linux-toradex.git/arch/x86/oprofile, branch v4.2.7

x86/asm/entry: Change all 'user_mode_vm()' calls to 'user_mode()'

2015-03-23T10:14:17+00:00

user_mode_vm() and user_mode() are now the same.  Change all callers
of user_mode_vm() to user_mode().

The next patch will remove the definition of user_mode_vm.

Signed-off-by: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brad Spengler 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/43b1f57f3df70df5a08b0925897c660725015554.1426728647.git.luto@kernel.org
[ Merged to a more recent kernel. ]
Signed-off-by: Ingo Molnar

percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t

2014-08-28T12:58:57+00:00

__get_cpu_var can paper over differences in the definitions of
cpumask_var_t and either use the address of the cpumask variable
directly or perform a fetch of the address of the struct cpumask
allocated elsewhere. This is important particularly when using per cpu
cpumask_var_t declarations because in one case we have an offset into
a per cpu area to handle and in the other case we need to fetch a
pointer from the offset.

This patch introduces a new macro

this_cpu_cpumask_var_ptr()

that is defined where cpumask_var_t is defined and performs the proper
actions. All use cases where __get_cpu_var is used with cpumask_var_t
are converted to the use of this_cpu_cpumask_var_ptr().

Signed-off-by: Christoph Lameter 
Signed-off-by: Tejun Heo

x86: Replace __get_cpu_var uses

2014-08-26T17:45:49+00:00

__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x).  This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.

Other use cases are for storing and retrieving data from the current
processors percpu area.  __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.

__get_cpu_var() is defined as :

#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))

__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.

This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset.  Thereby address calculations are avoided and less registers
are used when code is generated.

Transformations done to __get_cpu_var()

1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);

2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);

3. Retrieve the content of the current processors instance of a per cpu
variable.

	DEFINE_PER_CPU(int, y);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);

4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(&x, this_cpu_ptr(&y), sizeof(x));

5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	__this_cpu_write(y, x);

6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	__this_cpu_inc(y)

Cc: Thomas Gleixner 
Cc: x86@kernel.org
Acked-by: H. Peter Anvin 
Acked-by: Ingo Molnar 
Signed-off-by: Christoph Lameter 
Signed-off-by: Tejun Heo

x86, oprofile, nmi: Fix CPU hotplug callback registration

2014-03-20T12:43:43+00:00

Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:

	get_online_cpus();

	for_each_online_cpu(cpu)
		init_cpu(cpu);

	register_cpu_notifier(&foobar_cpu_notifier);

	put_online_cpus();

This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).

Instead, the correct and race-free way of performing the callback
registration is:

	cpu_notifier_register_begin();

	for_each_online_cpu(cpu)
		init_cpu(cpu);

	/* Note the use of the double underscored version of the API */
	__register_cpu_notifier(&foobar_cpu_notifier);

	cpu_notifier_register_done();

Fix the oprofile code in x86 by using this latter form of callback
registration. But retain the calls to get/put_online_cpus(), since they are
used in other places as well, to protect the variables 'nmi_enabled' and
'ctr_running'. Strictly speaking, this is not necessary since
cpu_notifier_register_begin/done() provide a stronger synchronization
with CPU hotplug than get/put_online_cpus(). However, let's retain the
calls to get/put_online_cpus() to be consistent with the other call-sites.

By nesting get/put_online_cpus() *inside* cpu_notifier_register_begin/done(),
we avoid the ABBA deadlock possibility mentioned above.

Cc: Robert Richter 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Signed-off-by: Srivatsa S. Bhat 
Signed-off-by: Rafael J. Wysocki

perf: Fix arch_perf_out_copy_user default

2013-11-06T11:34:25+00:00

The arch_perf_output_copy_user() default of
__copy_from_user_inatomic() returns bytes not copied, while all other
argument functions given DEFINE_OUTPUT_COPY() return bytes copied.

Since copy_from_user_nmi() is the odd duck out by returning bytes
copied where all other *copy_{to,from}* functions return bytes not
copied, change it over and ammend DEFINE_OUTPUT_COPY() to expect bytes
not copied.

Oddly enough DEFINE_OUTPUT_COPY() already returned bytes not copied
while expecting its worker functions to return bytes copied.

Signed-off-by: Peter Zijlstra 
Acked-by: will.deacon@arm.com
Cc: Frederic Weisbecker 
Link: http://lkml.kernel.org/r/20131030201622.GR16117@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar

oprofilefs_create_...() do not need superblock argument

2013-09-04T02:52:48+00:00

same story as with oprofilefs_mkdir()

Signed-off-by: Al Viro

oprofilefs_mkdir() doesn't need superblock argument

2013-09-04T02:52:47+00:00

it's always equal to ->d_sb of the second argument (parent dentry),
due to either being literally that, or ->d_sb of parent's parent.

Signed-off-by: Al Viro

oprofile: don't bother with passing superblock to ->create_files()

2013-09-04T02:52:46+00:00

Signed-off-by: Al Viro

oprofile, x86: Fix wrapping bug in op_x86_get_ctrl()

2012-10-15T12:38:24+00:00

The "event" variable is a u16 so the shift will always wrap to zero
making the line a no-op.

Signed-off-by: Dan Carpenter 
Cc:  v2.6.32..
Signed-off-by: Robert Richter

perf/x86/amd: Unify AMD's generic and family 15h pmus

2012-07-05T19:19:41+00:00

There is no need for keeping separate pmu structs. We can enable
amd_{get,put}_event_constraints() functions also for family 15h event.

The advantage is that there is only a single pmu struct for all AMD
cpus. This patch introduces functions to setup the pmu to enabe core
performance counters or counter constraints.

Also, cpuid checks are used instead of family checks where
possible. Thus, it enables the code independently of cpu families if
the feature flag is set.

Signed-off-by: Robert Richter 
Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1340217996-2254-4-git-send-email-robert.richter@amd.com
Signed-off-by: Ingo Molnar