabled (Jisheng Zhang)
   - Stop leaking MSI page in suspend/resume (Jisheng Zhang)
   - Add common iATU register support instead of keystone-specific code
     (Kunihiko Hayashi)
   - Major config space access and other cleanups in dwc core and
     drivers that use it (al, exynos, histb, imx6, intel-gw, keystone,
     kirin, meson, qcom, tegra) (Rob Herring)
   - Add multiple PFs support for endpoint (Xiaowei Bao)
   - Add MSI-X doorbell mode in endpoint mode (Xiaowei Bao)

  Miscellaneous:
   - Use fallthrough pseudo-keyword (Gustavo A. R. Silva)
   - Fix "0 used as NULL pointer" warnings (Gustavo Pimentel)
   - Fix "cast truncates bits from constant value" warnings (Gustavo
     Pimentel)
   - Remove redundant zeroing for sg_init_table() (Julia Lawall)
   - Use scnprintf(), not snprintf(), in sysfs "show" functions
     (Krzysztof Wilczyński)
   - Remove unused assignments (Krzysztof Wilczyński)
   - Fix "0 used as NULL pointer" warning (Krzysztof Wilczyński)
   - Simplify bool comparisons (Krzysztof Wilczyński)
   - Use for_each_child_of_node() and for_each_node_by_name() (Qinglang
     Miao)
   - Simplify return expressions (Qinglang Miao)"

* tag 'pci-v5.10-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (147 commits)
  PCI: vmd: Update VMD PM to correctly use generic PCI PM
  PCI: vmd: Create IRQ allocation helper
  PCI: vmd: Create IRQ Domain configuration helper
  PCI: vmd: Create bus offset configuration helper
  PCI: vmd: Create physical offset helper
  PCI: v3-semi: Remove unneeded break
  PCI: dwc: Add link up check in dw_child_pcie_ops.map_bus()
  PCI/ASPM: Remove struct pcie_link_state.l1ss
  PCI/ASPM: Remove struct aspm_register_info.l1ss_cap
  PCI/ASPM: Pass L1SS Capabilities value, not struct aspm_register_info
  PCI/ASPM: Remove struct aspm_register_info.l1ss_ctl1
  PCI/ASPM: Remove struct aspm_register_info.l1ss_ctl2 (unused)
  PCI/ASPM: Remove struct aspm_register_info.l1ss_cap_ptr
  PCI/ASPM: Remove struct aspm_register_info.latency_encoding
  PCI/ASPM: Remove struct aspm_register_info.enabled
  PCI/ASPM: Remove struct aspm_register_info.support
  PCI/ASPM: Use 'parent' and 'child' for readability
  PCI/ASPM: Move LTR path check to where it's used
  PCI/ASPM: Move pci_clear_and_set_dword() earlier
  PCI: dwc: Fix MSI page leakage in suspend/resume
  ...

The value of the constant POWER_FAILURE assigned to the variable rc
after the power fault check is never used for anything, so remove it.

Addresses-Coverity-ID: 1226899 ("Unused value")
Link: https://lore.kernel.org/r/20200923025225.471459-1-kw@linux.com
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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 80696f991424
("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
6c35a1ac3da6 ("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>

Use for_each_child_of_node() and for_each_node_by_name() macros instead of
open coding them.

Link: https://lore.kernel.org/r/20200916062128.190819-1-miaoqinglang@huawei.com
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>