linux-toradex.git/arch/x86/kernel/irq_64.c, branch v4.4.86

x86/irq: Drop unlikely before IS_ERR_OR_NULL

2015-10-01T09:08:56+00:00

IS_ERR_OR_NULL already contain an unlikely compiler flag. Drop it.

Signed-off-by: Geliang Tang 
Cc: Brian Gerst 
Cc: Andy Lutomirski 
Link: http://lkml.kernel.org/r/03d18502ed7ed417f136c091f417d2d88c147ec6.1443667610.git.geliangtang@163.com
Signed-off-by: Thomas Gleixner

genirq: Remove irq argument from irq flow handlers

2015-09-16T13:47:51+00:00

Most interrupt flow handlers do not use the irq argument. Those few
which use it can retrieve the irq number from the irq descriptor.

Remove the argument.

Search and replace was done with coccinelle and some extra helper
scripts around it. Thanks to Julia for her help!

Signed-off-by: Thomas Gleixner 
Cc: Julia Lawall 
Cc: Jiang Liu

x86/irq: Store irq descriptor in vector array

2015-08-05T22:14:59+00:00

We can spare the irq_desc lookup in the interrupt entry code if we
store the descriptor pointer in the vector array instead the interrupt
number.

Signed-off-by: Thomas Gleixner 
Cc: Jiang Liu 
Cc: Peter Zijlstra 
Cc: Rusty Russell 
Cc: Bjorn Helgaas 
Link: http://lkml.kernel.org/r/20150802203609.717724106@linutronix.de
Signed-off-by: Thomas Gleixner

x86/irq: Merge irq_regs & irq_stat

2015-05-10T10:34:27+00:00

Move irq_regs and irq_stat definitions to irq.c.

Signed-off-by: Brian Gerst 
Cc: Andrew Morton 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1431185813-15413-2-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar

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

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

irq: Consolidate do_softirq() arch overriden implementations

2013-10-01T10:53:25+00:00

All arch overriden implementations of do_softirq() share the following
common code: disable irqs (to avoid races with the pending check),
check if there are softirqs pending, then execute __do_softirq() on
a specific stack.

Consolidate the common parts such that archs only worry about the
stack switch.

Acked-by: Linus Torvalds 
Signed-off-by: Frederic Weisbecker 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: Peter Zijlstra 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Paul Mackerras 
Cc: James Hogan 
Cc: James E.J. Bottomley 
Cc: Helge Deller 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: David S. Miller 
Cc: Andrew Morton

x86: Add stack top margin for stack overflow checking

2011-12-07T08:27:11+00:00

It seems that a margin for stack overflow checking is added to
top of a kernel stack but is not added to IRQ and exception
stacks in stack_overflow_check(). Therefore, the overflows of
IRQ and exception stacks are always detected only after they
actually occurred and data corruption might occur due to them.

This patch adds the margin to top of IRQ and exception stacks
as well as a kernel stack to enhance reliability.

Signed-off-by: Mitsuo Hayasaka 
Cc: yrl.pp-manager.tt@hitachi.com
Cc: Linus Torvalds 
Cc: Andrew Morton 
Link: http://lkml.kernel.org/r/20111207082910.9847.3359.stgit@ltc219.sdl.hitachi.co.jp
[ removed the #undef - we typically don't do that for uncommon names ]
Signed-off-by: Ingo Molnar

x86: Clean up the range of stack overflow checking

2011-12-05T10:37:48+00:00

The overflow checking of kernel stack checks if the stack
pointer points to the available kernel stack range, which is
derived from the original overflow checking.

It is clear that curbase address is always less than low
boundary of available kernel stack. So, this patch removes the
first condition that checks if the pointer is higher than
curbase.

Signed-off-by: Mitsuo Hayasaka 
Cc: yrl.pp-manager.tt@hitachi.com
Cc: Randy Dunlap 
Link: http://lkml.kernel.org/r/20111129060845.11076.40916.stgit@ltc219.sdl.hitachi.co.jp
Signed-off-by: Ingo Molnar 
Cc: "H. Peter Anvin"

x86: Panic on detection of stack overflow

2011-12-05T10:37:47+00:00

Currently, messages are just output on the detection of stack
overflow, which is not sufficient for systems that need a
high reliability. This is because in general the overflow may
corrupt data, and the additional corruption may occur due to
reading them unless systems stop.

This patch adds the sysctl parameter
kernel.panic_on_stackoverflow and causes a panic when detecting
the overflows of kernel, IRQ and exception stacks except user
stack according to the parameter. It is disabled by default.

Signed-off-by: Mitsuo Hayasaka 
Cc: yrl.pp-manager.tt@hitachi.com
Cc: Randy Dunlap 
Cc: "H. Peter Anvin" 
Link: http://lkml.kernel.org/r/20111129060836.11076.12323.stgit@ltc219.sdl.hitachi.co.jp
Signed-off-by: Ingo Molnar