- Avoid bus resets on Atheros QCA6174, since they hang (Ingmar Klein)

- Use store and forward mode on Pericom PI7C9X2G switches to avoid ACS
  erratum with ACS P2P Request Redirect (Nathan Rossi)

* pci/virtualization:
  PCI: Add ACS quirk for Pericom PI7C9X2G switches
  PCI: Mark Atheros QCA6174 to avoid bus reset

- Check for CAP_SYS_ADMIN before validating sysfs user input, not after
  (Krzysztof Wilczyński)

- Always return -EINVAL from sysfs "store" functions for invalid user input
  instead of -EINVAL sometimes and -ERANGE others (Krzysztof Wilczyński)

- Use kstrtobool() directly instead of the strtobool() wrapper (Krzysztof
  Wilczyński)

* pci/sysfs:
  PCI: Use kstrtobool() directly, sans strtobool() wrapper
  PCI/sysfs: Return -EINVAL consistently from "store" functions
  PCI/sysfs: Check CAP_SYS_ADMIN before parsing user input

# Conflicts:
#	drivers/pci/iov.c

- 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)

* pci/switchtec:
  PCI/switchtec: Add check of event support
  PCI/switchtec: Replace ENOTSUPP with EOPNOTSUPP
  PCI/switchtec: Update the way of getting management VEP instance ID
  PCI/switchtec: Fix a MRPC error status handling issue
  PCI/switchtec: Error out MRPC execution when MMIO reads fail

- Coalesce host bridge contiguous apertures to allow P2P bridge windows
  that span several contiguous host bridge apertures (Kai-Heng Feng)

* pci/resource:
  PCI: Coalesce host bridge contiguous apertures

- Don't setup portdrv IRQs if there are no port drivers that use them, to
  conserve vectors and avoid spurious events (Jan Kiszka)

* pci/portdrv:
  PCI/portdrv: Do not setup up IRQs if there are no users

- Apply bus offset correctly in DMA address calculation, which used the
  wrong sign before (Wang Lu)

* pci/p2pdma:
  PCI/P2PDMA: Apply bus offset correctly in DMA address calculation

- Document sysfs "irq" attribute, which contains either the INTx IRQ (the
  intended behavior) or the first MSI IRQ (historical mistake retained for
  backwards compatibility) (Barry Song)

- Rework "irq" sysfs show function to explicitly fetch first MSI IRQ
  instead of depending on core to put it in dev->irq, to enable future core
  cleanup (Barry Song)

* pci/msi:
  PCI/sysfs: Explicitly show first MSI IRQ for 'irq'
  PCI: Document /sys/bus/pci/devices/.../irq

- Ignore Link Down/Up caused by error-induced Hot Reset so endpoint driver
  can remain bound to device during error recovery (Lukas Wunner)

- Remove unused resume err_handler (Lukas Wunner)

- Remove unused pcie_port_bus_{,un}register() declarations (Lukas Wunner)

- Skip compiling err.c when CONFIG_PCIEAER not set (Lukas Wunner)

* pci/hotplug:
  PCI/ERR: Reduce compile time for CONFIG_PCIEAER=n
  PCI/portdrv: Remove unused pcie_port_bus_{,un}register() declarations
  PCI/portdrv: Remove unused resume err_handler
  PCI: pciehp: Ignore Link Down/Up caused by error-induced Hot Reset
  PCI/portdrv: Rename pm_iter() to pcie_port_device_iter()

- Drop the struct pci_dev.driver pointer, which is redundant with the
  struct device.driver pointer (Uwe Kleine-König)

* pci/driver:
  PCI: Remove struct pci_dev->driver
  PCI: Use to_pci_driver() instead of pci_dev->driver
  x86/pci/probe_roms: Use to_pci_driver() instead of pci_dev->driver
  perf/x86/intel/uncore: Use to_pci_driver() instead of pci_dev->driver
  powerpc/eeh: Use to_pci_driver() instead of pci_dev->driver
  usb: xhci: Use to_pci_driver() instead of pci_dev->driver
  cxl: Use to_pci_driver() instead of pci_dev->driver
  cxl: Factor out common dev->driver expressions
  xen/pcifront: Use to_pci_driver() instead of pci_dev->driver
  xen/pcifront: Drop pcifront_common_process() tests of pcidev, pdrv
  nfp: use dev_driver_string() instead of pci_dev->driver->name
  mlxsw: pci: Use dev_driver_string() instead of pci_dev->driver->name
  net: marvell: prestera: use dev_driver_string() instead of pci_dev->driver->name
  net: hns3: use dev_driver_string() instead of pci_dev->driver->name
  crypto: hisilicon - use dev_driver_string() instead of pci_dev->driver->name
  powerpc/eeh: Use dev_driver_string() instead of struct pci_dev->driver->name
  ssb: Use dev_driver_string() instead of pci_dev->driver->name
  bcma: simplify reference to driver name
  crypto: qat - simplify adf_enable_aer()
  scsi: message: fusion: Remove unused mpt_pci driver .probe() 'id' parameter
  PCI/ERR: Factor out common dev->driver expressions
  PCI: Drop pci_device_probe() test of !pci_dev->driver
  PCI: Drop pci_device_remove() test of pci_dev->driver
  PCI: Return NULL for to_pci_driver(NULL)

- Rename pcibios_add_device() to pcibios_device_add() since it's called
  from pci_device_add() (Oliver O'Halloran)

- Don't try to enable AtomicOps on VFs, since they can only be enabled on
  the PF (Selvin Xavier)

* pci/enumeration:
  PCI: Do not enable AtomicOps on VFs
  PCI: Rename pcibios_add_device() to pcibios_device_add()

- Re-enable LTR in Downstream Ports after it has been disabled by reset or
  hotplug to allow use of ASPM L1.2 again and prevent Unsupported Request
  errors when Endpoint sends LTR messages (Mingchuang Qiao)

* pci/aspm:
  PCI: Re-enable Downstream Port LTR after reset or hotplug

- Simplify _OSC negotiation with platform for control of PCIe features
  (Joerg Roedel)

* pci/acpi:
  PCI/ACPI: Check for _OSC support in acpi_pci_osc_control_set()
  PCI/ACPI: Move _OSC query checks to separate function
  PCI/ACPI: Move supported and control calculations to separate functions
  PCI/ACPI: Remove OSC_PCI_SUPPORT_MASKS and OSC_PCI_CONTROL_MASKS

The Pericom PI7C9X2G404/PI7C9X2G304/PI7C9X2G303 PCIe switches have an
erratum for ACS P2P Request Redirect behaviour when used in the cut-through
forwarding mode. The recommended work around for this issue is to use the
switch in store and forward mode. The erratum results in packets being
queued and not being delivered upstream, which can be observed as very poor
downstream device performance and/or dropped device-generated
data/interrupts.

Add a fixup so that when enabling or resuming the downstream port we check
if it has enabled ACS P2P Request Redirect, and if so, change the device
(via the upstream port) to use the store and forward operating mode.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=177471
Link: https://lore.kernel.org/r/20210910025823.196508-1-nathan@nathanrossi.comTested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Nathan Rossi <nathan.rossi@digi.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Host crashes when pci_enable_atomic_ops_to_root() is called for VFs with
virtual buses. The virtual buses added to SR-IOV have bus->self set to NULL
and host crashes due to this.

  PID: 4481   TASK: ffff89c6941b0000  CPU: 53  COMMAND: "bash"
  ...
   #3 [ffff9a9481713808] oops_end at ffffffffb9025cd6
   #4 [ffff9a9481713828] page_fault_oops at ffffffffb906e417
   #5 [ffff9a9481713888] exc_page_fault at ffffffffb9a0ad14
   #6 [ffff9a94817138b0] asm_exc_page_fault at ffffffffb9c00ace
      [exception RIP: pcie_capability_read_dword+28]
      RIP: ffffffffb952fd5c  RSP: ffff9a9481713960  RFLAGS: 00010246
      RAX: 0000000000000001  RBX: ffff89c6b1096000  RCX: 0000000000000000
      RDX: ffff9a9481713990  RSI: 0000000000000024  RDI: 0000000000000000
      RBP: 0000000000000080   R8: 0000000000000008   R9: ffff89c64341a2f8
      R10: 0000000000000002  R11: 0000000000000000  R12: ffff89c648bab000
      R13: 0000000000000000  R14: 0000000000000000  R15: ffff89c648bab0c8
      ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
   #7 [ffff9a9481713988] pci_enable_atomic_ops_to_root at ffffffffb95359a6
   #8 [ffff9a94817139c0] bnxt_qplib_determine_atomics at ffffffffc08c1a33 [bnxt_re]
   #9 [ffff9a94817139d0] bnxt_re_dev_init at ffffffffc08ba2d1 [bnxt_re]

Per PCIe r5.0, sec 9.3.5.10, the AtomicOp Requester Enable bit in Device
Control 2 is reserved for VFs.  The PF value applies to all associated VFs.

Return -EINVAL if pci_enable_atomic_ops_to_root() is called for a VF.

Link: https://lore.kernel.org/r/1631354585-16597-1-git-send-email-selvin.xavier@broadcom.com
Fixes: 35f5ace5 ("RDMA/bnxt_re: Enable global atomic ops if platform supports")
Fixes: 430a2368 ("PCI: Add pci_enable_atomic_ops_to_root()")
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>

Per PCIe r5.0, sec 7.5.3.16, Downstream Ports must disable LTR if the link
goes down (the Port goes DL_Down status).  This is a problem because the
Downstream Port's dev->ltr_path is still set, so we think LTR is still
enabled, and we enable LTR in the Endpoint.  When it sends LTR messages,
they cause Unsupported Request errors at the Downstream Port.

This happens in the reset path, where we may enable LTR in
pci_restore_pcie_state() even though the Downstream Port disabled LTR
because the reset caused a link down event.

It also happens in the hot-remove and hot-add path, where we may enable LTR
in pci_configure_ltr() even though the Downstream Port disabled LTR when
the hot-remove took the link down.

In these two scenarios, check the upstream bridge and restore its LTR
enable if appropriate.

The Unsupported Request may be logged by AER as follows:

  pcieport 0000:00:1d.0: AER: Uncorrected (Non-Fatal) error received: id=00e8
  pcieport 0000:00:1d.0: PCIe Bus Error: severity=Uncorrected (Non-Fatal), type=Transaction Layer, id=00e8(Requester ID)
  pcieport 0000:00:1d.0:   device [8086:9d18] error status/mask=00100000/00010000
  pcieport 0000:00:1d.0:    [20] Unsupported Request    (First)

In addition, if LTR is not configured correctly, the link cannot enter the
L1.2 state, which prevents some machines from entering the S0ix low power
state.

[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20211012075614.54576-1-mingchuang.qiao@mediatek.comReported-by: Utkarsh H Patel <utkarsh.h.patel@intel.com>
Signed-off-by: Mingchuang Qiao <mingchuang.qiao@mediatek.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

The sysfs "irq" file contains the legacy INTx IRQ.  Or, if the device has
MSI enabled, it contains the first MSI IRQ instead.

Previously this file showed the pci_dev.irq value directly.  But we'd
prefer to use pci_dev.irq only for the INTx IRQ and decouple that from any
MSI or MSI-X IRQs.

If the device has MSI enabled, explicitly look up and show the first MSI
IRQ in the sysfs "irq" file.  Otherwise, show the INTx IRQ.

This removes the requirement that msi_capability_init() set pci_dev.irq to
the first MSI IRQ when enabling MSI and pci_msi_shutdown() restore the INTx
IRQ when disabling MSI.

[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20210825102636.52757-3-21cnbao@gmail.comSigned-off-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Document /sys/bus/pci/devices/.../irq.

This file contains the IRQ of the INTx interrupt (or zero if the device
doesn't support INTx interrupts).

If the device has enabled MSI (not MSI-X), it contains the first MSI IRQ
instead.  This is a historical mistake because devices may support several
MSI or MSI-X vectors, and this file can't contain them all.  But we
preserve this behavior to avoid breaking userspace.

[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20210825102636.52757-2-21cnbao@gmail.comSigned-off-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

There are no remaining uses of the struct pci_dev->driver pointer, so
remove it.

Link: https://lore.kernel.org/r/20211004125935.2300113-12-u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Struct pci_driver contains a struct device_driver, so for PCI devices, it's
easy to convert a device_driver * to a pci_driver * with to_pci_driver().
The device_driver * is in struct device, so we don't need to also keep
track of the pci_driver * in struct pci_dev.

Replace pci_dev->driver with to_pci_driver().  This is a step toward
removing pci_dev->driver.

[bhelgaas: split to separate patch]
Link: https://lore.kernel.org/r/20211004125935.2300113-11-u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Struct pci_driver contains a struct device_driver, so for PCI devices, it's
easy to convert a device_driver * to a pci_driver * with to_pci_driver().
The device_driver * is in struct device, so we don't need to also keep
track of the pci_driver * in struct pci_dev.

Replace pdev->driver with to_pci_driver().  This is a step toward removing
pci_dev->driver.

[bhelgaas: split to separate patch]
Link: https://lore.kernel.org/r/20211004125935.2300113-11-u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Struct pci_driver contains a struct device_driver, so for PCI devices, it's
easy to convert a device_driver * to a pci_driver * with to_pci_driver().
The device_driver * is in struct device, so we don't need to also keep
track of the pci_driver * in struct pci_dev.

Replace pdev->driver with to_pci_driver().  This is a step toward removing
pci_dev->driver.

[bhelgaas: split to separate patch]
Link: https://lore.kernel.org/r/20211004125935.2300113-11-u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Struct pci_driver contains a struct device_driver, so for PCI devices, it's
easy to convert a device_driver * to a pci_driver * with to_pci_driver().
The device_driver * is in struct device, so we don't need to also keep
track of the pci_driver * in struct pci_dev.

Replace pdev->driver with to_pci_driver().  This is a step toward removing
pci_dev->driver.

[bhelgaas: split to separate patch]
Link: https://lore.kernel.org/r/20211004125935.2300113-11-u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Struct pci_driver contains a struct device_driver, so for PCI devices, it's
easy to convert a device_driver * to a pci_driver * with to_pci_driver().
The device_driver * is in struct device, so we don't need to also keep
track of the pci_driver * in struct pci_dev.

Replace pdev->driver with to_pci_driver().  This is a step toward removing
pci_dev->driver.

[bhelgaas: split to separate patch]
Link: https://lore.kernel.org/r/20211004125935.2300113-11-u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Struct pci_driver contains a struct device_driver, so for PCI devices, it's
easy to convert a device_driver * to a pci_driver * with to_pci_driver().
The device_driver * is in struct device, so we don't need to also keep
track of the pci_driver * in struct pci_dev.

Replace pdev->driver with to_pci_driver().  This is a step toward removing
pci_dev->driver.

[bhelgaas: split to separate patch]
Link: https://lore.kernel.org/r/20211004125935.2300113-11-u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Save the struct pci_driver and struct pci_error_handlers pointers from
pdev->driver instead of chasing the pointers several times.  No functional
change intended.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

The sole non-static function in err.c, pcie_do_recovery(), is only
called from:

* aer.c (if CONFIG_PCIEAER=y)
* dpc.c (if CONFIG_PCIE_DPC=y, which depends on CONFIG_PCIEAER)
* edr.c (if CONFIG_PCIE_EDR=y, which depends on CONFIG_PCIE_DPC)

Thus, err.c need not be compiled if CONFIG_PCIEAER=n.

Also, pci_uevent_ers() and pcie_clear_device_status(), which are called
from err.c, can be #ifdef'ed away unless CONFIG_PCIEAER=y.

Since x86_64_defconfig doesn't enable CONFIG_PCIEAER, this change may
slightly reduce compile time for anyone doing a test build with that
config.

Link: https://lore.kernel.org/r/98f9041151268c1c035ab64cca320ad86803f64a.1627638184.git.lukas@wunner.deSigned-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Commit c6c889d9 ("PCI/portdrv: Remove pcie_port_bus_type link order
dependency") removed pcie_port_bus_{,un}register() but erroneously
retained their declarations in portdrv.h.  Remove them as well.

Link: https://lore.kernel.org/r/7fd76b0591c37287ab94d911d8fd9ab9a2afcd16.1627638184.git.lukas@wunner.deSigned-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Commit 3e41a317 ("PCI/AER: Remove unused aer_error_resume()")
removed the resume err_handler from AER.  Since no other port service
implements the callback, support for it can be removed from portdrv.
It can be revived later if need be, preferably by re-using the
pcie_port_device_iter() iterator.

Link: https://lore.kernel.org/r/25334149b604e005058aeb0fdf51e01f991d5d74.1627638184.git.lukas@wunner.deSigned-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Keith Busch <kbusch@kernel.org>

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: 6c2b374d ("PCI-Express AER implemetation: AER core and aerdriver")
Link: https://lore.kernel.org/r/251f4edcc04c14f873ff1c967bc686169cd07d2d.1627638184.git.lukas@wunner.deReported-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+: ba952824: PCI/portdrv: Report reset for frozen channel
Cc: Keith Busch <kbusch@kernel.org>

Rename pm_iter() to pcie_port_device_iter() and make it visible outside
CONFIG_PM and portdrv_core.c so it can be used for pciehp slot reset
recovery.

[bhelgaas: split into its own patch]
Link: https://lore.kernel.org/linux-pci/08c046b0-c9f2-3489-eeef-7e7aca435bb9@gmail.com/
Link: https://lore.kernel.org/r/251f4edcc04c14f873ff1c967bc686169cd07d2d.1627638184.git.lukas@wunner.deSigned-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Struct pci_driver contains a struct device_driver, so for PCI devices, it's
easy to convert a device_driver * to a pci_driver * with to_pci_driver().
The device_driver * is in struct device, so we don't need to also keep
track of the pci_driver * in struct pci_dev.

Replace pdev->driver with to_pci_driver().  This is a step toward removing
pci_dev->driver.

[bhelgaas: split to separate patch]
Link: https://lore.kernel.org/r/20211004125935.2300113-11-u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

pcifront_common_process() exits early if pcidev or pcidev->driver are NULL,
so simplify it by not checking them again.

[bhelgaas: split flag change to separate patch]
Link: https://lore.kernel.org/r/20211004125935.2300113-4-u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

Not all events are supported by every gen/variant of the Switchtec
firmware. To solve this, since Gen4, a new bit in each event header
is introduced to indicate if an event is supported by the firmware.

Link: https://lore.kernel.org/r/20211014141859.11444-6-kelvin.cao@microchip.comSigned-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

ENOTSUPP is not a SUSV4 error code, and the following checkpatch.pl
warning will be given for new patches which still use ENOTSUPP.

    WARNING: ENOTSUPP is not a SUSV4 error code, prefer EOPNOTSUPP

See the link below for the discussion.

  https://lore.kernel.org/netdev/20200511165319.2251678-1-kuba@kernel.org/

Replace ENOTSUPP with EOPNOTSUPP to align with future patches which will
be using EOPNOTSUPP.

Link: https://lore.kernel.org/r/20211014141859.11444-5-kelvin.cao@microchip.comSigned-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Gen4 firmware adds DMA VEP and NVMe VEP support in VEP (virtual EP)
instance ID register in addtion to management EP, update the way of
getting management VEP instance ID.

Link: https://lore.kernel.org/r/20211014141859.11444-4-kelvin.cao@microchip.comSigned-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

If an error is encountered when executing a MRPC command, the firmware
will set the status register to SWITCHTEC_MRPC_STATUS_ERROR and return
the error code in the return value register.

Add handling of SWITCHTEC_MRPC_STATUS_ERROR on status register when
completing a MRPC command.

Link: https://lore.kernel.org/r/20211014141859.11444-3-kelvin.cao@microchip.comSigned-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

A firmware hard reset may be initiated by various mechanisms including a
UART interface, TWI sideband interface from BMC, MRPC command from
userspace, etc. The switchtec management driver is unaware of these
resets.

The reset clears PCI state including the BARs and Memory Space Enable
bits, so the device no longer responds to the MMIO accesses the driver
uses to operate it.

MMIO reads to the device will fail with a PCIe error. When the root
complex handles that error, it typically fabricates ~0 data to complete
the CPU read.

Check for this sort of error by reading the device ID from MMIO space.
This ID can never be ~0, so if we see that value, it probably means the
PCIe Memory Read failed and we should return an error indication to the
application using the switchtec driver.

Link: https://lore.kernel.org/r/20211014141859.11444-2-kelvin.cao@microchip.comSigned-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Replace dev->driver_name() by dev_driver_string() for the corresponding
struct device.  This is a step toward removing pci_dev->driver.

[bhelgaas: split to separate patch]
Link: https://lore.kernel.org/r/20211004125935.2300113-8-u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Simon Horman <simon.horman@corigine.com>

Replace dev->driver_name() by dev_driver_string() for the corresponding
struct device.  This is a step toward removing pci_dev->driver.

[bhelgaas: split to separate patch]
Link: https://lore.kernel.org/r/20211004125935.2300113-8-u.kleine-koenig@pengutronix.deTested-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>

Replace dev->driver_name() by dev_driver_string() for the corresponding
struct device.  This is a step toward removing pci_dev->driver.

[bhelgaas: split to separate patch]
Link: https://lore.kernel.org/r/20211004125935.2300113-8-u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>