linux-toradex.git/drivers/s390/cio/cio.c, branch v3.4.1

[S390] rework idle code

2012-03-11T15:59:28+00:00

Whenever the cpu loads an enabled wait PSW it will appear as idle to the
underlying host system. The code in default_idle calls vtime_stop_cpu
which does the necessary voodoo to get the cpu time accounting right.
The udelay code just loads an enabled wait PSW. To correct this rework
the vtime_stop_cpu/vtime_start_cpu logic and move the difficult parts
to entry[64].S, vtime_stop_cpu can now be called from anywhere and
vtime_start_cpu is gone. The correction of the cpu time during wakeup
from an enabled wait PSW is done with a critical section in entry[64].S.
As vtime_start_cpu is gone, s390_idle_check can be removed as well.

Signed-off-by: Martin Schwidefsky

[S390] kdump backend code

2011-10-30T14:16:42+00:00

This patch provides the architecture specific part of the s390 kdump
support.

Signed-off-by: Michael Holzheu 
Signed-off-by: Martin Schwidefsky

[S390] fix mismatch in summation of I/O IRQ statistics

2011-10-30T14:16:15+00:00

Current IRQ statistics support does not show detail counts for I/O
interrupts which are processed internally only. The result is a
summation count which is way off such as this one:

           CPU0       CPU1       CPU2
I/O:       1331        710        442
[...]
QAI:         15         16         16   [I/O] QDIO Adapter Interrupt
QDI:          1          0          0   [I/O] QDIO Interrupt
DAS:        706        645        381   [I/O] DASD
C15:         26         10          0   [I/O] 3215
C70:          0          0          0   [I/O] 3270
TAP:          0          0          0   [I/O] Tape
VMR:          0          0          0   [I/O] Unit Record Devices
LCS:          0          0          0   [I/O] LCS
CLW:          0          0          0   [I/O] CLAW
CTC:          0          0          0   [I/O] CTC
APB:          0          0          0   [I/O] AP Bus

Fix this by moving I/O interrupt accounting into the common I/O layer.

Signed-off-by: Peter Oberparleiter 
Signed-off-by: Martin Schwidefsky

[S390] cio: fix cio_tpi ignoring adapter interrupts

2011-09-26T14:40:50+00:00

Ensure that adapter interrupts are correctly processed when they are
retrieved using TEST PENDING INTERRUPTION.

Signed-off-by: Peter Oberparleiter 
Signed-off-by: Martin Schwidefsky

[S390] cio: move options to io_sch_private

2011-03-15T16:08:23+00:00

Move the options member from struct subchannel to
io_subchannel_private since it's I/O subchannel specific.
Also remove the unused cio_get_options function.

Signed-off-by: Sebastian Ott 
Signed-off-by: Martin Schwidefsky

[S390] remove superfluous check from do_IRQ

2011-03-15T16:08:22+00:00

Don't check for the int_type if an adapter interrupt is presented.

Signed-off-by: Sebastian Ott 
Signed-off-by: Martin Schwidefsky

drivers: Replace __get_cpu_var with __this_cpu_read if not used for an address.

2010-12-17T14:07:18+00:00

__get_cpu_var() can be replaced with this_cpu_read and will then use a single
read instruction with implied address calculation to access the correct per cpu
instance.

However, the address of a per cpu variable passed to __this_cpu_read() cannot be
determed (since its an implied address conversion through segment prefixes).
Therefore apply this only to uses of __get_cpu_var where the addres of the
variable is not used.

V3->V4:
	- Move one instance of this_cpu_inc_return to a later patch
	  so that this one can go in without percpu infrastructrure
	  changes.

Sedat: fixed compile failure caused by an extra ')'.

Cc: Neil Horman 
Cc: Martin Schwidefsky 
Cc: Sedat Dilek 
Acked-by: H. Peter Anvin 
Signed-off-by: Christoph Lameter 
Signed-off-by: Tejun Heo

[S390] idle time accounting vs. machine checks

2010-05-17T08:00:15+00:00

A machine check can interrupt the i/o and external interrupt handler
anytime. If the machine check occurs while the interrupt handler is
waking up from idle vtime_start_cpu can get executed a second time
and the int_clock / async_enter_timer values in the lowcore get
clobbered. This can confuse the cpu time accounting.
To fix this problem two changes are needed. First the machine check
handler has to use its own copies of int_clock and async_enter_timer,
named mcck_clock and mcck_enter_timer. Second the nested execution
of vtime_start_cpu has to be prevented. This is done in s390_idle_check
by checking the wait bit in the program status word.

Signed-off-by: Martin Schwidefsky

[S390] cio: use exception-save stsch

2010-04-22T15:17:19+00:00

Using stsch on schids with ssid != 0 can lead to an operand
exception. Use stsch_err to handle potential exceptions
if we fail to reenable mss after hibernation.

Cc: 
Signed-off-by: Sebastian Ott 
Signed-off-by: Martin Schwidefsky

[S390] Cleanup struct _lowcore usage and defines.

2010-02-26T21:37:31+00:00

Use asm offsets to make sure the offset defines to struct _lowcore and
its layout don't get out of sync.
Also add a BUILD_BUG_ON() which checks that the size of the structure
is sane.
And while being at it change those sites which use odd casts to access
the current lowcore. These should use S390_lowcore instead.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky