Age | Commit message (Collapse) | Author | Files | Lines |
|
Introduce the child field in sched_domain struct and use it in
sched_balance_self().
We will also use this field in cleaning up the sched group cpu_power
setup(done in a different patch) code.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
|
|
The last change for partport_pc did fix the common case for all PowerMacs,
but it broke the case for PCI multiport IO cards. In fact, the config
option CONFIG_PARPORT_PC_SUPERIO=y lead to a hard crash when cups probed
the parport driver. It enables the winbond and smsc probing.
Remove the PARPORT_BASE check again, parport_pc_find_nonpci_ports() will
take care of it. All powerpc configs should have
CONFIG_PARPORT_PC_SUPERIO=n, the code did not find anything on the chrp
boards we tested it on.
Tested on a G4/466 with a PCI card:
0001:10:13.0 Serial controller: Timedia Technology Co Ltd PCI2S550 (Dual 16550 UART) (rev 01) (prog-if 02 [16550])
Subsystem: Timedia Technology Co Ltd Unknown device 5079
Control: I/O+ Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping+ SERR- FastB2B-
Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
Interrupt: pin A routed to IRQ 53
Region 0: I/O ports at f2000800 [size=32]
Region 2: I/O ports at f2000870 [size=8]
Region 3: I/O ports at f2000860 [size=8]
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Adam Belay <ambx1@neo.rr.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
|
|
Some architectures provide an execve function that does not set errno, but
instead returns the result code directly. Rename these to kernel_execve to
get the right semantics there. Moreover, there is no reasone for any of these
architectures to still provide __KERNEL_SYSCALLS__ or _syscallN macros, so
remove these right away.
[akpm@osdl.org: build fix]
[bunk@stusta.de: build fix]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andi Kleen <ak@muc.de>
Acked-by: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Hirokazu Takata <takata.hirokazu@renesas.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Richard Curnow <rc@rc0.org.uk>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
Cc: Chris Zankel <chris@zankel.net>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
|
|
Add the regs_return_value() macro to extract the return value in an
architecture agnostic manner, given the pt_regs.
Other architecture maintainers may want to add similar helpers.
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
|
|
kallsyms_lookup_name() allows for <module:symbol> style specification for
looking up symbol addresses. Handle the case where the user specifies
<module:.symbol> on powerpc, given that 64-bit powerpc uses function
descriptors.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
|
|
In an effort to make kprobe modules more portable, here is a patch that:
o Introduces the "symbol_name" field to struct kprobe.
The symbol->address resolution now happens in the kernel in an
architecture agnostic manner. 64-bit powerpc users no longer have
to specify the ".symbols"
o Introduces the "offset" field to struct kprobe to allow a user to
specify an offset into a symbol.
o The legacy mechanism of specifying the kprobe.addr is still supported.
However, if both the kprobe.addr and kprobe.symbol_name are specified,
probe registration fails with an -EINVAL.
o The symbol resolution code uses kallsyms_lookup_name(). So
CONFIG_KPROBES now depends on CONFIG_KALLSYMS
o Apparantly kprobe modules were the only legitimate out-of-tree user of
the kallsyms_lookup_name() EXPORT. Now that the symbol resolution
happens in-kernel, remove the EXPORT as suggested by Christoph Hellwig
o Modify tcp_probe.c that uses the kprobe interface so as to make it
work on multiple platforms (in its earlier form, the code wouldn't
work, say, on powerpc)
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
|
|
ppc can boot one single binary on prep, chrp and pmac boards. ppc64 can
boot one single binary on pseries and G5 boards. pmac has no legacy io,
probing for PC style legacy hardware (or accessing the legacy io area
regulary) may lead to a hard crash:
* add check for parport_pc, exit on pmac. 32bit chrp has no
->check_legacy_ioport, the probe is always called. 64bit chrp has
check_legacy_ioport, check for a "parallel" node
* add check for isapnp, only PReP boards may have real ISA slots. 32bit
PReP will have no ->check_legacy_ioport, the probe is always called.
* update code in i8042_platform_init. Run ->check_legacy_ioport first,
always call request_region. No functional change. Remove whitespace
before i8042_reset init.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Adam Belay <ambx1@neo.rr.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
|
|
Powerpc already has a directed yield for CONFIG_PREEMPT="n". To make it
work with CONFIG_PREEMPT="y" as well the _raw_{spin,read,write}_relax
primitives need to be defined to call __spin_yield() for spinlocks and
__rw_yield() for rw-locks.
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
|
|
On systems running with virtual cpus there is optimization potential in
regard to spinlocks and rw-locks. If the virtual cpu that has taken a lock
is known to a cpu that wants to acquire the same lock it is beneficial to
yield the timeslice of the virtual cpu in favour of the cpu that has the
lock (directed yield).
With CONFIG_PREEMPT="n" this can be implemented by the architecture without
common code changes. Powerpc already does this.
With CONFIG_PREEMPT="y" the lock loops are coded with _raw_spin_trylock,
_raw_read_trylock and _raw_write_trylock in kernel/spinlock.c. If the lock
could not be taken cpu_relax is called. A directed yield is not possible
because cpu_relax doesn't know anything about the lock. To be able to
yield the lock in favour of the current lock holder variants of cpu_relax
for spinlocks and rw-locks are needed. The new _raw_spin_relax,
_raw_read_relax and _raw_write_relax primitives differ from cpu_relax
insofar that they have an argument: a pointer to the lock structure.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
|
|
Letting WARN_ON/WARN_ON_ONCE return the condition means that you could do
if (WARN_ON(blah)) {
handle_impossible_case
}
Rather than
if (unlikely(blah)) {
WARN_ON(1)
handle_impossible_case
}
I checked all the newly added WARN_ON_ONCE users and none of them test the
return status so we can still change it.
[akpm@osdl.org: warning fix]
[akpm@osdl.org: build fix]
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
|
|
One of the changes necessary for shared page tables is to standardize the
pxx_page macros. pte_page and pmd_page have always returned the struct
page associated with their entry, while pte_page_kernel and pmd_page_kernel
have returned the kernel virtual address. pud_page and pgd_page, on the
other hand, return the kernel virtual address.
Shared page tables needs pud_page and pgd_page to return the actual page
structures. There are very few actual users of these functions, so it is
simple to standardize their usage.
Since this is basic cleanup, I am submitting these changes as a standalone
patch. Per Hugh Dickins' comments about it, I am also changing the
pxx_page_kernel macros to pxx_page_vaddr to clarify their meaning.
Signed-off-by: Dave McCracken <dmccr@us.ibm.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
|
|
They all contain the same thing. Instead, have a single generic one in
include/asm-generic, and permit an arch to override as needed.
Signed-off-by: Jeff Garzik <jeff@garzik.org>
|
|
|
|
* git://git.infradead.org/~dwmw2/hdroneline:
[HEADERS] One line per header in Kbuild files to reduce conflicts
Manual (trivial) conflict resolution in include/asm-s390/Kbuild
|
|
Ulrich Weigand found a bug with the current version of the
asm-powerpc/ptrace.h that prevents building at least the
SPU target version of gdb, since some ptrace opcodes are
not defined.
The problem seems to have originated in the merging of 32 and
64 bit versions of that file, the problem is that some opcodes
are only valid on 64 bit kernels, but are also used by 32 bit
programs, so they can't depends on the __powerpc64__ symbol.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
|
|
This looks like cruft to me, these functions don't exist AFAICT,
and I can't see that it's possible to even enable DISCONTIGMEM on
powerpc anymore. CC'ing some folks who might know better, based on
the who-touched-it-last principle.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
|
|
This patch changes the io operations so that they are out of line if
CONFIG_PPC_ISERIES is set and includes a firmware feature check in
that case.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
|
|
Add wrapper around the rtas call to enable MMIO or DMA on a frozen pci
slot.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
|
|
There are various places where we want to extract an unsigned long
value from a device-tree property that can be 1 or 2 cells in length.
This replaces some open-coded calculations, and one place where we
assumed without checking that properties were the length we wanted,
with a little of_read_ulong() helper.
Signed-off-by: Paul Mackerras <paulus@samba.org>
|
|
Copy and paste bug in io.h
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
|
|
This produces essentially the same code and will make the iSeries i/o
consolidation easier.
The count parameter is changed to long since that will produce the same
(better) code on 32 and 64 bit builds.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
|
|
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
|
|
_insw, _outsw, _insl amd _outsl are all unused, so remove them.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
|
|
The io accessors insw_ns, outsw_ns, insl_ns and outsl_ns are unused
(except for one unnecessary use in drivers/net/3c509.c that is addressed
in a previous patch) and are only defined in powerpc/ppc, so remove them.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
|
|
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
|
|
|
|
|
|
This changes the writeX family of functions to have a sync instruction
before the MMIO store rather than after, because the generally expected
behaviour is that the device receiving the MMIO store can be guaranteed
to see the effects of any preceding writes to normal memory.
To preserve ordering between writeX and readX, and to preserve ordering
between preceding stores and the readX, the readX family of functions
have had an sync added before the load.
Although writeX followed by spin_unlock is not officially guaranteed
to keep the writeX inside the spin-locked region unless an mmiowb()
is used, there are currently drivers that depend on the previous
behaviour on powerpc, which was that the mmiowb wasn't actually required.
Therefore we have a per-cpu flag that is set by writeX, cleared by
__raw_spin_lock and mmiowb, and tested by __raw_spin_unlock. If it is
set, __raw_spin_unlock does a sync and clears it.
This changes both 32-bit and 64-bit readX/writeX. 32-bit already has a
sync in __raw_spin_unlock (since lwsync doesn't exist on 32-bit), and thus
doesn't need the per-cpu flag.
Tested on G5 (PPC970) and POWER5.
Signed-off-by: Paul Mackerras <paulus@samba.org>
|
|
Add instrumentation for hypervisor calls on pseries. Call statistics
include number of calls, wall time and cpu cycles (if available) and
are made available via debugfs. Instrumentation code is behind the
HCALL_STATS config option and has no impact if not enabled.
Signed-off-by: Mike Kravetz <kravetz@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
|
|
Introduce PWRficient PA6T cputable entries and feature bits.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
|
|
The performance monitor implementation (including CTRL register behaviour)
is just included in PPC v2 as an example, it's not truly part of the base.
It's actually a somewhat misleading feature, but I'll leave that be for
now: The presence of the register is not what the feature bit is used
for, but instead it's used to determine if it contains the runlatch
bit for idle reporting of the performance monitor. For alternative
implementations, the register might still exist but the bit might have
different meaning (or no meaning at all).
For now, split it off and don't include it in CPU_FTR_PPCAS_ARCH_V2_BASE.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
|
|
This is required to generate proper core files using kdump on ppc64.
Create a backup region of 64K size irrespective of the PAGE SIZE.
At present 32K was used as backup size. In the case of 64K page size,
second PT_LOAD segments starts at 32K and the first one is not page
aligned. __ioremap() (crash_dump.c) fails if pfn = 0 which is the
case for the second PT_LOAD segment. This is not an issue for 4K page
size because the the first page (32K backup) is copied to second
kernel memory and thus referencing with the second kernel pfn.
Signed-off-by: Sachin Sant <sachinp@in.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
|
|
The sys_[gs]et_robust_list() syscalls were wired up on PowerPC but
didn't work correctly because futex_atomic_cmpxchg_inatomic() wasn't
implemented. Implement it, based on __cmpxchg_u32().
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
|
|
|
|
|
|
These are build fixes that enable (for example) libata and the ide
code to actually build on iSeries. The associated hardware will never
be supported on legacy iSeries, so the code paths don't actually need
to work, but it is useful (especially for a combined kernel) if the
code can build.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
|
|
This fixes a problem introduced in 5db9fa9593e2ff69f2b95f9d59229dc4faaa564d.
The last_jiffy per-cpu variable is only 32 bits on 32-bit machines, but it
was being compared with a 64-bit quantity (tb_next_jiffy), which resulted in
time not advancing.
This fixes it by changing last_jiffy to be 64 bits on all platforms. With
this, we no longer need tb_last_stamp as a 32-bit version of tb_last_jiffy,
so this gets rid of tb_last_stamp and we just use tb_last_jiffy instead.
This also fixes a bug when the boot cpu is not online, because using
tb_last_stamp could have caused the wrong timebase origin value to be used
when calculating the time of day.
Signed-off-by: Paul Mackerras <paulus@samba.org>
|
|
Device-tree bugs on js20 with some versions of SLOF were causing the
interrupt for IDE to not be parsed correctly and fail to boot. This
patch adds a bit more sanity checking to the parser to detect some of
those errors and fail instead of returning bogus information. The
powerpc PCI code can then trigger a fallback that works on those
machines.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
|
|
This adds a new hardware information table for mpic. This enables
the mpic code to deal with mpic controllers with different register
layouts and hardware behaviours.
This introduces CONFIG_MPIC_WEIRD. For boards with non standard mpic
controllers, select CONFIG_MPIC_WEIRD and add its hardware information
in the mpic_infos[] array.
TSI108/109 PIC takes the first index of weird hardware information
table. :) The table can be extended. The Tsi108/109 PIC looks like
standard OpenPIC but, in fact, is different in register mapping and
behavior.
The patch does not affect the behavior of standard mpic. If
CONFIG_MPIC_WEIRD is not defined, the code is essentially identical to
the current code.
[benh@kernel.crashing.org:
This patch is a slightly cleaned up version of Zang Roy's support for
the TSI108 MPIC variant. It also fixes up MPC7448_hpc2 to use the new
version of the type macros and changes the way MPIC is selected in
Kconfig to better match what is done for other system devices.
]
Signed-off-by: Roy Zang <tie-fei.zang@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
|
|
Keep from breaking 83xx arch/ppc build. Back up old school arch/powerpc/sysdev/ipic.[hc] to arch/ppc/syslib.
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
|
|
|
|
|
|
After going through the trouble of setting up the PIC base
address in the pic@40000 device tree node, use it instead
of the obsolete hard-coded value.
Signed-off-by: Jon Loeliger <jdl@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
|
|
Signed-off-by: Jon Loeliger <jdl@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
|
|
Several RTAS calls take a "config_addr" parameter, which is a particular
way of specifying a PCI busno, devfn and register number into a 32-bit word.
Currently these are open-coded, and I'll be adding another soon, replace
them with a helper that encapsulates the logic. Be more strict about masking
the busno too, just in case.
Booted on P5 LPAR.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
|
|
Signed-off-by: Jon Loeliger <jdl@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
|
|
Cleanup CPU inits a bit more, Geoff Levand already did some earlier.
* Move CPU state save to cpu_setup, since cpu_setup is only ever done
on cpu 0 on 64-bit and save is never done more than once.
* Rename __restore_cpu_setup to __restore_cpu_ppc970 and add
function pointers to the cputable to use instead. Powermac always
has 970 so no need to check there.
* Rename __970_cpu_preinit to __cpu_preinit_ppc970 and check PVR before
calling it instead of in it, it's too early to use cputable.
* Rename pSeries_secondary_smp_init to generic_secondary_smp_init since
everyone but powermac and iSeries use it.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
|
|
On Tue, 2006-08-15 at 08:22 -0700, Dave Hansen wrote:
> kernel BUG in cache_free_debugcheck at mm/slab.c:2748!
Alright, this one is only triggered when slab debugging is enabled. The
slabs are assumed to be aligned on a HUGEPTE_TABLE_SIZE boundary. The free
path makes use of this assumption and uses the lowest nibble to pass around
an index into an array of kmem_cache pointers. With slab debugging turned
on, the slab is still aligned, but the "working" object pointer is not.
This would break the assumption above that a full nibble is available for
the PGF_CACHENUM_MASK.
The following patch reduces PGF_CACHENUM_MASK to cover only the two least
significant bits, which is enough to cover the current number of 4 pgtable
cache types. Then use this constant to mask out the appropriate part of
the huge pte pointer.
Signed-off-by: Adam Litke <agl@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
|
|
The patch rewrites mpc7448hpc2 board irq support according to the new
mpic device tree interface.
Signed-off-by: Roy Zang <tie-fei.zang@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
|
|
There are two problems in the powerpc gettimeofday code which can
cause incorrect results to be returned.
The first is that there is a race between do_gettimeofday and the
timer interrupt:
1. do_gettimeofday does get_tb()
2. decrementer exception on boot cpu which runs timer_recalc_offset,
which also samples the timebase and updates the do_gtod structure
with a greater timebase value.
3. do_gettimeofday calls __do_gettimeofday, which leads to the
negative result from tb_val - temp_varp->tb_orig_stamp.
The second is caused by taking the boot cpu offline, which can cause
the value of tb_last_jiffy to be increased past the currently
available timebase, causing the same underflow as above.
[paulus@samba.org - define and use data_barrier() instead of mb().]
Signed-off-by: Nathan Lynch <ntl@pobox.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
|