linux-toradex.git/arch/s390/kernel/smp.c, branch v4.3.1

s390/smp: add missing init annotation to smp_store_cpu_state()

2015-07-29T07:11:42+00:00

 Section mismatch in reference from the function __smp_store_cpu_state()
  to the function .init.text:memblock_alloc()
The function __smp_store_cpu_state() references
the function __init memblock_alloc().

Reviewed-by: Michael Holzheu 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/kdump: fix compile for !SMP

2015-06-29T08:13:11+00:00

Fix this compile error:

arch/s390/kernel/setup.c:875:2: error:
 implicit declaration of function 'smp_save_dump_cpus'

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

s390/kdump: fix nosmt kernel parameter

2015-06-25T07:39:26+00:00

It turned out that SIGP set-multi-threading can only be done once.
Therefore switching to a different MT level after switching to
sclp.mtid_prev in the dump case fails.

As a symptom specifying the "nosmt" parameter currently fails for
the kdump kernel and the kernel starts with multi-threading enabled.

So fix this and issue diag 308 subcode 1 call after collecting the
CPU states for the dump. Also enhance the diag308_reset() function to
be usable also with enabled lowcore protection and prefix register != 0.
After the reset it is possible to switch the MT level again. We have
to do the reset very early in order not to kill the already initialized
console. Therefore instead of kmalloc() the corresponding memblock
functions have to be used. To avoid copying the sclp cpu code into
sclp_early, we now use the simple sigp loop method for CPU detection.

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

s390/smp: cleanup core vs. cpu in the SCLP interface

2015-06-25T07:39:24+00:00

The SCLP interface to query, configure and deconfigure CPUs actually
operates on cores. For a machine without the multi-threading faciltiy
a CPU and a core are equivalent but starting with System z13 a core
can have multiple hardware threads, also referred to as logical CPUs.

To avoid confusion replace the word 'cpu' with 'core' in the SCLP
interface. Also replace MAX_CPU_ADDRESS with SCLP_MAX_CORES.
The core-id is an 8-bit field, the maximum thread id is in the range
0-31. The theoretical limit for the CPU address is therefore 8191.

Signed-off-by: Martin Schwidefsky

s390/smp: fix sigp cpu detection loop

2015-06-25T07:39:24+00:00

On a (theoretical) system where the read-cpu-info SCLP command does
not work but SMT is enabled, the sigp detection loop may not find
all configured cores. The maximum CPU address needs to be shifted
with smp_cpu_mt_shift.

Signed-off-by: Martin Schwidefsky

s390/sclp: get rid of sclp_get_mtid() and sclp_get_mtid_max()

2015-05-13T07:58:17+00:00

As all relevant sclp data is now directly accessible, let's move the
logic of these two functions to the single caller.

Acked-by: Martin Schwidefsky 
Signed-off-by: David Hildenbrand 
Signed-off-by: Martin Schwidefsky

s390/sclp: unify basic sclp access by exposing "struct sclp"

2015-05-13T07:58:17+00:00

Let's unify basic access to sclp fields by storing the data in an external
struct in asm/sclp.h.

The values can now directly be accessed by other components, so there is
no need for most accessor functions and external variables anymore.

The mtid, mtid_max and facility part will be cleaned up separately.

Acked-by: Martin Schwidefsky 
Signed-off-by: David Hildenbrand 
Signed-off-by: Martin Schwidefsky

s390/sclp: prepare smp_fill_possible_mask for global "struct sclp"

2015-05-13T07:58:16+00:00

We need to rename sclp -> sclp_max to prepare for using the global variable
"sclp" for sclp access later in this function.

Acked-by: Martin Schwidefsky 
Signed-off-by: David Hildenbrand 
Signed-off-by: Martin Schwidefsky

s390/smp: wait until secondaries are active & online

2015-04-13T08:46:20+00:00

This is the s390 version of 875ebe940d77 ("powerpc/smp: Wait until secondaries
are active & online").
The race described in length within the commit message is also possible on s390
and every other architecture. So fix this race on s390 as well.

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

s390: remove 31 bit support

2015-03-25T10:49:33+00:00

Remove the 31 bit support in order to reduce maintenance cost and
effectively remove dead code. Since a couple of years there is no
distribution left that comes with a 31 bit kernel.

The 31 bit kernel also has been broken since more than a year before
anybody noticed. In addition I added a removal warning to the kernel
shown at ipl for 5 minutes: a960062e5826 ("s390: add 31 bit warning
message") which let everybody know about the plan to remove 31 bit
code. We didn't get any response.

Given that the last 31 bit only machine was introduced in 1999 let's
remove the code.
Anybody with 31 bit user space code can still use the compat mode.

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