Add a firmware feature flag, FW_FEATURE_PLPKS, to indicate availability of
Platform KeyStore related hcalls.
Check this flag in plpks_is_available() and pseries_plpks_init() before
trying to make an hcall.
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230224041012.772648-1-ajd@linux.ibm.com
Reducing the time taken by dscr_sysfs_test.c allows restoring the
default timeout, which was removed in
commit 850507f30c ("selftests/powerpc: Turn off timeout setting for
benchmarks, dscr, signal, tm") because that test took too long.
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230406043320.125138-8-bgray@linux.ibm.com
This test case is extremely slow, taking around a minute compared to
most of the other DSCR tests taking a second at most. Perf shows most
time is spent by the kernel switching to each CPU it reads in
/sys/devices/system/cpu. This switching is an unavoidable consequnce
of reading all the .../cpuN/dscr values.
Remove the outer iteration loop from this test case, reducing the reads
from 1600 to 16. This still updates the DSCR 16 times and verifies on
every CPU each time, so I do not expect the lower coverage to be
meaningful. The speedup is significant: back down to ~1 second like the
other tests.
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230406043320.125138-7-bgray@linux.ibm.com
The tests currently have a single writer thread updating the system
DSCR with a 1/1000 chance looped only 100 times. So only around one in
10 runs actually do anything.
* Add multiple threads to the dscr_explicit_random_test case.
* Use a barrier to make all the threads start work as simultaneously as
possible.
* Use a rwlock and make all threads have a reasonable chance to write to
the DSCR on each iteration.
PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP is used to prevent
writers from starving while all the other threads keep reading.
Logging the reads/writes shows a decent mix across the whole test.
* Allow all threads a chance to write.
* Make the chance of writing more likely.
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230406043320.125138-6-bgray@linux.ibm.com
Add new cases to the relevant tests that use explicitly synchronized
threads to test the behaviour across context switches with less
randomness. By locking the participants to the same CPU we guarantee a
context switch occurs each time they make progress, which is a likely
failure point if the kernel is not tracking the thread local DSCR
correctly.
The random case is left in to keep exercising potential edge cases.
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230406043320.125138-5-bgray@linux.ibm.com
All current users of bind_to_cpu() don't care _which_ CPU they get, just
that they are bound to a single free one. So alter the interface to
1. Accept a BIND_CPU_ANY value that tells it to automatically
pick a CPU
2. Return the picked CPU
And convert all these users to bind_to_cpu(BIND_CPU_ANY).
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230406043320.125138-4-bgray@linux.ibm.com
This function will be useful in the DSCR test patches later in this
series, so promote it to be shared by all powerpc selftests.
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230406043320.125138-3-bgray@linux.ibm.com
Correct a couple of typos while working on other improvements to the
DSCR tests.
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230406043320.125138-2-bgray@linux.ibm.com
There are two copies of these defines. Keep the older ones as they have
associated bit definitions.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230405045316.95003-1-joel@jms.id.au
Build modules using PCREL addressing when CONFIG_PPC_KERNEL_PCREL=y.
- The module loader must handle several new relocation types:
* R_PPC64_REL24_NOTOC is a function call handled like R_PPC_REL24, but
does not restore r2 upon return. The external function call stub is
changed to use pcrel addressing to load the function pointer rather
than based on the module TOC.
* R_PPC64_GOT_PCREL34 is a reference to external data. A GOT table
must be built by hand, because the linker adds this during the final
link (which is not done for kernel modules). The GOT table is built
similarly to the way the external function call stub table is. This
section is called .mygot because .got has a special meaning for the
linker and can become upset.
* R_PPC64_PCREL34 is used for local data addressing, but there is a
special case where the percpu section is moved at load-time to the
percpu area which is out of range of this relocation. This requires
the PCREL34 relocations are converted to use GOT_PCREL34 addressing.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Some coding style & formatting fixups]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408021752.862660-7-npiggin@gmail.com
PC-Relative or PCREL addressing is an extension to the ELF ABI which
uses Power ISA v3.1 PC-relative instructions to calculate addresses,
rather than the traditional TOC scheme.
Add an option to build vmlinux using pcrel addressing. Modules continue
to use TOC addressing.
- TOC address helpers and r2 are poisoned with -1 when running vmlinux.
r2 could be used for something useful once things are ironed out.
- Assembly must call C functions with @notoc annotation, or the linker
complains aobut a missing nop after the call. This is done with the
CFUNC macro introduced earlier.
- Boot: with the exception of prom_init, the execution branches to the
kernel virtual address early in boot, before any addresses are
generated, which ensures 34-bit pcrel addressing does not miss the
high PAGE_OFFSET bits. TOC relative addressing has a similar
requirement. prom_init does not go to the virtual address and its
addresses should not carry over to the post-prom kernel.
- Ftrace trampolines are converted from TOC addressing to pcrel
addressing, including module ftrace trampolines that currently use the
kernel TOC to find ftrace target functions.
- BPF function prologue and function calling generation are converted
from TOC to pcrel.
- copypage_64.S has an interesting problem, prefixed instructions have
alignment restrictions so the linker can add padding, which makes the
assembler treat the difference between two local labels as
non-constant even if alignment is arranged so padding is not required.
This may need toolchain help to solve nicely, for now move the prefix
instruction out of the alternate patch section to work around it.
This reduces kernel text size by about 6%.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408021752.862660-6-npiggin@gmail.com
This macro is to be used in assembly where C functions are called.
pcrel addressing mode requires branches to functions with a
localentry value of 1 to have either a trailing nop or @notoc.
This macro permits the latter without changing callers.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Add dummy definitions to fix selftests build]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408021752.862660-5-npiggin@gmail.com
Add an option to build kernel and module with prefixed instructions if
the CPU and toolchain support it.
This is not related to kernel support for userspace execution of
prefixed instructions.
Building with prefixed instructions breaks some extended inline asm
memory addressing, for example it will provide immediates that exceed
the range of simple load/store displacement. Whether this is a
toolchain or a kernel asm problem remains to be seen. For now, these
are replaced with simpler and less efficient direct register addressing
when compiling with prefixed.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408021752.862660-4-npiggin@gmail.com
This mostly consolidates the Book3E and Book3S behaviour in boot WRT
executing from the physical or virtual address.
Book3E sets up kernel virtual linear map in start_initialization_book3e
and runs from the virtual linear alias after that. This change makes
Book3S begin to execute from the virtual alias at the same point. Book3S
can not use its MMU for that at this point, but when the MMU is disabled,
the virtual linear address correctly aliases to physical memory because
the top bits of the address are ignored with MMU disabled.
Secondaries execute from the virtual address similarly early.
This reduces the differences between subarchs, but the main motivation
was to enable the PC-relative addressing ABI for Book3S, where pointer
calculations must execute from the virtual address or the top bits of
the pointer will be lost. This is similar to the requirement the TOC
relative addressing already has that the TOC pointer use its virtual
address.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408021752.862660-3-npiggin@gmail.com
A later change moves the non-prom case to run at the virtual address
earlier, which calls for virtual TOC and kernel base. Split these two
calculations for prom and non-prom to make that change simpler.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Retain relative_toc call for start_initialization_book3e]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408021752.862660-2-npiggin@gmail.com
"fsl,P2020RDB-PC" compatible string was present in Turris 1.x DTS file just
because Linux kernel required it for proper detection of P2020 processor
during boot.
This was quite a hack as CZ.NIC Turris 1.x is not compatible with
Freescale P2020-RDB-PC board.
Now when kernel has generic unified support for boards with P2020
processors, there is no need to have this "hack" in turris1x.dts file.
So remove incorrect "fsl,P2020RDB-PC" compatible string from turris1x.dts.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408140122.25293-14-pali@kernel.org
Generic unified P2020 machine description which supports all P2020-based
boards is now in separate file p2020.c. So create a separate config option
CONFIG_PPC_P2020 for it.
Previously machine descriptions for P2020 boards were enabled by
CONFIG_MPC85xx_DS or CONFIG_MPC85xx_RDB option. So set CONFIG_PPC_P2020 to
be enabled by default when one of those option is enabled.
This allows to compile support for P2020 boards without need to have
enabled support for older mpc85xx boards. And to compile kernel for old
mpc85xx boards without having enabled support for new P2020 boards.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408140122.25293-13-pali@kernel.org
Combine machine descriptions and code of all P2020 boards into just one
generic unified P2020 machine description. This allows kernel to boot on
any P2020-based board with P2020 DTS file without need to patch kernel and
define a new machine description in 85xx powerpc platform directory.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408140122.25293-12-pali@kernel.org
Make just one .setup_arch and one .init_IRQ callback implementation for all
P2020 board code. This deduplicate repeated and same code.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408140122.25293-11-pali@kernel.org
In order to share mpc85xx i8259 code between DS and P2020.
Prefix i8259 debug and error messages by i8259 word.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Fix some coding style warnings in the moved code]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408140122.25293-10-pali@kernel.org
This moves P2020 RDB machine descriptions into new p2020.c source file.
This is preparation for code de-duplication and providing one unified
machine description for all P2020 boards.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408140122.25293-9-pali@kernel.org
This moves P2020 DS machine descriptions into new p2020.c source file.
This is preparation for code de-duplication and providing one unified
machine description for all P2020 boards.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408140122.25293-8-pali@kernel.org
mpc85xx_qe_par_io_init() is a stub when CONFIG_QUICC_ENGINE is not set.
CONFIG_UCC_GETH and CONFIG_SERIAL_QE depend on CONFIG_QUICC_ENGINE.
Remove #ifdef CONFIG_QUICC_ENGINE
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408140122.25293-7-pali@kernel.org
All necessary items are declared all the time, no need to use
a #ifdef CONFIG_PPC_I8259.
Refactor CONFIG_PPC_I8259 actions into a dedicated init function.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408140122.25293-6-pali@kernel.org
Use pr_debug() instead of printk(KERN_DEBUG
Use pr_err() instead of printk(KERN_ERR
Use pr_info() instead of printk(KERN_INFO or printk("
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408140122.25293-5-pali@kernel.org
No need to BUG() in case mpic_alloc() fails. Use WARN_ON().
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408140122.25293-4-pali@kernel.org
Reduce number of lines in the call to mpic_alloc().
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408140122.25293-3-pali@kernel.org
DBG() macro is defined at three places while used only
one time at one place.
Replace its only use by a pr_debug() and remove the macro.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408140122.25293-2-pali@kernel.org
Function uli_exclude_device() is not used outside of the fsl_uli1575.c
source file anymore. So mark it as static and remove public prototype.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230409000812.18904-9-pali@kernel.org
After calling fsl_pci_assign_primary(), it is possible to use uli_init() to
conditionally initialize ppc_md.pci_exclude_device callback based on the
uli1575 detection.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230409000812.18904-8-pali@kernel.org
ULI1575 PCIe south bridge exists only on some Freescale boards. Allow to
disable CONFIG_FSL_ULI1575 symbol when it is not explicitly selected and
only implied. This is achieved by marking symbol as visible by providing
short description. Also adds dependency for this symbol to prevent enabling
it on platforms on which driver does not compile.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230409000812.18904-7-pali@kernel.org
Boards provided by CONFIG_MPC85xx_RDB option do not initialize
fsl_uli1575.c driver. So remove explicit select dependency on it.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230409000812.18904-6-pali@kernel.org
Move uli_init() function into existing driver fsl_uli1575.c file in order
to share its code between more platforms and board files.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230409000812.18904-5-pali@kernel.org
Function uli_exclude_device() is called only from mpc86xx_exclude_device()
and mpc85xx_exclude_device() functions. Both those functions are same, so
merge its logic directly into the uli_exclude_device() function.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230409000812.18904-4-pali@kernel.org
Function mpc85xx_exclude_device() is installed and used only when
pci_with_uli is fsl_pci_primary. So replace check for pci_with_uli by
fsl_pci_primary in mpc85xx_exclude_device() and move pci_with_uli variable
declaration into function mpc85xx_ds_uli_init() where it is used.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230409000812.18904-3-pali@kernel.org
Use a single line for uli_exclude_device().
Add uli_exclude_device() prototype in ppc-pci.h and guard it.
Remove that prototype from mpc85xx_ds.c and mpc86xx_hpcn.c files.
Make uli_pirq_to_irq[] static as it is used only in that file.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230409000812.18904-2-pali@kernel.org
-mcpu=power10 will generate prefixed and pcrel code by default, which
we do not support. The general kernel disables these with cflags, but
those were missed for the boot wrapper.
Fixes: 4b2a9315f2 ("powerpc/64s: POWER10 CPU Kconfig build option")
Cc: stable@vger.kernel.org # v6.1+
Reported-by: Danny Tsen <dtsen@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230407040909.230998-1-npiggin@gmail.com
Use the preferred form of branch-and-link for finding the current
address so objtool doesn't think it is an unannotated intra-function
call.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230407040924.231023-1-npiggin@gmail.com
When building with W=1 after commit 80b6093b55 ("kbuild: add -Wundef
to KBUILD_CPPFLAGS for W=1 builds"), the following warning occurs.
In file included from arch/powerpc/kvm/bookehv_interrupts.S:26:
arch/powerpc/kvm/../kernel/head_booke.h:20:6: warning: "THREAD_SHIFT" is not defined, evaluates to 0 [-Wundef]
20 | #if (THREAD_SHIFT < 15)
| ^~~~~~~~~~~~
THREAD_SHIFT is defined in thread_info.h but it is not directly included
in head_booke.h, so it is possible for THREAD_SHIFT to be undefined. Add
the include to ensure that THREAD_SHIFT is always defined.
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/202304050954.yskLdczH-lkp@intel.com/
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230406-wundef-thread_shift_booke-v1-1-8deffa4d84f9@kernel.org
syscalls do not set the PPR field in their interrupt frame and
return from syscall always sets the default PPR for userspace,
so setting the value in the ret_from_fork frame is not necessary
and mildly inconsistent. Remove it.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230325122904.2375060-9-npiggin@gmail.com
In the kernel user thread path, don't set _TIF_RESTOREALL because
the thread is required to call kernel_execve() before it returns,
which will set _TIF_RESTOREALL if necessary via start_thread().
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230325122904.2375060-8-npiggin@gmail.com
Kernel created user threads start similarly to kernel threads in that
they call a kernel function after first returning from _switch, so
they share ret_from_kernel_thread for this. Kernel threads never return
from that function though, whereas user threads often do (although some
don't, e.g., IO threads).
Split these startup functions in two, and catch kernel threads that
improperly return from their function. This is intended to make the
complicated code a little bit easier to understand.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230325122904.2375060-7-npiggin@gmail.com
When copy_thread is given a kernel function to run in arg->fn, this
does not necessarily mean it is a kernel thread. User threads can be
created this way (e.g., kernel_init, see also x86's copy_thread()).
These threads run a kernel function which may call kernel_execve()
and return, which returns like a userspace exec(2) syscall.
Kernel threads are to be differentiated with PF_KTHREAD, will always
have arg->fn set, and should never return from that function, instead
calling kthread_exit() to exit.
Create separate paths for the kthread and user kernel thread creation
logic. The kthread path will never exit and does not require a user
interrupt frame, so it gets a minimal stack frame.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230325122904.2375060-6-npiggin@gmail.com
If the system call return path always restores NVGPRs then there is no
need for ret_from_fork to do it. The HANDLER_RESTORE_NVGPRS does the
right thing for this.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230325122904.2375060-5-npiggin@gmail.com
The kernel thread path in copy_thread creates a user interrupt frame on
stack and stores the function and arg parameters there, and
ret_from_kernel_thread loads them. This is a slightly confusing way to
overload that frame. Non-volatile registers are loaded from the switch
frame, so the parameters can be stored there. The user interrupt frame
is now only used by user threads when they return to user.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230325122904.2375060-4-npiggin@gmail.com
The ret_from_fork code for 64e and 32-bit set r3 for
syscall_exit_prepare the same way that 64s does, so there should
be no need to special-case them in copy_thread.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230325122904.2375060-3-npiggin@gmail.com
The pkey registers (AMR, IAMR) do not get loaded from the switch frame
so it is pointless to save anything there. Remove the dead code.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230325122904.2375060-2-npiggin@gmail.com
The amdgpu driver builds some of its code with hard-float enabled,
whereas the rest of the kernel is built with soft-float.
When building with 64-bit long double, if soft-float and hard-float
objects are linked together, the build fails due to incompatible ABI
tags.
In the past there have been build errors in the amdgpu driver caused by
this, some of those were due to bad intermingling of soft & hard-float
code, but those issues have now all been fixed since commit 58ddbecb14
("drm/amd/display: move remaining FPU code to dml folder").
However it's still possible for soft & hard-float objects to end up
linked together, if the amdgpu driver is built-in to the kernel along
with the test_emulate_step.c code, which uses soft-float. That happens
in an allyesconfig build.
Currently those build errors are avoided because the amdgpu driver is
gated on 128-bit long double being enabled. But that's not a detail the
amdgpu driver should need to be aware of, and if another driver starts
using hard-float the same problem would occur.
All versions of the 64-bit ABI specify that long-double is 128-bits.
However some compilers, notably the kernel.org ones, are built to use
64-bit long double by default.
Apart from this issue of soft vs hard-float, the kernel doesn't care
what size long double is. In particular the kernel using 128-bit long
double doesn't impact userspace's ability to use 64-bit long double, as
musl does.
So always build the 64-bit kernel with 128-bit long double. That should
avoid any build errors due to the incompatible ABI tags. Excluding the
code that uses soft/hard-float, the vmlinux is identical with/without
the flag.
It does mean any code which is incorrectly intermingling soft &
hard-float code will build without error, so those bugs will need to be
caught by testing rather than at build time.
For more background see:
- commit d11219ad53 ("amdgpu: disable powerpc support for the newer display engine")
- commit c653c59178 ("drm/amdgpu: Re-enable DCN for 64-bit powerpc")
- https://lore.kernel.org/r/dab9cbd8-2626-4b99-8098-31fe76397d2d@app.fastmail.com
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Link: https://msgid.link/20230404102847.3303623-1-mpe@ellerman.id.au
Remove arch_atomic_try_cmpxchg_lock function as it is no longer used
since commit 9f61521c7a ("powerpc/qspinlock: powerpc qspinlock
implementation")
Signed-off-by: Nysal Jan K.A <nysal@linux.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230224103940.1328725-1-nysal@linux.ibm.com
Walks the stack when copy_{to,from}_user address is in the stack to
ensure that the object being copied is entirely a single stack frame and
does not contain stack metadata.
Substantially similar to the x86 implementation. The back chain is used
to traverse the stack and identify stack frame boundaries.
Signed-off-by: Nicholas Miehlbradt <nicholas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230228054355.300628-1-nicholas@linux.ibm.com
Andrew Donnellan
Benjamin Gray
Joel Stanley
Nicholas Piggin
Pali Rohár
Christophe Leroy
Nathan Chancellor
Michael Ellerman
Nysal Jan K.A
Nicholas Miehlbradt