linux-toradex.git/arch/sparc/kernel/leon_smp.c, branch v4.4.50

sparc32, leon: Align ccall_info to prevent unaligned traps on crosscall

2014-12-12T02:51:56+00:00

It is being filled in using std in leon_cross_call.

Signed-off-by: Andreas Larsson 
Signed-off-by: David S. Miller

sparc: Replace __get_cpu_var uses

2014-08-26T17:45:55+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.

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: sparclinux@vger.kernel.org
Acked-by: David S. Miller 
Signed-off-by: Christoph Lameter 
Signed-off-by: Tejun Heo

sparc32: fix sparse warnings in leon_smp.c

2014-04-29T05:12:27+00:00

Fix following warnings:
leon_smp.c:133:6: warning: symbol 'leon_smp_setbroadcast' was not declared. Should it be static?
leon_smp.c:151:14: warning: symbol 'leon_smp_getbroadcast' was not declared. Should it be static?
leon_smp.c:269:6: warning: symbol 'leon_irq_rotate' was not declared. Should it be static?
leon_smp.c:355:6: warning: symbol 'leonsmp_ipi_interrupt' was not declared. Should it be static?
leon_smp.c:457:6: warning: symbol 'leon_cross_call_irq' was not declared. Should it be static?

Add static.
Remove unused functions.

Signed-off-by: Sam Ravnborg 
Cc: Daniel Hellstrom 
Signed-off-by: David S. Miller

sparc: delete cpuinit/CPUINIT usage from all users

2013-07-14T23:36:52+00:00

The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit  -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings.  In any case, they are temporary and harmless.

This removes all the arch/sparc uses of the __cpuinit macros from
C files and removes __CPUINIT from assembly files.  Note that even
though arch/sparc/kernel/trampoline_64.S has instances of ".previous"
in it, they are all paired off against explicit ".section" directives,
and not implicitly paired with __CPUINIT (unlike mips and arm were).

[1] https://lkml.org/lkml/2013/5/20/589

Cc: "David S. Miller" 
Cc: sparclinux@vger.kernel.org
Signed-off-by: Paul Gortmaker

mm/SPARC: prepare for removing num_physpages and simplify mem_init()

2013-07-03T23:07:37+00:00

Prepare for removing num_physpages and simplify mem_init().

Signed-off-by: Jiang Liu 
Acked-by: Sam Ravnborg 
Cc: "David S. Miller" 
Cc: Yasuaki Ishimatsu 
Cc: Tang Chen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/SPARC: use common help functions to free reserved pages

2013-05-08T01:38:26+00:00

Use common help functions to free reserved pages.

Signed-off-by: Jiang Liu 
Acked-by: David S. Miller 
Acked-by: Sam Ravnborg 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

sparc32: refactor smp boot

2013-02-20T21:36:50+00:00

Introduce a common smp_callin() function to call
from trampoline_32.S.
Add platform specific functions to handle the
platform details.

This is in preparation for a patch that will
unify the smp boot stuff for all architectures.
sparc32 was significantly different to warrant
this patch in preparation.

Signed-off-by: Sam Ravnborg 
Acked-by: David S. Miller 
Cc: "Srivatsa S. Bhat" 
Acked-by: Srivatsa S. Bhat 
Signed-off-by: David S. Miller

sparc32,leon: fix section mismatch warning

2012-05-28T06:52:48+00:00

Fix following warning:

WARNING: arch/sparc/kernel/built-in.o(.cpuinit.text+0x9f4): Section mismatch in reference from the function leon_callin() to the function .init.text:leon_configure_cache_smp()
The function __cpuinit leon_callin() references
a function __init leon_configure_cache_smp().
If leon_configure_cache_smp is only used by leon_callin then
annotate leon_configure_cache_smp with a matching annotation.

Signed-off-by: Sam Ravnborg 
Cc: Daniel Hellstrom 
Cc: Konrad Eisele

sparc32,leon: always include leon_smp + leon_mm in build

2012-05-28T06:52:47+00:00

Fix-up leon specific assembler to use ASI_LEON_MMUREGS

Signed-off-by: Sam Ravnborg 
Cc: Daniel Hellstrom 
Cc: Konrad Eisele

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

2012-05-22T02:43:57+00:00

Pull smp hotplug cleanups from Thomas Gleixner:
 "This series is merily a cleanup of code copied around in arch/* and
  not changing any of the real cpu hotplug horrors yet.  I wish I'd had
  something more substantial for 3.5, but I underestimated the lurking
  horror..."

Fix up trivial conflicts in arch/{arm,sparc,x86}/Kconfig and
arch/sparc/include/asm/thread_info_32.h

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (79 commits)
  um: Remove leftover declaration of alloc_task_struct_node()
  task_allocator: Use config switches instead of magic defines
  sparc: Use common threadinfo allocator
  score: Use common threadinfo allocator
  sh-use-common-threadinfo-allocator
  mn10300: Use common threadinfo allocator
  powerpc: Use common threadinfo allocator
  mips: Use common threadinfo allocator
  hexagon: Use common threadinfo allocator
  m32r: Use common threadinfo allocator
  frv: Use common threadinfo allocator
  cris: Use common threadinfo allocator
  x86: Use common threadinfo allocator
  c6x: Use common threadinfo allocator
  fork: Provide kmemcache based thread_info allocator
  tile: Use common threadinfo allocator
  fork: Provide weak arch_release_[task_struct|thread_info] functions
  fork: Move thread info gfp flags to header
  fork: Remove the weak insanity
  sh: Remove cpu_idle_wait()
  ...