REMOTE_DEBUG does already appear in 2.2 kernel sources but didn't
appear as a config Option in the initial git import 2.6.12-rc. It's
currently just used in one single place of the linux kernel and should
probably be dropped totally
Signed-off-by: Christoph Egger <siccegge@cs.fau.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch makes it return -ENODEV if we run out of empty slots in the
probe function. It's unlikely to happen, but it makes the static
checkers happy.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use the resource_size function instead of manually calculating the
resource size. This actually fixes an off-by-one error.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Comment was not updated when tty_insert_flip_string was generalised.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add an UART driver for the UART component available as a SOPC (System on
Programmable Chip) component for Altera FPGAs.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add an UART driver for the JTAG UART component available as a SOPC
(System on Programmable Chip) component for Altera FPGAs.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix a problem in early versions of the FPGA IP.
In certain situations the IP reports that the FIFO is empty, but a byte is
still clocked out. If a flush is done at that point the currently clocked
byte is canceled.
This causes incompatibilities with the upper layers when a port is closed,
it waits until the FIFO is empty and then closes the port. During close
the FIFO is flushed -> the last byte is not sent properly.
Now the FIFO is only flushed if it is reported to be non-empty. Which
makes the currently clocked out byte to finish.
[akpm@linux-foundation.org: fix build]
Signed-off-by: Richard Röjfors <richard.rojfors@pelagicore.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
CTS is a read only bit and we are to stop signal RTS if modem line
TIOCM_RTS is not set.
Thanks for suggestions by Richard Röjfors.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: Richard Röjfors <richard.rojfors@pelagicore.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Byte accesses for I/O devices in Xilinx IP is going to be less
desired in the future such that the driver is being changed to
use 32 bit accesses.
This change facilitates using the uartlite IP over a PCIe bus
which only allows 32 bit accesses.
Signed-off-by: John Linn <john.linn@xilinx.com>
Tested-by: Michal Simek <monstr@monstr.eu>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
n_gsm uses skb functions, so it should depend on NET.
n_gsm.c:(.text+0x123d49): undefined reference to `skb_dequeue'
n_gsm.c:(.text+0x123d98): undefined reference to `kfree_skb'
n_gsm.c:(.text+0x123e1e): undefined reference to `skb_pull'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add an implementation of GSM 0710 MUX. The implementation currently supports
- Basic and advanced framing (as either end of the link)
- UI or UIH data frames
- Adaption layer 1-4 (1 and 2 via tty, 3 and 4 as skbuff lists)
- Modem and control messages including the correct retry process
- Flow control
and exposes the MUX channels as a set of virtual tty devices including modem
signals. This is an experimental driver.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Push the max ldiscs by a few number to allow ldiscs
to exist in the staging directory and elsewhere.
Signed-off-by: Pavan Savoy <pavan_savoy@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The BF54xM procs imply the related BF54x define, so no need to check both.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Now that the SPORT MMR defines have been unified, switch over to it.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Rather than always turn on the SPORT TX interrupt, only do it when we've
actually queued up data for transmission. This avoids useless interrupt
processing.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
These were all copied over from the Blackfin UART driver, but they don't
make sense here because these bits are all specific to the Blackfin UART.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Need to initialize the SPORT state rather than using random memory.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Common serial API says we need to grab the port lock before modifying
the port state to prevent inconsistent state between threads.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Some people need flow control on their ports, so now boards can support
that via any GPIOs.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Clarifies command line set up for devices between consoles and early
devices.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The driver doesn't care about this, but the common serial core wants it.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
All the resources are in the boards files now.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The waiting loop to stop SPORT TX from TX interrupt is too long. This may
block the SPORT RX interrupts and cause the RX FIFO to overflow. So, do
stop sport TX only after the last char in TX FIFO is moved into the shift
register.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We cannot let a 32-bit RX FIFO read be interrupted otherwise a fake RX
underflow error might be generated.
URL: http://blackfin.uclinux.org/gf/tracker/5145
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2: (23 commits)
nilfs2: disallow remount of snapshot from/to a regular mount
nilfs2: use huge_encode_dev/huge_decode_dev
nilfs2: update comment on deactivate_super at nilfs_get_sb
nilfs2: replace MS_VERBOSE with MS_SILENT
nilfs2: add missing initialization of s_mode
nilfs2: fix misuse of open_bdev_exclusive/close_bdev_exclusive
nilfs2: enlarge s_volume_name member in nilfs_super_block
nilfs2: use checkpoint number instead of timestamp to select super block
nilfs2: add missing endian conversion on super block magic number
nilfs2: make nilfs_sc_*_ops static
nilfs2: add kernel doc comments to persistent object allocator functions
nilfs2: change sc_timer from a pointer to an embedded one in struct nilfs_sc_info
nilfs2: remove nilfs_segctor_init() in segment.c
nilfs2: insert checkpoint number in segment summary header
nilfs2: add a print message after loading nilfs2
nilfs2: cleanup multi kmem_cache_{create,destroy} code
nilfs2: move out checksum routines to segment buffer code
nilfs2: move pointer to super root block into logs
nilfs2: change default of 'errors' mount option to 'remount-ro' mode
nilfs2: Combine nilfs_btree_release_path() and nilfs_btree_free_path()
...
* git://git.infradead.org/mtd-2.6: (154 commits)
mtd: cfi_cmdset_0002: use AMD standard command-set with Winbond flash chips
mtd: cfi_cmdset_0002: Fix MODULE_ALIAS and linkage for new 0701 commandset ID
mtd: mxc_nand: Remove duplicate NAND_CMD_RESET case value
mtd: update gfp/slab.h includes
jffs2: Stop triggering block erases from jffs2_write_super()
jffs2: Rename jffs2_erase_pending_trigger() to jffs2_dirty_trigger()
jffs2: Use jffs2_garbage_collect_trigger() to trigger pending erases
jffs2: Require jffs2_garbage_collect_trigger() to be called with lock held
jffs2: Wake GC thread when there are blocks to be erased
jffs2: Erase pending blocks in GC pass, avoid invalid -EIO return
jffs2: Add 'work_done' return value from jffs2_erase_pending_blocks()
mtd: mtdchar: Do not corrupt backing device of device node inode
mtd/maps/pcmciamtd: Fix printk format for ssize_t in debug messages
drivers/mtd: Use kmemdup
mtd: cfi_cmdset_0002: Fix argument order in bootloc warning
mtd: nand: add Toshiba TC58NVG0 device ID
pcmciamtd: add another ID
pcmciamtd: coding style cleanups
pcmciamtd: fixing obvious errors
mtd: chips: add SST39WF160x NOR-flashes
...
Trivial conflicts due to dev_node removal in drivers/mtd/maps/pcmciamtd.c
* 'linux-next' of git://git.infradead.org/ubi-2.6:
UBI: misc comment fixes
UBI: fix s/then/than/ typos
UBI: init even if MTD device cannot be attached, if built into kernel
UBI: remove reboot notifier
* 'for-linus' of git://oss.sgi.com/xfs/xfs: (54 commits)
xfs: mark xfs_iomap_write_ helpers static
xfs: clean up end index calculation in xfs_page_state_convert
xfs: clean up mapping size calculation in __xfs_get_blocks
xfs: clean up xfs_iomap_valid
xfs: move I/O type flags into xfs_aops.c
xfs: kill struct xfs_iomap
xfs: report iomap_bn in block base
xfs: report iomap_offset and iomap_bsize in block base
xfs: remove iomap_delta
xfs: remove iomap_target
xfs: limit xfs_imap_to_bmap to a single mapping
xfs: simplify buffer to transaction matching
xfs: Make fiemap work in query mode.
xfs: kill off l_sectbb_mask
xfs: record log sector size rather than log2(that)
xfs: remove dead XFS_LOUD_RECOVERY code
xfs: removed unused XFS_QMOPT_ flags
xfs: remove a few macro indirections in the quota code
xfs: access quotainfo structure directly
xfs: wait for direct I/O to complete in fsync and write_inode
...
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2: (47 commits)
ocfs2: Silence a gcc warning.
ocfs2: Don't retry xattr set in case value extension fails.
ocfs2:dlm: avoid dlm->ast_lock lockres->spinlock dependency break
ocfs2: Reset xattr value size after xa_cleanup_value_truncate().
fs/ocfs2/dlm: Use kstrdup
fs/ocfs2/dlm: Drop memory allocation cast
Ocfs2: Optimize punching-hole code.
Ocfs2: Make ocfs2_find_cpos_for_left_leaf() public.
Ocfs2: Fix hole punching to correctly do CoW during cluster zeroing.
Ocfs2: Optimize ocfs2 truncate to use ocfs2_remove_btree_range() instead.
ocfs2: Block signals for mkdir/link/symlink/O_CREAT.
ocfs2: Wrap signal blocking in void functions.
ocfs2/dlm: Increase o2dlm lockres hash size
ocfs2: Make ocfs2_extend_trans() really extend.
ocfs2/trivial: Code cleanup for allocation reservation.
ocfs2: make ocfs2_adjust_resv_from_alloc simple.
ocfs2: Make nointr a default mount option
ocfs2/dlm: Make o2dlm domain join/leave messages KERN_NOTICE
o2net: log socket state changes
ocfs2: print node # when tcp fails
...
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (182 commits)
[SCSI] aacraid: add an ifdef'd device delete case instead of taking the device offline
[SCSI] aacraid: prohibit access to array container space
[SCSI] aacraid: add support for handling ATA pass-through commands.
[SCSI] aacraid: expose physical devices for models with newer firmware
[SCSI] aacraid: respond automatically to volumes added by config tool
[SCSI] fcoe: fix fcoe module ref counting
[SCSI] libfcoe: FIP Keep-Alive messages for VPorts are sent with incorrect port_id and wwn
[SCSI] libfcoe: Fix incorrect MAC address clearing
[SCSI] fcoe: fix a circular locking issue with rtnl and sysfs mutex
[SCSI] libfc: Move the port_id into lport
[SCSI] fcoe: move link speed checking into its own routine
[SCSI] libfc: Remove extra pointer check
[SCSI] libfc: Remove unused fc_get_host_port_type
[SCSI] fcoe: fixes wrong error exit in fcoe_create
[SCSI] libfc: set seq_id for incoming sequence
[SCSI] qla2xxx: Updates to ISP82xx support.
[SCSI] qla2xxx: Optionally disable target reset.
[SCSI] qla2xxx: ensure flash operation and host reset via sg_reset are mutually exclusive
[SCSI] qla2xxx: Silence bogus warning by gcc for wrap and did.
[SCSI] qla2xxx: T10 DIF support added.
...
The whole point of making some of the drivers automatically selected
unless 'EMBEDDED' was to handle quirks transparently after their separation
from the generic core.
Over time, some of the later-added quirks grew into more standalone drivers,
implementing non-trivial features a being larger than a few bytes of code.
In addition to that, some of the standalone drivers don't make sense for
99.9% of the users, as they are very specific to rare devices.
Therefore build by default in only those drivers which
- we historically used to support even before quirk separation from the
core code
- are isolated enough and likely to hit quite large portion of the
users anyway (Microsoft, Logitech)
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
'protect4gb' boot parameter was introduced to avoid allocating dma
space acrossing 4GB boundary in 2007 (the commit
569975591c).
In 2008, the IOMMU was fixed to use the boundary_mask parameter per
device properly. So 'protect4gb' workaround was removed (the
383af9525b). But somehow I messed the
'protect4gb' boot parameter that was used to enable the
workaround.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The e1000e device is becoming more common these days, so let's just
build it in for pseries & ppc64_defconfig.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
At the moment only the RAS code uses event-sources interrupts (for EPOW
events and internal errors) so request_ras_irqs() (which actually requests
the event-sources interrupts) is found in ras.c and is static.
We want to be able to use event-sources interrupts in other pseries code,
so let's rename request_ras_irqs() to request_event_sources_irqs() and
move it to event_sources.c.
This will be used in an upcoming patch that adds support for IO Event
interrupts that come through as event sources.
Signed-off-by: Mark Nelson <markn@au1.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
I've been told that the architected way to determine we are in form 1
affinity mode is by reading the ibm,architecture-vec-5 property which
mirrors the layout of the fifth vector of the ibm,client-architecture
structure.
Eventually we may want to parse the ibm,architecture-vec-5 and create
FW_FEATURE_* bits.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
I noticed /proc/sys/vm/zone_reclaim_mode was 0 on a ppc64 NUMA box. It gets
enabled via this:
/*
* If another node is sufficiently far away then it is better
* to reclaim pages in a zone before going off node.
*/
if (distance > RECLAIM_DISTANCE)
zone_reclaim_mode = 1;
Since we use the default value of 20 for REMOTE_DISTANCE and 20 for
RECLAIM_DISTANCE it never kicks in.
The local to remote bandwidth ratios can be quite large on System p
machines so it makes sense for us to reclaim clean pagecache locally before
going off node.
The patch below sets a smaller value for RECLAIM_DISTANCE and thus enables
zone reclaim.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Right now if we want to busy loop and not give up any time to the hypervisor
we put a very large value into smt_snooze_delay. This is sometimes useful
when running a single partition and you want to avoid any latencies due
to the hypervisor or CPU power state transitions. While this works, it's a bit
ugly - how big a number is enough now we have NO_HZ and can be idle for a very
long time.
The patch below makes smt_snooze_delay signed, and a negative value means loop
forever:
echo -1 > /sys/devices/system/cpu/cpu0/smt_snooze_delay
This change shouldn't affect the existing userspace tools (eg ppc64_cpu), but
I'm cc-ing Nathan just to be sure.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
I'm not sure why we have code for parsing an ibm,smt-snooze-delay OF
property. Since we have a smt-snooze-delay= boot option and we can
also set it at runtime via sysfs, it should be safe to get rid of
this code.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
When we are crashing, the crashing/primary CPU IPIs the secondaries to
turn off IRQs, go into real mode and wait in kexec_wait. While this
is happening, the primary tears down all the MMU maps. Unfortunately
the primary doesn't check to make sure the secondaries have entered
real mode before doing this.
On PHYP machines, the secondaries can take a long time shutting down
the IRQ controller as RTAS calls are need. These RTAS calls need to
be serialised which resilts in the secondaries contending in
lock_rtas() and hence taking a long time to shut down.
We've hit this on large POWER7 machines, where some secondaries are
still waiting in lock_rtas(), when the primary tears down the HPTEs.
This patch makes sure all secondaries are in real mode before the
primary tears down the MMU. It uses the new kexec_state entry in the
paca. It times out if the secondaries don't reach real mode after
10sec.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
In kexec_prepare_cpus, the primary CPU IPIs the secondary CPUs to
kexec_smp_down(). kexec_smp_down() calls kexec_smp_wait() which sets
the hw_cpu_id() to -1. The primary does this while leaving IRQs on
which means the primary can take a timer interrupt which can lead to
the IPIing one of the secondary CPUs (say, for a scheduler re-balance)
but since the secondary CPU now has a hw_cpu_id = -1, we IPI CPU
-1... Kaboom!
We are hitting this case regularly on POWER7 machines.
There is also a second race, where the primary will tear down the MMU
mappings before knowing the secondaries have entered real mode.
Also, the secondaries are clearing out any pending IPIs before
guaranteeing that no more will be received.
This changes kexec_prepare_cpus() so that we turn off IRQs in the
primary CPU much earlier. It adds a paca flag to say that the
secondaries have entered the kexec_smp_down() IPI and turned off IRQs,
rather than overloading hw_cpu_id with -1. This new paca flag is
again used to in indicate when the secondaries has entered real mode.
It also ensures that all CPUs have their IRQs off before we clear out
any pending IPI requests (in kexec_cpu_down()) to ensure there are no
trailing IPIs left unacknowledged.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Currently for kexec the PTE tear down on 1TB segment systems normally
requires 3 hcalls for each PTE removal. On a machine with 32GB of
memory it can take around a minute to remove all the PTEs.
This optimises the path so that we only remove PTEs that are valid.
It also uses the read 4 PTEs at once HCALL. For the common case where
a PTEs is invalid in a 1TB segment, this turns the 3 HCALLs per PTE
down to 1 HCALL per 4 PTEs.
This gives an > 10x speedup in kexec times on PHYP, taking a 32GB
machine from around 1 minute down to a few seconds.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This adds plpar_pte_read_4_raw() which can be used read 4 PTEs from
PHYP at a time, while in real mode.
It also creates a new hcall9 which can be used in real mode. It's the
same as plpar_hcall9 but minus the tracing hcall statistics which may
require variables outside the RMO.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Author: Milton Miller <miltonm@bga.com>
On large machines we are running out of room below 256MB. In some cases we
only need to ensure the allocation is in the first segment, which may be
256MB or 1TB.
Add slb0_limit and use it to specify the upper limit for the irqstack and
emergency stacks.
On a large ppc64 box, this fixes a panic at boot when the crashkernel=
option is specified (previously we would run out of memory below 256MB).
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
I saw this in a kdump kernel:
IOMMU table initialized, virtual merging enabled
Interrupt 155954 (real) is invalid, disabling it.
Interrupt 155953 (real) is invalid, disabling it.
ie we took some spurious interrupts. default_machine_crash_shutdown tries
to disable all interrupt sources but uses chip->disable which maps to
the default action of:
static void default_disable(unsigned int irq)
{
}
If we use chip->shutdown, then we actually mask the IRQ:
static void default_shutdown(unsigned int irq)
{
struct irq_desc *desc = irq_to_desc(irq);
desc->chip->mask(irq);
desc->status |= IRQ_MASKED;
}
Not sure why we don't implement a ->disable action for xics.c, or why
default_disable doesn't mask the interrupt.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We wrap the crash_shutdown_handles[] calls with longjmp/setjmp, so if any
of them fault we can recover. The problem is we add a hook to the debugger
fault handler hook which calls longjmp unconditionally.
This first part of kdump is run before we marshall the other CPUs, so there
is a very good chance some CPU on the box is going to page fault. And when
it does it hits the longjmp code and assumes the context of the oopsing CPU.
The machine gets very confused when it has 10 CPUs all with the same stack,
all thinking they have the same CPU id. I get even more confused trying
to debug it.
The patch below adds crash_shutdown_cpu and uses it to specify which cpu is
in the protected region. Since it can only be -1 or the oopsing CPU, we don't
need to use memory barriers since it is only valid on the local CPU - no other
CPU will ever see a value that matches it's local CPU id.
Eventually we should switch the order and marshall all CPUs before doing the
crash_shutdown_handles[] calls, but that is a bigger fix.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>