Heiko Carstens says:
====================
Remove s390 compat support to allow for code simplification and especially
reduced test effort. To the best of our knowledge there aren't any 31 bit
binaries out in the world anymore that would matter for newer kernels or
newer distributions.
Distributions do not provide compat packages since quite some time or even
have CONFIG_COMPAT disabled.
Instead of adding deprecation warnings to config option, or adding kernel
messages, just remove the code. Deprecation warnings haven't proven to be
useful. If it turns out there is still a reason to keep the compat support
this series can be reverted at any time in the future.
====================
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The s390 syscall.tbl format differs slightly from most others, and
therefore requires an s390 specific system call table generation
script.
With compat support gone use the opportunity to switch to generic
system call table generation. The abi for all 64 bit system calls is
now common, since there is no need to specify if system call entry
points are only for 64 bit anymore.
Furthermore create the system call table in C instead of assembler
code in order to get type checking for all system call functions
contained within the table.
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
With compat support gone there is only one system call table
left. Therefore remove the sys_call_table pointer from
thread_struct and use the sys_call_table directly.
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Since the kernel does not support running 31 bit / compat binaries
anymore, remove also the corresponding 31 bit support from uapi header
files.
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
There shouldn't be any 31 bit code around anymore that matters.
Remove the compat layer support required to run 31 bit code.
Reason for removal is code simplification and reduced test effort.
Note that this comes without any deprecation warnings added to config
options, or kernel messages, since most likely those would be ignored
anyway.
If it turns out there is still a reason to keep the compat layer this
can be reverted at any time in the future.
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Remove s390 compat support from everything within tools, since s390 compat
support will be removed from the kernel.
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Weißschuh <linux@weissschuh.net> # tools/nolibc selftests/nolibc
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net> # selftests/vDSO
Acked-by: Alexei Starovoitov <ast@kernel.org> # bpf bits
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
All system call wrappers should match the sys_call_ptr_t type. This is not
the case for system calls without parameters. Add the missing pt_regs
parameter there too.
Note: this is currently not a problem, since the parameter is unused.
However it prevents to create a correctly typed system call table in
C. With the current assembler implementation this works because of
missing type checking.
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
kvm_s390_handle_lpsw() make use of the psw_compat_t type even though
the code has nothing to do with CONFIG_COMPAT, for which the type is
supposed to be used. Use psw32_t instead.
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Use a standard "_t" suffix for psw_t32 and rename it to psw32_t.
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
In case of a kernel crash caused by a protection exception, print the
unmodified PSW address as reported by the CPU. The protection exception
handler modifies the PSW address in order to keep fault handling easy,
however that leads to misleading call traces.
Therefore restore the original PSW address before printing it.
Before this change the output in case of a protection exception looks like
this:
Oops: 0004 ilc:2 [#1]SMP
Krnl PSW : 0704c00180000000 000003ffe0b40d78 (sysrq_handle_crash+0x28/0x40)
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
...
Krnl Code: 000003ffe0b40d66: e3e0f0980024 stg %r14,152(%r15)
000003ffe0b40d6c: c010fffffff2 larl %r1,000003ffe0b40d50
#000003ffe0b40d72: c0200046b6bc larl %r2,000003ffe1417aea
>000003ffe0b40d78: 92021000 mvi 0(%r1),2
000003ffe0b40d7c: c0e5ffae03d6 brasl %r14,000003ffe0101528
With this change it looks like this:
Oops: 0004 ilc:2 [#1]SMP
Krnl PSW : 0704c00180000000 000003ffe0b40dfc (sysrq_handle_crash+0x2c/0x40)
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
...
Krnl Code: 000003ffe0b40dec: c010fffffff2 larl %r1,000003ffe0b40dd0
000003ffe0b40df2: c0200046b67c larl %r2,000003ffe1417aea
*000003ffe0b40df8: 92021000 mvi 0(%r1),2
>000003ffe0b40dfc: c0e5ffae03b6 brasl %r14,000003ffe0101568
000003ffe0b40e02: 0707 bcr 0,%r7
Note that with this change the PSW address points to the instruction behind
the instruction which caused the exception like it is expected for
protection exceptions.
This also replaces the '#' marker in the disassembly with '*', which allows
to distinguish between new and old behavior.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
With adjust_psw_addr() the uprobes code contains more or less a private
__forward_psw() implementation. Switch it to use __forward_psw(), and
remove adjust_psw_addr().
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Similar to __rewind_psw() add the counter part __forward_psw(). This
helps to make code more readable if a PSW address has to be forwarded,
since it is more natural to write
addr = __forward_psw(psw, ilen);
instead of
addr = __rewind_psw(psw, -ilen);
This renames also the ilc parameter of __rewind_psw() to ilen, since
the parameter reflects an instruction length, and not an instruction
length code. Also change the type of ilen from unsigned long to long
so it reflects that lengths can be negative or positive.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The PAI extension 1 control block area is 512 bytes in total.
It currently contains three address pointer which refer to counter
memory blocks followed by a reserved area.
Calculate the reserved area instead of hardcoding its size. This
makes the code more readable and maintainable.
No functional chance.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Suggested-by: Jan Polensky <japo@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Let dump_fault_info() print additional information to make debugging
easier:
Print "FSI" if the access-exception-fetch/store-indication facility is
installed. If it is installed the TEID may also indicate if an exception
happened because of a fetch or a store operation.
Print "SOP", "ESOP-1", or "ESOP-2" depending on the type of the installed
Suppression-on-Protection facility. This also gives additional information
about the validity and meaning of the TEID bits.
The output is changed from something like:
Failing address: 0000000000000000 TEID: 0000000000000803
to
Failing address: 0000000000000000 TEID: 0000000000000803 ESOP-2 FSI
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The comments in do_protection() give the impression that a TEID, where bit
61 is zero, indicates a low address protection exception. This is not
necessarily true, and it depends on the type of Suppression-on-Protection
facility of the machine (see Princples of Operation) what this means.
Rework the comments and the die() message to reflect this. This may also
help to avoid confusion.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
flush_tlb() exists for historic reasons and was never used. Remove it.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Thomas Richter says:
====================
The PAI PMUs pai_crypto and pai_ext both operate on memory
mapped counters supported by z16 and follow on machines.
These memory mapped counters have a lot in common, like:
- validation, installing and removing events
- starting and stopping events
- retrieving counter values
- collecting sample data.
However both PMU drivers have slightly different parameters,
for example:
- different mapped memory size
- different number of supported counters
- different counter numbers and names
- different bits in the CR0 register
- different anchor address in lowcore
Due to these different parameters, two independent
PMUs have been developed. However both PMU drivers
have very much in common and most of the PMU call back
functions look very similar and are sometimes identical.
This patch set combines both independent PMU device drivers
perf_pai_crypto.c and per_pai_ext.c into one device driver.
The new device driver operations on a table which contains
the different parameters and uses common functions for
event operations.
Result is one PAI PMU driver which supports both PMUs.
It is also extendable to support new PAI PMUs.
====================
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Rename perf_pai_crypto.c to perf_pai.c. The new perf_pai.c
contains both PAI device drivers:
- pai_crypto for PAI crypto counter set
- pai_ext for PAI NNPA counter set
The rename reflects this common driver supporting both PMUs.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Combine PAI cryptography and PAI extension (NNPA) PMUs in one driver.
Remove file perf_pai_ext.c and registration of PMU "pai_ext"
from perf_pai_crypto.c.
Includes:
- Shared alloc/free and sched_task handling
- NNPA events with exclude_kernel enforced, exclude_user rejected
- Setup CR0 bits for both PMUs
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Introduce PAI crypto specific event delete function to handle
additional actions to be done at event removal.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Prepare the common PAI PMU driver to handle multiple PMUs.
Convert pai_root into an array indexed by PAI_PMU_IDX(event)
so that per-CPU state becomes per-PMU. Adjust all call sites
accordingly. Rename KMSG_COMPONENT and the s390dbf buffer from
"pai_crypto" to "pai" for consistent naming.
No functional change intended beyond log identifiers.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Rename paicrypt_copy() to pai_copy() to indicate its common usage.
No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Add a common usable function pai_stop() for the event on a CPU.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Add a common usable function pai_stop() for the event on a CPU.
Call this common pai_stop() from paicrypt_del().
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Add a common usable function pai_add() for the event on a CPU.
Call this common pai_add() from paicrypt_add().
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Add a common usable function pai_start() to the event on a CPU.
The function expects a PAI PMU specific read function as second
parameter to read out the start value for an event.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Add a common usable function pai_read() to read counter values.
The function expects a PAI PMU specific read function as second
parameter.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Unify naming and logic for PAI PMU drivers to support both PMUs
pai_crypto and pai_ext.
Rename paicrypt_push_sample() to pai_push_sample() to reflect
its common usage. Add detailed comments about invocation context
and scheduler callbacks. Use struct pai_pmu to determine area_size
instead of PAGE_SIZE for counter backup.
Remove obsolete variable paicrypt_cnt.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Rename paicrypt_have_samples() to pai_have_samples() to reflect
its common usage. No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Rename paicrypt_getctr() to pai_getctr() to reflect is common
purpose. pai_getctr() now uses pai_pmu table to extract PAI PMU
characteristics such as kernel_offset inside the counter area page.
Also rename paicrypt_have_sample() to pai_have_sample().
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Rename paicrypt_getdata() to pai_getdata(). Use the PAI PMU
characteristics in the pai_pmu table to determine the number
of counters to be extracted.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Rename functions
- paicrypt_free() -> pai_free()
- paicrypt_destroy_event() -> pai_destroy_event()
- paicrypt_destroy_event_cpu() -> pai_destroy_event_cpu()
to reflect their future common usage.
No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Rework PAI crypto event initialization. Add a common
function for event initialization. It uses the PAI characteristics
stored in the pai_pmu table instead of hardcoded values.
Enlarge pai_event_valid() to check all event validation aspects.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Create and add a PMU characteristics table to store the parameters
of the PAI crypto PMU. This table contains PMU details such as
- number of available counters
- name of these counters to export to /sysfs
- Size of the memory mapped counter area
- base number of first counter
- etc
Also define a PMU specific initialization function to be called when
a PAI PMU feature is supported. At device driver initialization
test these features and if available use instruction qpaci to
retrieve the number of available counters. Also export these counter
names to /sysfs and register this PMU.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Rename functions paicrypt_root_alloc() and paicrypt_root_free()
to pai_root_alloc() and pai_root_free().
No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Rename structure paicrypt_root to pai_root.
No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Rename structure paicrypt_map to pai_map.
No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Rename structure paicrypt_mapptr to pai_mapptr.
No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Rename member page in struct paicrypt_map to area. This rename
creates consistent naming for both PMU drivers paicrypto and PMU
paiext. No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The global variable cfm_dbg points to the s390dbf debug buffer.
Rename it to paidbg to better reflect its purpose.
No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
When the global kernel command line parameter
memory_hotplug.memmap_on_memory is set to false, per-memory-block
memmap_on_memory setting can still be set to true. However, when
configuring memory block, add_memory_resource() would configure it
without memmap_on_memory.
i.e.
Even if the MHP_MEMMAP_ON_MEMORY flag is set,
mhp_supports_memmap_on_memory() returns false unless the kernel command
line parameter "memory_hotplug.memmap_on_memory" is enabled. When both
the flag and the cmdline parameter are set, the memory block can be
configured with or without memmap_on_memory support.
To ensure consistent behavior, permit configuring per-memory-block
memmap_on_memory only when the memory_hotplug.memmap_on_memory kernel
command line parameter is enabled.
This is similar to commit 73954d379e ("dax: add a sysfs knob to
control memmap_on_memory behavior")
Fixes: ff18dcb19a ("s390/sclp: Add support for dynamic (de)configuration of memory")
Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Higher steal time thresholds favor low utilization scenarios, which is not
the common case for s390. Set steal time threshold to a lower value to
prioritize vertical high and medium CPUs sooner and allow high utilization
scenarios to benefit from it.
Suggested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Mete Durlu <meted@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
pcpu_delegate() never returns to its caller. If the target CPU is the
current CPU, it calls __pcpu_delegate(), whose delegate function is not
supposed to return. In any case, even if __pcpu_delegate() unexpectedly
returns, pcpu_delegate() sends SIGP_STOP to the current CPU and waits
in an infinite loop. Annotate pcpu_delegate() with the __noreturn
attribute to improve compiler optimizations.
Also annotate smp_call_ipl_cpu() accordingly since it always calls
pcpu_delegate().
[hca: Merge two patches from Thorsten Blum]
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
s390_handle_damage() ends by calling the non-returning function
disabled_wait() and therefore also never returns. Annotate it with the
__noreturn compiler attribute to improve compiler optimizations.
Remove the unreachable infinite while loop.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Heiko Carstens says:
====================
Add the Dat-Enhancement facility 1 to the list of facilities which are
required to start the kernel. The facility provides the CSPG and IDTE
instructions. In particular the CSPG instruction can be used to replace a
valid page table entry with a different page table entry, which also
differs in the page frame real address.
Without the CSPG instruction it is possible to use the CSP instruction to
change valid page table entries, however it only allows to change the lower
or higher 32 bits of such entries, which means it cannot be used to change
the page frame real address of valid page table entries.
Given that there is code around (e.g. HugeTLB vmemmap optimization) which
requires to change valid page table entries of the kernel mapping, without
the detour over an invalid page table entry, make the CSPG instruction
unconditionally available.
The Dat-Enhancement facility 1 is available since z990, which is older than
the currently supported minimum architecture (z10). Therefore adding this
the architecture level set shouldn't cause any problems.
====================
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The CSPG instruction is part of the Dat-Enhancement facility 1, which
is always available. Given that it can be used everywhere where also
the CSP instruction can be used, replace CSP with CSPG everywhere.
This allows to remove the csp() inline assembly. Also remove the
unused gmap_pmdp_csp() function.
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Remove cpu_has_idte(). The IDTE instruction is part of the
Dat-Enhancement facility 1, which is always available.
Therefore remove the helper and now superfluous code.
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Add the Dat-Enhancement facility 1 to the list of facilities which are
required to start the kernel. The facility provides the CSPG and IDTE
instructions. In particular the CSPG instruction can be used to replace a
valid page table entry with a different page table entry, which also
differs in the page frame real address.
Without the CSPG instruction it is possible to use the CSP instruction to
change valid page table entries, however it only allows to change the lower
or higher 32 bits of such entries, which means it cannot be used to change
the page frame real address of valid page table entries.
Given that there is code around (e.g. HugeTLB vmemmap optimization) which
requires to change valid page table entries of the kernel mapping, without
the detour over an invalid page table entry, make the CSPG instruction
unconditionally available.
The Dat-Enhancement facility 1 is available since z990, which is older than
the currently supported minimum architecture (z10). Therefore adding this
to the architecture level set shouldn't cause any problems.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
