Revert "parisc: Only list existing CPUs in cpu_possible_mask"

This reverts commit 0921244f6f4f0d05698b953fe632a99b38907226.

It broke CPU hotplugging because it modifies the __cpu_possible_mask
after bootup, so that it will be different than nr_cpu_ids, which
then effictively breaks the workqueue setup code and triggers crashes
when shutting down CPUs at runtime.

Guenter was the first who noticed the wrong values in __cpu_possible_mask,
since the cpumask Kunit tests were failig.

Reverting this commit fixes both issues, but sadly brings back this
uncritical runtime warning:
register_cpu_capacity_sysctl: too early to get CPU4 device!

Signed-off-by: Helge Deller <deller@gmx.de>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lkml.org/lkml/2024/2/4/146
Link: https://lore.kernel.org/lkml/Zb0mbHlIud_bqftx@slm.duckdns.org/t/
Cc: stable@vger.kernel.org # 6.0+

parisc: Replace strlcpy() with strscpy()

strlcpy() reads the entire source buffer first. This read may exceed
the destination size limit. This is both inefficient and can lead
to linear read overflows if a source string is not NUL-terminated[1].
Additionally, it returns the size of the source string, not the
resulting size of the destination string. In an effort to remove strlcpy()
completely[2], replace strlcpy() here with strscpy().

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [1]
Link: https://github.com/KSPP/linux/issues/89 [2]
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Azeem Shaikh <azeemshaikh38@gmail.com>
Cc: linux-parisc@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Show default CPU PSW.W setting as reported by PDC

The last word shows the default PSW.W setting.

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: BTLB: Initialize BTLB tables at CPU startup

Initialize the BTLB entries when starting up a CPU.
Note that BTLBs are not available on 64-bit CPUs.

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Fix /proc/cpuinfo output for lscpu

The lscpu command is broken since commit cab56b51ec0e ("parisc: Fix
device names in /proc/iomem") added the PA pathname to all PA
devices, includig the CPUs.

lscpu parses /proc/cpuinfo and now believes it found different CPU
types since every CPU is listed with an unique identifier (PA
pathname).

Fix this problem by simply dropping the PA pathname when listing the
CPUs in /proc/cpuinfo. There is no need to show the pathname in this
procfs file.

Fixes: cab56b51ec0e ("parisc: Fix device names in /proc/iomem")
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v4.9+

parisc: processor: Include asm/smp.h for init_per_cpu()

Fix sparse warning that init_per_cpu() isn't declared.

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: processor: Fix kdoc for init_cpu_profiler()

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Show MPE/iX model string at bootup

Some (mostly 64-bit machines) machines allow to run MPE/iX and report the MPE
model string via firmware call. Enhance the pdc_model_sysmodel() function to
report that model string.
Note that some 32-bit machines like the B160L wrongly report success for the
firmware call, so include a check to prevent showing wrong info.

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: fix a crash with multicore scheduler

With the kernel 5.18, the system will hang on boot if it is compiled with
CONFIG_SCHED_MC. The last printed message is "Brought up 1 node, 1 CPU".

The crash happens in sd_init
tl->mask (which is cpu_coregroup_mask) returns an empty mask. This happens
because cpu_topology[0].core_sibling is empty.
Consequently, sd_span is set to an empty mask
sd_id = cpumask_first(sd_span) sets sd_id == NR_CPUS (because the mask is
empty)
sd->shared = *per_cpu_ptr(sdd->sds, sd_id); sets sd->shared to NULL
because sd_id is out of range
atomic_inc(&sd->shared->ref); crashes without printing anything

We can fix it by calling reset_cpu_topology() from init_cpu_topology() -
this will initialize the sibling masks on CPUs, so that they're not empty.

This patch also removes the variable "dualcores_found", it is useless,
because during boot, init_cpu_topology is called before
store_cpu_topology. Thus, set_sched_topology(parisc_mc_topology) is never
called. We don't need to call it at all because default_topology in
kernel/sched/topology.c contains the same items as parisc_mc_topology.

Note that we should not call store_cpu_topology() from init_per_cpu()
because it is called too early in the kernel initialization process and it
results in the message "Failure to register CPU0 device". Before this
patch, store_cpu_topology() would exit immediatelly because
cpuid_topo->core id was uninitialized and it was 0.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org # v5.18
Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Merge model and model name into one line in /proc/cpuinfo

The Linux tool "lscpu" shows the double amount of CPUs if we have
"model" and "model name" in two different lines in /proc/cpuinfo.
This change combines the model and the model name into one line.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org

parisc: Only list existing CPUs in cpu_possible_mask

The inventory knows which CPUs are in the system, so this bitmask should
be in cpu_possible_mask instead of the bitmask based on CONFIG_NR_CPUS.

Reset the cpu_possible_mask before scanning the system for CPUs, and
mark each existing CPU as possible during initialization of that CPU.

This avoids those warnings later on too:

register_cpu_capacity_sysctl: too early to get CPU4 device!

Signed-off-by: Helge Deller <deller@gmx.de>
Noticed-by: John David Anglin <dave.anglin@bell.net>

parisc: Move CPU startup-related functions into .text section

If CONFIG_HOTPLUG_CPU is enabled, those functions will be run again
after bootup. So they need to reside in the .text section.

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Switch from GENERIC_CPU_DEVICES to GENERIC_ARCH_TOPOLOGY

Switch away from the own cpu topology code to common code which is used
by ARM64 and RISCV. That will allow us to enable CPU hotplug later on.

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Drop loops_per_jiffy from per_cpu struct

There is no need to keep a loops_per_jiffy value per cpu. Drop it.

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Replace cpu_up/down() with add/remove_cpu()

The core device API performs extra housekeeping bits that are missing
from directly calling cpu_up/down().

See commit a6717c01ddc2 ("powerpc/rtas: use device model APIs and
serialization during LPM") for an example description of what might go
wrong.

This also prepares to make cpu_up/down() a private interface of the CPU
subsystem.

Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Helge Deller <deller@gmx.de>
Link: https://lkml.kernel.org/r/20200323135110.30522-13-qais.yousef@arm.com

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 153

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 or at your option any
later version this program is distributed in the hope that it will
be useful but without any warranty without even the implied warranty
of merchantability or fitness for a particular purpose see the gnu
general public license for more details you should have received a
copy of the gnu general public license along with this program if
not write to the free software foundation inc 675 mass ave cambridge
ma 02139 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 77 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.837555891@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parisc: Use __ro_after_init in processor.c

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Show n/a if product number not available

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Show machine product number during boot

Ask PDC firmware during boot for the original and current product
number as well as the serial number and show it (if available).

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Add hardware description to stack traces

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Add CPU topology support

Add topology support, including multi-core scheduler support on
PA8800/PA8900 CPUs and enhanced output in /proc/cpuinfo, e.g.
lscpu now reports on a single-socket, dual-core machine:

Architecture: parisc64
CPU(s): 2
On-line CPU(s) list: 0,1
Thread(s) per core: 1
Core(s) per socket: 2
Socket(s): 1
CPU family: PA-RISC 2.0
Model name: PA8800 (Mako)

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Move init_per_cpu() into init section

Signed-off-by: Helge Deller <deller@gmx.de>

parisc/core: Fix section mismatches

Signed-off-by: Helge Deller <deller@gmx.de>

parisc/random: Add machine specific randomness

Add some machine-specific information like values of cr16 cycle counter,
machine-specific software ID and machine model to the random generator.

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Enhance detection of synchronous cr16 clocksources

The cr16 clocks of the physical PARISC CPUs are usually nonsynchronous.
Nevertheless, it seems that each CPU socket (which holds two cores) of
PA8800 and PA8900 CPUs (e.g. in a C8000 workstation) is fed by the same
clock source, which makes the cr16 clocks of each CPU socket syncronous.
Let's try to detect such situations and mark the cr16 clocksource stable
on single-socket and single-core machines.

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Optimize timer interrupt function

Restructure the timer interrupt function to better cope with missed timer irqs.
Optimize the calculation when the next interrupt should happen and skip irqs if
they would happen too shortly after exit of the irq function.

The update_process_times() call is done anyway at every timer irq, so we can
safely drop the prof_counter and prof_multiplier variables from the per_cpu
structure.

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Enhance CPU detection code on PAT machines

This patch fixes the debug code which runs during the inventory scan on
machines with PAT firmware.

Additionally print out the relationship between the detected logical CPU
number and it's physical location and physical cpu number.
This leads to information which can be used to feed numa-structures in
the kernel in later patches. An example output is from my single-CPU (2
cores) C8000 machine is:

Logical CPU #0 is physical cpu #0 at 0xffff0000ffff15, hpa 0xfffffffffe780000
Logical CPU #1 is physical cpu #1 at 0xffff0000ffff15, hpa 0xfffffffffe781000

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Fix automatic selection of cr16 clocksource

Commit 54b66800907 (parisc: Add native high-resolution sched_clock()
implementation) added support to use the CPU-internal cr16 counters as reliable
clocksource with the help of HAVE_UNSTABLE_SCHED_CLOCK.

Sadly the commit missed to remove the hack which prevented cr16 to become the
default clocksource even on SMP systems.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 4.7+

parisc: Fix printk time during boot

Avoid showing invalid printk time stamps during boot.

Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Aaro Koskinen <aaro.koskinen@iki.fi>

parisc: Reduce overhead of parisc_requires_coherency()

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: delete __cpuinit usage from all users

The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

This removes all the parisc uses of the __cpuinit macros.

[1] https://lkml.org/lkml/2013/5/20/589

Acked-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

parisc: more capabilities info in /proc/cpuinfo

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # 3.10

parisc: processor.c, fix bloated stack frame

The pa_pdc_cell struct can be kmalloc'd, so do that instead.

Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

parisc: remove CVS keywords

Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Acked-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

parisc: expose 32/64-bit capabilities in cpuinfo

It'd be rather useful for debian-installer if we could get hold of
accurate firmware information on whether only 32-bit kernels are
supported, only 64-bit kernels, or both; this would allow us to present
an accurate menu of kernel packages if more than one is available,
rather than the user having to guess. This patch attempts to expose it
in cpuinfo.

I adjusted pdc_model_capabilities to cope with a potential
PDC_INVALID_ARG return as the firmware manual instructs, by assuming
32-bit only. This may be the wrong place for it.

I made up user-visible capability names by total fiat and for the moment
ignored the other bits that may appear in the capabilities word.

I have no PA-RISC machine myself to test on, and no PA experience
either, so I rather hope that somebody will kind-heartedly take this and
fix it up if needed. I ran it past Dann Frazier on IRC and he said
"looks good to me", but I think without testing.

Also, this is against the Ubuntu 2.6.28 kernel tree since that's what I
had handy and I was a bit tight on disk space to slurp down another
tree. Sorry if it's skewed in any relevant way; I'll be happy to adjust
if necessary.

Thanks in advance!

Signed-off-by: Colin Watson <cjwatson@canonical.com>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

cpumask: Use accessors code.: parisc

Impact: use new API

Use the accessors rather than frobbing bits directly. Most of this is
in arch code I haven't even compiled, but it is mostly straightforward.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>

cpumask: prepare for iterators to only go to nr_cpu_ids/nr_cpumask_bits.: parisc

Impact: cleanup, futureproof

In fact, all cpumask ops will only be valid (in general) for bit
numbers < nr_cpu_ids. So use that instead of NR_CPUS in various
places.

This is always safe: no cpu number can be >= nr_cpu_ids, and
nr_cpu_ids is initialized to NR_CPUS at boot.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Ingo Molnar <mingo@elte.hu>

parisc: Replace NR_CPUS in parisc code

parisc: Replace most arrays sized by NR_CPUS with percpu variables.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

[PARISC] Unbreak processor_probe when we have more than NR_CPUS

If we already have NR_CPUS worth of cpus online, we obviously shouldn't
be trying to bring up more... Fixes a particularly vexing issue I had when
running another machines kernel on my rp3440.

Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

[PARISC] fix section mismatches in arch/parisc/kernel

Hi Kyle,

this patch fixes two section mismatches in arch/parisc/kernel:
WARNING: arch/parisc/kernel/built-in.o(.data.read_mostly+0xd8): Section mismatch: reference to .init.text:processor_probe (between 'cpu_driver' and 'boot_cpu_data')
WARNING: arch/parisc/kernel/built-in.o(.text.alloc_pa_dev+0x140): Section mismatch: reference to .init.text:parisc_hardware_description (after 'alloc_pa_dev')

Additionally, mark some tables as constants.

Please apply, Helge

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

[PARISC] spelling fixes: arch/parisc/

Spelling fixes in arch/parisc/.

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Acked-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

Detach sched.h from mm.h

First thing mm.h does is including sched.h solely for can_do_mlock() inline
function which has "current" dereference inside. By dealing with can_do_mlock()
mm.h can be detached from sched.h which is good. See below, why.

This patch
a) removes unconditional inclusion of sched.h from mm.h
b) makes can_do_mlock() normal function in mm/mlock.c
c) exports can_do_mlock() to not break compilation
d) adds sched.h inclusions back to files that were getting it indirectly.
e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were
getting them indirectly

Net result is:
a) mm.h users would get less code to open, read, preprocess, parse, ... if
they don't need sched.h
b) sched.h stops being dependency for significant number of files:
on x86_64 allmodconfig touching sched.h results in recompile of 4083 files,
after patch it's only 3744 (-8.3%).

Cross-compile tested on

all arm defconfigs, all mips defconfigs, all powerpc defconfigs,
alpha alpha-up
arm
i386 i386-up i386-defconfig i386-allnoconfig
ia64 ia64-up
m68k
mips
parisc parisc-up
powerpc powerpc-up
s390 s390-up
sparc sparc-up
sparc64 sparc64-up
um-x86_64
x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig

as well as my two usual configs.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[PARISC] clocksource: Move update_cr16_clocksource later in boot

smp_cpus_done is too early for us... before we even do a device
inventory! Move update_cr16_clocksource into the tail end of
processor_probe() and stub it out on CONFIG_SMP=n builds.

Verified that clocksource0 is properly updated to use jiffies
on an SMP build.

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

[PARISC] use CONFIG_64BIT instead of __LP64__

- additionally update my copyright timestamps

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

[PARISC] kill ENTRY_SYS_CPUS

it's unlikely iCOD will ever happen on parisc-linux now... ;-)

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

[PARISC] Fix thinko in cpu_data.lock removal

Need to remove the initializer as well. Doh.

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

[PARISC] Prevent processor_probe() from clobbering cpu_data[0]

processor_probe() shouldn't clobber cpu_data[0]
cpu_data[0].it_value (used by timer_interrupt()) is already set.

Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

Remove obsolete #include <linux/config.h>

Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

[PARISC] Add __read_mostly section for parisc

Flag a whole bunch of things as __read_mostly on parisc. Also flag a few
branches as unlikely() and cleanup a bit of code.

Signed-off-by: Helge Deller <deller@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

[PARISC] Convert parisc_device to use struct resource for hpa

Convert pa_dev->hpa from an unsigned long to a struct resource.

Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>

Fix up users of ->hpa to use ->hpa.start instead.

Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!