linux-toradex.git/drivers/s390/char/sclp_cmd.c, branch v4.4.38

s390/numa: add emulation support

2015-08-04T12:06:53+00:00

NUMA emulation (aka fake NUMA) distributes the available memory to nodes
without using real topology information about the physical memory of the
machine.

Splitting the system memory into nodes replicates the memory management
structures for each node. Particularly each node has its own "mm locks"
and its own "kswapd" task.

For large systems, under certain conditions, this results in improved
system performance and/or latency based on reduced pressure on the mm
locks and the kswapd tasks.

NUMA emulation distributes CPUs to nodes while respecting the original
machine topology information. This is done by trying to avoid to separate
CPUs which reside on the same book or even on the same MC. Because the
current Linux scheduler code requires a stable cpu to node mapping, cores
are pinned to nodes when the first CPU thread is set online.

This patch is based on the initial implementation from Philipp Hachtmann.

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/sclp: Use DECLARE_BITMAP

2015-06-15T08:50:33+00:00

Use the generic mechanism to declare a bitmap instead of unsigned long.

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

s390/sclp: move sclp_facilities into "struct sclp"

2015-05-13T07:58:18+00:00

Let's also move the facilities into the sclp struct, so we can avoid
another separate external variable.

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/mm: Fix memory hotplug for unaligned standby memory

2015-04-15T10:23:49+00:00

Commit 27356f54c8c3 ("mm/hotplug: verify hotplug memory range")
introduced a check that makes add_memory() only accept section size
aligned memory.

Therefore on z/VM systems, where standby memory is not aligned, no
standby memory is registered at all.

Example:

 #cp def store 3504M standby 2336M
 00: CP Q V STORE
 00: STORAGE = 3504M MAX = 6G INC = 8M STANDBY = 2336M RESERVED = 0

For this setup the following error message is printed:

 Section-unaligned hotplug range: start 0xdb000000, size 0x92000000

So fix this and register aligned memory in "sclp_cmd.c". This means
that for the corner cases where the standby memory is not aligned we
loose some memory.

In order to inform the user about the potential loss of standby memory,
we add a new message for each added standby block and print how
much of the standby memory is usable, for example:

 sclp_cmd.4336b4: Standby memory at 0x50000000 (256M of 256M usable)
 sclp_cmd.4336b4: Standby memory at 0xb0000000 (256M of 256M usable)
 sclp_cmd.4336b4: Standby memory at 0xdb000000 (2048M of 2336M usable)

We also ensure that a potential memory block that contains both "assigned"
and "standby" memory cannot be setup offline.

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

s390/sclp_cmd: replace PTR_RET with PTR_ERR_OR_ZERO

2014-04-11T11:53:42+00:00

PTR_RET is deprecated. Do not recommend its usage anymore.
Use PTR_ERR_OR_ZERO instead.

Signed-off-by: Duan Jiong 
Signed-off-by: Martin Schwidefsky

s390/sclp: add timeout for queued requests

2014-04-01T11:25:26+00:00

This patch adds a timeout option for queued requests and introduces
sclp_sync_request_timeout() to use this timer. With this, blocking the
system too long, e.g. during an SE reboot, can be avoided in critical
situations like CPU and memory hotplug.
Since there is no way to cancel a running request, this timeout only
applies to queued requests that have not yet been started.

Reviewed-by: Peter Oberparleiter 
Signed-off-by: Gerald Schaefer 
Signed-off-by: Martin Schwidefsky

s390/hypfs: add interface for diagnose 0x304

2014-01-24T08:40:59+00:00

To provide access to the set-partition-resource-parameter interface
to user space add a new attribute to hypfs/debugfs:
 * s390_hypsfs/diag_304
The data for the query-partition-resource-parameters command can
be access by a read on the attribute. All other diagnose 0x304
requests need to be submitted via ioctl with CAP_SYS_ADMIN rights.

Signed-off-by: Martin Schwidefsky

s390/sclp_early: Get rid of sclp_early_read_info_sccb_valid

2013-12-16T13:37:47+00:00

The early sclp detect functions gather the available SCLP facility
information. The sclp_early_read_info_sccb_valid indicates whether the
early sclp request was valid.  However, one external reference to it
checks for particular sclp facility bits and this should be sufficient.
Another occurance is in the sclp_get_ipl_info() function that is called
later.  Because all information are available at the early stage, save
the ipl information when detecting the sclp facilities.  Hence, no more
checks for sclp_early_read_info_sccb_valid are required.

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