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

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

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

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>

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>

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

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>

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>

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>

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

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

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