The PCI bus config accessors could be inlined into other accessor
functions, which makes it so they can't be traced. Force them to never be
inlined so that ftrace can hook into these functions.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Remove pointless comments that tell us the file name, remove blank line
comments, follow multi-line comment conventions. No functional change
intended.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Move the VPD-related code from access.c to vpd.c. The goal is to
encapsulate all the VPD code and structures in vpd.c.
No functional change intended.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
* pci/spdx:
PCI: Add SPDX GPL-2.0+ to replace implicit GPL v2 or later statement
PCI: Add SPDX GPL-2.0+ to replace GPL v2 or later boilerplate
PCI: Add SPDX GPL-2.0 to replace COPYING boilerplate
PCI: Add SPDX GPL-2.0 to replace GPL v2 boilerplate
PCI: Add SPDX GPL-2.0 when no license was specified
b24413180f ("License cleanup: add SPDX GPL-2.0 license identifier to
files with no license") added SPDX GPL-2.0 to several PCI files that
previously contained no license information.
Add SPDX GPL-2.0 to all other PCI files that did not contain any license
information and hence were under the default GPL version 2 license of the
kernel.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add PCI-specific dev_printk() wrappers and use them to simplify the code
slightly. No functional change intended.
Signed-off-by: Frederick Lawler <fred@fredlawl.com>
[bhelgaas: squash into one patch]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The generic PCI configuration space accessors are globally serialized via
pci_lock. On larger systems this causes massive lock contention when the
configuration space has to be accessed frequently. One such access pattern
is the Intel Uncore performance counter unit.
Provide a kernel config option which can be selected by an architecture
when the low level PCI configuration space accessors in the architecture
use their own serialization or can operate completely lockless.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Bjorn Helgaas <helgaas@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: linux-pci@vger.kernel.org
Link: http://lkml.kernel.org/r/20170316215057.205961140@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Callers normally treat the config space accessors as returning PCBIOS_*
error codes, not Linux error codes (or they don't look at them at all). We
have pcibios_err_to_errno() in case the error code needs to be translated.
Fixes: 4b10388347 ("PCI: Don't attempt config access to disconnected devices")
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
A PCI/PCI-X to PCI Express bridge, sometimes referred to as a "reverse
bridge", is a bridge with conventional PCI or PCI-X on its primary side and
a PCI Express Port on its secondary (downstream) side.
That PCIe Port is a Downstream Port and could be connected to a slot, just
like a Root Port or a Switch Downstream Port. Make pcie_downstream_port()
return true for them, so we can access the Slot registers in the PCIe
capability.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
There is no pci_cfg_access_unlocked(). I think the author meant
pci_cfg_access_unlock().
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
If we've detected the PCI device is disconnected, there is no need to
attempt to access its config space since we know the operation will fail.
Make all the config reads and writes return -ENODEV error immediately when
in such a state.
If a caller requests a config read to a disconnected device, return a data
value of all 1's. This is the same as what hardware is expected to return
when accessing a removed device, but software can do this faster without
relying on hardware.
Tested-by: Krishna Dhulipala <krishnad@fb.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Wei Zhang <wzhang@fb.com>
Replace the inline PCI device config read and write accessors with exported
functions. This is preparing for these functions to make use of private
data.
Tested-by: Krishna Dhulipala <krishnad@fb.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Wei Zhang <wzhang@fb.com>
The PCI core uses a fixed 50ms timeout when waiting for VPD accesses to
complete. When an access does not complete within this period, a warning
is logged and an error returned to the caller.
While this default timeout is valid for most hardware, some devices can
experience longer access delays under certain circumstances. For example,
one of the IBM CXL Flash devices can take up to ~120ms in a worst-case
scenario. These types of devices can benefit from an extended timeout.
To support devices with a longer access delay, increase the timeout in
pci_vpd_wait() to 125ms. The PCI specification is silent with respect to
VPD delays, therefore there is no concern for violating a threshold.
Tested-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
pci_lock is an IRQ-safe spinlock that protects all accesses to PCI
configuration space (see PCI_OP_READ() and PCI_OP_WRITE() in pci/access.c).
The pci_cfg_access_unlock() path acquires pci_lock, then p->pi_lock (inside
wake_up_all()). According to lockdep, there is a possible path involving
snbep_uncore_pci_read_counter() that could acquire them in the reverse
order: acquiring p->pi_lock, then pci_lock, which could result in a
deadlock. Lockdep details are in the bugzilla below.
Avoid the possible deadlock by dropping pci_lock before waking up any
config access waiters.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=192901
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Hardware that supports only 32-bit config writes is not spec-compliant.
For example, if software performs a 16-bit write, we must do a 32-bit read,
merge in the 16 bits we intend to write, followed by a 32-bit write. If
the 16 bits we *don't* intend to write happen to have any RW1C (write-one-
to-clear) bits set, we just inadvertently cleared something we shouldn't
have.
Add a rate-limited warning when we do sub-32 bit config writes. Remove
similar probe-time warnings from some of the affected host bridge drivers.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Enthusiastically-Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Shawn Lin <shawn.lin@rock-chips.com> # rockchip
Acked-by: Thierry Reding <treding@nvidia.com>
After 104daa71b3 ("PCI: Determine actual VPD size on first access"), the
PCI core computes the valid VPD size by parsing the VPD starting at offset
0x0. We don't attempt to read past that valid size because that causes
some devices to crash.
However, some devices do have data past that valid size. For example,
Chelsio adapters contain two VPD structures, and the driver needs both of
them.
Add pci_set_vpd_size(). If a driver knows it is safe to read past the end
of the VPD data structure at offset 0, it can use pci_set_vpd_size() to
allow access to as much data as it needs.
[bhelgaas: changelog, split patches, rename to pci_set_vpd_size() and
return int (not ssize_t)]
Fixes: 104daa71b3 ("PCI: Determine actual VPD size on first access")
Tested-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Casey Leedom <leedom@chelsio.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Use usleep_range() instead of udelay() while waiting for a VPD access to
complete. This is not a performance path, so no need to hog the CPU.
Rationale for usleep_range() parameters:
We clear PCI_VPD_ADDR_F for a read (or set it for a write), then wait for
the device to change it. For a device that updates PCI_VPD_ADDR between
our config write and subsequent config read, we won't sleep at all and
can get the device's maximum rate.
Sleeping a minimum of 10 usec per 4-byte access limits throughput to
about 400Kbytes/second. VPD is small (32K bytes at most), and most
devices use only a fraction of that.
We back off exponentially up to 1024 usec per iteration. If we reach
1024, we've already waited up to 1008 usec (16 + 32 + ... + 512), so if
we miss an update and wait an extra 1024 usec, we can still get about
1/2 of the device's maximum rate.
Tested-by: Shane Seymour <shane.seymour@hpe.com>
Tested-by: Babu Moger <babu.moger@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
We only support one flavor of VPD, so there's no need to complicate things
by having a "generic" struct pci_vpd and a more specific struct
pci_vpd_pci22.
Fold struct pci_vpd_pci22 directly into struct pci_vpd.
[bhelgaas: remove NULL check before kfree of dev->vpd (per kfreeaddr.cocci)]
Tested-by: Shane Seymour <shane.seymour@hpe.com>
Tested-by: Babu Moger <babu.moger@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
There's only one kind of VPD, so we don't need to qualify it as "the
version described by PCI spec rev 2.2."
Rename the following symbols to remove unnecessary "pci22":
PCI_VPD_PCI22_SIZE -> PCI_VPD_MAX_SIZE
pci_vpd_pci22_size() -> pci_vpd_size()
pci_vpd_pci22_wait() -> pci_vpd_wait()
pci_vpd_pci22_read() -> pci_vpd_read()
pci_vpd_pci22_write() -> pci_vpd_write()
pci_vpd_pci22_ops -> pci_vpd_ops
pci_vpd_pci22_init() -> pci_vpd_init()
Tested-by: Shane Seymour <shane.seymour@hpe.com>
Tested-by: Babu Moger <babu.moger@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
The struct pci_vpd_ops.release function pointer is always
pci_vpd_pci22_release(), so there's no need for the flexibility of a
function pointer.
Inline the pci_vpd_pci22_release() body into pci_vpd_release() and remove
pci_vpd_pci22_release() and the struct pci_vpd_ops.release function
pointer.
Tested-by: Shane Seymour <shane.seymour@hpe.com>
Tested-by: Babu Moger <babu.moger@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Move pci_vpd_release() so it's next to the other VPD functions. This puts
it next to pci_vpd_pci22_init(), which allocates the space freed by
pci_vpd_release().
Tested-by: Shane Seymour <shane.seymour@hpe.com>
Tested-by: Babu Moger <babu.moger@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Keith Busch
Bjorn Helgaas
Frederick Lawler
Thomas Gleixner
Brian Norris
Ingo Molnar
Matthew R. Ochs
Hariprasad Shenai