linux-toradex.git/include/linux/math64.h, branch v4.8-rc1

KVM: x86: Replace call-back set_tsc_khz() with a common function

2015-11-10T11:06:16+00:00

Both VMX and SVM propagate virtual_tsc_khz in the same way, so this
patch removes the call-back set_tsc_khz() and replaces it with a common
function.

Signed-off-by: Haozhong Zhang 
Signed-off-by: Paolo Bonzini

KVM: x86: Add a common TSC scaling function

2015-11-10T11:06:15+00:00

VMX and SVM calculate the TSC scaling ratio in a similar logic, so this
patch generalizes it to a common TSC scaling function.

Signed-off-by: Haozhong Zhang 
[Inline the multiplication and shift steps into mul_u64_u64_shr.  Remove
 BUG_ON.  - Paolo]
Signed-off-by: Paolo Bonzini

math64: Add mul_u64_u32_shr()

2013-12-11T14:52:34+00:00

Introduce mul_u64_u32_shr() as proposed by Andy a while back; it
allows using 64x64->128 muls on 64bit archs and recent GCC
which defines __SIZEOF_INT128__ and __int128.

(This new method will be used by the scheduler.)

Signed-off-by: Peter Zijlstra 
Cc: fweisbec@gmail.com
Cc: Andy Lutomirski 
Cc: Linus Torvalds 
Link: http://lkml.kernel.org/n/tip-hxjoeuzmrcaumR0uZwjpe2pv@git.kernel.org
Signed-off-by: Ingo Molnar

math64: New separate div64_u64_rem helper

2013-08-23T13:02:14+00:00

Commit f792685006274a850e6cc0ea9ade275ccdfc90bc ("math64: New
div64_u64_rem helper") implemented div64_u64 in terms of div64_u64_rem.
But div64_u64_rem was removed because it slowed down div64_u64 (and
there were no other users of div64_u64_rem).

Device Mapper's I/O statistics support has a need for div64_u64_rem;
reintroduce this helper as a separate method that doesn't slow down
div64_u64, especially on 32-bit systems.

Signed-off-by: Mike Snitzer 
Cc: Stanislaw Gruszka 
Cc: Ingo Molnar 
Cc: Frederic Weisbecker 
Cc: Mikulas Patocka 
Signed-off-by: Alasdair G Kergon

include/linux/math64.h: add div64_ul()

2013-06-12T23:29:47+00:00

There is div64_long() to handle the s64/long division, but no mocro do
u64/ul division.  It is necessary in some scenarios, so add this
function.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alex Shi 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Revert "math64: New div64_u64_rem helper"

2013-04-30T17:13:05+00:00

This reverts commit f792685006274a850e6cc0ea9ade275ccdfc90bc.

The cputime scaling code was changed/fixed and does not need the
div64_u64_rem() primitive anymore. It has no other users, so let's
remove them.

Signed-off-by: Stanislaw Gruszka 
Cc: Frederic Weisbecker 
Cc: rostedt@goodmis.org
Cc: Linus Torvalds 
Cc: Dave Hansen 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1367314507-9728-4-git-send-email-sgruszka@redhat.com
Signed-off-by: Ingo Molnar

math64: New div64_u64_rem helper

2013-03-13T17:03:27+00:00

Provide an extended version of div64_u64() that
also returns the remainder of the division.

We are going to need this to refine the cputime
scaling code.

Signed-off-by: Frederic Weisbecker 
Cc: Stanislaw Gruszka 
Cc: Steven Rostedt 
Cc: Peter Zijlstra 
Cc: Ingo Molnar 
Cc: Andrew Morton

math: Introduce div64_long

2012-03-15T20:41:34+00:00

Add a div64_long macro which is used to devide a 64bit number by a long (which
can be 4 bytes on 32bit systems and 8 bytes on 64bit systems).

Suggested-by: Thomas Gleixner 
Signed-off-by: Sasha Levin 
Cc: johnstul@us.ibm.com
Link: http://lkml.kernel.org/r/1331829374-31543-1-git-send-email-levinsasha928@gmail.com
Signed-off-by: Thomas Gleixner

div64_u64(): improve precision on 32bit platforms

2010-10-26T23:52:19+00:00

The current implementation of div64_u64 for 32bit systems returns an
approximately correct result when the divisor exceeds 32bits.  Since doing
64bit division using 32bit hardware is a long since solved problem we just
use one of the existing proven methods.

Additionally, add a div64_s64 function to correctly handle doing signed
64bit division.

Addresses https://bugzilla.redhat.com/show_bug.cgi?id=616105

Signed-off-by: Brian Behlendorf 
Signed-off-by: Oleg Nesterov 
Cc: Ben Woodard 
Cc: Jeremy Fitzhardinge 
Cc: Mark Grondona 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

add an inlined version of iter_div_u64_rem

2008-06-12T08:47:58+00:00

iter_div_u64_rem is used in the x86-64 vdso, which cannot call other
kernel code.  For this case, provide the always_inlined version,
__iter_div_u64_rem.

Signed-off-by: Jeremy Fitzhardinge 
Signed-off-by: Ingo Molnar