Enable the contiguous memory allocator but set the default size to
zero. If somebody wants to use the cma allocator the "cma=" kernel
parameter has to be used.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

In order to make the cma infrastructure usable we need to add a small
architecture backend which calls dma_contiguous_reserve.
Otherwise we would end up with the cma allocator enabled, but no pool
where memory can be allocated from.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Use the psw_bits macro and simplify the code. The generated code is
also better since it doesn't contain any conditional branches anymore.
Reviewed-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

We have the s390 specific THREAD_ORDER define and the THREAD_SIZE_ORDER
define which is also used in common code. Both have exactly the same
semantics. Therefore get rid of THREAD_ORDER and always use
THREAD_SIZE_ORDER instead.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

For an unknown (historic) reason the s390 specific implementation of
set_fs returns whatever the __ctl_load would return. The set_fs macro
however is supposed to return void.
Change the macro to do that.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Get rid of a useless memset from dma_alloc. Users of dma_alloc who want
zero initialized memory can get it by specifying __GFP_ZERO or use one
of the zalloc variants.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

We have 2 strategies to reduce the number of RPCIT instructions:
* A HW feature indicated via the tlb_refresh bit allows us to omit RPCIT for
  invalid -> valid translation-table entry updates.
* With "lazy flush" we omit RPCIT for valid -> invalid updates until we run
  out of dma addresses. When we have to reuse dma addresses we issue a global
  tlb flush using only one RPCIT instruction.

Currently lazy flushing depends on tlb_refresh. Since there is no technical
reason for this remove this dependency.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

__s390_dma_map_sg maps a dma-contiguous area. Although we only map
whole pages we have to take into account that the area doesn't start
or stop at a page boundary because we use the dma address to loop
over the individual sg entries. Failing to do that might lead to an
access of the wrong sg entry.

Fixes: ee877b81 ("s390/pci_dma: improve map_sg")
Reported-and-tested-by: NChristoph Raisch <raisch@de.ibm.com>
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The TOD clock offset injected by an STP sync check can be negative.
If the resulting total tod_steering_delta gets negative the kernel
will panic.

Change the type of tod_steering_delta to a signed type.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Fixes: 75c7b6f3 ("s390/time: steer clocksource on STP sync events")
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Move the last two architecture specific fields from the thread_info
structure to the thread_struct. All that is left in thread_info is
the flags field.
Reviewed-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The user_timer and system_timer fields are used for the per-thread
cputime accounting code. The access to these values is simpler if
they are moved to the thread_struct as the task_thread_info(tsk)
indirection is not needed anymore.
Reviewed-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The system_call field in thread_info structure is used by the signal
code to store the number of the current system call while the debugger
interacts with its inferior. A better location for the system_call
field is with the other debugger related information in the
thread_struct.
Reviewed-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This is the s390 variant of commit 15f4eae7 ("x86: Move
thread_info into task_struct").
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Convert s390 to use a field in the struct lowcore for the CPU
preemption count. It is a bit cheaper to access a lowcore field
compared to a thread_info variable and it removes the depencency
on a task related structure.

bloat-o-meter on the vmlinux image for the default configuration
(CONFIG_PREEMPT_NONE=y) reports a small reduction in text size:

add/remove: 0/0 grow/shrink: 18/578 up/down: 228/-5448 (-5220)

A larger improvement is achieved with the default configuration
but with CONFIG_PREEMPT=y and CONFIG_DEBUG_PREEMPT=n:

add/remove: 2/6 grow/shrink: 59/4477 up/down: 1618/-228762 (-227144)
Reviewed-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Replace the bitops specific atomic update code by the functions
from atomic_ops.h. This saves a few lines of non-trivial code.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Rework atomic.h to make the low level functions avaible for use
in other headers without using atomic_t, e.g. in bitops.h.
Reviewed-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The dependency between the object and the source is handled by
scripts/Makefile.host, so only "hostprogs-y += gen_facilities"
is fine.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

We generally expect headers in arch/$(ARCH)/include/asm directory
are included from kernel sources, but facilities_src.h is not;
it is included from the arch/s390/tools/gen_facilities.c tool.

There is no reason to expose this header to the public include path.
Furthermore, facilities_src.h makes sure to be included only from
gen_facilities.c by the following:

  #ifndef S390_GEN_FACILITIES_C
  #error "This file can only be included by gen_facilities.c"
  #endif

This check can be removed by merging the two files.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The header facilities_src.h is only included from gen_facilities.c
and the tool is compiled with the following extra options:

    HOSTCFLAGS_gen_facilities.o += -Wall $(LINUXINCLUDE)

Please note $(LINUXINCLUDE) is expanded into build options including:

    -include $(srctree)/include/linux/kconfig.h

So, the Makefile always forces the tool to include kconfig.h, i.e.,
the #include <linux/kconfig.h> directive in the header is redundant.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The Kconfig currently controlling compilation of this code is:

arch/s390/Kconfig:config S390_GUEST
arch/s390/Kconfig:      def_bool y

...meaning that it currently is not being built as a module by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.

We replace module.h with moduleparam.h since the file does declare
some module_param() and leaving that as-is is currently the easiest
way to remain compatible with existing boot arg use cases.

Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The Kconfig currently controlling compilation of this code is:

drivers/pci/hotplug/Kconfig:config HOTPLUG_PCI_S390
drivers/pci/hotplug/Kconfig:    bool "System z PCI Hotplug Support"

...meaning that it currently is not being built as a module by anyone.

Lets remove the couple traces of modular infrastructure use, so that
when reading the driver there is no doubt it is builtin-only.

We also delete the MODULE_LICENSE tag etc. since all that information
was (or is now) contained at the top of the file in the comments.

We don't exchange module.h for init.h or export.h since the file
does not contain any initcalls or EXPORT of symbols.

Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-s390@vger.kernel.org
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The Makefile currently controlling compilation of this code is obj-y
meaning that it currently is not being built as a module by anyone.

Lets remove the couple traces of modular infrastructure use, so that
when reading the driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

We replace module.h with init.h and export.h since the file does
export some symbols.

Cc: linux-s390@vger.kernel.org
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The Kconfig currently controlling compilation of this code is:

arch/s390/Kconfig:config S390_HYPFS_FS
arch/s390/Kconfig:      def_bool y

...meaning that it currently is not being built as a module by anyone.

Lets remove the couple traces of modular infrastructure use, so that
when reading the driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

Also note that MODULE_ALIAS is a no-op for non-modular code.

We also delete the MODULE_LICENSE tag etc. since all that information
was (or is now) contained at the top of the file in the comments.

Build testing indicated the presence of module.h was masking an
implicit include of kobject.h, hence the addition of that.

Cc: linux-s390@vger.kernel.org
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The Makefile currently controlling compilation of this code is obj-y,
meaning that it currently is not being built as a module by anyone.

Lets remove the couple traces of modular infrastructure, so that
when reading the driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

Cc: linux-s390@vger.kernel.org
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The Kconfig currently controlling compilation of this code is:

drivers/s390/char/Kconfig:config SCLP_TTY
drivers/s390/char/Kconfig:      def_bool y

...meaning that it currently is not being built as a module by anyone.

Lets remove the couple traces of modular infrastructure use, so that
when reading the driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

We don't replace module.h with init.h since the file already has that.

Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: linux-s390@vger.kernel.org
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The Kconfig currently controlling compilation of this code is:

drivers/s390/char/Kconfig:config TN3215
drivers/s390/char/Kconfig:      def_bool y

...meaning that it currently is not being built as a module by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

We don't replace module.h with init.h since the file already has that.

Cc: linux-s390@vger.kernel.org
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The Kconfig currently controlling compilation of this code is:

arch/s390/Kconfig:config CRASH_DUMP
arch/s390/Kconfig:      bool "kernel crash dumps"

...meaning that it currently is not being built as a module by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.

Since module_init wasn't even being used by this file, the init
ordering remains unchanged with this commit.

We also delete the MODULE_LICENSE tag etc. since all that information
was (or is now) contained at the top of the file in the comments.

We don't replace module.h with init.h since the file already has that.

Cc: linux-s390@vger.kernel.org
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The Makefile currently controlling compilation of this code is:

  obj-y += airq.o blacklist.o chsc.o cio.o css.o chp.o idset.o isc.o \
          fcx.o itcw.o crw.o ccwreq.o trace.o ioasm.o
  ccw_device-objs += device.o device_fsm.o device_ops.o
  ccw_device-objs += device_id.o device_pgid.o device_status.o
  obj-y += ccw_device.o cmf.o

...meaning that the files here are not being built as modular.

Lets remove the couple traces of modular infrastructure use, so that
when reading the code there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.

We delete the MODULE_LICENSE tag etc. since all that information
was (or is now) contained at the top of the file in the comments.

We replace module.h with export.h where the file does export some
symbols.

Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Arnd Bergmann <arndb@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The function dasd_ro_store() calls set_disk_ro() to set the device in
question read-only. Since set_disk_ro() might sleep, we can't call it
while holding a lock. However, we also can't simply check if the device,
block, and gdp references are valid before we call set_disk_ro() because
an offline processing might have been started in the meanwhile which
will destroy those references.

In order to reliably call set_disk_ro() we have to ensure several
things:

- Still check validity of the mentioned references but additionally
  check if offline processing is running and bail out accordingly. Also,
  do this while holding the device lock.
- To ensure that the block device is still safe after the lock, increase
  the open_count while still holding the device lock.
Reviewed-by: NStefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: NJan Höppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The reference to a device in question may get lost when the extended
error reporting (EER) attribute is being enabled/disabled while the
device is set offline at the same time. This is due to missing
refcounting and incorrect locking. Fix this by the following:

- In dasd_eer_store() get the device directly and handle the refcount
  accordingly.
- Move the lock in dasd_eer_enable() up so we can ensure safe
  processing.
- Check if the device is being set offline and return with -EBUSY if so.
- While at it, change the return code from -EPERM to -EMEDIUMTYPE as
  suggested by a FIXME, since that is what we're actually checking.
Reviewed-by: NStefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: NJan Höppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Before we set a device offline, the open_count for the block device is
checked and certain flags are checked and set as well.
However, this is all done without holding any lock. Potentially, if the
open_count was checked but the DASD_FLAG_OFFLINE wasn't set yet, a
different process might want to increase the open_count depending on
whether DASD_FLAG_OFFLINE is set or not in the meanwhile.

This is quite racy and can lead to the loss of the device for that
process and subsequently lead to a panic.

Fix this by checking the open_count and setting the offline flags while
holding the ccwdev lock.
Reviewed-by: NStefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: NJan Höppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When setting certain attributes, we actually set the according feature
flag. Do this by using dasd_set_feature() at a few occurrences and
remove duplicate code.

In dasd_set_feature() dasd_find_busid() is used to retrieve the devmap
for the device in question. Combined with the change above, this would
require the device to be set online at least once so that a devmap is
being created. Change that by using dasd_devmap_from_cdev() instead,
which uses dasd_find_busid() first and will create a devmap accordingly
if there is none yet.
Reviewed-by: NStefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: NJan Höppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

simple_strtoul() has been marked obsolete for quite some time now.
Replace a few last occurrences with kstrtouint().
Reviewed-by: NStefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: NJan Höppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Clean up DEV_STATE_SENSE_PGID related code, since it's not
used anymore. Everything related to path verification is
handled within DEV_STATE_VERIFY.
Signed-off-by: NDong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Acked-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

On STP sync events the TOD clock will jump in time, either forward or
backward. The TOD clocksource claims to be continuous but in case of
an STP sync with a negative offset it is not.

Subtract the offset injected by the STP sync check from the result of
the TOD clocksource to make it continuous again. Add code to drift the
offset towards zero with a fixed rate, steering 1 second in ~9 hours.
Suggested-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The last_update_clock time stamp in the lowcore should be adjusted by
the TOD clock delta that is created by the clock synchronization.
Otherwise the calculation of the steal time will be incorrect.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Merge clock_sync_cpu into stp_sync_clock and split out the update
of the global and per-CPU clock fields into clock_sync_global
and clock_sync_local.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

block->request_queue is used many times in dasd_setup_queue. Define a
separate variable to increase readability a bit and to make it better
reusable.
Reviewed-by: NStefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: NJan Höppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Currently the block queue value max_segments is set to -1L, which
is then implicitly casted to unsigned short in blk_queue_max_segments.
This results in 65535 (64k) max_segments.

Even though the resulting value is correct, setting it implicitly using
-1L is rather confusing. Set the value explicitly using the USHRT_MAX
macro instead.
Reviewed-by: NStefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: NJan Höppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>