linux-toradex.git/arch/powerpc/kernel/irq.c, branch v4.2.7

powerpc: Remove superfluous bootmem includes

2014-11-09T22:59:26+00:00

Lots of places included bootmem.h even when not using bootmem.

Signed-off-by: Anton Blanchard 
Tested-by: Emil Medve 
Signed-off-by: Michael Ellerman

powerpc: Replace __get_cpu_var uses

2014-11-03T01:12:32+00:00

This still has not been merged and now powerpc is the only arch that does
not have this change. Sorry about missing linuxppc-dev before.

V2->V2
  - Fix up to work against 3.18-rc1

__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 :

__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.

At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.

The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e.  using a global
register that may be set to the per cpu base.

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: Benjamin Herrenschmidt 
CC: Paul Mackerras 
Signed-off-by: Christoph Lameter 
[mpe: Fix build errors caused by set/or_softirq_pending(), and rework
      assignment in __set_breakpoint() to use memcpy().]
Signed-off-by: Michael Ellerman

powerpc: Rename __get_SP() to current_stack_pointer()

2014-10-15T00:23:20+00:00

Michael points out that __get_SP() is a pretty horrible
function name. Let's give it a better name.

Signed-off-by: Anton Blanchard 
Signed-off-by: Michael Ellerman

powerpc: Add printk levels to powerpc code

2014-10-02T07:33:55+00:00

Add printk levels to some places in the powerpc port.

Signed-off-by: Anton Blanchard 
Signed-off-by: Michael Ellerman

powerpc/book3s: Add basic infrastructure to handle HMI in Linux.

2014-08-05T06:33:48+00:00

Handle Hypervisor Maintenance Interrupt (HMI) in Linux. This patch implements
basic infrastructure to handle HMI in Linux host. The design is to invoke
opal handle hmi in real mode for recovery and set irq_pending when we hit HMI.
During check_irq_replay pull opal hmi event and print hmi info on console.

Signed-off-by: Mahesh Salgaonkar 
Signed-off-by: Benjamin Herrenschmidt

powerpc: update comments for generic idle conversion

2014-06-06T23:08:18+00:00

As of commit 799fef06123f ("powerpc: Use generic idle loop"), this
applies to arch_cpu_idle() instead of cpu_idle().

Signed-off-by: Geert Uytterhoeven 
Cc: Benjamin Herrenschmidt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

powerpc: Irq: Use generic_handle_irq

2014-03-04T16:37:52+00:00

No functional change

Signed-off-by: Thomas Gleixner 
Cc: Peter Zijlstra 
Cc: Benjamin Herrenschmidt 
Cc: ppc 
Link: http://lkml.kernel.org/r/20140223212736.333718121@linutronix.de
Signed-off-by: Thomas Gleixner

powerpc/ppc32: Fix the bug in the init of non-base exception stack for UP

2014-02-11T00:24:52+00:00

We would allocate one specific exception stack for each kind of
non-base exceptions for every CPU. For ppc32 the CPU hard ID is
used as the subscript to get the specific exception stack for
one CPU. But for an UP kernel, there is only one element in the
each kind of exception stack array. We would get stuck if the
CPU hard ID is not equal to '0'. So in this case we should use the
subscript '0' no matter what the CPU hard ID is.

Signed-off-by: Kevin Hao 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Make irq_stat.timers_irqs counting more specific

2013-12-02T03:14:50+00:00

Current irq_stat.timers_irqs counting doesn't discriminate timer event handler
and other timer interrupt(like arch_irq_work_raise). Sometimes we need to know
exactly how much interrupts timer event handler fired, so let's be more specific
on this.

Signed-off-by: Fan Du 
Signed-off-by: Benjamin Herrenschmidt

Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2013-11-12T01:02:59+00:00

Pull IRQ changes from Ingo Molnar:
 "The biggest change this cycle are the softirq/hardirq stack
  interaction and nesting fixes, cleanups and reorganizations from
  Frederic.  This is the longer followup story to the softirq nesting
  fix that is already upstream (commit ded797547548: "irq: Force hardirq
  exit's softirq processing on its own stack")"

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip: bcm2835: Convert to use IRQCHIP_DECLARE macro
  powerpc: Tell about irq stack coverage
  x86: Tell about irq stack coverage
  irq: Optimize softirq stack selection in irq exit
  irq: Justify the various softirq stack choices
  irq: Improve a bit softirq debugging
  irq: Optimize call to softirq on hardirq exit
  irq: Consolidate do_softirq() arch overriden implementations
  x86/irq: Correct comment about i8259 initialization