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path: root/drivers/pci/access.c
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2018-04-04Merge branch 'pci/vpd'Bjorn Helgaas
- consolidate VPD code in vpd.c (Bjorn Helgaas) * pci/vpd: PCI/VPD: Move VPD structures to vpd.c PCI/VPD: Move VPD quirks to vpd.c PCI/VPD: Move VPD sysfs code to vpd.c PCI/VPD: Move VPD access code to vpd.c
2018-03-19PCI: Tidy commentsBjorn Helgaas
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>
2018-03-19PCI/VPD: Move VPD access code to vpd.cBjorn Helgaas
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>
2018-02-01Merge branch 'pci/spdx' into nextBjorn Helgaas
* 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
2018-01-26PCI: Add SPDX GPL-2.0 when no license was specifiedBjorn Helgaas
b24413180f56 ("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>
2018-01-18PCI: Add wrappers for dev_printk()Frederick Lawler
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>
2017-06-28PCI: Provide Kconfig option for lockless config space accessorsThomas Gleixner
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>
2017-05-26PCI: Make error code types consistent in pci_{read,write}_config_*Brian Norris
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: 4b1038834739 ("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>
2017-04-28Merge branch 'pci/misc' into nextBjorn Helgaas
* pci/misc: PCI: Change pci_host_common_probe() visibility PCI: Fix typo pci_cfg_access_lock() comment PCI: Include pci.h for struct pci_ops definition
2017-04-19PCI: Include PCI-to-PCIe bridges as "Downstream Ports"Bjorn Helgaas
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>
2017-04-04PCI: Fix typo pci_cfg_access_lock() commentBrian Norris
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>
2017-03-29PCI: Don't attempt config access to disconnected devicesKeith Busch
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>
2017-03-29PCI: Export PCI device config accessorsKeith Busch
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>
2017-03-02sched/headers: Prepare to move signal wakeup & sigpending methods from ↵Ingo Molnar
<linux/sched.h> into <linux/sched/signal.h> Fix up affected files that include this signal functionality via sched.h. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-15Merge branch 'pci/vpd' into nextBjorn Helgaas
* pci/vpd: PCI: Increase VPD access timeout to 125ms
2017-02-03PCI: Increase VPD access timeout to 125msMatthew R. Ochs
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>
2017-01-30PCI: Avoid possible deadlock on pci_lock and p->pi_lockBjorn Helgaas
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>
2016-11-21PCI: Warn on possible RW1C corruption for sub-32 bit config writesBjorn Helgaas
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>
2016-04-15PCI: Add pci_set_vpd_size() to set VPD sizeHariprasad Shenai
After 104daa71b396 ("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: 104daa71b396 ("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>
2016-03-10PCI: Sleep rather than busy-wait for VPD access completionBjorn Helgaas
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>
2016-02-29PCI: Fold struct pci_vpd_pci22 into struct pci_vpdBjorn Helgaas
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>
2016-02-29PCI: Rename VPD symbols to remove unnecessary "pci22"Bjorn Helgaas
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>
2016-02-29PCI: Remove struct pci_vpd_ops.release function pointerBjorn Helgaas
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>
2016-02-29PCI: Move pci_vpd_release() from header file to pci/access.cBjorn Helgaas
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>
2016-02-29PCI: Move pci_read_vpd() and pci_write_vpd() close to other VPD codeBjorn Helgaas
pci_read_vpd() and pci_write_vpd() were stranded in the middle of config accessor functions. Move them close to the other VPD code in the file. No functional change. 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>
2016-02-29PCI: Determine actual VPD size on first accessHannes Reinecke
PCI-2.2 VPD entries have a maximum size of 32k, but might actually be smaller than that. To figure out the actual size one has to read the VPD area until the 'end marker' is reached. Per spec, reading outside of the VPD space is "not allowed." In practice, it may cause simple read errors or even crash the card. To make matters worse not every PCI card implements this properly, leaving us with no 'end' marker or even completely invalid data. Try to determine the size of the VPD data when it's first accessed. If no valid data can be read an I/O error will be returned when reading or writing the sysfs attribute. As the amount of VPD data is unknown initially the size of the sysfs attribute will always be set to '0'. [bhelgaas: changelog, use 0/1 (not false/true) for bitfield, tweak pci_vpd_pci22_read() error checking] Tested-by: Shane Seymour <shane.seymour@hpe.com> Tested-by: Babu Moger <babu.moger@oracle.com> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Alexander Duyck <alexander.duyck@gmail.com>
2016-02-29PCI: Use bitfield instead of bool for struct pci_vpd_pci22.busyBjorn Helgaas
Make struct pci_vpd_pci22.busy a 1-bit field instead of a bool. We intend to add another flag, and two bitfields are cheaper than two bools. 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>
2016-01-08PCI: Fix all whitespace issuesBogicevic Sasa
Fix all whitespace issues (missing or needed whitespace) in all files in drivers/pci. Code is compiled with allyesconfig before and after code changes and objects are recorded and checked with objdiff and they are not changed after this commit. Signed-off-by: Bogicevic Sasa <brutallesale@gmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2015-09-24PCI: Use function 0 VPD for identical functions, regular VPD for othersAlex Williamson
932c435caba8 ("PCI: Add dev_flags bit to access VPD through function 0") added PCI_DEV_FLAGS_VPD_REF_F0. Previously, we set the flag on every non-zero function of quirked devices. If a function turned out to be different from function 0, i.e., it had a different class, vendor ID, or device ID, the flag remained set but we didn't make VPD accessible at all. Flip this around so we only set PCI_DEV_FLAGS_VPD_REF_F0 for functions that are identical to function 0, and allow regular VPD access for any other functions. [bhelgaas: changelog, stable tag] Fixes: 932c435caba8 ("PCI: Add dev_flags bit to access VPD through function 0") Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Bjorn Helgaas <helgaas@kernel.org> Acked-by: Myron Stowe <myron.stowe@redhat.com> Acked-by: Mark Rustad <mark.d.rustad@intel.com> CC: stable@vger.kernel.org
2015-09-24PCI: Fix devfn for VPD access through function 0Alex Williamson
Commit 932c435caba8 ("PCI: Add dev_flags bit to access VPD through function 0") passes PCI_SLOT(devfn) for the devfn parameter of pci_get_slot(). Generally this works because we're fairly well guaranteed that a PCIe device is at slot address 0, but for the general case, including conventional PCI, it's incorrect. We need to get the slot and then convert it back into a devfn. Fixes: 932c435caba8 ("PCI: Add dev_flags bit to access VPD through function 0") Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Bjorn Helgaas <helgaas@kernel.org> Acked-by: Myron Stowe <myron.stowe@redhat.com> Acked-by: Mark Rustad <mark.d.rustad@intel.com> CC: stable@vger.kernel.org
2015-07-21PCI: Add dev_flags bit to access VPD through function 0Mark Rustad
Add a dev_flags bit, PCI_DEV_FLAGS_VPD_REF_F0, to access VPD through function 0 to provide VPD access on other functions. This is for hardware devices that provide copies of the same VPD capability registers in multiple functions. Because the kernel expects that each function has its own registers, both the locking and the state tracking are affected by VPD accesses to different functions. On such devices for example, if a VPD write is performed on function 0, *any* later attempt to read VPD from any other function of that device will hang. This has to do with how the kernel tracks the expected value of the F bit per function. Concurrent accesses to different functions of the same device can not only hang but also corrupt both read and write VPD data. When hangs occur, typically the error message: vpd r/w failed. This is likely a firmware bug on this device. will be seen. Never set this bit on function 0 or there will be an infinite recursion. Signed-off-by: Mark Rustad <mark.d.rustad@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Alexander Duyck <alexander.h.duyck@redhat.com> CC: stable@vger.kernel.org
2015-07-14PCI: Add pcie_downstream_port() (true for Root and Switch Downstream Ports)Bjorn Helgaas
As used in the PCIe spec, "Downstream Port" includes both Root Ports and Switch Downstream Ports. We sometimes checked for PCI_EXP_TYPE_DOWNSTREAM when we should have checked for PCI_EXP_TYPE_ROOT_PORT or PCI_EXP_TYPE_DOWNSTREAM. For a Root Port without a slot, the effect of this was that using pcie_capability_read_word() to read PCI_EXP_SLTSTA returned zero instead of showing the Presence Detect State bit hardwired to one as the PCIe Spec, r3.0, sec 7.8, requires. (This read is completed in software because previous PCIe spec versions didn't require PCI_EXP_SLTSTA to exist at all.) Nothing in the kernel currently depends on this (pciehp only reads PCI_EXP_SLTSTA on ports with slots), so this is a cleanup and not a functional change. Add a pcie_downstream_port() helper function and use it. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-01-22PCI: Add generic config accessorsRob Herring
Many PCI controllers' configuration space accesses are memory-mapped and vary only in address calculation and access checks. There are 2 main access methods: a decoded address space such as ECAM or a single address and data register similar to x86. This implementation can support both cases as well as be used in cases that need additional pre- or post-access handling. Add a new pci_ops member, map_bus, which can do access checks and any necessary setup. It returns the address to use for the configuration space access. The access types supported are 32-bit only accesses or correct byte, word, or dword sized accesses. Tested-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Thierry Reding <treding@nvidia.com>
2014-11-13PCI: Apply _HPX Link Control settings to all devices with a linkYinghai Lu
Previously we applied _HPX type 2 record Link Control register settings only to bridges with a subordinate bus. But it's better to apply them to all devices with a link because if the subordinate bus has not been allocated yet, we won't apply settings to the device. Use pcie_cap_has_lnkctl() to determine whether the device has a Link Control register instead of looking at dev->subordinate. [bhelgaas: changelog] Fixes: 6cd33649fa83 ("PCI: Add pci_configure_device() during enumeration") Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2014-06-10PCI: Merge multi-line quoted stringsRyan Desfosses
Merge quoted strings that are broken across lines into a single entity. The compiler merges them anyway, but checkpatch complains about it, and merging them makes it easier to grep for strings. No functional change. [bhelgaas: changelog, do the same for everything under drivers/pci] Signed-off-by: Ryan Desfosses <ryan@desfo.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2014-05-27PCI: Fix return value from pci_user_{read,write}_config_*()Gavin Shan
The PCI user-space config accessors pci_user_{read,write}_config_*() return negative error numbers, which were introduced by commit 34e3207205ef ("PCI: handle positive error codes"). That patch converted all positive error numbers from platform-specific PCI config accessors to -EINVAL, which means the callers don't know anything about the specific cause of the failure. The patch fixes the issue by converting the positive PCIBIOS_* error values to generic negative error numbers with pcibios_err_to_errno(). [bhelgaas: changelog] Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Greg Thelen <gthelen@google.com>
2014-01-13PCI: Remove unused pci_vpd_truncate()Stephen Hemminger
My philosophy is unused code is dead code. And dead code is subject to bit rot and is a likely source of bugs. Use it or lose it. This reverts db5679437a2b ("PCI: add interface to set visible size of VPD"), removing this interface: pci_vpd_truncate() [bhelgaas: split to separate patch, also remove prototype from pci.h] Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2013-08-28PCI: Remove pcie_cap_has_devctl()Bjorn Helgaas
pcie_cap_has_devctl() does nothing, so remove it. Simplicity over consistency in this case. No functional change. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-By: Jiang Liu <jiang.liu@huawei.com>
2013-08-28PCI: Support PCIe Capability Slot registers only for ports with slotsBjorn Helgaas
Previously we allowed callers to access Slot Capabilities, Status, and Control for Root Ports even if the Root Port did not implement a slot. This seems dubious because the spec only requires these registers if a slot is implemented. It's true that even Root Ports without slots must have *space* for these slot registers, because the Root Capabilities, Status, and Control registers are after the slot registers in the capability. However, for a v1 PCIe Capability, the *semantics* of the slot registers are undefined unless a slot is implemented. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-By: Jiang Liu <jiang.liu@huawei.com>
2013-08-28PCI: Remove PCIe Capability version checksBjorn Helgaas
Previously we relied on the PCIe r3.0, sec 7.8, spec language that says "For Functions that do not implement the [Link, Slot, Root] registers, these spaces must be hardwired to 0b," which means that for v2 PCIe capabilities, we don't need to check the device type at all. But it's simpler if we don't need to check the capability version at all, and I think the spec is explicit enough about which registers are required for which types that we can remove the version checks. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-By: Jiang Liu <jiang.liu@huawei.com>
2013-08-28PCI: Allow PCIe Capability link-related register access for switchesBjorn Helgaas
Every PCIe device has a link, except Root Complex Integrated Endpoints and Root Complex Event Collectors. Previously we didn't give access to PCIe capability link-related registers for Upstream Ports, Downstream Ports, and Bridges, so attempts to read PCI_EXP_LNKCTL incorrectly returned zero. See PCIe spec r3.0, sec 7.8 and 1.3.2.3. Reference: http://lkml.kernel.org/r/979A8436335E3744ADCD3A9F2A2B68A52AD136BE@SJEXCHMB10.corp.ad.broadcom.com Reported-by: Yuval Mintz <yuvalmin@broadcom.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-By: Jiang Liu <jiang.liu@huawei.com>
2013-02-15PCI: Fix PCI Express Capability accessors for PCI_EXP_FLAGSAlex Williamson
PCI_EXP_FLAGS_TYPE is a mask, not an offset. Fix it. Previously, pcie_capability_read_word(..., PCI_EXP_FLAGS, ...) would fail. [bhelgaas: tweak changelog] Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org # v3.7+
2013-01-30PCI: Use PCI Express Capability accessorMyron Stowe
Use PCI Express Capability access functions to simplify device Capabilities Register usages. Signed-off-by: Myron Stowe <myron.stowe@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-08-23PCI: Add accessors for PCI Express CapabilityJiang Liu
The PCI Express Capability (PCIe spec r3.0, sec 7.8) comes in two versions, v1 and v2. In v1 Capability structures (PCIe spec r1.0 and r1.1), some fields are optional, so the structure size depends on the device type. This patch adds functions to access this capability so drivers don't have to be aware of the differences between v1 and v2. Note that these new functions apply only to the "PCI Express Capability," not to any of the other "PCI Express Extended Capabilities" (AER, VC, ACS, MFVC, etc.) Function pcie_capability_read_word/dword() reads the PCIe Capabilities register and returns the value in the reference parameter "val". If the PCIe Capabilities register is not implemented on the PCIe device, "val" is set to 0. Function pcie_capability_write_word/dword() writes the value to the specified PCIe Capability register. Function pcie_capability_clear_and_set_word/dword() sets and/or clears bits of a PCIe Capability register. [bhelgaas: changelog, drop "pci_" prefixes, don't export pcie_capability_reg_implemented()] Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-12PCI: export pci_user functions for use by other driversAlex Williamson
VFIO PCI support will make use of these for user-initiated PCI config accesses. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-01-06PCI: Introduce INTx check & mask APIJan Kiszka
These new PCI services allow to probe for 2.3-compliant INTx masking support and then use the feature from PCI interrupt handlers. The services are properly synchronized with concurrent config space access via sysfs or on device reset. This enables generic PCI device drivers like uio_pci_generic or KVM's device assignment to implement the necessary kernel-side IRQ handling without any knowledge about device-specific interrupt status and control registers. Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-01-06PCI: Rework config space blocking servicesJan Kiszka
pci_block_user_cfg_access was designed for the use case that a single context, the IPR driver, temporarily delays user space accesses to the config space via sysfs. This assumption became invalid by the time pci_dev_reset was added as locking instance. Today, if you run two loops in parallel that reset the same device via sysfs, you end up with a kernel BUG as pci_block_user_cfg_access detect the broken assumption. This reworks the pci_block_user_cfg_access to a sleeping service pci_cfg_access_lock and an atomic-compatible variant called pci_cfg_access_trylock. The former not only blocks user space access as before but also waits if access was already locked. The latter service just returns false in this case, allowing the caller to resolve the conflict instead of raising a BUG. Adaptions of the ipr driver were originally written by Brian King. Acked-by: Brian King <brking@linux.vnet.ibm.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-05-10PCI: handle positive error codesGreg Thelen
Callers expect pci_user_{read,write}_config_*() to indicate errors by returning negative values. Prior to this change, the indicated routines could return positive error codes (e.g. PCIBIOS_BAD_REGISTER_NUMBER) which callers would mistakenly interpret as success. This change converts any non-zero return from the mentioned routines into unambiguous negative value return codes. Signed-off-by: Greg Thelen <gthelen@google.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-05-10PCI: check pci_vpd_pci22_wait() returnGreg Thelen
pci_vpd_pci22_write() calls pci_vpd_pci22_wait() after writing PCI_VPD_DATA and PCI_VPD_ADDR to wait for the VPD operation to complete. The result pci_vpd_pci22_wait() was not checked for error. This change checks for error. Signed-off-by: Greg Thelen <gthelen@google.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-05-18PCI: output FW warning in pci_read/write_vpdPrarit Bhargava
pci_read/write_vpd() can fail due to a timeout. Usually the command times out because of firmware issues (incorrect vpd length, etc.) on the PCI card. Currently, the timeout occurs silently. Output a message to the user indicating that they should check with their vendor for new firmware. Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
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