We have to use bootmem during init_IRQ and page alloc
for sibling cpu calls.
Also, fix incorrect hypervisor call return value
checks in the hypervisor SMP cpu mondo send code.
Signed-off-by: David S. Miller <davem@davemloft.net>
Yes, you heard it right, they changed the PTE layout for
SUN4V. Ho hum...
This is the simple and inefficient way to support this.
It'll get optimized, don't worry.
Signed-off-by: David S. Miller <davem@davemloft.net>
Code patching did not sign extend negative branch
offsets correctly.
Kernel TLB miss path needs patching and %g4 register
preservation in order to handle SUN4V correctly.
Signed-off-by: David S. Miller <davem@davemloft.net>
prom_sun4v_name should be "sun4v" not "SUNW,sun4v"
Also, this is too early to make use of the
.sun4v_Xinsn_patch code patching, so just check
things manually.
This gets us at least to prom_init() on Niagara.
Signed-off-by: David S. Miller <davem@davemloft.net>
We need to restore the %asi register properly.
For the kernel this means get_fs(), for user this
means ASI_PNF.
Also, NGcopy_to_user.S was including U3memcpy.S instead
of NGmemcpy.S, oops :-)
Signed-off-by: David S. Miller <davem@davemloft.net>
There was also a bug in sun4v_itlb_miss, it loaded the
MMU Fault Status base into %g3 instead of %g2.
This pointed out a fast path for TSB miss processing,
since we have %g2 with the MMU Fault Status base, we
can use that to quickly load up the PGD phys address.
Signed-off-by: David S. Miller <davem@davemloft.net>
This is where the virtual address of the fault status
area belongs.
To set it up we don't make a hypervisor call, instead
we call OBP's SUNW,set-trap-table with the real address
of the fault status area as the second argument. And
right before that call we write the virtual address into
ASI_SCRATCHPAD vaddr 0x0.
Signed-off-by: David S. Miller <davem@davemloft.net>
Add assembler file for PCI hypervisor calls.
Setup basic skeleton of SUN4V PCI controller driver.
Add 32-bit devhandle to PBM struct, as this is needed for
hypervisor calls.
Signed-off-by: David S. Miller <davem@davemloft.net>
Abstract out IOMMU operations so that we can have a different
set of calls on sun4v, which needs to do things through
hypervisor calls.
Signed-off-by: David S. Miller <davem@davemloft.net>
When we register a TSB with the hypervisor, so that it or hardware can
handle TLB misses and do the TSB walk for us, the hypervisor traps
down to these trap when it incurs a TSB miss.
Processing is simple, we load the missing virtual address and context,
and do a full page table walk.
Signed-off-by: David S. Miller <davem@davemloft.net>
We look for "SUNW,sun4v" in the 'compatible' property
of the root OBP device tree node.
Protect every %ver register access, to make sure it is
not touched on sun4v, as %ver is hyperprivileged there.
Lock kernel TLB entries using hypervisor calls instead of
calls into OBP.
Signed-off-by: David S. Miller <davem@davemloft.net>
Technically the hypervisor call supports sending in a list
of all cpus to get the cross-call, but I only pass in one
cpu at a time for now.
The multi-cpu support is there, just ifdef'd out so it's easy to
enable or delete it later.
Signed-off-by: David S. Miller <davem@davemloft.net>
Sun4v has 4 interrupt queues: cpu, device, resumable errors,
and non-resumable errors. A set of head/tail offset pointers
help maintain a work queue in physical memory. The entries
are 64-bytes in size.
Each queue is allocated then registered with the hypervisor
as we bring cpus up.
The two error queues each get a kernel side buffer that we
use to quickly empty the main interrupt queue before we
call up to C code to log the event and possibly take evasive
action.
Signed-off-by: David S. Miller <davem@davemloft.net>
Happily we have no D-cache aliasing issues on these
chips, so the implementation is very straightforward.
Add a stub in bootup which will be where the patching
calls will be made for niagara/sun4v/hypervisor.
Signed-off-by: David S. Miller <davem@davemloft.net>
Things are a little tricky because, unlike sun4u, we have
to:
1) do a hypervisor trap to do the TLB load.
2) do the TSB lookup calculations by hand
Signed-off-by: David S. Miller <davem@davemloft.net>
If we're just switching between different alternate global
sets, nop it out on sun4v. Also, get rid of all of the
alternate global save/restore in the OBP CIF trampoline code.
Signed-off-by: David S. Miller <davem@davemloft.net>
They are totally unnecessary because:
1) Interrupts are already disabled when switch_to()
runs.
2) We don't use hard-coded alternate globals any longer.
This found a case in rtrap, which still assumed alternate
global %g6 was current_thread_info(), and that is fixed
by this changeset as well.
Signed-off-by: David S. Miller <davem@davemloft.net>
As we save trap state onto the stack, the store buffer fills up
mid-way through and we stall for several cycles as the store buffer
trickles out to the L2 cache. Meanwhile we can do some privileged
register reads and other calculations, essentially for free.
Signed-off-by: David S. Miller <davem@davemloft.net>
And more consistently check cheetah{,_plus} instead
of assuming anything not spitfire is cheetah{,_plus}.
Signed-off-by: David S. Miller <davem@davemloft.net>
When saving and restoing trap state, do the window spill/fill
handling inline so that we never trap deeper than 2 trap levels.
This is important for chips like Niagara.
The window fixup code is massively simplified, and many more
improvements are now possible.
Signed-off-by: David S. Miller <davem@davemloft.net>
On uniprocessor, it's always zero for optimize that.
On SMP, the jmpl to the stub kills the return address stack in the cpu
branch prediction logic, so expand the code sequence inline and use a
code patching section to fix things up. This also always better and
explicit register selection, which will be taken advantage of in a
future changeset.
The hard_smp_processor_id() function is big, so do not inline it.
Fix up tests for Jalapeno to also test for Serrano chips too. These
tests want "jbus Ultra-IIIi" cases to match, so that is what we should
test for.
Signed-off-by: David S. Miller <davem@davemloft.net>
There are several tricky races involved with growing the TSB. So just
use base-size TSBs for user contexts and we can revisit enabling this
later.
One part of the SMP problems is that tsb_context_switch() can see
partially updated TSB configuration state if tsb_grow() is running in
parallel. That's easily solved with a seqlock taken as a writer by
tsb_grow() and taken as a reader to capture all the TSB config state
in tsb_context_switch().
Then there is flush_tsb_user() running in parallel with a tsb_grow().
In theory we could take the seqlock as a reader there too, and just
resample the TSB pointer and reflush but that looks really ugly.
Lastly, I believe there is a case with threads that results in a TSB
entry lock bit being set spuriously which will cause the next access
to that TSB entry to wedge the cpu (since the TSB entry lock bit will
never clear). It's either copy_tsb() or some bug elsewhere in the TSB
assembly.
Signed-off-by: David S. Miller <davem@davemloft.net>
The are distrupting, which by the sparc v9 definition means they
can only occur when interrupts are enabled in the %pstate register.
This never occurs in any of the trap handling code running at
trap levels > 0.
So just mark it as an unexpected trap.
This allows us to kill off the cee_stuff member of struct thread_info.
Signed-off-by: David S. Miller <davem@davemloft.net>
This way we don't need to lock the TSB into the TLB.
The trick is that every TSB load/store is registered into
a special instruction patch section. The default uses
virtual addresses, and the patch instructions use physical
address load/stores.
We can't do this on all chips because only cheetah+ and later
have the physical variant of the atomic quad load.
Signed-off-by: David S. Miller <davem@davemloft.net>
If we are returning back to kernel mode, %g4 could be live
(for example, in the case where we window spill in the etrap
code). So do not change it's value if going back to kernel.
Signed-off-by: David S. Miller <davem@davemloft.net>
Since we use %g5 itself as a temporary, it can get clobbered
if we take an interrupt mid-stream and thus cause end up with
the final %g5 value too early as a result of rtrap processing.
Set %g5 at the very end, atomically, to avoid this problem.
Signed-off-by: David S. Miller <davem@davemloft.net>
%g6 is not necessarily set to current_thread_info()
at sparc64_realfault_common. So store the fault
code and address after we invoke etrap and %g6 is
properly set up.
Signed-off-by: David S. Miller <davem@davemloft.net>
Just flip the bit off of whatever it's currently set to.
PSTATE_IE is guarenteed to be enabled when we get here.
Signed-off-by: David S. Miller <davem@davemloft.net>
It is totally unnecessary complexity. After we take over
the trap table, we handle all PROM tlb misses fully.
Signed-off-by: David S. Miller <davem@davemloft.net>
Some of the trap code was still assuming that alternate
global %g6 was hard coded with current_thread_info().
Let's just consistently flush at KERNBASE when we need
a pipeline synchronization. That's locked into the TLB
and will always work.
Signed-off-by: David S. Miller <davem@davemloft.net>
The TSB_LOCK_BIT define is actually a special
value shifted down by 32-bits for the assembler
code macros.
In C code, this isn't what we want.
Signed-off-by: David S. Miller <davem@davemloft.net>
As the RSS grows, grow the TSB in order to reduce the likelyhood
of hash collisions and thus poor hit rates in the TSB.
This definitely needs some serious tuning.
Signed-off-by: David S. Miller <davem@davemloft.net>
This also cleans up tsb_context_switch(). The assembler
routine is now __tsb_context_switch() and the former is
an inline function that picks out the bits from the mm_struct
and passes it into the assembler code as arguments.
setup_tsb_parms() computes the locked TLB entry to map the
TSB. Later when we support using the physical address quad
load instructions of Cheetah+ and later, we'll simply use
the physical address for the TSB register value and set
the map virtual and PTE both to zero.
Signed-off-by: David S. Miller <davem@davemloft.net>
Move {init_new,destroy}_context() out of line.
Do not put huge pages into the TSB, only base page size translations.
There are some clever things we could do here, but for now let's be
correct instead of fancy.
Signed-off-by: David S. Miller <davem@davemloft.net>
UltraSPARC has special sets of global registers which are switched to
for certain trap types. There is one set for MMU related traps, one
set of Interrupt Vector processing, and another set (called the
Alternate globals) for all other trap types.
For what seems like forever we've hard coded the values in some of
these trap registers. Some examples include:
1) Interrupt Vector global %g6 holds current processors interrupt
work struct where received interrupts are managed for IRQ handler
dispatch.
2) MMU global %g7 holds the base of the page tables of the currently
active address space.
3) Alternate global %g6 held the current_thread_info() value.
Such hardcoding has resulted in some serious issues in many areas.
There are some code sequences where having another register available
would help clean up the implementation. Taking traps such as
cross-calls from the OBP firmware requires some trick code sequences
wherein we have to save away and restore all of the special sets of
global registers when we enter/exit OBP.
We were also using the IMMU TSB register on SMP to hold the per-cpu
area base address, which doesn't work any longer now that we actually
use the TSB facility of the cpu.
The implementation is pretty straight forward. One tricky bit is
getting the current processor ID as that is different on different cpu
variants. We use a stub with a fancy calling convention which we
patch at boot time. The calling convention is that the stub is
branched to and the (PC - 4) to return to is in register %g1. The cpu
number is left in %g6. This stub can be invoked by using the
__GET_CPUID macro.
We use an array of per-cpu trap state to store the current thread and
physical address of the current address space's page tables. The
TRAP_LOAD_THREAD_REG loads %g6 with the current thread from this
table, it uses __GET_CPUID and also clobbers %g1.
TRAP_LOAD_IRQ_WORK is used by the interrupt vector processing to load
the current processor's IRQ software state into %g6. It also uses
__GET_CPUID and clobbers %g1.
Finally, TRAP_LOAD_PGD_PHYS loads the physical address base of the
current address space's page tables into %g7, it clobbers %g1 and uses
__GET_CPUID.
Many refinements are possible, as well as some tuning, with this stuff
in place.
Signed-off-by: David S. Miller <davem@davemloft.net>
Taking a nod from the powerpc port.
With the per-cpu caching of both the page allocator and SLAB, the
pgtable quicklist scheme becomes relatively silly and primitive.
Signed-off-by: David S. Miller <davem@davemloft.net>
We now use the TSB hardware assist features of the UltraSPARC
MMUs.
SMP is currently knowingly broken, we need to find another place
to store the per-cpu base pointers. We hid them away in the TSB
base register, and that obviously will not work any more :-)
Another known broken case is non-8KB base page size.
Also noticed that flush_tlb_all() is not referenced anywhere, only
the internal __flush_tlb_all() (local cpu only) is used by the
sparc64 port, so we can get rid of flush_tlb_all().
The kernel gets it's own 8KB TSB (swapper_tsb) and each address space
gets it's own private 8K TSB. Later we can add code to dynamically
increase the size of per-process TSB as the RSS grows. An 8KB TSB is
good enough for up to about a 4MB RSS, after which the TSB starts to
incur many capacity and conflict misses.
We even accumulate OBP translations into the kernel TSB.
Another area for refinement is large page size support. We could use
a secondary address space TSB to handle those.
Signed-off-by: David S. Miller <davem@davemloft.net>
this changes if() BUG(); constructs to BUG_ON() which is
cleaner and can better optimized away
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The patch "[SPARC64]: Get rid of fast IRQ feature"
moved the the code from arch/sparc64/kernel/entry.S:
lduba [%g7] ASI_PHYS_BYPASS_EC_E, %g5
or %g5, AUXIO_AUX1_FTCNT, %g5
stba %g5, [%g7] ASI_PHYS_BYPASS_EC_E
andn %g5, AUXIO_AUX1_FTCNT, %g5
stba %g5, [%g7] ASI_PHYS_BYPASS_EC_E
to arch/sparc64/kernel/irq.c:
val = readb(auxio_register);
val |= AUXIO_AUX1_FTCNT;
writeb(val, auxio_register);
val &= AUXIO_AUX1_FTCNT;
writeb(val, auxio_register);
This looks like it it missing a bitwise not, which is reintroduced
by this patch.
Due to lack of a floppy device, I could not test it, but it looks
evident.
Signed-off-by: Bernhard R Link <brlink@debian.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
From Dave Johnson <djohnson+linuxmips@sw.starentnetworks.com>:
sb1250_gettimeoffset() simply reads the current cpu 0 timer remaining
value, however once this counter reaches 0 and the interrupt is raised,
it immediately resets and begins to count down again.
If sb1250_gettimeoffset() is called on cpu 1 via do_gettimeofday() after
the timer has reset but prior to cpu 0 processing the interrupt and
taking write_seqlock() in timer_interrupt() it will return a full value
(or close to it) causing time to jump backwards 1ms. Once cpu 0 handles
the interrupt and timer_interrupt() gets far enough along it will jump
forward 1ms.
Fix this problem by implementing mips_hpt_*() on sb1250 using a spare
timer unrelated to the existing periodic interrupt timers. It runs at
1Mhz with a full 23bit counter. This eliminated the custom
do_gettimeoffset() for sb1250 and allowed use of the generic
fixed_rate_gettimeoffset() using mips_hpt_*() and timerhi/timerlo.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
From Dave Johnson <djohnson+linuxmips@sw.starentnetworks.com>:
The timers need to be loaded with 1 less than the desired interval not
the interval itself.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
From Dave Johnson <djohnson+linuxmips@sw.starentnetworks.com>:
* do_timer() expects the arch-specific handler to take the lock as it
modifies jiffies[_64] and xtime.
* writing timerhi/lo in timer_interrupt() will mess up
fixed_rate_gettimeoffset() which reads timerhi/lo.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
If dcache_size != icache_size or dcache_size != scache_size, or
set-associative cache, icache/scache does not flushed properly. Make
blast_?cache_page_indexed() masks its index value correctly. Also,
use physical address for physically indexed pcache/scache.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Bryce reported a bug wherein offlining CPU0 (on x86 box) and then
subsequently onlining it resulted in a lockup.
On x86, CPU0 is never offlined. The subsequent attempt to online CPU0
doesn't take that into account. It actually tries to bootup the already
booted CPU. Following patch fixes the problem (as acknowledged by Bryce).
Please consider for inclusion in 2.6.16.
Check if cpu is already online.
Signed-off-by: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc-merge:
powerpc: update defconfigs
[PATCH] powerpc: properly configure DDR/P5IOC children devs
[PATCH] powerpc: remove duplicate EXPORT_SYMBOLS
[PATCH] powerpc: RTC memory corruption
[PATCH] powerpc: enable NAP only on cpus who support it to avoid memory corruption
[PATCH] powerpc: Clarify wording for CRASH_DUMP Kconfig option
[PATCH] powerpc/64: enable CONFIG_BLK_DEV_SL82C105
[PATCH] powerpc: correct cacheflush loop in zImage
powerpc: Fix problem with time going backwards
powerpc: Disallow lparcfg being a module
The dynamic add path for PCI Host Bridges can fail to configure children
adapters under P5IOC controllers. It fails to properly fixup bus/device
resources, and it fails to properly enable EEH. Both of these steps
need to occur before any children devices are enabled in
pci_bus_add_devices().
Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
remove warnings when building a 64bit kernel.
smp_call_function triggers also with 32bit kernel.
WARNING: vmlinux: duplicate symbol 'smp_call_function' previous definition was in vmlinux
arch/powerpc/kernel/ppc_ksyms.c:164:EXPORT_SYMBOL(smp_call_function);
arch/powerpc/kernel/smp.c:300:EXPORT_SYMBOL(smp_call_function);
WARNING: vmlinux: duplicate symbol 'ioremap' previous definition was in vmlinux
arch/powerpc/kernel/ppc_ksyms.c:113:EXPORT_SYMBOL(ioremap);
arch/powerpc/mm/pgtable_64.c:321:EXPORT_SYMBOL(ioremap);
WARNING: vmlinux: duplicate symbol '__ioremap' previous definition was in vmlinux
arch/powerpc/kernel/ppc_ksyms.c:117:EXPORT_SYMBOL(__ioremap);
arch/powerpc/mm/pgtable_64.c:322:EXPORT_SYMBOL(__ioremap);
WARNING: vmlinux: duplicate symbol 'iounmap' previous definition was in vmlinux
arch/powerpc/kernel/ppc_ksyms.c:118:EXPORT_SYMBOL(iounmap);
arch/powerpc/mm/pgtable_64.c:323:EXPORT_SYMBOL(iounmap);
Signed-off-by: Olaf Hering <olh@suse.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
We should be memset'ing the data we are pointing to, not the pointer
itself. This is in an error path so we probably don't hit it much.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch fixes incorrect setting of powersave_nap to 1 on all
PowerMacs, potentially causing memory corruption on some models. This
bug was introuced by me during the 32/64 bits merge.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The wording of the CRASH_DUMP Kconfig option is not very clear. It gives you a
kernel that can be used _as_ the kdump kernel, not a kernel that can boot into
a kdump kernel.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Enable the onboard IDE driver for p610, p615 and p630.
They have the CD connected to this card. All other RS/6000 systems with this
controller have no connectors and dont need this option.
Signed-off-by: Olaf Hering <olh@suse.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Correct the loop for cacheflush. No idea where I copied the code from,
but the original does not work correct. Maybe the flush is not needed.
Signed-off-by: Olaf Hering <olh@suse.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The recent changes to keep gettimeofday in sync with xtime had the side
effect that it was occasionally possible for the time reported by
gettimeofday to go back by a microsecond. There were two reasons:
(1) when we recalculated the offsets used by gettimeofday every 2^31
timebase ticks, we lost an accumulated fractional microsecond, and
(2) because the update is done some time after the notional start of
jiffy, if ntp is slowing the clock, it is possible to see time go backwards
when the timebase factor gets reduced.
This fixes it by (a) slowing the gettimeofday clock by about 1us in
2^31 timebase ticks (a factor of less than 1 in 3.7 million), and (b)
adjusting the timebase offsets in the rare case that the gettimeofday
result could possibly go backwards (i.e. when ntp is slowing the clock
and the timer interrupt is late). In this case the adjustment will
reduce to zero eventually because of (a).
Signed-off-by: Paul Mackerras <paulus@samba.org>
Patch from Ben Dooks
arch/arm/kernel/setup.c declares mem_fclk_21285 when
this is already declared in include/asm-arm/system.h
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Ben Dooks
arch/arm/kernel/compat.c exports two functions,
convert_to_tag_list and squash_mem_tags which
are not defined in any header files, and not
used outside arch/arm/kernel.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Ben Dooks
Fix the following warnings from sparse:
arch/arm/kernel/process.c:86:6: warning: symbol 'default_idle' was not declared. Should it be static?
arch/arm/kernel/process.c:378:5: warning: symbol 'dump_fpu' was not declared. Should it be static?
Include <linux/elfcore.h> for dump_fpu() decleration, and
make default_idle() static as it is not used outside the file.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Albrecht Dreß
Add DMA resources to s3c2410 spi platform devices - dma_(alloc|free)_coherent should now work as expected.
Signed-off-by: Albrecht Dreß <albrecht.dress@lios-tech.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Pavel Machek
Enable frontlight during collie bootup, so that display is actually
readable in anything other than bright sunlight.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
lapic_shutdown() re-enables interrupts which is un-desirable for panic
case, so use local_irq_save() and local_irq_restore() to keep the irqs
disabled for kexec on panic case, and close a possible race window while
kdump shutdown as shown in this stack trace
-- BUG: spinlock lockup on CPU#1, bash/4396, c52781a0
[<c01c1870>] _raw_spin_lock+0xb7/0xd2
[<c029e148>] _spin_lock+0x6/0x8
[<c011b33f>] scheduler_tick+0xe7/0x328
[<c0128a7c>] update_process_times+0x51/0x5d
[<c0114592>] smp_apic_timer_interrupt+0x4f/0x58
[<c01141ff>] lapic_shutdown+0x76/0x7e
[<c0104d7c>] apic_timer_interrupt+0x1c/0x30
[<c01141ff>] lapic_shutdown+0x76/0x7e
[<c0116659>] machine_crash_shutdown+0x83/0xaa
[<c013cc36>] crash_kexec+0xc1/0xe3
[<c029e148>] _spin_lock+0x6/0x8
[<c013cc22>] crash_kexec+0xad/0xe3
[<c0215280>] __handle_sysrq+0x84/0xfd
[<c018d937>] write_sysrq_trigger+0x2c/0x35
[<c015e47b>] vfs_write+0xa2/0x13b
[<c015ea73>] sys_write+0x3b/0x64
[<c0103c69>] syscall_call+0x7/0xb
Signed-off-by: Maneesh Soni <maneesh@in.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This reverts commit c33d4568ac.
Andrew Clayton and Hugh Dickins report that it's broken for them and
causes strange page table and slab corruption, and spontaneous reboots.
Let's get it right next time.
Cc: Andrew Clayton <andrew@rootshell.co.uk>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The lparcfg code needs several things which are pretty arcane internal
details and which we don't want to export, which means that lparcfg
doesn't work when built as a module. This makes it a bool instead of
a tristate in the Kconfig so that users can't try to build it as a
module.
Signed-off-by: Paul Mackerras <paulus@samba.org>
EM64T CPUs have somewhat weird error reporting for non canonical RIPs in
SYSRET.
We can't handle any exceptions there because the exception handler would
end up running on the user stack which is unsafe.
To avoid problems any code that might end up with a user touched pt_regs
should return using int_ret_from_syscall. int_ret_from_syscall ends up
using IRET, which allows safe exceptions.
Cc: Ernie Petrides <petrides@redhat.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
