Commit Graph

56 Commits

Author SHA1 Message Date
Randy Dunlap
e63340ae6b header cleaning: don't include smp_lock.h when not used
Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.

Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:15:07 -07:00
Jeremy Fitzhardinge
b6e3590f81 [PATCH] x86: Allow percpu variables to be page-aligned
Let's allow page-alignment in general for per-cpu data (wanted by Xen, and
Ingo suggested KVM as well).

Because larger alignments can use more room, we increase the max per-cpu
memory to 64k rather than 32k: it's getting a little tight.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2007-05-02 19:27:12 +02:00
David S. Miller
112f48716d [SPARC64]: Add clocksource/clockevents support.
I'd like to thank John Stul and others for helping
me along the way.

A lot of cleanups fell out of this.  For example, the get_compare()
tick_op was totally unused, so was deleted.  And the most often used
tick_op members were grouped together for cache-friendlyness.

The sparc64 TSC is given to the kernel as a one-shot timer.

tick_ops->init_timer() simply turns off the privileged bit in
the tick register (when possible), and disables the interrupt
by setting bit 63 in the compare register.  The ->disable_irq()
op also sets this bit.

tick_ops->add_compare() is changed to:

1) Add the given delta to "tick" not to "compare"
2) Return a boolean which, if true, means that the tick
   value read after writing the compare value was found
   to have incremented past the initial tick value.  This
   mirrors logic used in the HPET driver's ->next_event()
   method.

Each tick_ops implementation also now provides a name string.
And we feed this into the clocksource and clockevents layers.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 01:54:15 -07:00
David S. Miller
777a447529 [SPARC64]: Unify timer interrupt handler.
Things were scattered all over the place, split between
SMP and non-SMP.

Unify it all so that dyntick support is easier to add.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 01:54:11 -07:00
Gautham R Shenoy
b282b6f8a8 [PATCH] Change cpu_up and co from __devinit to __cpuinit
Compiling the kernel with CONFIG_HOTPLUG = y and CONFIG_HOTPLUG_CPU = n
with CONFIG_RELOCATABLE = y generates the following modpost warnings

WARNING: vmlinux - Section mismatch: reference to .init.data: from
.text between '_cpu_up' (at offset 0xc0141b7d) and 'cpu_up'
WARNING: vmlinux - Section mismatch: reference to .init.data: from
.text between '_cpu_up' (at offset 0xc0141b9c) and 'cpu_up'
WARNING: vmlinux - Section mismatch: reference to .init.text:__cpu_up
from .text between '_cpu_up' (at offset 0xc0141bd8) and 'cpu_up'
WARNING: vmlinux - Section mismatch: reference to .init.data: from
.text between '_cpu_up' (at offset 0xc0141c05) and 'cpu_up'
WARNING: vmlinux - Section mismatch: reference to .init.data: from
.text between '_cpu_up' (at offset 0xc0141c26) and 'cpu_up'
WARNING: vmlinux - Section mismatch: reference to .init.data: from
.text between '_cpu_up' (at offset 0xc0141c37) and 'cpu_up'

This is because cpu_up, _cpu_up and __cpu_up (in some architectures) are
defined as __devinit
AND
__cpu_up calls some __cpuinit functions.

Since __cpuinit would map to __init with this kind of a configuration,
we get a .text refering .init.data warning.

This patch solves the problem by converting all of __cpu_up, _cpu_up
and cpu_up from __devinit to __cpuinit. The approach is justified since
the callers of cpu_up are either dependent on CONFIG_HOTPLUG_CPU or
are of __init type.

Thus when CONFIG_HOTPLUG_CPU=y, all these cpu up functions would land up
in .text section, and when CONFIG_HOTPLUG_CPU=n, all these functions would
land up in .init section.

Tested on a i386 SMP machine running linux-2.6.20-rc3-mm1.

Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2007-01-11 18:18:20 -08:00
David S. Miller
5a089006bf [SPARC64]: Mirror x86_64's PERCPU_ENOUGH_ROOM definition.
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-17 14:06:59 -08:00
Al Viro
6d24c8dc2e [PATCH] sparc64 pt_regs fixes
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-08 12:32:35 -07:00
David S. Miller
07f8e5f358 [SPARC64]: Convert cpu_find_by_*() interface to in-kernel PROM device tree.
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-23 23:15:17 -07:00
David S. Miller
9145bcf635 [SPARC64]: Set appropriate max_cache_size.
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-10 22:02:17 -07:00
David S. Miller
951bc82c53 [SPARC64]: Make smp_processor_id() functional before start_kernel()
Uses of smp_processor_id() get pushed earlier and earlier in
the start_kernel() sequence.  So just get it working before
we call start_kernel() to avoid all possible problems.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-05-31 01:24:02 -07:00
KAMEZAWA Hiroyuki
a283a52520 [PATCH] for_each_possible_cpu: sparc64
for_each_cpu() actually iterates across all possible CPUs.  We've had mistakes
in the past where people were using for_each_cpu() where they should have been
iterating across only online or present CPUs.  This is inefficient and
possibly buggy.

We're renaming for_each_cpu() to for_each_possible_cpu() to avoid this in the
future.

This patch replaces for_each_cpu with for_each_possible_cpu.
for sparc64.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11 06:18:31 -07:00
David S. Miller
aa1d1a0af6 [SPARC64]: smp_call_function() fixups...
1) Take doc-book function comment from i386 implementation.
2) cacheline align call_lock, taken from powerpc
3) Need memory barrier after setting call_data
4) Remove timeout

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-04-09 22:56:44 -07:00
David S. Miller
6f25f3986a [SPARC64]: Make tsb_sync() mm comparison more precise.
switch_mm() changes the mm state and does a tsb_context_switch()
first, then we do the cpu register state switch which changes
current_thread_info() and current().

So it's safer to check the PGD physical address stored in the
trap block (which will be updated by the tsb_context_switch() in
switch_mm()) than current->active_mm.

Technically we should never run here in between those two
updates, because interrupts are disabled during the entire
context switch operation.  But some day we might like to leave
interrupts enabled during the context switch and this change
allows that to happen without any surprises.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-31 23:03:34 -08:00
David S. Miller
7d3aee9a96 [SPARC64]: Keep cpu_present_map in sync with phys_cpu_present_map.
Don't rely on fixup_cpu_present_map() to do this as that function
is about to be removed.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-25 13:00:17 -08:00
Andrew Morton
394e3902c5 [PATCH] more for_each_cpu() conversions
When we stop allocating percpu memory for not-possible CPUs we must not touch
the percpu data for not-possible CPUs at all.  The correct way of doing this
is to test cpu_possible() or to use for_each_cpu().

This patch is a kernel-wide sweep of all instances of NR_CPUS.  I found very
few instances of this bug, if any.  But the patch converts lots of open-coded
test to use the preferred helper macros.

Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Acked-by: Kyle McMartin <kyle@parisc-linux.org>
Cc: Anton Blanchard <anton@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Christian Zankel <chris@zankel.net>
Cc: Philippe Elie <phil.el@wanadoo.fr>
Cc: Nathan Scott <nathans@sgi.com>
Cc: Jens Axboe <axboe@suse.de>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23 07:38:17 -08:00
David S. Miller
8935dced54 [SPARC64]: Add SMT scheduling support for Niagara.
The mapping is a simple "(cpuid >> 2) == core" for now.
Later we'll add more sophisticated code that will walk
the sun4v machine description and figure this out from
there.

We should also add core mappings for jaguar and panther
processors.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:14:24 -08:00
David S. Miller
ee29074d3b [SPARC64]: Fix new context version SMP handling.
Don't piggy back the SMP receive signal code to do the
context version change handling.

Instead allocate another fixed PIL number for this
asynchronous cross-call.  We can't use smp_call_function()
because this thing is invoked with interrupts disabled
and a few spinlocks held.

Also, fix smp_call_function_mask() to count "cpus" correctly.
There is no guarentee that the local cpu is in the mask
yet that is exactly what this code was assuming.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:14:21 -08:00
David S. Miller
3cab0c3e86 [SPARC64]: More SUN4V cpu mondo bug fixing.
This cpu mondo sending interface isn't all that easy to
use correctly...

We were clearing out the wrong bits from the "mask" after getting
something other than EOK from the hypervisor.

It turns out the hypervisor can just be resent the same cpu_list[]
array, with the 0xffff "done" entries still in there, and it will do
the right thing.

So don't update or try to rebuild the cpu_list[] array to condense it.

This requires the "forward_progress" check to be done slightly
differently, but this new scheme is less bug prone than what we were
doing before.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:14:17 -08:00
David S. Miller
b830ab665a [SPARC64]: Fix bugs in SUN4V cpu mondo dispatch.
There were several bugs in the SUN4V cpu mondo dispatch code.

In fact, if we ever got a EWOULDBLOCK or other error from
the hypervisor call, we'd potentially send a cpu mondo multiple
times to the same cpu and even worse we could loop until the
timeout resending the same mondo over and over to such cpus.

So let's bulletproof this thing as follows:

1) Implement cpu_mondo_send() and cpu_state() hypervisor calls
   in arch/sparc64/kernel/entry.S, add prototypes to asm/hypervisor.h

2) Don't build and update the cpulist using inline functions, this
   was causing the cpu mask to not get updated in the caller.

3) Disable interrupts during the entire mondo send, otherwise our
   cpu list and/or mondo block could get overwritten if we take
   an interrupt and do a cpu mondo send on the current cpu.

4) Check for all possible error return types from the cpu_mondo_send()
   hypervisor call.  In particular:

   HV_EOK) Our work is done, all cpus have received the mondo.
   HV_CPUERROR) One or more of the cpus in the cpu list we passed
                to the hypervisor are in error state.  Use cpu_state()
                calls over the entries in the cpu list to see which
		ones.  Record them in "error_mask" and report this
		after we are done sending the mondo to cpus which are
		not in error state.
   HV_EWOULDBLOCK) We need to keep trying.

   Any other error we consider fatal, we report the event and exit
   immediately.

5) We only timeout if forward progress is not made.  Forward progress
   is defined as having at least one cpu get the mondo successfully
   in a given cpu_mondo_send() call.  Otherwise we bump a counter
   and delay a little.  If the counter hits a limit, we signal an
   error and report the event.

Also, smp_call_function_mask() error handling reports the number
of cpus incorrectly.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:14:09 -08:00
David S. Miller
aac0aadf09 [SPARC64]: Fix bugs in SMP TLB context version expiration handling.
1) We must flush the TLB, duh.

2) Even if the sw context was seen to be valid, the local cpu's
   hw context can be out of date, so reload it unconditionally.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:14:08 -08:00
David S. Miller
6cc80cfab8 [SPARC64]: Report mondo error correctly in hypervisor_xcall_deliver().
It's in "arg0" not "func".

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:14:04 -08:00
David S. Miller
a0663a79ad [SPARC64]: Fix TLB context allocation with SMT style shared TLBs.
The context allocation scheme we use depends upon there being a 1<-->1
mapping from cpu to physical TLB for correctness.  Chips like Niagara
break this assumption.

So what we do is notify all cpus with a cross call when the context
version number changes, and if necessary this makes them allocate
a valid context for the address space they are running at the time.

Stress tested with make -j1024, make -j2048, and make -j4096 kernel
builds on a 32-strand, 8 core, T2000 with 16GB of ram.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:14:00 -08:00
David S. Miller
1bd0cd74d1 [SPARC64]: Kill cpudata->idle_volume.
Set, but never used.

We used to use this for dynamic IRQ retargetting, but that
code died a long time ago.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:13:51 -08:00
David S. Miller
d371c0c174 [SPARC64]: Pass multiple CPUs at once to hypervisor cross-call API.
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:13:49 -08:00
David S. Miller
72aff53f1f [SPARC64]: Get SUN4V SMP working.
The sibling cpu bringup is extremely fragile.  We can only
perform the most basic calls until we take over the trap
table from the firmware/hypervisor on the new cpu.

This means no accesses to %g4, %g5, %g6 since those can't be
TLB translated without our trap handlers.

In order to achieve this:

1) Change sun4v_init_mondo_queues() so that it can operate in
   several modes.

   It can allocate the queues, or install them in the current
   processor, or both.

   The boot cpu does both in it's call early on.

   Later, the boot cpu allocates the sibling cpu queue, starts
   the sibling cpu, then the sibling cpu loads them in.

2) init_cur_cpu_trap() is changed to take the current_thread_info()
   as an argument instead of reading %g6 directly on the current
   cpu.

3) Create a trampoline stack for the sibling cpus.  We do our basic
   kernel calls using this stack, which is locked into the kernel
   image, then go to our proper thread stack after taking over the
   trap table.

4) While we are in this delicate startup state, we put 0xdeadbeef
   into %g4/%g5/%g6 in order to catch accidental accesses.

5) On the final prom_set_trap_table*() call, we put &init_thread_union
   into %g6.  This is a hack to make prom_world(0) work.  All that
   wants to do is restore the %asi register using
   get_thread_current_ds().

Longer term we should just do the OBP calls to set the trap table by
hand just like we do for everything else.  This would avoid that silly
prom_world(0) issue, then we can remove the init_thread_union hack.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:13:22 -08:00
David S. Miller
7890f794e0 [SPARC64]: Add prom_{start,stop}cpu_cpuid().
Use prom_startcpu_cpuid() on SUN4V instead of prom_startcpu().

We should really test for "SUNW,start-cpu-by-cpuid" presence
and use it if present even on SUN4U.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:13:04 -08:00
David S. Miller
f03b8a5468 [SPARC64]: Use different cache sizing defaults on SUN4V.
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:13:01 -08:00
David S. Miller
4a07e646c5 [SPARC64]: Kill sun4v_register_fault_status() on SMP.
That now gets done as a side effect of taking over the
trap table from OBP.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:12:54 -08:00
David S. Miller
02fead7505 [SPARC64]: Do not try to synchronize %stick registers on SUN4V.
Writes by privileged code are not allowed.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:12:27 -08:00
David S. Miller
b5a37e96b8 [SPARC64]: Fix mondo queue allocations.
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>
2006-03-20 01:12:26 -08:00
David S. Miller
490384e752 [SPARC64]: Register kernel TSB with hypervisor.
We do this right after we take over the trap table from OBP.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:12:23 -08:00
David S. Miller
164c220fa3 [SPARC64]: Fix hypervisor call arg passing.
Function goes in %o5, args go in %o0 --> %o5.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:12:14 -08:00
David S. Miller
1d2f1f90a1 [SPARC64]: Sun4v cross-call sending support.
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>
2006-03-20 01:12:02 -08:00
David S. Miller
481295f982 [SPARC64]: Register per-cpu fault status area with sun4v hypervisor.
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:11:55 -08:00
David S. Miller
a43fe0e789 [SPARC64]: Add some hypervisor tlb_type checks.
And more consistently check cheetah{,_plus} instead
of assuming anything not spitfire is cheetah{,_plus}.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:11:40 -08:00
David S. Miller
92704a1c63 [SPARC64]: Refine code sequences to get the cpu id.
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>
2006-03-20 01:11:35 -08:00
David S. Miller
3487d1d441 [SPARC64]: Kill PROM locked TLB entry preservation code.
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>
2006-03-20 01:11:24 -08:00
David S. Miller
96c6e0d8e2 [SPARC64]: Kill {save,restore}_alternate_globals()
No longer needed now that we no longer have hard-coded
alternate global register usage.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:11:20 -08:00
David S. Miller
bd40791e1d [SPARC64]: Dynamically grow TSB in response to RSS growth.
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>
2006-03-20 01:11:18 -08:00
David S. Miller
56fb4df6da [SPARC64]: Elminate all usage of hard-coded trap globals.
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>
2006-03-20 01:11:16 -08:00
David S. Miller
74bf4312ff [SPARC64]: Move away from virtual page tables, part 1.
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>
2006-03-20 01:11:13 -08:00
David S. Miller
7abea92145 [SPARC64]: Make cpu_present_map available earlier.
The change to kernel/sched.c's init code to use for_each_cpu()
requires that the cpu_possible_map be setup much earlier.

Set it up via setup_arch(), constrained to NR_CPUS, and later
constrain it to max_cpus in smp_prepare_cpus().

This fixes SMP booting on sparc64.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-26 19:36:00 -08:00
Al Viro
f3169641c1 [PATCH] sparc64: task_thread_info()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-12 09:08:52 -08:00
David S. Miller
4d45cbacb8 [SPARC64]: Restore 2.4.x /proc/cpuinfo behavior for "ncpus probed" field.
Noticed by Tom 'spot' Callaway.

Even on uniprocessor we always reported the number of physical
cpus in the system via /proc/cpuinfo.  But when this got changed
to use num_possible_cpus() it always reads as "1" on uniprocessor.
This change was unintentional.

So scan the firmware device tree and count the number of cpu
nodes, and report that, as we always did.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-11 12:48:56 -08:00
Nick Piggin
64c7c8f885 [PATCH] sched: resched and cpu_idle rework
Make some changes to the NEED_RESCHED and POLLING_NRFLAG to reduce
confusion, and make their semantics rigid.  Improves efficiency of
resched_task and some cpu_idle routines.

* In resched_task:
- TIF_NEED_RESCHED is only cleared with the task's runqueue lock held,
  and as we hold it during resched_task, then there is no need for an
  atomic test and set there. The only other time this should be set is
  when the task's quantum expires, in the timer interrupt - this is
  protected against because the rq lock is irq-safe.

- If TIF_NEED_RESCHED is set, then we don't need to do anything. It
  won't get unset until the task get's schedule()d off.

- If we are running on the same CPU as the task we resched, then set
  TIF_NEED_RESCHED and no further action is required.

- If we are running on another CPU, and TIF_POLLING_NRFLAG is *not* set
  after TIF_NEED_RESCHED has been set, then we need to send an IPI.

Using these rules, we are able to remove the test and set operation in
resched_task, and make clear the previously vague semantics of
POLLING_NRFLAG.

* In idle routines:
- Enter cpu_idle with preempt disabled. When the need_resched() condition
  becomes true, explicitly call schedule(). This makes things a bit clearer
  (IMO), but haven't updated all architectures yet.

- Many do a test and clear of TIF_NEED_RESCHED for some reason. According
  to the resched_task rules, this isn't needed (and actually breaks the
  assumption that TIF_NEED_RESCHED is only cleared with the runqueue lock
  held). So remove that. Generally one less locked memory op when switching
  to the idle thread.

- Many idle routines clear TIF_POLLING_NRFLAG, and only set it in the inner
  most polling idle loops. The above resched_task semantics allow it to be
  set until before the last time need_resched() is checked before going into
  a halt requiring interrupt wakeup.

  Many idle routines simply never enter such a halt, and so POLLING_NRFLAG
  can be always left set, completely eliminating resched IPIs when rescheduling
  the idle task.

  POLLING_NRFLAG width can be increased, to reduce the chance of resched IPIs.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Con Kolivas <kernel@kolivas.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:33 -08:00
Nick Piggin
5bfb5d690f [PATCH] sched: disable preempt in idle tasks
Run idle threads with preempt disabled.

Also corrected a bugs in arm26's cpu_idle (make it actually call schedule()).
How did it ever work before?

Might fix the CPU hotplugging hang which Nigel Cunningham noted.

We think the bug hits if the idle thread is preempted after checking
need_resched() and before going to sleep, then the CPU offlined.

After calling stop_machine_run, the CPU eventually returns from preemption and
into the idle thread and goes to sleep.  The CPU will continue executing
previous idle and have no chance to call play_dead.

By disabling preemption until we are ready to explicitly schedule, this bug is
fixed and the idle threads generally become more robust.

From: alexs <ashepard@u.washington.edu>

  PPC build fix

From: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>

  MIPS build fix

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:33 -08:00
David S. Miller
62dbec78be [SPARC64] mm: Do not flush TLB mm in tlb_finish_mmu()
It isn't needed any longer, as noted by Hugh Dickins.

We still need the flush routines, due to the one remaining
call site in hugetlb_prefault_arch_hook().  That can be
eliminated at some later point, however.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-07 14:09:58 -08:00
Hugh Dickins
dedeb0029b [SPARC64] mm: context switch ptlock
sparc64 is unique among architectures in taking the page_table_lock in
its context switch (well, cris does too, but erroneously, and it's not
yet SMP anyway).

This seems to be a private affair between switch_mm and activate_mm,
using page_table_lock as a per-mm lock, without any relation to its uses
elsewhere.  That's fine, but comment it as such; and unlock sooner in
switch_mm, more like in activate_mm (preemption is disabled here).

There is a block of "if (0)"ed code in smp_flush_tlb_pending which would
have liked to rely on the page_table_lock, in switch_mm and elsewhere;
but its comment explains how dup_mmap's flush_tlb_mm defeated it.  And
though that could have been changed at any time over the past few years,
now the chance vanishes as we push the page_table_lock downwards, and
perhaps split it per page table page.  Just delete that block of code.

Which leaves the mysterious spin_unlock_wait(&oldmm->page_table_lock)
in kernel/fork.c copy_mm.  Textual analysis (supported by Nick Piggin)
suggests that the comment was written by DaveM, and that it relates to
the defeated approach in the sparc64 smp_flush_tlb_pending.  Just delete
this block too.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-07 14:09:01 -08:00
David S. Miller
b4d1b82578 [SPARC64]: Fix powering off on SMP.
Doing a "SUNW,stop-self" firmware call on the other cpus is not the
correct thing to do when dropping into the firmware for a halt,
reboot, or power-off.

For now, just do nothing to quiet the other cpus, as the system should
be quiescent enough.  Later we may decide to implement smp_send_stop()
like the other SMP platforms do.

Based upon a report from Christopher Zimmermann.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-14 15:26:08 -07:00
David S. Miller
80dc0d6b44 [SPARC64]: Probe D/I/E-cache config and use.
At boot time, determine the D-cache, I-cache and E-cache size and
line-size.  Use them in cache flushes when appropriate.

This change was motivated by discovering that the D-cache on
UltraSparc-IIIi and later are 64K not 32K, and the flushes done by the
Cheetah error handlers were assuming a 32K size.

There are still some pieces of code that are hard coding things and
will need to be fixed up at some point.

While we're here, fix the D-cache and I-cache parity error handlers
to run with interrupts disabled, and when the trap occurs at trap
level > 1 log the event via a counter displayed in /proc/cpuinfo.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-26 00:32:17 -07:00