Commit Graph

166728 Commits

Author SHA1 Message Date
WANG Cong
22b737f4c7 percpu: refactor the code in pcpu_[de]populate_chunk()
Using break statement at the end of a for loop is confusing,
refactor it by replacing the for loop.

Signed-off-by: WANG Cong <amwang@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-12-08 10:28:54 +09:00
Tejun Heo
85438592f1 percpu: remove compile warnings caused by __verify_pcpu_ptr()
If percpu pointer is const, __verify_pcpu_ptr() triggers warnings like
the following.

 drivers/net/loopback.c: In function 'loopback_get_stats':
 drivers/net/loopback.c:109: warning: initialization discards qualifiers from pointer target type

Fix it by adding const to the verification target pointer used in
__verify_pcpu_ptr().

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
2009-12-08 10:28:50 +09:00
Tejun Heo
545695fb41 percpu: make accessors check for percpu pointer in sparse
The previous patch made sparse warn about percpu variables being used
directly without going through percpu accessors.  This patch
implements the other half - checking whether non percpu variable is
passed into percpu accessors.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Al Viro <viro@zeniv.linux.org.uk>
2009-10-29 22:34:15 +09:00
Rusty Russell
e0fdb0e050 percpu: add __percpu for sparse.
We have to make __kernel "__attribute__((address_space(0)))" so we can
cast to it.

tj: * put_cpu_var() update.

    * Annotations added to dynamic allocator interface.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-10-29 22:34:15 +09:00
Tejun Heo
f7b64fe806 percpu: make access macros universal
Now that per_cpu__ prefix is gone, there's no distinction between
static and dynamic percpu variables.  Make get_cpu_var() take dynamic
percpu variables and ensure that all macros have parentheses around
the parameter evaluation and evaluate the variable parameter only once
such that any expression which evaluates to percpu address can be used
safely.

Signed-off-by: Tejun Heo <tj@kernel.org>
2009-10-29 22:34:15 +09:00
Rusty Russell
dd17c8f729 percpu: remove per_cpu__ prefix.
Now that the return from alloc_percpu is compatible with the address
of per-cpu vars, it makes sense to hand around the address of per-cpu
variables.  To make this sane, we remove the per_cpu__ prefix we used
created to stop people accidentally using these vars directly.

Now we have sparse, we can use that (next patch).

tj: * Updated to convert stuff which were missed by or added after the
      original patch.

    * Kill per_cpu_var() macro.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
2009-10-29 22:34:15 +09:00
Tejun Heo
390dfd95c5 percpu: make misc percpu symbols unique
This patch updates misc percpu related symbols such that percpu
symbols are unique and don't clash with local symbols.  This serves
two purposes of decreasing the possibility of global percpu symbol
collision and allowing dropping per_cpu__ prefix from percpu symbols.

* drivers/crypto/padlock-aes.c: s/last_cword/paes_last_cword/

* drivers/lguest/x86/core.c: s/last_cpu/lg_last_cpu/

* drivers/s390/net/netiucv.c: rename the variable used in a macro to
  avoid clashing with percpu symbol

* arch/mn10300/kernel/kprobes.c: replace current_ prefix with cur_ for
  static variables.  Please note that percpu symbol current_kprobe
  can't be changed as it's used by generic code.

Partly based on Rusty Russell's "alloc_percpu: rename percpu vars
which cause name clashes" patch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Chuck Ebbert <cebbert@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
2009-10-29 22:34:14 +09:00
Tejun Heo
877105cc49 percpu: make percpu symbols in ia64 unique
This patch updates percpu related symbols in ia64 such that percpu
symbols are unique and don't clash with local symbols.  This serves
two purposes of decreasing the possibility of global percpu symbol
collision and allowing dropping per_cpu__ prefix from percpu symbols.

* arch/ia64/kernel/setup.c: s/cpu_info/ia64_cpu_info/

Partly based on Rusty Russell's "alloc_percpu: rename percpu vars
which cause name clashes" patch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: linux-ia64@vger.kernel.org
2009-10-29 22:34:14 +09:00
Tejun Heo
6b7487fc65 percpu: make percpu symbols in powerpc unique
This patch updates percpu related symbols in powerpc such that percpu
symbols are unique and don't clash with local symbols.  This serves
two purposes of decreasing the possibility of global percpu symbol
collision and allowing dropping per_cpu__ prefix from percpu symbols.

* arch/powerpc/kernel/perf_callchain.c: s/callchain/cpu_perf_callchain/

* arch/powerpc/kernel/setup-common.c: s/pvr/cpu_pvr/

* arch/powerpc/platforms/pseries/dtl.c: s/dtl/cpu_dtl/

* arch/powerpc/platforms/cell/interrupt.c: s/iic/cpu_iic/

Partly based on Rusty Russell's "alloc_percpu: rename percpu vars
which cause name clashes" patch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@ozlabs.org
2009-10-29 22:34:14 +09:00
Tejun Heo
0fe1e00954 percpu: make percpu symbols in x86 unique
This patch updates percpu related symbols in x86 such that percpu
symbols are unique and don't clash with local symbols.  This serves
two purposes of decreasing the possibility of global percpu symbol
collision and allowing dropping per_cpu__ prefix from percpu symbols.

* arch/x86/kernel/cpu/common.c: rename local variable to avoid collision

* arch/x86/kvm/svm.c: s/svm_data/sd/ for local variables to avoid collision

* arch/x86/kernel/cpu/cpu_debug.c: s/cpu_arr/cpud_arr/
  				   s/priv_arr/cpud_priv_arr/
				   s/cpu_priv_count/cpud_priv_count/

* arch/x86/kernel/cpu/intel_cacheinfo.c: s/cpuid4_info/ici_cpuid4_info/
  					 s/cache_kobject/ici_cache_kobject/
					 s/index_kobject/ici_index_kobject/

* arch/x86/kernel/ds.c: s/cpu_context/cpu_ds_context/

Partly based on Rusty Russell's "alloc_percpu: rename percpu vars
which cause name clashes" patch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: (kvm) Avi Kivity <avi@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: x86@kernel.org
2009-10-29 22:34:14 +09:00
Tejun Heo
c6e22f9e3e percpu: make percpu symbols in xen unique
This patch updates percpu related symbols in xen such that percpu
symbols are unique and don't clash with local symbols.  This serves
two purposes of decreasing the possibility of global percpu symbol
collision and allowing dropping per_cpu__ prefix from percpu symbols.

* arch/x86/xen/smp.c, arch/x86/xen/time.c, arch/ia64/xen/irq_xen.c:
  add xen_ prefix to percpu variables

* arch/ia64/xen/time.c: add xen_ prefix to percpu variables, drop
  processed_ prefix and make them static

Partly based on Rusty Russell's "alloc_percpu: rename percpu vars
which cause name clashes" patch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
2009-10-29 22:34:13 +09:00
Tejun Heo
f16250669d percpu: make percpu symbols in cpufreq unique
This patch updates percpu related symbols in cpufreq such that percpu
symbols are unique and don't clash with local symbols.  This serves
two purposes of decreasing the possibility of global percpu symbol
collision and allowing dropping per_cpu__ prefix from percpu symbols.

* drivers/cpufreq/cpufreq.c: s/policy_cpu/cpufreq_policy_cpu/
* drivers/cpufreq/freq_table.c: s/show_table/cpufreq_show_table/
* arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c: s/drv_data/acfreq_data/
  					      s/old_perf/acfreq_old_perf/

Partly based on Rusty Russell's "alloc_percpu: rename percpu vars
which cause name clashes" patch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
2009-10-29 22:34:13 +09:00
Tejun Heo
b3e9f672b6 percpu: make percpu symbols in oprofile unique
This patch updates percpu related symbols in oprofile such that percpu
symbols are unique and don't clash with local symbols.  This serves
two purposes of decreasing the possibility of global percpu symbol
collision and allowing dropping per_cpu__ prefix from percpu symbols.

* drivers/oprofile/cpu_buffer.c: s/cpu_buffer/op_cpu_buffer/

Partly based on Rusty Russell's "alloc_percpu: rename percpu vars
which cause name clashes" patch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Robert Richter <robert.richter@amd.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
2009-10-29 22:34:13 +09:00
Tejun Heo
9705f69ed0 percpu: make percpu symbols in tracer unique
This patch updates percpu related symbols in kernel tracer such that
percpu symbols are unique and don't clash with local symbols.  This
serves two purposes of decreasing the possibility of global percpu
symbol collision and allowing dropping per_cpu__ prefix from percpu
symbols.

* kernel/trace/trace.c: s/max_data/max_tr_data/
* kernel/trace/trace_hw_branches: s/tracer/hwb_tracer/, s/buffer/hwb_buffer/

Partly based on Rusty Russell's "alloc_percpu: rename percpu vars
which cause name clashes" patch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
2009-10-29 22:34:13 +09:00
Tejun Heo
1871e52c76 percpu: make percpu symbols under kernel/ and mm/ unique
This patch updates percpu related symbols under kernel/ and mm/ such
that percpu symbols are unique and don't clash with local symbols.
This serves two purposes of decreasing the possibility of global
percpu symbol collision and allowing dropping per_cpu__ prefix from
percpu symbols.

* kernel/lockdep.c: s/lock_stats/cpu_lock_stats/

* kernel/sched.c: s/init_rq_rt/init_rt_rq_var/	(any better idea?)
  		  s/sched_group_cpus/sched_groups/

* kernel/softirq.c: s/ksoftirqd/run_ksoftirqd/a

* kernel/softlockup.c: s/(*)_timestamp/softlockup_\1_ts/
  		       s/watchdog_task/softlockup_watchdog/
		       s/timestamp/ts/ for local variables

* kernel/time/timer_stats: s/lookup_lock/tstats_lookup_lock/

* mm/slab.c: s/reap_work/slab_reap_work/
  	     s/reap_node/slab_reap_node/

* mm/vmstat.c: local variable changed to avoid collision with vmstat_work

Partly based on Rusty Russell's "alloc_percpu: rename percpu vars
which cause name clashes" patch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: (slab/vmstat) Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Nick Piggin <npiggin@suse.de>
2009-10-29 22:34:13 +09:00
Tejun Heo
0f5e4816db percpu: remove some sparse warnings
Make the following changes to remove some sparse warnings.

* Make DEFINE_PER_CPU_SECTION() declare __pcpu_unique_* before
  defining it.

* Annotate pcpu_extend_area_map() that it is entered with pcpu_lock
  held, releases it and then reacquires it.

* Make percpu related macros use unique nested variable names.

* While at it, add pcpu prefix to __size_call[_return]() macros as
  to-be-implemented sparse annotations will add percpu specific stuff
  to these macros.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
2009-10-29 22:34:12 +09:00
Tejun Heo
64ef291f46 percpu: make alloc_percpu() handle array types
alloc_percpu() couldn't handle array types like "int [100]" due to the
way return type was casted.  Fix it by using typeof() instead.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
2009-10-29 22:34:12 +09:00
Tejun Heo
3f04ba8595 vmalloc: fix use of non-existent percpu variable in put_cpu_var()
vmalloc used non-existent percpu variable vmap_cpu_blocks instead of
the intended vmap_block_queue.  This went unnoticed because
put_cpu_var() didn't evaluate the parameter.  Fix it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Nick Piggin <npiggin@suse.de>
2009-10-29 22:34:12 +09:00
Tejun Heo
dec54bf538 this_cpu: Use this_cpu_xx in trace_functions_graph.c
ftrace_cpu_disabled usage in trace_functions_graph.c were left out
during this_cpu_xx conversion in commit 9288f99a causing compile
failure.  Convert them.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Christoph Lameter <cl@linux-foundation.org>
2009-10-13 23:23:02 +09:00
Christoph Lameter
9288f99aa5 this_cpu: Use this_cpu_xx for ftrace
this_cpu_xx can reduce the instruction count here and also
avoid address arithmetic.

Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-10-12 19:51:49 +09:00
Christoph Lameter
494f6a9e12 this_cpu: Use this_cpu_xx in nmi handling
this_cpu_inc/dec reduces the number of instructions needed.

Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-10-12 19:51:49 +09:00
Tejun Heo
b7a4c946d0 Merge branch 'for-linus' into for-next 2009-10-12 17:14:18 +09:00
Tejun Heo
1a0c3298d6 percpu: fix compile warnings
Fix the following two compile warnings which show up on i386.

mm/percpu.c:1873: warning: comparison of distinct pointer types lacks a cast
mm/percpu.c:1879: warning: format '%lx' expects type 'long unsigned int', but argument 2 has type 'size_t'

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
2009-10-12 17:04:42 +09:00
Christoph Lameter
e800879d50 this_cpu: Use this_cpu operations in RCU
RCU does not do dynamic allocations but it increments per cpu variables
a lot. These instructions results in a move to a register and then back
to memory. This patch will make it use the inc/dec instructions on x86
that do not need a register.

Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-10-03 19:48:23 +09:00
Christoph Lameter
4dac3e9884 this_cpu: Use this_cpu ops for VM statistics
Using per cpu atomics for the vm statistics reduces their overhead.
And in the case of x86 we are guaranteed that they will never race even
in the lax form used for vm statistics.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-10-03 19:48:23 +09:00
Christoph Lameter
0b44f4861f this_cpu: Use this_cpu_ptr in crypto subsystem
Just a slight optimization that removes one array lookup.
The processor number is needed for other things as well so the
get/put_cpu cannot be removed.

Acked-by: Tejun Heo <tj@kernel.org>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-10-03 19:48:23 +09:00
Christoph Lameter
7a9e02d6bb this_cpu: xfs_icsb_modify_counters does not need "cpu" variable
The xfs_icsb_modify_counters() function no longer needs the cpu variable
if we use this_cpu_ptr() and we can get rid of get/put_cpu().

Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Olaf Weber <olaf@sgi.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-10-03 19:48:23 +09:00
Christoph Lameter
e7dcaa4755 this_cpu: Eliminate get/put_cpu
There are cases where we can use this_cpu_ptr and as the result
of using this_cpu_ptr() we no longer need to determine the
currently executing cpu.

In those places no get/put_cpu combination is needed anymore.
The local cpu variable can be eliminated.

Preemption still needs to be disabled and enabled since the
modifications of the per cpu variables is not atomic. There may
be multiple per cpu variables modified and those must all
be from the same processor.

Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Tejun Heo <tj@kernel.org>
cc: Eric Biederman <ebiederm@aristanetworks.com>
cc: Stephen Hemminger <shemminger@vyatta.com>
cc: David L Stevens <dlstevens@us.ibm.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-10-03 19:48:23 +09:00
Christoph Lameter
ca0c9584b1 this_cpu: Straight transformations
Use this_cpu_ptr and __this_cpu_ptr in locations where straight
transformations are possible because per_cpu_ptr is used with
either smp_processor_id() or raw_smp_processor_id().

cc: David Howells <dhowells@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
cc: Ingo Molnar <mingo@elte.hu>
cc: Rusty Russell <rusty@rustcorp.com.au>
cc: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-10-03 19:48:22 +09:00
Christoph Lameter
4ea7334b6d this_cpu: Use this_cpu ops for network statistics
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-10-03 19:48:22 +09:00
Christoph Lameter
fce22848a1 this_cpu: Use this_cpu operations for NFS statistics
Simplify NFS statistics and allow the use of optimized
arch instructions.

Acked-by: Tejun Heo <tj@kernel.org>
CC: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-10-03 19:48:22 +09:00
Christoph Lameter
4eb41d10c7 this_cpu: Use this_cpu operations for SNMP statistics
SNMP statistic macros can be signficantly simplified.
This will also reduce code size if the arch supports these operations
in hardware.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-10-03 19:48:22 +09:00
Christoph Lameter
30ed1a79f5 this_cpu: Implement X86 optimized this_cpu operations
Basically the existing percpu ops can be used for this_cpu variants that allow
operations also on dynamically allocated percpu data. However, we do not pass a
reference to a percpu variable in. Instead a dynamically or statically
allocated percpu variable is provided.

Preempt, the non preempt and the irqsafe operations generate the same code.
It will always be possible to have the requires per cpu atomicness in a single
RMW instruction with segment override on x86.

64 bit this_cpu operations are not supported on 32 bit.

Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-10-03 19:48:22 +09:00
Christoph Lameter
7340a0b152 this_cpu: Introduce this_cpu_ptr() and generic this_cpu_* operations
This patch introduces two things: First this_cpu_ptr and then per cpu
atomic operations.

this_cpu_ptr
------------

A common operation when dealing with cpu data is to get the instance of the
cpu data associated with the currently executing processor. This can be
optimized by

this_cpu_ptr(xx) = per_cpu_ptr(xx, smp_processor_id).

The problem with per_cpu_ptr(x, smp_processor_id) is that it requires
an array lookup to find the offset for the cpu. Processors typically
have the offset for the current cpu area in some kind of (arch dependent)
efficiently accessible register or memory location.

We can use that instead of doing the array lookup to speed up the
determination of the address of the percpu variable. This is particularly
significant because these lookups occur in performance critical paths
of the core kernel. this_cpu_ptr() can avoid memory accesses and

this_cpu_ptr comes in two flavors. The preemption context matters since we
are referring the the currently executing processor. In many cases we must
insure that the processor does not change while a code segment is executed.

__this_cpu_ptr 	-> Do not check for preemption context
this_cpu_ptr	-> Check preemption context

The parameter to these operations is a per cpu pointer. This can be the
address of a statically defined per cpu variable (&per_cpu_var(xxx)) or
the address of a per cpu variable allocated with the per cpu allocator.

per cpu atomic operations: this_cpu_*(var, val)
-----------------------------------------------
this_cpu_* operations (like this_cpu_add(struct->y, value) operate on
abitrary scalars that are members of structures allocated with the new
per cpu allocator. They can also operate on static per_cpu variables
if they are passed to per_cpu_var() (See patch to use this_cpu_*
operations for vm statistics).

These operations are guaranteed to be atomic vs preemption when modifying
the scalar. The calculation of the per cpu offset is also guaranteed to
be atomic at the same time. This means that a this_cpu_* operation can be
safely used to modify a per cpu variable in a context where interrupts are
enabled and preemption is allowed. Many architectures can perform such
a per cpu atomic operation with a single instruction.

Note that the atomicity here is different from regular atomic operations.
Atomicity is only guaranteed for data accessed from the currently executing
processor. Modifications from other processors are still possible. There
must be other guarantees that the per cpu data is not modified from another
processor when using these instruction. The per cpu atomicity is created
by the fact that the processor either executes and instruction or not.
Embedded in the instruction is the relocation of the per cpu address to
the are reserved for the current processor and the RMW action. Therefore
interrupts or preemption cannot occur in the mids of this processing.

Generic fallback functions are used if an arch does not define optimized
this_cpu operations. The functions come also come in the two flavors used
for this_cpu_ptr().

The firstparameter is a scalar that is a member of a structure allocated
through allocpercpu or a per cpu variable (use per_cpu_var(xxx)). The
operations are similar to what percpu_add() and friends do.

this_cpu_read(scalar)
this_cpu_write(scalar, value)
this_cpu_add(scale, value)
this_cpu_sub(scalar, value)
this_cpu_inc(scalar)
this_cpu_dec(scalar)
this_cpu_and(scalar, value)
this_cpu_or(scalar, value)
this_cpu_xor(scalar, value)

Arch code can override the generic functions and provide optimized atomic
per cpu operations. These atomic operations must provide both the relocation
(x86 does it through a segment override) and the operation on the data in a
single instruction. Otherwise preempt needs to be disabled and there is no
gain from providing arch implementations.

A third variant is provided prefixed by irqsafe_. These variants are safe
against hardware interrupts on the *same* processor (all per cpu atomic
primitives are *always* *only* providing safety for code running on the
*same* processor!). The increment needs to be implemented by the hardware
in such a way that it is a single RMW instruction that is either processed
before or after an interrupt.

cc: David Howells <dhowells@redhat.com>
cc: Ingo Molnar <mingo@elte.hu>
cc: Rusty Russell <rusty@rustcorp.com.au>
cc: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-10-03 19:48:22 +09:00
Tejun Heo
23fb064bb9 percpu: kill legacy percpu allocator
With ia64 converted, there's no arch left which still uses legacy
percpu allocator.  Kill it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Delightedly-acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
2009-10-02 13:29:29 +09:00
Tejun Heo
52594762a3 ia64: convert to dynamic percpu allocator
Unlike other archs, ia64 reserves space for percpu areas during early
memory initialization.  These areas occupy a contiguous region indexed
by cpu number on contiguous memory model or are grouped by node on
discontiguous memory model.

As allocation and initialization are done by the arch code, all that
setup_per_cpu_areas() needs to do is communicating the determined
layout to the percpu allocator.  This patch implements
setup_per_cpu_areas() for both contig and discontig memory models and
drops HAVE_LEGACY_PER_CPU_AREA.

Please note that for contig model, the allocation itself is modified
only to allocate for possible cpus instead of NR_CPUS.  As dynamic
percpu allocator can handle non-direct mapping, there's no reason to
allocate memory for cpus which aren't possible.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: linux-ia64 <linux-ia64@vger.kernel.org>
2009-10-02 13:28:56 +09:00
Tejun Heo
36886478f5 ia64: allocate percpu area for cpu0 like percpu areas for other cpus
cpu0 used special percpu area reserved by the linker, __cpu0_per_cpu,
which is set up early in boot by head.S.  However, this doesn't
guarantee that the area will be on the same node as cpu0 and the
percpu area for cpu0 ends up very far away from percpu areas for other
cpus which cause problems for congruent percpu allocator.

This patch makes percpu area initialization allocate percpu area for
cpu0 like any other cpus and copy it from __cpu0_per_cpu which now
resides in the __init area.  This means that for cpu0, percpu area is
first setup at __cpu0_per_cpu early by head.S and then moved to an
area in the linear mapping during memory initialization and it's not
allowed to take a pointer to percpu variables between head.S and
memory initialization.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: linux-ia64 <linux-ia64@vger.kernel.org>
2009-10-02 13:28:56 +09:00
Tejun Heo
12cda81777 ia64: initialize cpu maps early
All information necessary to initialize cpu possible and present maps
are available once early_acpi_boot_init() is complete.  Reorganize
setup_arch() and acpi init functions such that,

* CPU information is printed after LAPIC entries are parsed in
  early_acpi_boot_init().

* smp_build_cpu_map() is called by setup_arch() instead of acpi
  functions.

* smp_build_cpu_map() is called once all CPU related information is
  available before memory is initialized.

This is primarily to allow find_memory() to use cpu maps but is also a
general cleanup.  Please note that with this change, the somewhat
ad-hoc early_cpu_possible_map defined and used for NUMA configurations
is probably unnecessary.  Something to clean up another day.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: linux-ia64 <linux-ia64@vger.kernel.org>
2009-10-02 13:28:56 +09:00
Tejun Heo
126b3fcdec ia64: don't alias VMALLOC_END to vmalloc_end
If CONFIG_VIRTUAL_MEM_MAP is enabled, ia64 defines macro VMALLOC_END
as unsigned long variable vmalloc_end which is adjusted to prepare
room for vmemmap.  This becomes probnlematic if a local variables
vmalloc_end is defined in some function (not very unlikely) and
VMALLOC_END is used in the function - the function thinks its
referencing the global VMALLOC_END value but would be referencing its
own local vmalloc_end variable.

There's no reason VMALLOC_END should be a macro.  Just define it as an
unsigned long variable if CONFIG_VIRTUAL_MEM_MAP is set to avoid nasty
surprises.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: linux-ia64 <linux-ia64@vger.kernel.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
2009-10-02 13:28:55 +09:00
Linus Torvalds
0efe5e32c8 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: fix data space leak fix
  Btrfs: remove duplicates of filemap_ helpers
  Btrfs: take i_mutex before generic_write_checks
  Btrfs: fix arguments to btrfs_wait_on_page_writeback_range
  Btrfs: fix deadlock with free space handling and user transactions
  Btrfs: fix error cases for ioctl transactions
  Btrfs: Use CONFIG_BTRFS_POSIX_ACL to enable ACL code
  Btrfs: introduce missing kfree
  Btrfs: Fix setting umask when POSIX ACLs are not enabled
  Btrfs: proper -ENOSPC handling
2009-10-01 20:23:15 -07:00
Uwe Kleine-König
e6a0a8bfef spi-imx: strip down chipselect function to only drive the chipselect
spi_imx_chipselect() made things that should be (and mostly are) done by
spi_imx_setupxfer.  Only setting the tx and rx functions was missing.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01 16:11:17 -07:00
Uwe Kleine-König
d1c627b59c spi-imx: initialize complete config struct
Otherwise the config function uses random data from the stack.  This
didn't stick out because config is called once more in the chipselect
function with correct parameters.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01 16:11:17 -07:00
Uwe Kleine-König
4388eb1135 spi-imx: no need to assert bits_per_word being initialized
spi_imx_setup() is only called by spi_setup().  The latter does the
initialization already.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01 16:11:16 -07:00
Sascha Hauer
3910f2cff9 spi-imx: setup mode_bits we can handle
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01 16:11:16 -07:00
Sascha Hauer
6c23e5d433 spi-imx: fix initial chipselect settings
We can only setup the gpio pins in spi_setup time when we know the
SPI_CS_HIGH setting.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01 16:11:16 -07:00
Sascha Hauer
462d26b5d2 spi-imx: update state correctly
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01 16:11:16 -07:00
Uwe Kleine-König
6cdeb00218 spi-imx: rename source file to spi_imx.c
This makes the filename match the Kconfig symbol and the driver name.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01 16:11:16 -07:00
Christoph Hellwig
80e50be422 afs: remove cache.h
It's just a wrapper for <linux/fscache.h>, so remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01 16:11:16 -07:00
Andy Spencer
8fccae2c95 sscanf(): fix %*s%n
When using %*s, sscanf should honor conversion specifiers immediately
following the %*s.  For example, the following code should find the
position of the end of the string "hello".

  int end;
  char buf[] = "hello    world";
  sscanf(buf, "%*s%n", &end);
  printf("%d\n", end);

Ideally, sscanf would advance the fmt and str pointers the same as it
would without the *, but the code for that is rather complicated and is
not included in the patch.

Signed-off-by: Andy Spencer <andy753421@gmail.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01 16:11:16 -07:00
Chuck Ebbert
d41a4b515e serial: add parameter to force skipping the test for the TXEN bug
Allow users to force skipping the TXEN test at init time. Applies
to all serial ports. Intended for debugging only.

There is a blacklist for devices where we need to skip the test but the
list is not complete.  This lets users force skipping the test so we can
determine if they need to be added to the list.

Some HP machines with weird serial consoles have this problem and there
may be more.

Signed-off-by: Chuck Ebbert <cebbert@redhat.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01 16:11:16 -07:00