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162 commits

Author SHA1 Message Date
Heiko Carstens
fd2527f209 s390/fpu: move, rename, and merge header files
Move, rename, and merge the fpu and vx header files. This way fpu header
files have a consistent naming scheme (fpu*.h).

Also get rid of the fpu subdirectory and move header files to asm
directory, so that all fpu and vx header files can be found at the same
location.

Merge internal.h header file into other header files, since the internal
helpers are used at many locations. so those helper functions are really
not internal.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-02-16 14:30:14 +01:00
Heiko Carstens
304103736b s390/acrs: cleanup access register handling
save_access_regs() and restore_access_regs() are only available by
including switch_to.h. This is done by a couple of C files, which have
nothing to do with switch_to(), but only need these functions.

Move both functions to a new header file and improve the implementation:

- Get rid of typedef

- Add memory access instrumentation support

- Use long displacement instructions lamy/stamy instead of lam/stam - all
  current users end up with better code because of this

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-02-12 15:03:33 +01:00
Heiko Carstens
18564756ab s390/fpu: get rid of MACHINE_HAS_VX
Get rid of MACHINE_HAS_VX and replace it with cpu_has_vx() which is a
short readable wrapper for "test_facility(129)".

Facility bit 129 is set if the vector facility is present. test_facility()
returns also true for all bits which are set in the architecture level set
of the cpu that the kernel is compiled for. This means that
test_facility(129) is a compile time constant which returns true for z13
and later, since the vector facility bit is part of the z13 kernel ALS.

In result the compiled code will have less runtime checks, and less code.

Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2023-12-11 14:33:07 +01:00
Heiko Carstens
af6ed37eb0 s390/fpu: remove "novx" option
Remove the "novx" kernel command line option: the vector code runs
without any problems since many years.

Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2023-12-11 14:33:06 +01:00
Heiko Carstens
468a3bc2b7 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>
2023-11-05 22:34:57 +01:00
Heiko Carstens
99441a38c3 s390: use control register bit defines
Use control register bit defines instead of plain numbers where
possible.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-09-19 13:26:57 +02:00
Heiko Carstens
103dde702d s390/early: use system_ctl_set_bit() instead of local_ctl_set_bit()
Use system_ctl_set_bit() instead of local_ctl_set_bit() to reflect
that the control register changes are supposed to be global. This
change is just for documentation purposes, since it still results only
in local control register contents being changed.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-09-19 13:26:57 +02:00
Heiko Carstens
8d5e98f8d6 s390/ctlreg: add local and system prefix to some functions
Add local and system prefix to some functions to clarify they change
control register contents on either the local CPU or the on all CPUs.

This results in the following API:

Two defines which load and save multiple control registers.
The defines correlate with the following C prototypes:

void __local_ctl_load(unsigned long *, unsigned int cr_low, unsigned int cr_high);
void __local_ctl_store(unsigned long *, unsigned int cr_low, unsigned int cr_high);

Two functions which locally set or clear one bit for a specified
control register:

void local_ctl_set_bit(unsigned int cr, unsigned int bit);
void local_ctl_clear_bit(unsigned int cr, unsigned int bit);

Two functions which set or clear one bit for a specified control
register on all CPUs:

void system_ctl_set_bit(unsigned int cr, unsigned int bit);
void system_ctl_clear_bit(unsigend int cr, unsigned int bit);

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-09-19 13:26:56 +02:00
Heiko Carstens
4a1725281f s390/smp,mcck: fix early IPI handling
Both the external call as well as the emergency signal submask bits in
control register 0 are set before any interrupt handler is registered.

Change the order and first register the interrupt handler and only then
enable the interrupts by setting the corresponding bits in control
register 0.

This prevents that the second part of the machine check handler for
early machine check handling is not executed: the machine check handler
sends an IPI to the CPU it runs on. If the corresponding interrupts are
enabled, but no interrupt handler is present, the interrupt is ignored.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-09-19 13:26:55 +02:00
Heiko Carstens
c0f1d47812 s390/mm: simplify kernel mapping setup
The kernel mapping is setup in two stages: in the decompressor map all
pages with RWX permissions, and within the kernel change all mappings to
their final permissions, where most of the mappings are changed from RWX to
RWNX.

Change this and map all pages RWNX from the beginning, however without
enabling noexec via control register modification. This means that
effectively all pages are used with RWX permissions like before. When the
final permissions have been applied to the kernel mapping enable noexec via
control register modification.

This allows to remove quite a bit of non-obvious code.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-08-30 11:03:27 +02:00
Heiko Carstens
b6f10e2f66 s390: remove "noexec" option
Do the same like x86 with commit 76ea0025a2 ("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>
2023-08-30 11:03:27 +02:00
Vasily Gorbik
557b19709d 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>
2023-03-20 11:02:51 +01:00
Vasily Gorbik
53fcc7dbf1 s390/boot: remove non-functioning image bootable check
check_image_bootable() has been introduced with commit 627c9b6205
("s390/boot: block uncompressed vmlinux booting attempts") to make sure
that users don't try to boot uncompressed vmlinux ELF image in qemu. It
used to be possible quite some time ago. That commit prevented confusion
with uncompressed vmlinux image starting to boot and even printing
kernel messages until it crashed. Users might have tried to report the
problem without realizing they are doing something which was not intended.
Since commit f1d3c53237 ("s390/boot: move sclp early buffer from fixed
address in asm to C") check_image_bootable() doesn't function properly
anymore, as well as booting uncompressed vmlinux image in qemu doesn't
really produce any output and crashes. Moving forward it doesn't make
sense to fix check_image_bootable() anymore, so simply remove it.

Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-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>
2023-03-20 11:02:50 +01:00
Vasily Gorbik
8ee0d2fb4d s390/setup: do not complain about parameters handled in decompressor
Currently there are several kernel command line parameters which are
only parsed and handled in decompressor and not known to the kernel.
This leads to the following error message during kernel boot:

Unknown kernel command line parameters "mem=3G nokaslr", will be passed
to user space.

To avoid confusion, register those parameters with an empty stub so that
kernel does not complain about them.

Reported-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
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>
2023-02-27 15:29:36 +01:00
Gerald Schaefer
0807b85652 s390/mm: add support for RDP (Reset DAT-Protection)
RDP instruction allows to reset DAT-protection bit in a PTE, with less
CPU synchronization overhead than IPTE instruction. In particular, IPTE
can cause machine-wide synchronization overhead, and excessive IPTE usage
can negatively impact machine performance.

RDP can be used instead of IPTE, if the new PTE only differs in SW bits
and _PAGE_PROTECT HW bit, for PTE protection changes from RO to RW.
SW PTE bit changes are allowed, e.g. for dirty and young tracking, but none
of the other HW-defined part of the PTE must change. This is because the
architecture forbids such changes to an active and valid PTE, which
is why invalidation with IPTE is always used first, before writing a new
entry.

The RDP optimization helps mainly for fault-driven SW dirty-bit tracking.
Writable PTEs are initially always mapped with HW _PAGE_PROTECT bit set,
to allow SW dirty-bit accounting on first write protection fault, where
the DAT-protection would then be reset. The reset is now done with RDP
instead of IPTE, if RDP instruction is available.

RDP cannot always guarantee that the DAT-protection reset is propagated
to all CPUs immediately. This means that spurious TLB protection faults
on other CPUs can now occur. For this, common code provides a
flush_tlb_fix_spurious_fault() handler, which will now be used to do a
CPU-local TLB flush. However, this will clear the whole TLB of a CPU, and
not just the affected entry. For more fine-grained flushing, by simply
doing a (local) RDP again, flush_tlb_fix_spurious_fault() would need to
also provide the PTE pointer.

Note that spurious TLB protection faults cannot really be distinguished
from racing pagetable updates, where another thread already installed the
correct PTE. In such a case, the local TLB flush would be unnecessary
overhead, but overall reduction of CPU synchronization overhead by not
using IPTE is still expected to be beneficial.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-02-14 11:45:39 +01:00
Alexander Gordeev
bb1520d581 s390/mm: start kernel with DAT enabled
The setup of the kernel virtual address space is spread
throughout the sources, boot stages and config options
like this:

1. The available physical memory regions are queried
   and stored as mem_detect information for later use
   in the decompressor.

2. Based on the physical memory availability the virtual
   memory layout is established in the decompressor;

3. If CONFIG_KASAN is disabled the kernel paging setup
   code populates kernel pgtables and turns DAT mode on.
   It uses the information stored at step [1].

4. If CONFIG_KASAN is enabled the kernel early boot
   kasan setup populates kernel pgtables and turns DAT
   mode on. It uses the information stored at step [1].

   The kasan setup creates early_pg_dir directory and
   directly overwrites swapper_pg_dir entries to make
   shadow memory pages available.

Move the kernel virtual memory setup to the decompressor
and start the kernel with DAT turned on right from the
very first istruction. That completely eliminates the
boot phase when the kernel runs in DAT-off mode, simplies
the overall design and consolidates pgtables setup.

The identity mapping is created in the decompressor, while
kasan shadow mappings are still created by the early boot
kernel code.

Share with decompressor the existing kasan memory allocator.
It decreases the size of a newly requested memory block from
pgalloc_pos and ensures that kernel image is not overwritten.
pgalloc_low and pgalloc_pos pointers are made preserved boot
variables for that.

Use the bootdata infrastructure to setup swapper_pg_dir
and invalid_pg_dir directories used by the kernel later.
The interim early_pg_dir directory established by the
kasan initialization code gets eliminated as result.

As the kernel runs in DAT-on mode only the PSW_KERNEL_BITS
define gets PSW_MASK_DAT bit by default. Additionally, the
setup_lowcore_dat_off() and setup_lowcore_dat_on() routines
get merged, since there is no DAT-off mode stage anymore.

The memory mappings are created with RW+X protection that
allows the early boot code setting up all necessary data
and services for the kernel being booted. Just before the
paging is enabled the memory protection is changed to
RO+X for text, RO+NX for read-only data and RW+NX for
kernel data and the identity mapping.

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>
2023-01-13 14:15:05 +01:00
Alexander Gordeev
639886b71d s390/early: fix sclp_early_sccb variable lifetime
Commit ada1da31ce ("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: ada1da31ce ("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>
2023-01-13 14:15:04 +01:00
Wolfram Sang
820109fb11 s390: move from strlcpy with unused retval to strscpy
Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Benjamin Block <bblock@linux.ibm.com>
Acked-by: Alexandra Winter <wintera@linux.ibm.com>
Link: https://lore.kernel.org/r/20220818205948.6360-1-wsa+renesas@sang-engineering.com
Link: https://lore.kernel.org/r/20220818210102.7301-1-wsa+renesas@sang-engineering.com
[gor@linux.ibm.com: squashed two changes linked above together]
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-08-30 22:00:33 +02:00
Heiko Carstens
85806016ac s390: simplify early program check handler
Due to historic reasons the base program check handler calls a
configurable function. Given that there is only the early program
check handler left, simplify the code by directly calling that
function.

The only other user was removed with commit d485235b00 ("s390:
assume diag308 set always works").

Also rename all functions and the asm file to reflect this.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-05-25 11:46:02 +02:00
Heiko Carstens
46fee16f57 s390/extable: add and use fixup_exception helper function
Add and use fixup_exception helper function in order to remove the
duplicated exception handler fixup code at several places.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-08 00:33:00 +01:00
Heiko Carstens
cfa45c5e0d s390/base: pass pt_regs to early program check handler
Pass pt_regs to early program check handler like it is done for every
other interrupt and exception handler.

Also the passed pt_regs can be changed by the called function and the
changes register contents and psw contents will be taken into account
when returning. In addition the return psw will not be copied to the
program check old psw in lowcore, but to the usual return psw
location, like it is also done by the regular program check handler.
This allows also to get rid of the code that disabled lowcore
protection when changing the return address.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-08 00:33:00 +01:00
Heiko Carstens
d09a307fde s390/extable: move EX_TABLE define to asm-extable.h
Follow arm64 and riscv and move the EX_TABLE define to asm-extable.h
which is a lot less generic than the current linkage.h.

Also make sure that all files which contain EX_TABLE usages actually
include the new header file. This should make sure that the files
always compile and there won't be any random compile breakage due to
other header file dependencies.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-08 00:33:00 +01:00
Heiko Carstens
a156f09c90 s390/extable: sort amode31 extable early
The early program check handler is active before the amode31 extable
is sorted. Therefore in case a program check happens early within the
amode31 code the extable entry might not be found.

Fix this by sorting the amode31 extable early.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-08 00:33:00 +01:00
Heiko Carstens
f36e7c9845 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>
2022-02-06 23:31:29 +01:00
Sven Schnelle
5ecb2da660 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>
2021-10-26 15:21:31 +02:00
Alexander Gordeev
ada1da31ce s390/sclp: sort out physical vs virtual pointers usage
Provide physical addresses whenever the hardware interface
expects it or a 32-bit value used for tracking.

Variable sclp_early_sccb gets initialized in the decompressor
and points to an address in physcal memory. Yet, it is used
as virtual memory pointer and therefore should be converted.

Note, the other two __bootdata variables sclp_info_sccb and
sclp_info_sccb_valid contain plain data, but no pointers and
do need any special care.

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>
2021-10-26 15:21:28 +02:00
Niklas Schnelle
3322ba0d7b s390: make PCI mio support a machine flag
Kernel support for the newer PCI mio instructions can be toggled off
with the pci=nomio command line option which needs to integrate with
common code PCI option parsing. However this option then toggles static
branches which can't be toggled yet in an early_param() call.

Thus commit 9964f396f1 ("s390: fix setting of mio addressing control")
moved toggling the static branches to the PCI init routine.

With this setup however we can't check for mio support outside the PCI
code during early boot, i.e. before switching the static branches, which
we need to be able to export this as an ELF HWCAP.

Improve on this by turning mio availability into a machine flag that
gets initially set based on CONFIG_PCI and the facility bit and gets
toggled off if pci=nomio is found during PCI option parsing allowing
simple access to this machine flag after early init.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-07-27 09:39:19 +02:00
Alexander Egorenkov
9f744abb46 s390/boot: replace magic string check with a bootdata flag
The magic string "S390EP" at offset 0x10008 indicated to the decompressed
kernel that it was booted by the decompressor. Introduce a new bootdata
flag instead which conveys the same information in an explicit and
a cleaner way. But keep the magic string because it is a kernel ABI.

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>
2021-07-05 12:44:23 +02:00
Sven Schnelle
17e89e1340 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>
2021-06-07 17:06:58 +02:00
Heiko Carstens
f8d8977a3d s390/time: convert tod_clock_base to union
Convert tod_clock_base to union tod_clock. This simplifies quite a bit
of code and also fixes a bug in read_persistent_clock64();

void read_persistent_clock64(struct timespec64 *ts)
{
        __u64 delta;

        delta = initial_leap_seconds + TOD_UNIX_EPOCH;
        get_tod_clock_ext(clk);
        *(__u64 *) &clk[1] -= delta;
        if (*(__u64 *) &clk[1] > delta)
                clk[0]--;
        ext_to_timespec64(clk, ts);
}

Assume &clk[1] == 3 and delta == 2; then after the substraction the if
condition becomes true and the epoch part of the clock is decremented
by one because of an assumed overflow, even though there is none.

Fix this by using 128 bit arithmetics and let the compiler do the
right thing:

void read_persistent_clock64(struct timespec64 *ts)
{
        union tod_clock clk;
        u64 delta;

        delta = initial_leap_seconds + TOD_UNIX_EPOCH;
        store_tod_clock_ext(&clk);
        clk.eitod -= delta;
        ext_to_timespec64(&clk, ts);
}

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13 17:17:54 +01:00
Heiko Carstens
530f639f1e s390/time: rename store_tod_clock_ext() and use union tod_clock
Rename store_tod_clock_ext() to store_tod_clock_ext_cc() to reflect
that it returns a condition code and also use union tod_clock as
parameter.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13 17:17:54 +01:00
Heiko Carstens
b22446d00a s390/time: use stcke instead of stck
Use STORE CLOCK EXTENDED instead of STORE CLOCK in early tod clock
setup. This is just to remove another usage of stck, trying to remove
all usages of STORE CLOCK.  This doesn't fix anything.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-09 15:57:05 +01:00
Vasily Gorbik
f38b0a7439 s390: remove unused s390_base_ext_handler
s390_base_ext_handler_fn haven't been used since its introduction in
commit ab14de6c37 ("[S390] Convert memory detection into C code.").

s390_base_ext_handler itself is currently falsely storing 16 registers
at __LC_SAVE_AREA_ASYNC rewriting several following lowcore values:
cpu_flags, return_psw, return_mcck_psw, sync_enter_timer and
async_enter_timer.

Besides that s390_base_ext_handler itself is only potentially hiding
EXT interrupts which should not have happen in the first place. Any
piece of code which requires EXT interrupts before fully functional
ext_int_handler is enabled has to do it on its own, like this is done
by sclp_early_cmd() which is doing EXT interrupts handling synchronously
in sclp_early_wait_irq().

With s390_base_ext_handler removed unexpected EXT interrupt leads
to disabled wait with the address 0x1b0 (__LC_EXT_NEW_PSW), which is
currently setup 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>
2020-11-09 11:20:58 +01:00
Sven Schnelle
ad3e6948f9 s390: remove cad commandline option
remove the cad command line option as the instruction was never
published and never used by userspace.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-09-30 12:09:54 +02:00
Vasily Gorbik
998f5bbe3d s390/kasan: fix early pgm check handler execution
Currently if early_pgm_check_handler is called it ends up in pgm check
loop. The problem is that early_pgm_check_handler is instrumented by
KASAN but executed without DAT flag enabled which leads to addressing
exception when KASAN checks try to access shadow memory.

Fix that by executing early handlers with DAT flag on under KASAN as
expected.

Reported-and-tested-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2020-06-23 14:05:50 +02:00
Heiko Carstens
1b68ac8678 s390: remove last diag 0x44 caller
diag 0x44 is a voluntary undirected yield of a virtual CPU. This has
caused a lot of performance issues in the past.

There is only one caller left, and that one is only executed if diag
0x9c (directed yield) is not present. Given that all hypervisors
implement diag 0x9c anyway, remove the last diag 0x44 to avoid that
more callers will be added.

Worst case that could happen now, if diag 0x9c is not present, is that
a virtual CPU would loop a bit instead of giving its time slice up.

diag 0x44 statistics in debugfs are kept and will always be zero, so
that user space can tell that there are no calls.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-12-11 19:53:24 +01:00
Vasily Gorbik
c231359421 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>
2019-11-20 12:58:13 +01:00
Vasily Gorbik
c02ee6a16a 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>
2019-11-20 12:58:12 +01:00
Vasily Gorbik
d3baaeb5ae s390: avoid double handling of "noexec" option
"noexec" option is already parsed during startup and its value is
exposed via noexec_disabled variable. Simply reuse that value during
machine facilities detection.

Suggested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-10-31 17:20:52 +01:00
Vasily Gorbik
2e83e0eb85 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>
2019-08-21 12:58:52 +02:00
Sebastian Ott
9964f396f1 s390: fix setting of mio addressing control
Move enablement of mio addressing control from detect_machine_facilities
to pci_base_init. detect_machine_facilities runs so early that the
static branches have not been toggled yet, thus mio addressing control
was always off. In pci_base_init we have to use the SMP aware
ctl_set_bit though.

Fixes: 833b441ec0 ("s390: enable processes for mio instructions")
Signed-off-by: Sebastian Ott <sebott@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-07-11 20:40:02 +02:00
Martin Schwidefsky
98587c2d89 s390: simplify disabled_wait
The disabled_wait() function uses its argument as the PSW address when
it stops the CPU with a wait PSW that is disabled for interrupts.
The different callers sometimes use a specific number like 0xdeadbeef
to indicate a specific failure, the early boot code uses 0 and some
other calls sites use __builtin_return_address(0).

At the time a dump is created the current PSW and the registers of a
CPU are written to lowcore to make them avaiable to the dump analysis
tool. For a CPU stopped with disabled_wait the PSW and the registers
do not really make sense together, the PSW address does not point to
the function the registers belong to.

Simplify disabled_wait() by using _THIS_IP_ for the PSW address and
drop the argument to the function.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-05-02 13:54:11 +02:00
Gerald Schaefer
a80313ff91 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>
2019-04-29 10:47:10 +02:00
Sebastian Ott
833b441ec0 s390: enable processes for mio instructions
Allow for userspace to use PCI MIO instructions.

Signed-off-by: Sebastian Ott <sebott@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29 10:47:01 +02:00
Vasily Gorbik
1e941d3949 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>
2019-04-10 17:47:11 +02:00
Linus Torvalds
3591b19511 s390 updates for the 5.1 merge window
- A copy of Arnds compat wrapper generation series
 
  - Pass information about the KVM guest to the host in form the control
    program code and the control program version code
 
  - Map IOV resources to support PCI physical functions on s390
 
  - Add vector load and store alignment hints to improve performance
 
  - Use the "jdd" constraint with gcc 9 to make jump labels working again
 
  - Remove amode workaround for old z/VM releases from the DCSS code
 
  - Add support for in-kernel performance measurements using the
    CPU measurement counter facility
 
  - Introduce a new PMU device cpum_cf_diag to capture counters and
    store thenn as event raw data.
 
  - Bug fixes and cleanups
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Merge tag 's390-5.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Martin Schwidefsky:

 - A copy of Arnds compat wrapper generation series

 - Pass information about the KVM guest to the host in form the control
   program code and the control program version code

 - Map IOV resources to support PCI physical functions on s390

 - Add vector load and store alignment hints to improve performance

 - Use the "jdd" constraint with gcc 9 to make jump labels working again

 - Remove amode workaround for old z/VM releases from the DCSS code

 - Add support for in-kernel performance measurements using the CPU
   measurement counter facility

 - Introduce a new PMU device cpum_cf_diag to capture counters and store
   thenn as event raw data.

 - Bug fixes and cleanups

* tag 's390-5.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (54 commits)
  Revert "s390/cpum_cf: Add kernel message exaplanations"
  s390/dasd: fix read device characteristic with CONFIG_VMAP_STACK=y
  s390/suspend: fix prefix register reset in swsusp_arch_resume
  s390: warn about clearing als implied facilities
  s390: allow overriding facilities via command line
  s390: clean up redundant facilities list setup
  s390/als: remove duplicated in-place implementation of stfle
  s390/cio: Use cpa range elsewhere within vfio-ccw
  s390/cio: Fix vfio-ccw handling of recursive TICs
  s390: vfio_ap: link the vfio_ap devices to the vfio_ap bus subsystem
  s390/cpum_cf: Handle EBUSY return code from CPU counter facility reservation
  s390/cpum_cf: Add kernel message exaplanations
  s390/cpum_cf_diag: Add support for s390 counter facility diagnostic trace
  s390/cpum_cf: add ctr_stcctm() function
  s390/cpum_cf: move common functions into a separate file
  s390/cpum_cf: introduce kernel_cpumcf_avail() function
  s390/cpu_mf: replace stcctm5() with the stcctm() function
  s390/cpu_mf: add store cpu counter multiple instruction support
  s390/cpum_cf: Add minimal in-kernel interface for counter measurements
  s390/cpum_cf: introduce kernel_cpumcf_alert() to obtain measurement alerts
  ...
2019-03-05 11:13:10 -08:00
Vasily Gorbik
d8901f2b2d s390: clean up redundant facilities list setup
Facilities list in the lowcore is initially set up by verify_facilities
from als.c and later initializations are redundant, so cleaning them up.

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>
2019-03-01 08:00:39 +01:00
Christian Borntraeger
03aa047ef2 s390/early: improve machine detection
Right now the early machine detection code check stsi 3.2.2 for "KVM"
and set MACHINE_IS_VM if this is different. As the console detection
uses diagnose 8 if MACHINE_IS_VM returns true this will crash Linux
early for any non z/VM system that sets a different value than KVM.
So instead of assuming z/VM, do not set any of MACHINE_IS_LPAR,
MACHINE_IS_VM, or MACHINE_IS_KVM.

CC: stable@vger.kernel.org
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-01-11 17:12:02 +01:00
Vasily Gorbik
49698745e5 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>
2018-10-09 11:21:14 +02:00
Vasily Gorbik
627c9b6205 s390/boot: block uncompressed vmlinux booting attempts
Since the plain vmlinux ELF file no longer carries all necessary parts
for starting up (like the entry point and decompressor), add a check
which would block boot process and encourage users to use bzImage or
arch/s390/boot/compressed/vmlinux instead.

The check relies on s390 linux entry point ABI definition, which is only
present in bzImage and arch/s390/boot/compressed/vmlinux.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Christian Borntraeger <borntraeger@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>
2018-07-02 11:25:05 +02:00