Accessing the VPD area can take a long time. The existing
VPD access code fails consistently on my hardware. There are comments
in the SysKonnect vendor driver that it can take up to 13ms per word.
Change the access routines to:
* use a mutex rather than spinning with IRQ's disabled and lock held
* have a much longer timeout
* call cond_resched while spinning
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
For Broadcom 5706, 5708, 5709 rev. A nics, any read beyond the
VPD end tag will hang the device. This problem was initially
observed when a vpd entry was created in sysfs
('/sys/bus/pci/devices/<id>/vpd'). A read to this sysfs entry
will dump 32k of data. Reading a full 32k will cause an access
beyond the VPD end tag causing the device to hang. Once the device
is hung, the bnx2 driver will not be able to reset the device.
We believe that it is legal to read beyond the end tag and
therefore the solution is to limit the read/write length.
A majority of this patch is from Matthew Wilcox who gave code for
reworking the PCI vpd size information. A PCI quirk added for the
Broadcom NIC's to limit the read/write's.
Signed-off-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Vital Product Data (VPD) may be exposed by PCI devices in several
ways. It is generally unsafe to read this information through the
existing interfaces to user-land because of stateful interfaces.
This adds:
- abstract operations for VPD access (struct pci_vpd_ops)
- VPD state information in struct pci_dev (struct pci_vpd)
- an implementation of the VPD access method specified in PCI 2.2
(in access.c)
- a 'vpd' binary file in sysfs directories for PCI devices with VPD
operations defined
It adds a probe for PCI 2.2 VPD in pci_scan_device() and release of
VPD state in pci_release_dev().
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The existing implementation of pci_block_user_cfg_access() was recently
criticised for providing out of date information and for returning errors
on write, which applications won't be expecting.
This reimplementation uses a global wait queue and a bit per device.
I've open-coded prepare_to_wait() / finish_wait() as I could optimise
it significantly by knowing that the pci_lock protected us at all points.
It looked a bit funny to be doing a spin_unlock_irqsave(); schedule(),
so I used spin_lock_irq() for the _user versions of pci_read_config and
pci_write_config. Not carrying a flags pointer around made the code
much less nasty.
Attempts to block an already blocked device hit a BUG() and attempts to
unblock an already unblocked device hit a WARN(). If we need to block
access to a device from userspace, it's because it's unsafe for even
another bit of the kernel to access the device. An attempt to block
a device for a second time means we're about to access the device to
perform some other operation, which could provoke undefined behaviour
from the device.
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Acked-by: Adam Belay <abelay@novell.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch contains the following cleanups:
- access.c should #include "pci.h" for getting the prototypes of it's
global functions
- hotplug/shpchp_pci.c: make the needlessly global function
program_fw_provided_values() static
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Some PCI adapters (eg. ipr scsi adapters) have an exposure today in that they
issue BIST to the adapter to reset the card. If, during the time it takes to
complete BIST, userspace attempts to access PCI config space, the host bus
bridge will master abort the access since the ipr adapter does not respond on
the PCI bus for a brief period of time when running BIST. On PPC64 hardware,
this master abort results in the host PCI bridge isolating that PCI device
from the rest of the system, making the device unusable until Linux is
rebooted. This patch is an attempt to close that exposure by introducing some
blocking code in the PCI code. When blocked, writes will be humored and reads
will return the cached value. Ben Herrenschmidt has also mentioned that he
plans to use this in PPC power management.
Signed-off-by: Brian King <brking@us.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/pci/access.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++
drivers/pci/pci-sysfs.c | 20 +++++-----
drivers/pci/pci.h | 7 +++
drivers/pci/proc.c | 28 +++++++--------
drivers/pci/syscall.c | 14 +++----
include/linux/pci.h | 7 +++
6 files changed, 134 insertions(+), 31 deletions(-)
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Stephen Hemminger