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Rohan McLure
016ff72bd2 powerpc: Fix fallocate and fadvise64_64 compat parameter combination
As reported[1] by Arnd, the arch-specific fadvise64_64 and fallocate
compatibility handlers assume parameters are passed with 32-bit
big-endian ABI. This affects the assignment of odd-even parameter pairs
to the high or low words of a 64-bit syscall parameter.

Fix fadvise64_64 fallocate compat handlers to correctly swap upper/lower
32 bits conditioned on endianness.

A future patch will replace the arch-specific compat fallocate with an
asm-generic implementation. This patch is intended for ease of
back-port.

[1]: https://lore.kernel.org/all/be29926f-226e-48dc-871a-e29a54e80583@www.fastmail.com/

Fixes: 57f48b4b74 ("powerpc/compat_sys: swap hi/lo parts of 64-bit syscall args in LE mode")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220921065605.1051927-9-rmclure@linux.ibm.com
2022-09-26 23:00:15 +10:00
Rohan McLure
620f5c59c8 powerpc/64s: Fix comment on interrupt handler prologue
Interrupt handlers on 64s systems will often need to save register state
from the interrupted process to make space for loading special purpose
registers or for internal state.

Fix a comment documenting a common code path macro in the beginning of
interrupt handlers where r10 is saved to the PACA to afford space for
the value of the CFAR. Comment is currently written as if r10-r12 are
saved to PACA, but in fact only r10 is saved, with r11-r12 saved much
later. The distance in code between these saves has grown over the many
revisions of this macro. Fix this by signalling with a comment where
r11-r12 are saved to the PACA.

Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reported-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220921065605.1051927-8-rmclure@linux.ibm.com
2022-09-26 23:00:15 +10:00
Rohan McLure
53ecaa6778 powerpc/64e: Clarify register saves and clears with {SAVE,ZEROIZE}_GPRS
The common interrupt handler prologue macro and the bad_stack
trampolines include consecutive sequences of register saves, and some
register clears. Neaten such instances by expanding use of the SAVE_GPRS
macro and employing the ZEROIZE_GPR macro when appropriate.

Also simplify an invocation of SAVE_GPRS targetting all non-volatile
registers to SAVE_NVGPRS.

Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reported-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220921065605.1051927-7-rmclure@linux.ibm.com
2022-09-26 23:00:15 +10:00
Rohan McLure
15ba74502c powerpc/32: Clarify interrupt restores with REST_GPR macro in entry_32.S
Restoring the register state of the interrupted thread involves issuing
a large number of predictable loads to the kernel stack frame. Issue the
REST_GPR{,S} macros to clearly signal when this is happening, and bunch
together restores at the end of the interrupt handler where the saved
value is not consumed earlier in the handler code.

Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220921065605.1051927-6-rmclure@linux.ibm.com
2022-09-26 23:00:15 +10:00
Rohan McLure
2b1dac4b5f powerpc/64s: Use {ZEROIZE,SAVE,REST}_GPRS macros in sc, scv 0 handlers
Use the convenience macros for saving/clearing/restoring gprs in keeping
with syscall calling conventions. The plural variants of these macros
can store a range of registers for concision.

This works well when the user gpr value we are hoping to save is still
live. In the syscall interrupt handlers, user register state is
sometimes juggled between registers. Hold-off from issuing the SAVE_GPR
macro for applicable neighbouring lines to highlight the delicate
register save logic.

Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220921065605.1051927-5-rmclure@linux.ibm.com
2022-09-26 23:00:15 +10:00
Rohan McLure
2c27d4a419 powerpc: Save caller r3 prior to system_call_exception
This reverts commit 8875f47b76 ("powerpc/syscall: Save r3 in regs->orig_r3
").

Save caller's original r3 state to the kernel stackframe before entering
system_call_exception. This allows for user registers to be cleared by
the time system_call_exception is entered, reducing the influence of
user registers on speculation within the kernel.

Prior to this commit, orig_r3 was saved at the beginning of
system_call_exception. Instead, save orig_r3 while the user value is
still live in r3.

Also replicate this early save in 32-bit. A similar save was removed in
commit 6f76a01173 ("powerpc/syscall: implement system call entry/exit
logic in C for PPC32") when 32-bit adopted system_call_exception. Revert
its removal of orig_r3 saves.

Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220921065605.1051927-3-rmclure@linux.ibm.com
2022-09-26 23:00:14 +10:00
Rohan McLure
5ba6c9a912 powerpc: Remove asmlinkage from syscall handler definitions
The asmlinkage macro has no special meaning in powerpc, and prior to
this patch is used sporadically on some syscall handler definitions. On
architectures that do not define asmlinkage, it resolves to extern "C"
for C++ compilers and a nop otherwise. The current invocations of
asmlinkage provide far from complete support for C++ toolchains, and so
the macro serves no purpose in powerpc.

Remove all invocations of asmlinkage in arch/powerpc. These incidentally
only occur in syscall definitions and prototypes.

Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220921065605.1051927-2-rmclure@linux.ibm.com
2022-09-26 23:00:14 +10:00
Christophe Leroy
6556fd1a1e powerpc: Cleanup idle for e500
e500 idle setup is a bit messy.

e500_idle() is used for PPC32 while book3e_idle() is used for PPC64.
As they are mutually exclusive, call them all e500_idle().

Use CONFIG_MPC_85xx instead of PPC32 + E500 in Makefile and rename
idle_e500.c to idle_85xx.c .

Rename idle_book3e.c to idle_64e.c and remove #ifdef PPC64 in
as it's only built on PPC64.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/8039301334e948974c85ec5ef2db37751075185b.1663606876.git.christophe.leroy@csgroup.eu
2022-09-26 23:00:14 +10:00
Christophe Leroy
aa5f59df20 powerpc: Remove CONFIG_PPC_BOOK3E_MMU
CONFIG_PPC_BOOK3E_MMU is redundant with CONFIG_PPC_E500.

Remove it.

Also rename mmu-book3e.h to mmu-e500.h

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c5549cd59a131204ff94ab909cad2e2dad4ddf2f.1663606876.git.christophe.leroy@csgroup.eu
2022-09-26 23:00:14 +10:00
Christophe Leroy
3e7318584d powerpc: Remove CONFIG_PPC_FSL_BOOK3E
CONFIG_PPC_FSL_BOOK3E is redundant with CONFIG_PPC_E500.

Remove it.

And rename five files accordingly.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Rename include guards to match new file names]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/795cb93b88c9a0279289712e674f39e3b108a1b4.1663606876.git.christophe.leroy@csgroup.eu
2022-09-26 23:00:13 +10:00
Christophe Leroy
688de017ef powerpc: Change CONFIG_E500 to CONFIG_PPC_E500
It will be used outside arch/powerpc, make it clear its a
powerpc configuration item.

And we already have CONFIG_PPC_E500MC, so that will make
it more consistent.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e63b22083c11c4300f4a82d3123a46e5fdd54fa6.1663606876.git.christophe.leroy@csgroup.eu
2022-09-26 23:00:13 +10:00
Christophe Leroy
e0d68273d7 powerpc: Remove CONFIG_PPC_BOOK3E
CONFIG_PPC_BOOK3E is redundant with CONFIG_PPC_BOOK3E_64.

The later is more explicit about the fact that it's a 64 bits target.

Remove CONFIG_PPC_BOOK3E.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5d0891490813c19cdcfc04678f512ea68cba3e64.1663606876.git.christophe.leroy@csgroup.eu
2022-09-26 23:00:13 +10:00
Christophe Leroy
d7216567c6 powerpc/cputable: Split cpu_specs[] for mpc85xx and e500mc
e500v1/v2 and e500mc are said to be mutually exclusive in Kconfig.

Split e500 cpu_specs[] and then restrict the non e500mc to PPC32
which is then 85xx.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Tweak formatting]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/553b901ea91e393df231103da4b018e9b251b0e9.1663606876.git.christophe.leroy@csgroup.eu
2022-09-26 23:00:05 +10:00
Christophe Leroy
dfc3095cec powerpc: Remove CONFIG_FSL_BOOKE
PPC_85xx is PPC32 only.
PPC_85xx always selects E500 and is the only PPC32 that
selects E500.
FSL_BOOKE is selected when E500 and PPC32 are selected.

So FSL_BOOKE is redundant with PPC_85xx.

Remove FSL_BOOKE.

And rename four files accordingly.

cpu_setup_fsl_booke.S is not renamed because it is linked to
PPC_FSL_BOOK3E and not to FSL_BOOKE as suggested by its name.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/08e3e15594e66d63b9e89c5b4f9c35153913c28f.1663606875.git.christophe.leroy@csgroup.eu
2022-09-26 22:47:37 +10:00
Christophe Leroy
e320a76db4 powerpc/cputable: Split cpu_specs[] out of cputable.h
cpu_specs[] is full of #ifdefs depending on the different
types of CPU.

CPUs are mutually exclusive, it is therefore possible to split
cpu_specs[] into smaller more readable pieces.

Create cpu_specs_XXX.h that will each be dedicated on one
of the following mutually exclusive families:
- 40x
- 44x
- 47x
- 8xx
- e500
- book3s/32
- book3s/64

In book3s/32, the block for 603 has been moved in front in order
to not have two 604 blocks.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Fix CONFIG_47x to be CONFIG_PPC_47x, tweak some formatting]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a44b865e0318286155273b10cdf524ab697928c1.1663606875.git.christophe.leroy@csgroup.eu
2022-09-26 22:47:13 +10:00
Christophe Leroy
76b719881a powerpc/cputable: Move __cpu_setup() prototypes out of cputable.h
Move all prototypes out of cputable.h

For that rename cpu_setup_power.h to cpu_setup.h and move all
prototypes in it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Standardise cpu_spec *spec formatting]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f45118489ee450db654db8bbcdfd8f5907337c22.1663606875.git.christophe.leroy@csgroup.eu
2022-09-26 22:26:49 +10:00
Christophe Leroy
afd2288a4c powerpc/cputable: Remove __machine_check_early_realmode_p{7/8/9} prototypes
__machine_check_early_realmode_p{7/8/9} are already in mce.h
which is included. Remove them from cputable.c

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b77fc0f90e3a9c065324cbff549b718ccf0809f8.1663606875.git.christophe.leroy@csgroup.eu
2022-09-26 21:00:42 +10:00
Christophe Leroy
b6100bedf1 powerpc/64e: Remove unnecessary #ifdef CONFIG_PPC_FSL_BOOK3E
CONFIG_PPC_BOOK3E_64 implies CONFIG_PPC_FSL_BOOK3E so no need of
additional #ifdefs in files built exclusively for CONFIG_PPC_BOOK3E_64.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/df16255c13b63b0221c9be63b94a6864bed22c12.1663606875.git.christophe.leroy@csgroup.eu
2022-09-26 21:00:41 +10:00
Christophe Leroy
0069f3d14e powerpc/64e: Tie PPC_BOOK3E_64 to PPC_E500MC
The only 64-bit Book3E CPUs we support require the selection
of CONFIG_PPC_E500MC.

However our Kconfig allows configurating a kernel that has 64-bit
Book3E support, but without CONFIG_PPC_E500MC enabled. Such a kernel
would never boot, it doesn't know about any CPUs.

To fix this, force CONFIG_PPC_E500MC to be selected whenever we are
building a 64-bit Book3E kernel.

And add a test to detect future situations where cpu_specs is empty.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ae5d8b8b3ccc346e61d2ec729767f92766273f0b.1663606875.git.christophe.leroy@csgroup.eu
2022-09-26 21:00:41 +10:00
David Hildenbrand
c4167aec98 powerpc/prom_init: drop PROM_BUG()
Unused, let's drop it.

Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220920122302.99195-3-david@redhat.com
2022-09-26 20:58:18 +10:00
Michael Ellerman
456c300510 powerpc/microwatt: Remove unused early debug code
The original microwatt submission[1] included some early debug code for
using the Microwatt "potato" UART.

The series that was eventually merged switched to using a standard UART,
and so doesn't need any special early debug handling. But some of the
original code was merged accidentally under the non-existent
CONFIG_PPC_EARLY_DEBUG_MICROWATT.

Drop the unused code.

1: https://lore.kernel.org/linuxppc-dev/20200509050340.GD1464954@thinks.paulus.ozlabs.org/

Fixes: 48b545b801 ("powerpc/microwatt: Use standard 16550 UART for console")
Reported-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220919052755.800907-1-mpe@ellerman.id.au
2022-09-26 20:58:17 +10:00
Michael Ellerman
e74611aa91 powerpc/64: Remove unused SYS_CALL_TABLE symbol
In interrupt_64.S, formerly entry_64.S, there are two toc entries
created for sys_call_table and compat_sys_call_table.

These are no longer used, since the system call entry was converted from
asm to C, so remove them.

Fixes: 68b34588e2 ("powerpc/64/sycall: Implement syscall entry/exit logic in C")
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220913124545.2817825-1-mpe@ellerman.id.au
2022-09-26 20:58:17 +10:00
Nicholas Piggin
fdfdcfd504 powerpc/build: put sys_call_table in .data.rel.ro if RELOCATABLE
Const function pointers by convention live in .data.rel.ro if they need
to be relocated. Now that .data.rel.ro is linked into the read-only
region, put them in the right section. This doesn't make much practical
difference, but it will make the C conversion of sys_call_table a
smaller change as far as linking goes.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-8-npiggin@gmail.com
2022-09-26 20:58:17 +10:00
Nicholas Piggin
1e9eca485a powerpc/64/build: merge .got and .toc input sections
Follow the binutils ld internal linker script and merge .got and .toc
input sections in the .got output section.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-7-npiggin@gmail.com
2022-09-26 20:58:17 +10:00
Nicholas Piggin
c787fed118 powerpc/64/build: only include .opd with ELFv1
ELFv2 does not use function descriptors so .opd is not required.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-6-npiggin@gmail.com
2022-09-26 20:58:17 +10:00
Nicholas Piggin
b6adc6d6d3 powerpc/build: move .data.rel.ro, .sdata2 to read-only
.sdata2 is a readonly small data section for ppc32, and .data.rel.ro
is data that needs relocating but is read-only after that so these
can both be moved to the read only memory region.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-5-npiggin@gmail.com
2022-09-26 20:58:17 +10:00
Nicholas Piggin
f21ba4499a powerpc/build: move got, toc, plt, branch_lt sections to read-only
This moves linker-related tables from .data to read-only area.
Relocations are performed at early boot time before memory is protected,
after which there should be no modifications required.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Don't use SPECIAL as reported by lkp@intel.com]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-4-npiggin@gmail.com
2022-09-26 20:58:17 +10:00
Nicholas Piggin
1faa1235c1 powerpc/32/build: move got1/got2 sections out of text
Following the example from the binutils default linker script, move
.got1 and .got2 out of .text, to just after RO_DATA.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-3-npiggin@gmail.com
2022-09-26 20:58:17 +10:00
Nicholas Piggin
7082f8e7d2 powerpc: move __end_rodata to cover arch read-only sections
powerpc has a number of read-only sections and tables that are put after
RO_DATA(). Move the __end_rodata symbol to cover these as well.

Setting memory to read-only at boot is done using __init_begin, change
that to use __end_rodata.

This makes is_kernel_rodata() exactly cover the read-only region, as
well as other things using __end_rodata (e.g., kernel/dma/debug.c).
Boot dmesg also prints the rodata size more accurately.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-2-npiggin@gmail.com
2022-09-26 20:58:16 +10:00
Michael Ellerman
b150a4d12b powerpc/vmlinux.lds: Add an explicit symbol for the SRWX boundary
Currently __init_begin is used as the boundary for strict RWX between
executable/read-only text and data, and non-executable (after boot) code
and data.

But that's a little subtle, so add an explicit symbol to document that
the SRWX boundary lies there, and add a comment making it clear that
__init_begin must also begin there.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916131422.318752-2-mpe@ellerman.id.au
2022-09-26 20:58:16 +10:00
Michael Ellerman
331771e836 powerpc/vmlinux.lds: Ensure STRICT_ALIGN_SIZE is at least page aligned
Add a check that STRICT_ALIGN_SIZE is aligned to at least PAGE_SIZE.

That then makes the alignment to PAGE_SIZE immediately after the
alignment to STRICT_ALIGN_SIZE redundant, so remove it.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916131422.318752-1-mpe@ellerman.id.au
2022-09-26 20:58:16 +10:00
Michael Ellerman
0c32903197 powerpc/64: Remove unused prom_init_toc symbols
Commit 24d33ac5b8 ("powerpc/64s: Make prom_init require RELOCATABLE")
made prom_init depend on CONFIG_RELOCATABLE.

But it missed cleaning up a case in the linker script for RELOCATABLE=n,
and associated symbols. Remove them now.

Fixes: 24d33ac5b8 ("powerpc/64s: Make prom_init require RELOCATABLE")
Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220920131157.1032707-1-mpe@ellerman.id.au
2022-09-26 20:58:16 +10:00
Michael Ellerman
ec5c3a359c Merge branch 'fixes' into next
Merge our fixes branch to bring in a few things that new feature patches
rely on or conflict with.
2022-09-24 00:40:14 +10:00
Yury Norov
546a073d62 powerpc/64: don't refer nr_cpu_ids in asm code when it's undefined
generic_secondary_common_init() calls LOAD_REG_ADDR(r7, nr_cpu_ids)
conditionally on CONFIG_SMP. However, if 'NR_CPUS == 1', kernel doesn't
use the nr_cpu_ids, and in C code, it's just:
  #if NR_CPUS == 1
  #define nr_cpu_ids
  ...

This series makes declaration of nr_cpu_ids conditional on NR_CPUS == 1,
and that reveals the issue, because compiler can't link the
LOAD_REG_ADDR(r7, nr_cpu_ids) against nonexisting symbol.

Current code looks unsafe for those who build kernel with CONFIG_SMP=y and
NR_CPUS == 1. This is weird configuration, but not disallowed.

Fix the linker error by replacing LOAD_REG_ADDR() with LOAD_REG_IMMEDIATE()
conditionally on NR_CPUS == 1.

As the following patch adds CONFIG_FORCE_NR_CPUS option that has the
similar effect on nr_cpu_ids, make the generic_secondary_common_init()
conditional on it too.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
2022-09-20 16:11:44 -07:00
Nathan Lynch
f88aabad33 Revert "powerpc/rtas: Implement reentrant rtas call"
At the time this was submitted by Leonardo, I confirmed -- or thought
I had confirmed -- with PowerVM partition firmware development that
the following RTAS functions:

- ibm,get-xive
- ibm,int-off
- ibm,int-on
- ibm,set-xive

were safe to call on multiple CPUs simultaneously, not only with
respect to themselves as indicated by PAPR, but with arbitrary other
RTAS calls:

https://lore.kernel.org/linuxppc-dev/875zcy2v8o.fsf@linux.ibm.com/

Recent discussion with firmware development makes it clear that this
is not true, and that the code in commit b664db8e3f ("powerpc/rtas:
Implement reentrant rtas call") is unsafe, likely explaining several
strange bugs we've seen in internal testing involving DLPAR and
LPM. These scenarios use ibm,configure-connector, whose internal state
can be corrupted by the concurrent use of the "reentrant" functions,
leading to symptoms like endless busy statuses from RTAS.

Fixes: b664db8e3f ("powerpc/rtas: Implement reentrant rtas call")
Cc: stable@vger.kernel.org # v5.8+
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Laurent Dufour <laurent.dufour@fr.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220907220111.223267-1-nathanl@linux.ibm.com
2022-09-14 22:43:13 +10:00
Kefeng Wang
2be9880dc8 kernel: exit: cleanup release_thread()
Only x86 has own release_thread(), introduce a new weak release_thread()
function to clean empty definitions in other ARCHs.

Link: https://lkml.kernel.org/r/20220819014406.32266-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Guo Ren <guoren@kernel.org>				[csky]
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Brian Cain <bcain@quicinc.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>			[powerpc]
Acked-by: Stafford Horne <shorne@gmail.com>			[openrisc]
Acked-by: Catalin Marinas <catalin.marinas@arm.com>		[arm64]
Acked-by: Huacai Chen <chenhuacai@kernel.org>			[LoongArch]
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Chris Zankel <chris@zankel.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Guo Ren <guoren@kernel.org> [csky]
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Xuerui Wang <kernel@xen0n.name>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 21:55:07 -07:00
Linus Torvalds
f448dda895 asm-generic: SOFTIRQ_ON_OWN_STACK rework
Just one fixup patch, reworking the softirq_on_own_stack logic for
 preempt-rt kernels as discussed in
 https://lore.kernel.org/all/CAHk-=wgZSD3W2y6yczad2Am=EfHYyiPzTn3CfXxrriJf9i5W5w@mail.gmail.com/
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Merge tag 'asm-generic-fixes-6.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

Pull SOFTIRQ_ON_OWN_STACK rework from Arnd Bergmann:
 "Just one fixup patch, reworking the softirq_on_own_stack logic for
  preempt-rt kernels as discussed in

    https://lore.kernel.org/all/CAHk-=wgZSD3W2y6yczad2Am=EfHYyiPzTn3CfXxrriJf9i5W5w@mail.gmail.com/"

* tag 'asm-generic-fixes-6.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  asm-generic: Conditionally enable do_softirq_own_stack() via Kconfig.
2022-09-09 07:23:29 -04:00
Christophe Leroy
78c73c80fd powerpc/math-emu: Inhibit W=1 warnings
When building with W=1 you get:

	arch/powerpc/math-emu/fre.c:6:5: error: no previous prototype for 'fre' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fsqrt.c:11:1: error: no previous prototype for 'fsqrt' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fsqrts.c:12:1: error: no previous prototype for 'fsqrts' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/frsqrtes.c:6:5: error: no previous prototype for 'frsqrtes' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/mtfsf.c:10:1: error: no previous prototype for 'mtfsf' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/mtfsfi.c:10:1: error: no previous prototype for 'mtfsfi' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fabs.c:7:1: error: no previous prototype for 'fabs' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fadd.c:11:1: error: no previous prototype for 'fadd' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fadds.c:12:1: error: no previous prototype for 'fadds' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fcmpo.c:11:1: error: no previous prototype for 'fcmpo' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fcmpu.c:11:1: error: no previous prototype for 'fcmpu' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fcmpu.c:14:19: error: variable 'B_c' set but not used [-Werror=unused-but-set-variable]
	arch/powerpc/math-emu/fcmpu.c:13:19: error: variable 'A_c' set but not used [-Werror=unused-but-set-variable]
	arch/powerpc/math-emu/fctiw.c:11:1: error: no previous prototype for 'fctiw' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fctiwz.c:11:1: error: no previous prototype for 'fctiwz' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fdiv.c:11:1: error: no previous prototype for 'fdiv' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fdivs.c:12:1: error: no previous prototype for 'fdivs' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fmadd.c:11:1: error: no previous prototype for 'fmadd' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fmadds.c:12:1: error: no previous prototype for 'fmadds' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fmsub.c:11:1: error: no previous prototype for 'fmsub' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fmsubs.c:12:1: error: no previous prototype for 'fmsubs' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fmul.c:11:1: error: no previous prototype for 'fmul' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fmuls.c:12:1: error: no previous prototype for 'fmuls' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fnabs.c:7:1: error: no previous prototype for 'fnabs' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fneg.c:7:1: error: no previous prototype for 'fneg' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fnmadd.c:11:1: error: no previous prototype for 'fnmadd' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fnmadds.c:12:1: error: no previous prototype for 'fnmadds' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fnmsub.c:11:1: error: no previous prototype for 'fnmsub' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fnmsubs.c:12:1: error: no previous prototype for 'fnmsubs' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fres.c:7:1: error: no previous prototype for 'fres' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/frsp.c:12:1: error: no previous prototype for 'frsp' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fsel.c:11:1: error: no previous prototype for 'fsel' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/lfs.c:12:1: error: no previous prototype for 'lfs' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/frsqrte.c:7:1: error: no previous prototype for 'frsqrte' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fsub.c:11:1: error: no previous prototype for 'fsub' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fsubs.c:12:1: error: no previous prototype for 'fsubs' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/mcrfs.c:10:1: error: no previous prototype for 'mcrfs' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/mffs.c:10:1: error: no previous prototype for 'mffs' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/mtfsb0.c:10:1: error: no previous prototype for 'mtfsb0' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/mtfsb1.c:10:1: error: no previous prototype for 'mtfsb1' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/stfiwx.c:7:1: error: no previous prototype for 'stfiwx' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/stfs.c:12:1: error: no previous prototype for 'stfs' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/fmr.c:7:1: error: no previous prototype for 'fmr' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/lfd.c:10:1: error: no previous prototype for 'lfd' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/stfd.c:7:1: error: no previous prototype for 'stfd' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/math_efp.c:177:5: error: no previous prototype for 'do_spe_mathemu' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/math_efp.c:726:5: error: no previous prototype for 'speround_handler' [-Werror=missing-prototypes]
	arch/powerpc/math-emu/math_efp.c:893:12: error: no previous prototype for 'spe_mathemu_init' [-Werror=missing-prototypes]

Fix the warnings in math_efp.c by adding prototypes of do_spe_mathemu()
and speround_handler() to asm/processor.h and declare spe_mathemu_init()
static.

The other warnings are benign and not worth the churn of fixing them,
expecially the 'unused-but-set-variable' which would impact the core
part of 'math-emu'.

So silence them by adding -Wno-missing-prototypes -Wno-unused-but-set-variable.

But then you get:

	arch/powerpc/math-emu/fre.c:6:5: error: no previous declaration for 'fre' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fsqrt.c:11:1: error: no previous declaration for 'fsqrt' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fsqrts.c:12:1: error: no previous declaration for 'fsqrts' [-Werror=missing-declarations]
	arch/powerpc/math-emu/frsqrtes.c:6:5: error: no previous declaration for 'frsqrtes' [-Werror=missing-declarations]
	arch/powerpc/math-emu/mtfsf.c:10:1: error: no previous declaration for 'mtfsf' [-Werror=missing-declarations]
	arch/powerpc/math-emu/mtfsfi.c:10:1: error: no previous declaration for 'mtfsfi' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fabs.c:7:1: error: no previous declaration for 'fabs' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fadd.c:11:1: error: no previous declaration for 'fadd' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fadds.c:12:1: error: no previous declaration for 'fadds' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fcmpo.c:11:1: error: no previous declaration for 'fcmpo' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fcmpu.c:11:1: error: no previous declaration for 'fcmpu' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fctiw.c:11:1: error: no previous declaration for 'fctiw' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fctiwz.c:11:1: error: no previous declaration for 'fctiwz' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fdiv.c:11:1: error: no previous declaration for 'fdiv' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fdivs.c:12:1: error: no previous declaration for 'fdivs' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fmadd.c:11:1: error: no previous declaration for 'fmadd' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fmadds.c:12:1: error: no previous declaration for 'fmadds' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fmsub.c:11:1: error: no previous declaration for 'fmsub' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fmsubs.c:12:1: error: no previous declaration for 'fmsubs' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fmul.c:11:1: error: no previous declaration for 'fmul' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fmuls.c:12:1: error: no previous declaration for 'fmuls' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fnabs.c:7:1: error: no previous declaration for 'fnabs' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fneg.c:7:1: error: no previous declaration for 'fneg' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fnmadd.c:11:1: error: no previous declaration for 'fnmadd' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fnmadds.c:12:1: error: no previous declaration for 'fnmadds' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fnmsub.c:11:1: error: no previous declaration for 'fnmsub' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fnmsubs.c:12:1: error: no previous declaration for 'fnmsubs' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fres.c:7:1: error: no previous declaration for 'fres' [-Werror=missing-declarations]
	arch/powerpc/math-emu/frsp.c:12:1: error: no previous declaration for 'frsp' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fsel.c:11:1: error: no previous declaration for 'fsel' [-Werror=missing-declarations]
	arch/powerpc/math-emu/lfs.c:12:1: error: no previous declaration for 'lfs' [-Werror=missing-declarations]
	arch/powerpc/math-emu/frsqrte.c:7:1: error: no previous declaration for 'frsqrte' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fsub.c:11:1: error: no previous declaration for 'fsub' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fsubs.c:12:1: error: no previous declaration for 'fsubs' [-Werror=missing-declarations]
	arch/powerpc/math-emu/mcrfs.c:10:1: error: no previous declaration for 'mcrfs' [-Werror=missing-declarations]
	arch/powerpc/math-emu/mffs.c:10:1: error: no previous declaration for 'mffs' [-Werror=missing-declarations]
	arch/powerpc/math-emu/mtfsb0.c:10:1: error: no previous declaration for 'mtfsb0' [-Werror=missing-declarations]
	arch/powerpc/math-emu/mtfsb1.c:10:1: error: no previous declaration for 'mtfsb1' [-Werror=missing-declarations]
	arch/powerpc/math-emu/stfiwx.c:7:1: error: no previous declaration for 'stfiwx' [-Werror=missing-declarations]
	arch/powerpc/math-emu/stfs.c:12:1: error: no previous declaration for 'stfs' [-Werror=missing-declarations]
	arch/powerpc/math-emu/fmr.c:7:1: error: no previous declaration for 'fmr' [-Werror=missing-declarations]
	arch/powerpc/math-emu/lfd.c:10:1: error: no previous declaration for 'lfd' [-Werror=missing-declarations]
	arch/powerpc/math-emu/stfd.c:7:1: error: no previous declaration for 'stfd' [-Werror=missing-declarations]

So also add -Wno-missing-declarations.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/688084b40b5ac88f2905cb207d5dad947d8d34dc.1662531153.git.christophe.leroy@csgroup.eu
2022-09-08 11:11:18 +10:00
Sebastian Andrzej Siewior
8cbb2b50ee asm-generic: Conditionally enable do_softirq_own_stack() via Kconfig.
Remove the CONFIG_PREEMPT_RT symbol from the ifdef around
do_softirq_own_stack() and move it to Kconfig instead.

Enable softirq stacks based on SOFTIRQ_ON_OWN_STACK which depends on
HAVE_SOFTIRQ_ON_OWN_STACK and its default value is set to !PREEMPT_RT.
This ensures that softirq stacks are not used on PREEMPT_RT and avoids
a 'select' statement on an option which has a 'depends' statement.

Link: https://lore.kernel.org/YvN5E%2FPrHfUhggr7@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2022-09-05 17:20:55 +02:00
Liang He
ce63c44b63 powerpc/pci-common: Fix refcount bug for 'phb->dn'
In pcibios_alloc_controller(), 'phb' is allocated and escaped into
global 'hose_list'. So we should call of_node_get() when a new reference
created into 'phb->dn'. And when phb is freed, we should call
of_node_put() on it.

NOTE: This function is called in the iteration of for_each_xx in
chrp_find_bridges() and pSeries_discover_phbs(). If there is no
of_node_get(), the object may be prematurely freed.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220702022936.266146-1-windhl@126.com
2022-09-05 17:30:29 +10:00
Liang He
110a1fcb6c powerpc/pci_dn: Add missing of_node_put()
In pci_add_device_node_info(), use of_node_put() to drop the reference
to 'parent' returned by of_get_parent() to keep refcount balance.

Fixes: cca87d303c ("powerpc/pci: Refactor pci_dn")
Co-authored-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Link: https://lore.kernel.org/r/20220701131750.240170-1-windhl@126.com
2022-09-05 17:30:25 +10:00
Liang He
d1aabbbb25 powerpc/kernel: Add missing of_node_put() in legacy_serial.c
In find_legacy_serial_ports(), of_find_node_by_path() will return a node
pointer with refcount incremented. The reference should be dropped with
of_node_put() when it is not used anymore.

Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220619070811.4067215-1-windhl@126.com
2022-09-05 17:28:26 +10:00
Christophe Leroy
1d53c0192b powerpc/vdso: link with -z noexecstack
With recent binutils, the following warning appears:

  VDSO32L arch/powerpc/kernel/vdso/vdso32.so.dbg
/opt/gcc-12.2.0-nolibc/powerpc64-linux/bin/../lib/gcc/powerpc64-linux/12.2.0/../../../../powerpc64-linux/bin/ld: warning: arch/powerpc/kernel/vdso/getcpu-32.o: missing .note.GNU-stack section implies executable stack
/opt/gcc-12.2.0-nolibc/powerpc64-linux/bin/../lib/gcc/powerpc64-linux/12.2.0/../../../../powerpc64-linux/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker

To avoid that, explicitly tell the linker we don't want executable
stack.

For more explanations, see commit ffcf9c5700 ("x86: link vdso
and boot with -z noexecstack --no-warn-rwx-segments")

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b95f2e3216a574837dd61208444e9515c3423da4.1662132312.git.christophe.leroy@csgroup.eu
2022-09-05 17:28:25 +10:00
Nicholas Piggin
6ba5aa541a powerpc/pseries: Move dtl scanning and steal time accounting to pseries platform
dtl is the PAPR Dispatch Trace Log, which is entirely a pseries feature.
The pseries platform alrady has a file dealing with the dtl, so move
scanning for stolen time accounting there from kernel/time.c.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220902085316.2071519-5-npiggin@gmail.com
2022-09-05 14:14:27 +10:00
Marco Elver
f95e5a3d59 powerpc/hw_breakpoint: Avoid relying on caller synchronization
Internal data structures (cpu_bps, task_bps) of powerpc's hw_breakpoint
implementation have relied on nr_bp_mutex serializing access to them.

Before overhauling synchronization of kernel/events/hw_breakpoint.c,
introduce 2 spinlocks to synchronize cpu_bps and task_bps respectively,
thus avoiding reliance on callers synchronizing powerpc's hw_breakpoint.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20220829124719.675715-10-elver@google.com
2022-08-30 10:56:23 +02:00
Wolfram Sang
14be375634 powerpc: 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.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Link: https://lore.kernel.org/r/20220818205946.6336-1-wsa+renesas@sang-engineering.com
2022-08-26 11:02:20 +10:00
Michael Ellerman
eb316ae798 powerpc: Move patch sites out of asm-prototypes.h
The definitions for the patch sites etc. don't belong in
asm-prototypes.h, they are not EXPORT'ed asm symbols.

Move them into sections.h which is traditionally used for asm symbols.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220818050659.187181-1-mpe@ellerman.id.au
2022-08-26 11:02:20 +10:00
Michael Ellerman
91926d8b7e powerpc/rtas: Fix RTAS MSR[HV] handling for Cell
The semi-recent changes to MSR handling when entering RTAS (firmware)
cause crashes on IBM Cell machines. An example trace:

  kernel tried to execute user page (2fff01a8) - exploit attempt? (uid: 0)
  BUG: Unable to handle kernel instruction fetch
  Faulting instruction address: 0x2fff01a8
  Oops: Kernel access of bad area, sig: 11 [#1]
  BE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=4 NUMA Cell
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper/0 Tainted: G        W          6.0.0-rc2-00433-gede0a8d3307a #207
  NIP:  000000002fff01a8 LR: 0000000000032608 CTR: 0000000000000000
  REGS: c0000000015236b0 TRAP: 0400   Tainted: G        W           (6.0.0-rc2-00433-gede0a8d3307a)
  MSR:  0000000008001002 <ME,RI>  CR: 00000000  XER: 20000000
  ...
  NIP 0x2fff01a8
  LR  0x32608
  Call Trace:
    0xc00000000143c5f8 (unreliable)
    .rtas_call+0x224/0x320
    .rtas_get_boot_time+0x70/0x150
    .read_persistent_clock64+0x114/0x140
    .read_persistent_wall_and_boot_offset+0x24/0x80
    .timekeeping_init+0x40/0x29c
    .start_kernel+0x674/0x8f0
    start_here_common+0x1c/0x50

Unlike PAPR platforms where RTAS is only used in guests, on the IBM Cell
machines Linux runs with MSR[HV] set but also uses RTAS, provided by
SLOF.

Fix it by copying the MSR[HV] bit from the MSR value we've just read
using mfmsr into the value used for RTAS.

It seems like we could also fix it using an #ifdef CELL to set MSR[HV],
but that doesn't work because it's possible to build a single kernel
image that runs on both Cell native and pseries.

Fixes: b6b1c3ce06 ("powerpc/rtas: Keep MSR[RI] set when calling RTAS")
Cc: stable@vger.kernel.org # v5.19+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Jordan Niethe <jniethe5@gmail.com>
Link: https://lore.kernel.org/r/20220823115952.1203106-2-mpe@ellerman.id.au
2022-08-26 08:41:54 +10:00
Masahiro Yamada
c7acee3d2f powerpc: align syscall table for ppc32
Christophe Leroy reported that commit 7b4537199a ("kbuild: link
symbol CRCs at final link,  removing CONFIG_MODULE_REL_CRCS") broke
mpc85xx_defconfig + CONFIG_RELOCATABLE=y.

    LD      vmlinux
    SYSMAP  System.map
    SORTTAB vmlinux
    CHKREL  vmlinux
  WARNING: 451 bad relocations
  c0b312a9 R_PPC_UADDR32     .head.text-0x3ff9ed54
  c0b312ad R_PPC_UADDR32     .head.text-0x3ffac224
  c0b312b1 R_PPC_UADDR32     .head.text-0x3ffb09f4
  c0b312b5 R_PPC_UADDR32     .head.text-0x3fe184dc
  c0b312b9 R_PPC_UADDR32     .head.text-0x3fe183a8
      ...

The compiler emits a bunch of R_PPC_UADDR32, which is not supported by
arch/powerpc/kernel/reloc_32.S.

The reason is there exists an unaligned symbol.

  $ powerpc-linux-gnu-nm -n vmlinux
    ...
  c0b31258 d spe_aligninfo
  c0b31298 d __func__.0
  c0b312a9 D sys_call_table
  c0b319b8 d __func__.0

Commit 7b4537199a is not the root cause. Even before that, I can
reproduce the same issue for mpc85xx_defconfig + CONFIG_RELOCATABLE=y
+ CONFIG_MODVERSIONS=n.

It is just that nobody noticed because when CONFIG_MODVERSIONS is
enabled, a __crc_* symbol inserted before sys_call_table was hiding the
unalignment issue.

Adding alignment to the syscall table for ppc32 fixes the issue.

Cc: stable@vger.kernel.org
Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Trim change log discussion, add Cc stable]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/lkml/38605f6a-a568-f884-f06f-ea4da5b214f0@csgroup.eu/
Link: https://lore.kernel.org/r/20220820165129.1147589-1-masahiroy@kernel.org
2022-08-26 08:41:40 +10:00
Pali Rohár
0382a35bef powerpc/pci: Enable PCI domains in /proc when PCI bus numbers are not unique
On 32-bit powerpc systems with more PCIe controllers and more PCI
domains, where on more PCI domains are same PCI numbers, when kernel is
compiled with CONFIG_PROC_FS=y and
CONFIG_PPC_PCI_BUS_NUM_DOMAIN_DEPENDENT=y options, kernel prints
"proc_dir_entry 'pci/01' already registered" error message.

  proc_dir_entry 'pci/01' already registered
  WARNING: CPU: 0 PID: 1 at fs/proc/generic.c:377 proc_register+0x1a8/0x1ac
  ...
  NIP proc_register+0x1a8/0x1ac
  LR  proc_register+0x1a8/0x1ac
  Call Trace:
    proc_register+0x1a8/0x1ac (unreliable)
    _proc_mkdir+0x78/0xa4
    pci_proc_attach_device+0x11c/0x168
    pci_proc_init+0x80/0x98
    do_one_initcall+0x80/0x284
    kernel_init_freeable+0x1f4/0x2a0
    kernel_init+0x24/0x150
    ret_from_kernel_thread+0x5c/0x64

This regression started appearing after commit
5663568130 ("powerpc/pci: Add config option for using all 256 PCI
buses") in case in each mPCIe slot is connected PCIe card and therefore
PCI bus 1 is populated in for every PCIe controller / PCI domain.

The reason is that PCI procfs code expects that when PCI bus numbers are
not unique across all PCI domains, function pci_proc_domain() returns
true for domain dependent buses.

Fix this issue by setting PCI_ENABLE_PROC_DOMAINS and
PCI_COMPAT_DOMAIN_0 flags for 32-bit powerpc code when
CONFIG_PPC_PCI_BUS_NUM_DOMAIN_DEPENDENT is enabled. Same approach is
already implemented for 64-bit powerpc code (where PCI bus numbers are
always domain dependent).

Fixes: 5663568130 ("powerpc/pci: Add config option for using all 256 PCI buses")
Signed-off-by: Pali Rohár <pali@kernel.org>
[mpe: Trim change log oops message]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220820115113.30581-1-pali@kernel.org
2022-08-25 17:47:08 +10:00