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(-)
This is an updated version of Ben's fix-pci-mmap-on-ppc-and-ppc64.patch
which is in 2.6.12-rc4-mm1.
It fixes the patch to work on PPC iSeries, removes some debug printks
at Ben's request, and incorporates your
fix-pci-mmap-on-ppc-and-ppc64-fix.patch also.
Originally from Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch was discussed at length on linux-pci and so far, the last
iteration of it didn't raise any comment. It's effect is a nop on
architecture that don't define the new pci_resource_to_user() callback
anyway. It allows architecture like ppc who put weird things inside of
PCI resource structures to convert to some different value for user
visible ones. It also fixes mmap'ing of IO space on those archs.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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!
Brian King