s390/boot: always align vmalloc area on segment boundary

The size of vmalloc area depends from various factors
on boot and could be set to:

1. Default size as determined by VMALLOC_DEFAULT_SIZE macro;
2. One half of the virtual address space not occupied by
modules and fixed mappings;
3. The size provided by user with vmalloc= kernel command
line parameter;

In cases [1] and [2] the vmalloc area base address is aligned
on Region3 table type boundary, while in case [3] in might get
aligned on page boundary.

Limit the waste of page tables and always align vmalloc area
size and base address on segment boundary.

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

s390/cmma: move parsing of cmma kernel parameter to early boot code

The "cmma=" kernel command line parameter needs to be parsed early for
upcoming changes. Therefore move the parsing code.

Note that EX_TABLE handling of cmma_test_essa() needs to be open-coded,
since the early boot code doesn't have infrastructure for handling expected
exceptions.

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

s390: remove "noexec" option

Do the same like x86 with commit 76ea0025a214 ("x86/cpu: Remove "noexec"")
and remove the "noexec" kernel command line option.

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

s390/kaslr: provide kaslr_enabled() function

Just like other architectures provide a kaslr_enabled() function, instead
of directly accessing a global variable.

Also pass the renamed __kaslr_enabled variable from the decompressor to the
kernel, so that kalsr_enabled() is available there too. This will be used
by a subsequent patch which randomizes the module base load address.

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>

s390/ipl: add eckd dump support

This adds support to use ECKD disks as dump device
to linux. The new dump type is called 'eckd_dump', parameters
are the same as for eckd ipl.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

s390/ipl: add eckd support

This adds support to IPL from ECKD DASDs to linux.
It introduces a few sysfs files in /sys/firmware/reipl/eckd:

bootprog: the boot program selector
clear: whether to issue a diag308 LOAD_NORMAL or LOAD_CLEAR
device: the device to ipl from
br_chr: Cylinder/Head/Record number to read the bootrecord from.
Might be '0' or 'auto' if it should be read from the
volume label.
scpdata: data to be passed to the ipl'd program.

The new ipl type is called 'eckd'.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

s390/boot: convert parmarea to C

Convert parmarea to C, which makes it much easier to initialize it. No need
to keep offsets in assembler code in sync with struct parmarea anymore.

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

s390: support command lines longer than 896 bytes

Currently s390 supports a fixed maximum command line length of 896
bytes. This isn't enough as some installers are trying to pass all
configuration data via kernel command line, and even with zfcp alone
it is easy to generate really long command lines. Therefore extend
the command line to 4 kbytes.

In the parm area where the command line is stored there is no indication
of the maximum allowed length, so a new field which contains the maximum
length is added.

The parm area has always been initialized to zero, so with old kernels
this field would read zero. This is important because tools like zipl
could read this field. If it contains a number larger than zero zipl
knows the maximum length that can be stored in the parm area, otherwise
it must assume that it is booting a legacy kernel and only 896 bytes are
available.

The removing of trailing whitespace in head.S is also removed because
code to do this is already present in setup_boot_command_line().

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

s390/ipl_parm: use register pair instead of register asm

...and slightly cleanup the inline asm.

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

s390/ipl_parm: fix program check new psw handling

The __diag308() inline asm temporarily changes the program check new
psw to redirect a potential program check on the diag instruction.
Restoring of the program check new psw is done in C code behind the
inline asm.

This can be problematic, especially if the function is inlined, since
the compiler can reorder instructions in such a way that a different
instruction, which may result in a program check, might be executed
before the program check new psw has been restored.

To avoid such a scenario move restoring into the inline asm. For
consistency reasons move also saving of the original program check new
psw into the inline asm.

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

s390: setup kernel memory layout early

Currently there are two separate places where kernel memory layout has
to be known and adjusted:
1. early kasan setup.
2. paging setup later.

Those 2 places had to be kept in sync and adjusted to reflect peculiar
technical details of one another. With additional factors which influence
kernel memory layout like ultravisor secure storage limit, complexity
of keeping two things in sync grew up even more.

Besides that if we look forward towards creating identity mapping and
enabling DAT before jumping into uncompressed kernel - that would also
require full knowledge of and control over kernel memory layout.

So, de-duplicate and move kernel memory layout setup logic into
the decompressor.

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

s390/boot: access kernel command line via parmarea

Access the kernel command line via parmarea instead of using the
COMMAND_LINE define.
With this the following gcc11 warning is removed:

arch/s390/boot/ipl_parm.c: In function ‘setup_boot_command_line’:
arch/s390/boot/ipl_parm.c:168:50: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=]

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

s390/facilities: move stfl information from lowcore to global data

With gcc-11, there are a lot of warnings because the facility functions
are accessing lowcore through a null pointer. Fix this by moving the
facility arrays away from lowcore.

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

s390: unify identity mapping limits handling

Currently we have to consider too many different values which
in the end only affect identity mapping size. These are:
1. max_physmem_end - end of physical memory online or standby.
Always <= end of the last online memory block (get_mem_detect_end()).
2. CONFIG_MAX_PHYSMEM_BITS - the maximum size of physical memory the
kernel is able to support.
3. "mem=" kernel command line option which limits physical memory usage.
4. OLDMEM_BASE which is a kdump memory limit when the kernel is executed as
crash kernel.
5. "hsa" size which is a memory limit when the kernel is executed during
zfcp/nvme dump.

Through out kernel startup and run we juggle all those values at once
but that does not bring any amusement, only confusion and complexity.

Unify all those values to a single one we should really care, that is
our identity mapping size.

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

s390/mm: let vmalloc area size depend on physical memory size

To make sure that the vmalloc area size is for almost all cases large
enough let it depend on the (potential) physical memory size. There is
still the possibility to override this with the vmalloc kernel command
line parameter.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/nvme: support firmware-assisted dump to NVMe disks

From the kernel perspective NVMe dump works exactly like zFCP dump.
Therefore, adapt all places where code explicitly tests only for
IPL of type FCP DUMP. And also set the memory end correctly in this case.

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

s390/ipl: support NVMe IPL kernel parameters

Enable extracting of extra kernel command-line parameters
from the NVMe IPL block passed by the firmware to the kernel
at boot.

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

s390/startup: correct "dfltcc" option parsing

Currently if just "dfltcc" is passed as a kernel command line option
"val" going to be NULL, this leads to reading at address 0 in
strcmp(val, "off")

Fix that by making sure "val" is not NULL. This does not affect option
handling logic.

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

s390/protvirt: parse prot_virt option in the decompressor

To make early kernel address space layout definition possible parse
prot_virt option in the decompressor and pass it to the uncompressed
kernel. This enables kasan to take ultravisor secure storage limit into
consideration and pre-define vmalloc position correctly.

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

s390/boot: enable .bss section for compressed kernel

- Support static uninitialized variables in compressed kernel.
- Remove chkbss script
- Get rid of workarounds for not having .bss section

Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

mm: reorder includes after introduction of linux/pgtable.h

The replacement of <asm/pgrable.h> with <linux/pgtable.h> made the include
of the latter in the middle of asm includes. Fix this up with the aid of
the below script and manual adjustments here and there.

import sys
import re

if len(sys.argv) is not 3:
print "USAGE: %s <file> <header>" % (sys.argv[0])
sys.exit(1)

hdr_to_move="#include <linux/%s>" % sys.argv[2]
moved = False
in_hdrs = False

with open(sys.argv[1], "r") as f:
lines = f.readlines()
for _line in lines:
line = _line.rstrip('
')
if line == hdr_to_move:
continue
if line.startswith("#include <linux/"):
in_hdrs = True
elif not moved and in_hdrs:
moved = True
print hdr_to_move
print line

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-4-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: introduce include/linux/pgtable.h

The include/linux/pgtable.h is going to be the home of generic page table
manipulation functions.

Start with moving asm-generic/pgtable.h to include/linux/pgtable.h and
make the latter include asm/pgtable.h.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-3-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

s390/boot: add dfltcc= kernel command line parameter

Add the new kernel command line parameter 'dfltcc=' to configure s390
zlib hardware support.

Format: { on | off | def_only | inf_only | always }
on: s390 zlib hardware support for compression on
level 1 and decompression (default)
off: No s390 zlib hardware support
def_only: s390 zlib hardware support for deflate
only (compression on level 1)
inf_only: s390 zlib hardware support for inflate
only (decompression)
always: Same as 'on' but ignores the selected compression
level always using hardware support (used for debugging)

Link: http://lkml.kernel.org/r/20200103223334.20669-5-zaslonko@linux.ibm.com
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Cc: Chris Mason <clm@fb.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Eduard Shishkin <edward6@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

s390/startup: correct command line options parsing

Check val is not NULL before accessing it. This might happen if
corresponding kernel command line options are used without specifying
values.

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

s390/startup: round down "mem" option to page boundary

Make a usable value out of "mem" option once and for all. Kasan memory
allocator just takes memory_end or online memory size as allocation
base. If memory_end is not aligned paging structures allocated in kasan
end up unaligned as well. So this change fixes potential kasan crash
as well.

Fixes: 78333d1f908a ("s390/kasan: add support for mem= kernel parameter")
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390: move vmalloc option parsing to startup code

Few other crucial memory setup options are already handled in
the startup code. Those values are needed by kaslr and kasan
implementations. "vmalloc" is the last piece required for future
improvements such as early decision on kernel page levels depth required
for actual memory setup, as well as vmalloc memory area access monitoring
in kasan.

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

s390/protvirt: avoid memory sharing for diag 308 set/store

This reverts commit db9492cef45e ("s390/protvirt: add memory sharing for
diag 308 set/store") which due to ultravisor implementation change is
not needed after all.

Fixes: db9492cef45e ("s390/protvirt: add memory sharing for diag 308 set/store")
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390: fix clang -Wpointer-sign warnigns in boot code

The arch/s390/boot directory is built with its own set of compiler
options that does not include -Wno-pointer-sign like the rest of
the kernel does, this causes a lot of harmless but correct warnings
when building with clang.

For the atomics, we can add type casts to avoid the warnings, for
everything else the easiest way is to slightly adapt the types
to be more consistent.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/kernel: add support for kernel address space layout randomization (KASLR)

This patch adds support for relocating the kernel to a random address.
The random kernel offset is obtained from cpacf, using either TRNG, PRNO,
or KMC_PRNG, depending on supported MSA level.

KERNELOFFSET is added to vmcoreinfo, for crash --kaslr support.

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>

s390/ipl: provide uapi header for list directed IPL

The IPL parameter block is used as an interface between Linux and
the machine to query and change the boot device and boot options.
To be able to create IPL parameter block in user space and pass it
as segment to kexec provide an uapi header with proper structure
definitions for the block.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/ipl: make ipl_info less confusing

The ipl_info union in struct ipl_parameter_block has the same name as
the struct ipl_info. This does not help while reading the code and the
union in struct ipl_parameter_block does not need to be named. Drop
the name from the union.

Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/protvirt: block kernel command line alteration

Disallow kernel command line alteration via ipl parameter block if
running in protected virtualization environment.

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

s390/protvirt: add memory sharing for diag 308 set/store

Add sharing of ipl parameter block for diag 308 set/store calls to allow
kvm access in protected virtualization environment.

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

s390: move ipl block to .boot.preserved.data section

.boot.preserved.data is a better fit for ipl block than .boot.data
which is discarded after init. Reusing .boot.preserved.data allows to
simplify code a little bit and avoid copying data from .boot.data to
persistent variables.

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

s390: warn about clearing als implied facilities

Add a warning about removing required architecture level set facilities
via "facilities=" command line option.

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>

s390: allow overriding facilities via command line

Add "facilities=" command line option which allows to override
facility bits returned by stfle. The main purpose of that is debugging
aids which allows to test specific kernel behaviour depending on
specific facilities presence. It also affects CPU alternatives.

"facilities=" command line option format is comma separated list of
integer values to be additionally set or cleared (if value is starting
with "!"). Values ranges are also supported. e.g.:

facilities=!130-160,159,167-169

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>

s390/kasan: use noexec and large pages

To lower memory footprint and speed up kasan initialisation detect
EDAT availability and use large pages if possible. As we know how
much memory is needed for initialisation, another simplistic large
page allocator is introduced to avoid memory fragmentation.

Since facilities list is retrieved anyhow, detect noexec support and
adjust pages attributes. Handle noexec kernel option to avoid inconsistent
kasan shadow memory pages flags.

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

s390: move ipl block and cmd line handling to early boot phase

To distinguish zfcpdump case and to be able to parse some of the kernel
command line arguments early (e.g. mem=) ipl block retrieval and command
line construction code is moved to the early boot phase.

"memory_end" is set up correctly respecting "mem=" and hsa_size in case
of the zfcpdump.

arch/s390/boot/string.c is introduced to provide string handling and
command line parsing functions to early boot phase code for the compressed
kernel image case.

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