s390: Rename head64.S to head.S

All the code is 64 bit, therefore remove the superfluous suffix.

Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/time: Convert MACHINE_HAS_SCC to machine_has_scc()

Use static branch(es) to implement and use machine_has_scc() instead
of a runtime check via MACHINE_HAS_SCC.

This comes with a cleanup of ear

s390/time: Convert MACHINE_HAS_SCC to machine_has_scc()

Use static branch(es) to implement and use machine_has_scc() instead
of a runtime check via MACHINE_HAS_SCC.

This comes with a cleanup of early time initialization: the initial
tod_clock_base value is now passed via the bootdata mechanism, instead
of using absolute lowcore as transport vehicle from the decompressor
to the kernel.

Also the early tod clock initialization is moved to the decompressor
which allows to use a static branch with machine_has_scc() within the
kernel.

Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

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s390/head64: Make startup code ready for lowcore relocation

In preparation of having lowcore at different address than zero,
add the base register to all lowcore accesses in startup_continue().

Rev

s390/head64: Make startup code ready for lowcore relocation

In preparation of having lowcore at different address than zero,
add the base register to all lowcore accesses in startup_continue().

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

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s390: consistently use .balign instead of .align

The .align directive has inconsistent behavior across architectures. Use
.balign instead everywhere. This is a no-op for s390, but with this there
is

s390: consistently use .balign instead of .align

The .align directive has inconsistent behavior across architectures. Use
.balign instead everywhere. This is a no-op for s390, but with this there
is no mix in using .align and .balign anymore.

Future code is supposed to use only .balign.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

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s390/head64: use SYM* macros instead of ENTRY(), etc.

Consistently use the SYM* family of macros instead of the
deprecated ENTRY(), ENDPROC(), etc. family of macros.

Signed-off-by: Heiko Carstens <

s390/head64: use SYM* macros instead of ENTRY(), etc.

Consistently use the SYM* family of macros instead of the
deprecated ENTRY(), ENDPROC(), etc. family of macros.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

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s390/stack: set lowcore kernel stack pointer early

Make sure the lowcore kernel stack pointer reflects the kernel stack of the
current task as early as possible, instead of having a NULL pointer the

s390/stack: set lowcore kernel stack pointer early

Make sure the lowcore kernel stack pointer reflects the kernel stack of the
current task as early as possible, instead of having a NULL pointer there.

Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

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s390/stack: use STACK_INIT_OFFSET where possible

Make STACK_INIT_OFFSET also available for assembler code, and
use it everywhere instead of open-coding it at several places.

Reviewed-by: Vasily Gor

s390/stack: use STACK_INIT_OFFSET where possible

Make STACK_INIT_OFFSET also available for assembler code, and
use it everywhere instead of open-coding it at several places.

Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

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s390/kasan: move shadow mapping to decompressor

Since regular paging structs are initialized in decompressor already
move KASAN shadow mapping to decompressor as well. This helps to avoid
allocating

s390/kasan: move shadow mapping to decompressor

Since regular paging structs are initialized in decompressor already
move KASAN shadow mapping to decompressor as well. This helps to avoid
allocating KASAN required memory in 1 large chunk, de-duplicate paging
structs creation code and start the uncompressed kernel with KASAN
instrumentation right away. This also allows to avoid all pitfalls
accidentally calling KASAN instrumented code during KASAN initialization.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

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s390/early: fix sclp_early_sccb variable lifetime

Commit ada1da31ce34 ("s390/sclp: sort out physical vs
virtual pointers usage") fixed the notion of virtual
address for sclp_early_sccb pointer. Howe

s390/early: fix sclp_early_sccb variable lifetime

Commit ada1da31ce34 ("s390/sclp: sort out physical vs
virtual pointers usage") fixed the notion of virtual
address for sclp_early_sccb pointer. However, it did
not take into account that kasan_early_init() can also
output messages and sclp_early_sccb should be adjusted
by the time kasan_early_init() is called.

Currently it is not a problem, since virtual and physical
addresses on s390 are the same. Nevertheless, should they
ever differ, this would cause an invalid pointer access.

Fixes: ada1da31ce34 ("s390/sclp: sort out physical vs virtual pointers usage")
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

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s390: remove invalid email address of Heiko Carstens

Remove my old invalid email address which can be found in a couple of
files. Instead of updating it, just remove my contact data completely
from

s390: remove invalid email address of Heiko Carstens

Remove my old invalid email address which can be found in a couple of
files. Instead of updating it, just remove my contact data completely
from source files.
We have git and other tools which allow to figure out who is responsible
for what with recent contact data.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

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s390/boot: initialize control registers in decompressor

Partially revert commit 4555b9f34296 ("s390/boot: move
dma sections from decompressor to decompressed kernel").
This is a prerequisite to allo

s390/boot: initialize control registers in decompressor

Partially revert commit 4555b9f34296 ("s390/boot: move
dma sections from decompressor to decompressed kernel").
This is a prerequisite to allow initialization of virtual
memory in decompressor and avoid overwriting of ASCEs in
the decompressed kernel otherwise.

Since the control registers 2, 5 and 15 are reinitialized
in the decompressed kernel again, this change does not
prevent relocating of amode31 section in any way.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

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s390/boot: move dma sections from decompressor to decompressed kernel

This change simplifies the task of making the decompressor relocatable.

The decompressor's image contains special DMA sections

s390/boot: move dma sections from decompressor to decompressed kernel

This change simplifies the task of making the decompressor relocatable.

The decompressor's image contains special DMA sections between _sdma and
_edma. This DMA segment is loaded at boot as part of the decompressor and
then simply handed over to the decompressed kernel. The decompressor itself
never uses it in any way. The primary reason for this is the need to keep
the aforementioned DMA segment below 2GB which is required by architecture,
and because the decompressor is always loaded at a fixed low physical
address, it is guaranteed that the DMA region will not cross the 2GB
memory limit. If the DMA region had been placed in the decompressed kernel,
then KASLR would make this guarantee impossible to fulfill or it would
be restricted to the first 2GB of memory address space.

This commit moves all DMA sections between _sdma and _edma from
the decompressor's image to the decompressed kernel's image. The complete
DMA region is placed in the init section of the decompressed kernel and
immediately relocated below 2GB at start-up before it is needed by other
parts of the decompressed kernel. The relocation of the DMA region happens
even if the decompressed kernel is already located below 2GB in order
to keep the first implementation simple. The relocation should not have
any noticeable impact on boot time because the DMA segment is only a couple
of pages.

After relocating the DMA sections, the kernel has to fix all references
which point into it. In order to automate this, place all variables
pointing into the DMA sections in a special .dma.refs section. All such
variables must be defined using the new __dma_ref macro. Only variables
containing addresses within the DMA sections must be placed in the new
.dma.refs section.

Furthermore, move the initialization of control registers from
the decompressor to the decompressed kernel because some control registers
reference tables that must be placed in the DMA data section to
guarantee that their addresses are below 2G. Because the decompressed
kernel relocates the DMA sections at startup, the content of control
registers CR2, CR5 and CR15 must be updated with new addresses after
the relocation. The decompressed kernel initializes all control registers
early at boot and then updates the content of CR2, CR5 and CR15
as soon as the DMA relocation has occurred. This practically reverts
the commit a80313ff91ab ("s390/kernel: introduce .dma sections").

Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

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s390/early: rewrite program parameter setup in C

And move it earlier in the decompressor.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off

s390/early: rewrite program parameter setup in C

And move it earlier in the decompressor.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

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s390/head64: correct init_task stack setup

Add missing allocation of pt_regs at the bottom of the stack. This
makes it consistent with other stack setup cases and also what stack
unwinder expects.

s390/head64: correct init_task stack setup

Add missing allocation of pt_regs at the bottom of the stack. This
makes it consistent with other stack setup cases and also what stack
unwinder expects.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

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s390/early: move access registers setup in C code

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/head64: remove unnecessary vdso_per_cpu_data setup

vdso_per_cpu_data lowcore value is only needed for fully functional
exception handlers, which are activated in setup_lowcore_dat_off. The
same

s390/head64: remove unnecessary vdso_per_cpu_data setup

vdso_per_cpu_data lowcore value is only needed for fully functional
exception handlers, which are activated in setup_lowcore_dat_off. The
same function does init vdso_per_cpu_data via vdso_alloc_boot_cpu.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

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s390/early: move control registers setup in C code

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

Merge tag 's390-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Vasily Gorbik:

- Add support for IBM z15 machines.

- Add SHA3 and CCA AES cipher key sup

Merge tag 's390-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Vasily Gorbik:

- Add support for IBM z15 machines.

- Add SHA3 and CCA AES cipher key support in zcrypt and pkey
refactoring.

- Move to arch_stack_walk infrastructure for the stack unwinder.

- Various kasan fixes and improvements.

- Various command line parsing fixes.

- Improve decompressor phase debuggability.

- Lift no bss usage restriction for the early code.

- Use refcount_t for reference counters for couple of places in mm
code.

- Logging improvements and return code fix in vfio-ccw code.

- Couple of zpci fixes and minor refactoring.

- Remove some outdated documentation.

- Fix secure boot detection.

- Other various minor code clean ups.

* tag 's390-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (48 commits)
s390: remove pointless drivers-y in drivers/s390/Makefile
s390/cpum_sf: Fix line length and format string
s390/pci: fix MSI message data
s390: add support for IBM z15 machines
s390/crypto: Support for SHA3 via CPACF (MSA6)
s390/startup: add pgm check info printing
s390/crypto: xts-aes-s390 fix extra run-time crypto self tests finding
vfio-ccw: fix error return code in vfio_ccw_sch_init()
s390: vfio-ap: fix warning reset not completed
s390/base: remove unused s390_base_mcck_handler
s390/sclp: Fix bit checked for has_sipl
s390/zcrypt: fix wrong handling of cca cipher keygenflags
s390/kasan: add kdump support
s390/setup: avoid using strncmp with hardcoded length
s390/sclp: avoid using strncmp with hardcoded length
s390/module: avoid using strncmp with hardcoded length
s390/pci: avoid using strncmp with hardcoded length
s390/kaslr: reserve memory for kasan usage
s390/mem_detect: provide single get_mem_detect_end
s390/cmma: reuse kstrtobool for option value parsing
...

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s390: clean .bss before running uncompressed kernel

Clean uncompressed kernel .bss section in the startup code before
the uncompressed kernel is executed. At this point of time initrd and
certificat

s390: clean .bss before running uncompressed kernel

Clean uncompressed kernel .bss section in the startup code before
the uncompressed kernel is executed. At this point of time initrd and
certificates have been already rescued. Uncompressed kernel .bss size
is known from vmlinux_info. It is also taken into consideration during
uncompressed kernel positioning by kaslr (so it is safe to clean it).

With that uncompressed kernel is starting with .bss section zeroed and
no .bss section usage restrictions apply. Which makes chkbss checks for
uncompressed kernel objects obsolete and they can be removed.

early_nobss.c is also not needed anymore. Parts of it which are still
relevant are moved to early.c. Kasan initialization code is now called
directly from head64 (early.c is instrumented and should not be
executed before kasan shadow memory is set up).

Reviewed-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

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s390/head64: cleanup unused labels

Cleanup labels in head64 some of which are not being used since git
recorded history.

Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily G

s390/head64: cleanup unused labels

Cleanup labels in head64 some of which are not being used since git
recorded history.

Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

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s390/kernel: introduce .dma sections

With a relocatable kernel that could reside at any place in memory, code
and data that has to stay below 2 GB needs special handling.

This patch introduces .dma

s390/kernel: introduce .dma sections

With a relocatable kernel that could reside at any place in memory, code
and data that has to stay below 2 GB needs special handling.

This patch introduces .dma sections for such text, data and ex_table.
The sections will be part of the decompressor kernel, so they will not
be relocated and stay below 2 GB. Their location is passed over to the
decompressed / relocated kernel via the .boot.preserved.data section.

The duald and aste for control register setup also need to stay below
2 GB, so move the setup code from arch/s390/kernel/head64.S to
arch/s390/boot/head.S. The duct and linkage_stack could reside above
2 GB, but their content has to be preserved for the decompresed kernel,
so they are also moved into the .dma section.

The start and end address of the .dma sections is added to vmcoreinfo,
for crash support, to help debugging in case the kernel crashed there.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Reviewed-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

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s390: remove dead code

Remove some dead code from head64.S, which was left over since commit
da292bbe1f62 ("[S390] eliminate ipl_device from lowcore") removed
ipl_device from lowcore.

Reviewed-by:

s390: remove dead code

Remove some dead code from head64.S, which was left over since commit
da292bbe1f62 ("[S390] eliminate ipl_device from lowcore") removed
ipl_device from lowcore.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

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s390: add support for virtually mapped kernel stacks

With virtually mapped kernel stacks the kernel stack overflow detection
is now fault based, every stack has a guard page in the vmalloc space.
Th

s390: add support for virtually mapped kernel stacks

With virtually mapped kernel stacks the kernel stack overflow detection
is now fault based, every stack has a guard page in the vmalloc space.
The panic_stack is renamed to nodat_stack and is used for all function
that need to run without DAT, e.g. memcpy_real or do_start_kdump.

The main effect is a reduction in the kernel image size as with vmap
stacks the old style overflow checking that adds two instructions per
function is not needed anymore. Result from bloat-o-meter:

add/remove: 20/1 grow/shrink: 13/26854 up/down: 2198/-216240 (-214042)

In regard to performance the micro-benchmark for fork has a hit of a
few microseconds, allocating 4 pages in vmalloc space is more expensive
compare to an order-2 page allocation. But with real workload I could
not find a noticeable difference.

Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

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s390: clean up stacks setup

Replace hard coded stack frame overhead values with STACK_FRAME_OVERHEAD
definition. Avoid unnecessary arithmetic instructions.

Signed-off-by: Vasily Gorbik <gor@linux.i

s390: clean up stacks setup

Replace hard coded stack frame overhead values with STACK_FRAME_OVERHEAD
definition. Avoid unnecessary arithmetic instructions.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

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s390: correct _stext offset

Avoid unnecessary rewrite of psw and merge _stext into
startup_continue. This allows to move _stext definition to vmlinux.lds.S,
where _etext is also defined and set _ste

s390: correct _stext offset

Avoid unnecessary rewrite of psw and merge _stext into
startup_continue. This allows to move _stext definition to vmlinux.lds.S,
where _etext is also defined and set _stext to the actual beginning of
.text at 0x100000.

This fixes the problem with setting the last .text page as
not-executable due to vmem_map_init relying on page alinged _stext and
_etext.

Fixes: bd79d6632958 ("s390/decompressor: trim the kernel image up to 1M")
Reported-by: Nils Hoppmann <niho@de.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

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