Currently we allocate the stale_map for a cpu when it comes online,
this leaves open a small window where a process can be scheduled
on the cpu before the stale_map is allocated. Instead allocate
the stale_map at CPU_UP_PREPARE time, that way it will be always
available before tasks start running.
It is possible the cpu fails to come up, in which case we should free
the stale_map, so add a CPU_UP_CANCELED case to do that.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
When we start a cpu we use smp_ops->kick_cpu(), which currently
returns void, it should be able to fail. Convert it to return
int, and update all uses.
Convert all the current error cases to return -ENOENT, which is
what would eventually be returned by __cpu_up() currently when
it doesn't detect the cpu as coming up in time.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This is a first cut at making bootwrapper code which will
produce a zImage compliant with the requirements set down
by ePAPR.
This is a very simple bootwrapper, taking the device tree
blob supplied by the ePAPR boot program and passing it on
to the kernel. It builds on the earlier patch to build a
relocatable ET_DYN zImage to meet the other ePAPR image
requirements.
For good measure we have some paranoid checks which will
generate warnings if some of the ePAPR entry condition
guarantees are not met.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch adds code, linker script and makefile support to allow
building the zImage wrapper around the kernel as a position independent
executable. This results in an ET_DYN instead of an ET_EXEC ELF output
file, which can be loaded at any location by the firmware and will
process its own relocations to work correctly at the loaded address.
This is of interest particularly since the standard ePAPR image format
must be an ET_DYN (although this patch alone is not sufficient to
produce a fully ePAPR compliant boot image).
Note for now we don't enable building with -pie for anything.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
On Book3E, MMU_NO_CONTEXT != 0, but the slice_mm_new_context()
macro assumes that it is. This means that the map of the
page sizes for each slice is always initialized to zeroes
(which happens to be 4k pages), rather than to the correct
default base page size value - which might be 64k.
This patch corrects the problem.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Use MMU_NO_CONTEXT as the initialiser for mm_context.id on
nohash and hash64.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We need to do that to guarantee they see any code change done by
dynamic patching during boot.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Wakeup comes from the system reset handler with a potential loss of
the non-hypervisor CPU state. We save the non-volatile state on the
stack and a pointer to it in the PACA, which the system reset handler
uses to restore things
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We need to wait a bit for them to have done their CPU setup
or we might end up with translation and EE on with different
LPCR values between threads
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We do it before we loop on the PACA start flag. This way, we get a
chance to set critical SPRs on all CPUs before Linux tries to start
them up, which avoids problems when changing some bits such as LPCR
bits that need to be identical on all threads of a core or similar
things like that. Ideally, some of that should also be done before
the MMU is enabled, but that's a separate issue which would require
moving some of the SMP startup code earlier, let's not get there
for now, it works with that change alone.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This sets the default data stream prefetch size for operating
systems that don't set their own value in DSCR. We use 4 which
is "medium".
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This uses feature sections to arrange that we always use HSPRG1
as the scratch register in the interrupt entry code rather than
SPRG2 when we're running in hypervisor mode on POWER7. This will
ensure that we don't trash the guest's SPRG2 when we are running
KVM guests. To simplify the code, we define GET_SCRATCH0() and
SET_SCRATCH0() macros like the GET_PACA/SET_PACA macros.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Rework exception macros a bit to split offset from vector and add
some basic support for HDEC, HDSI, HISI and a few more.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Pass the register type to the prolog, also provides alternate "HV"
version of hardware interrupt (0x500) and adjust LPES accordingly
We tag those interrupts by setting bit 0x2 in the trap number
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
When running in Hypervisor mode (arch 2.06 or later), we store the PACA
in HSPRG0 instead of SPRG1. The architecture specifies that SPRGs may be
lost during a "nap" power management operation (though they aren't
currently on POWER7) and this enables use of SPRG1 by KVM guests.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This bit indicates that we are operating in hypervisor mode on a CPU
compliant to architecture 2.06 or later (currently server only).
We set it on POWER7 and have a boot-time CPU setup function that
clears it if MSR:HV isn't set (booting under a hypervisor).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Even when nothing is specified in the device tree, and despite the
fact that we don't setup links properly yet, we still need a reasonable
value in there or some interrupts won't be setup properly to point to
an existing processor.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This adds more SPR definitions used on newer processors when running
in hypervisor mode. Along with some other P7 specific bits and pieces
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This is a significant rework of the XICS driver, too significant to
conveniently break it up into a series of smaller patches to be honest.
The driver is moved to a more generic location to allow new platforms
to use it, and is broken up into separate ICP and ICS "backends". For
now we have the native and "hypervisor" ICP backends and one common
RTAS ICS backend.
The driver supports one ICP backend instanciation, and many ICS ones,
in order to accomodate future platforms with multiple possibly different
interrupt "sources" mechanisms.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: xen-kbdfront - fix mouse getting stuck after save/restore
Input: estimate number of events per packet
Input: evdev - indicate buffer overrun with SYN_DROPPED
Input: document event types and codes and their intended use
Input: add KEY_IMAGES specifically for AL Image Browser
Input: twl4030_keypad - fix potential NULL dereference in twl4030_kp_probe()
Input: h3600_ts - fix error handling at connect
Input: twl4030_keypad - avoid potential NULL-pointer dereference
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
block: add blk_run_queue_async
block: blk_delay_queue() should use kblockd workqueue
md: fix up raid1/raid10 unplugging.
md: incorporate new plugging into raid5.
md: provide generic support for handling unplug callbacks.
md - remove old plugging code.
md/dm - remove remains of plug_fn callback.
md: use new plugging interface for RAID IO.
block: drop queue lock before calling __blk_run_queue() for kblockd punt
Revert "block: add callback function for unplug notification"
block: Enhance new plugging support to support general callbacks
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc/powermac: Build fix with SMP and CPU hotplug
powerpc/perf_event: Skip updating kernel counters if register value shrinks
powerpc: Don't write protect kernel text with CONFIG_DYNAMIC_FTRACE enabled
powerpc: Fix oops if scan_dispatch_log is called too early
powerpc/pseries: Use a kmem cache for DTL buffers
powerpc/kexec: Fix regression causing compile failure on UP
powerpc/85xx: disable Suspend support if SMP enabled
powerpc/e500mc: Remove CPU_FTR_MAYBE_CAN_NAP/CPU_FTR_MAYBE_CAN_DOZE
powerpc/book3e: Fix CPU feature handling on 64-bit e5500
powerpc: Check device status before adding serial device
powerpc/85xx: Don't add disabled PCIe devices
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: (24 commits)
Btrfs: fix free space cache leak
Btrfs: avoid taking the chunk_mutex in do_chunk_alloc
Btrfs end_bio_extent_readpage should look for locked bits
Btrfs: don't force chunk allocation in find_free_extent
Btrfs: Check validity before setting an acl
Btrfs: Fix incorrect inode nlink in btrfs_link()
Btrfs: Check if btrfs_next_leaf() returns error in btrfs_real_readdir()
Btrfs: Check if btrfs_next_leaf() returns error in btrfs_listxattr()
Btrfs: make uncache_state unconditional
btrfs: using cached extent_state in set/unlock combinations
Btrfs: avoid taking the trans_mutex in btrfs_end_transaction
Btrfs: fix subvolume mount by name problem when default mount subvolume is set
fix user annotation in ioctl.c
Btrfs: check for duplicate iov_base's when doing dio reads
btrfs: properly handle overlapping areas in memmove_extent_buffer
Btrfs: fix memory leaks in btrfs_new_inode()
Btrfs: check for duplicate iov_base's when doing dio reads
Btrfs: reuse the extent_map we found when calling btrfs_get_extent
Btrfs: do not use async submit for small DIO io's
Btrfs: don't split dio bios if we don't have to
...
Rather than pass in some random truncated offset to the pid-related
functions, check that the offset is in range up-front.
This is just cleanup, the previous commit fixed the real problem.
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
next_pidmap() just quietly accepted whatever 'last' pid that was passed
in, which is not all that safe when one of the users is /proc.
Admittedly the proc code should do some sanity checking on the range
(and that will be the next commit), but that doesn't mean that the
helper functions should just do that pidmap pointer arithmetic without
checking the range of its arguments.
So clamp 'last' to PID_MAX_LIMIT. The fact that we then do "last+1"
doesn't really matter, the for-loop does check against the end of the
pidmap array properly (it's only the actual pointer arithmetic overflow
case we need to worry about, and going one bit beyond isn't going to
overflow).
[ Use PID_MAX_LIMIT rather than pid_max as per Eric Biederman ]
Reported-by: Tavis Ormandy <taviso@cmpxchg8b.com>
Analyzed-by: Robert Święcki <robert@swiecki.net>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mouse gets "stuck" after restore of PV guest but buttons are in working
condition.
If driver has been configured for ABS coordinates at start it will get
XENKBD_TYPE_POS events and then suddenly after restore it'll start getting
XENKBD_TYPE_MOTION events, that will be dropped later and they won't get
into user-space.
Regression was introduced by hunk 5 and 6 of
5ea5254aa0ad269cfbd2875c973ef25ab5b5e9db
("Input: xen-kbdfront - advertise either absolute or relative
coordinates").
Driver on restore should ask xen for request-abs-pointer again if it is
available. So restore parts that did it before 5ea5254.
Acked-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
[v1: Expanded the commit description]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Calculate a default based on the number of ABS axes, REL axes,
and MT slots for the device during input device registration.
Signed-off-by: Jeff Brown <jeffbrown@android.com>
Reviewed-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
The free space caching code was recently reworked to
cache all the pages it needed instead of using find_get_page everywhere.
One loop was missed though, so it ended up leaking pages. This fixes
it to use our page array instead of find_get_page.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Instead of overloading __blk_run_queue to force an offload to kblockd
add a new blk_run_queue_async helper to do it explicitly. I've kept
the blk_queue_stopped check for now, but I suspect it's not needed
as the check we do when the workqueue items runs should be enough.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
We just need to make sure that an unplug event wakes up the md
thread, which is exactly what mddev_check_plugged does.
Also remove some plug-related code that is no longer needed.
Signed-off-by: NeilBrown <neilb@suse.de>
In raid5 plugging is used for 2 things:
1/ collecting writes that require a bitmap update
2/ collecting writes in the hope that we can create full
stripes - or at least more-full.
We now release these different sets of stripes when plug_cnt
is zero.
Also in make_request, we call mddev_check_plug to hopefully increase
plug_cnt, and wake up the thread at the end if plugging wasn't
achieved for some reason.
Signed-off-by: NeilBrown <neilb@suse.de>
When an md device adds a request to a queue, it can call
mddev_check_plugged.
If this succeeds then we know that the md thread will be woken up
shortly, and ->plug_cnt will be non-zero until then, so some
processing can be delayed.
If it fails, then no unplug callback is expected and the make_request
function needs to do whatever is required to make the request happen.
Signed-off-by: NeilBrown <neilb@suse.de>
md has some plugging infrastructure for RAID5 to use because the
normal plugging infrastructure required a 'request_queue', and when
called from dm, RAID5 doesn't have one of those available.
This relied on the ->unplug_fn callback which doesn't exist any more.
So remove all of that code, both in md and raid5. Subsequent patches
with restore the plugging functionality.
Signed-off-by: NeilBrown <neilb@suse.de>
Now that unplugging is done differently, the unplug_fn callback is
never called, so it can be completely discarded.
Signed-off-by: NeilBrown <neilb@suse.de>
md/raid submits a lot of IO from the various raid threads.
So adding start/finish plug calls to those so that some
plugging happens.
Signed-off-by: NeilBrown <neilb@suse.de>
If we know we are going to punt to kblockd, we can drop the queue
lock before calling into __blk_run_queue() since it only does a
safe bit test and a workqueue call. Since kblockd needs to grab
this very lock as one of the first things it does, it's a good
optimization to drop the lock before waking kblockd.
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
MD can't use this since it really requires us to be able to
keep more than a single piece of state for the unplug. Commit
048c9374 added the required support for MD, so get rid of this
now unused code.
This reverts commit f75664570d.
Conflicts:
block/blk-core.c
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
md/raid requires an unplug callback, but as it does not uses
requests the current code cannot provide one.
So allow arbitrary callbacks to be attached to the blk_plug.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Because of speculative event roll back, it is possible for some event coutners
to decrease between reads on POWER7. This causes a problem with the way that
counters are updated. Delta calues are calculated in a 64 bit value and the
top 32 bits are masked. If the register value has decreased, this leaves us
with a very large positive value added to the kernel counters. This patch
protects against this by skipping the update if the delta would be negative.
This can lead to a lack of precision in the coutner values, but from my testing
the value is typcially fewer than 10 samples at a time.
Signed-off-by: Eric B Munson <emunson@mgebm.net>
Cc: stable@kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This problem was noticed on an MPC855T platform. Ftrace did oops
when trying to write to the kernel text segment.
Many thanks to Joakim for finding the root cause of this problem.
Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Joakim Tjernlund <joakim.tjernlund@transmode.se>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We currently enable interrupts before the dispatch log for the boot
cpu is setup. If a timer interrupt comes in early enough we oops in
scan_dispatch_log:
Unable to handle kernel paging request for data at address 0x00000010
...
.scan_dispatch_log+0xb0/0x170
.account_system_vtime+0xa0/0x220
.irq_enter+0x88/0xc0
.do_IRQ+0x48/0x230
The patch below adds a check to scan_dispatch_log to ensure the
dispatch log has been allocated.
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: <stable@kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
PAPR specifies that DTL buffers can not cross AMS environments (aka CMO
in the PAPR) and can not cross a memory entitlement granule boundary
(4k). This is found in section 14.11.3.2 H_REGISTER_VPA of the PAPR.
kmalloc does not guarantee an alignment of the allocation, though,
beyond 8 bytes (at least in my understanding). Create a special kmem
cache for DTL buffers with the alignment requirement.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Recent commit b987812b3f caused
a compile failure on UP because a considerably large block
of the file was included within CONFIG_SMP, hence making a stub
function not exposed on UP builds when it needed to be.
Relocate the stub to the #else /* ! CONFIG_SMP */ section
and also annotate the relevant else/endif so that nobody
else falls into the same trap I did.
Reported-by: Michael Guntsche <mike@it-loops.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
