linux.git/arch/powerpc/kernel/sysfs.c, branch v5.1

powerpc: change CONFIG_6xx to CONFIG_PPC_BOOK3S_32

2018-11-26T11:33:37+00:00

Today we have:

config PPC_BOOK3S_32
	bool "512x/52xx/6xx/7xx/74xx/82xx/83xx/86xx"
	[depends on PPC32 within a choice]

config PPC_BOOK3S
	def_bool y
	depends on PPC_BOOK3S_32 || PPC_BOOK3S_64

config 6xx
	def_bool y
	depends on PPC32 && PPC_BOOK3S

6xx is therefore redundant with PPC_BOOK3S_32.

In order to make the code clearer, lets use preferably PPC_BOOK3S_32.
This will allow to remove CONFIG_6xx in a later patch.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman

Merge branch 'topic/paca' into next

2018-03-30T22:09:36+00:00

Bring in yet another series that touches KVM code, and might need to
be merged into the kvm-ppc branch to resolve conflicts.

This required some changes in pnv_power9_force_smt4_catch/release()
due to the paca array becomming an array of pointers.

powerpc/64: move default SPR recording

2018-03-30T12:34:26+00:00

Move this into the early setup code, and don't iterate over CPU masks.
We don't want to call into sysfs so early from setup, and a future patch
won't initialize CPU masks by the time this is called.

Signed-off-by: Nicholas Piggin 
[mpe: Fold in incremental fix from Nick for DSCR handling]
Signed-off-by: Michael Ellerman

powerpc/64: Use array of paca pointers and allocate pacas individually

2018-03-30T12:34:23+00:00

Change the paca array into an array of pointers to pacas. Allocate
pacas individually.

This allows flexibility in where the PACAs are allocated. Future work
will allocate them node-local. Platforms that don't have address limits
on PACAs would be able to defer PACA allocations until later in boot
rather than allocate all possible ones up-front then freeing unused.

This is slightly more overhead (one additional indirection) for cross
CPU paca references, but those aren't too common.

Signed-off-by: Nicholas Piggin 
Signed-off-by: Michael Ellerman

powerpc: Expose TSCR via sysfs only on powernv

2018-02-14T22:54:42+00:00

The TSCR can only be accessed in hypervisor mode.

Fixes: 88b5e12eeb11 ("powerpc: Expose TSCR via sysfs")
Signed-off-by: Cyril Bur 
Signed-off-by: Michael Ellerman

powerpc: Expose TSCR via sysfs

2018-01-21T18:48:36+00:00

The thread switch control register (TSCR) is a per core register
that configures how the CPU shares resources between SMT threads.

Exposing it via sysfs allows us to tune it at run time.

Signed-off-by: Anton Blanchard 
Signed-off-by: Michael Ellerman

powerpc/64: Set DSCR default initially from SPR

2017-11-10T11:11:35+00:00

Take the DSCR value set by firmware as the dscr_default value,
rather than zero.

POWER9 recommends DSCR default to a non-zero value.

Signed-off-by: From: Nicholas Piggin 
[mpe: Make record_spr_defaults() __init]
Signed-off-by: Michael Ellerman

powerpc/sysfs: Move #ifdef CONFIG_HOTPLUG_CPU out of the function body

2017-05-03T04:45:38+00:00

The entire body of unregister_cpu_online() is inside an #ifdef
CONFIG_HOTPLUG_CPU block. This is ugly and means we create an empty function
when hotplug is disabled for no reason.

Instead move the #ifdef out of the function body and define the function to be
NULL in the else case. This means we'll pass NULL to cpuhp_setup_state(), but
that's fine because it accepts NULL to mean there is no teardown callback, which
is exactly what we want.

Signed-off-by: Michael Ellerman

powerpc/sysfs: Fix reference leak of cpu device_nodes present at boot

2017-04-24T14:24:59+00:00

For CPUs present at boot each logical CPU acquires a reference to the
associated device node of the core. This happens in register_cpu() which
is called by topology_init(). The result of this is that we end up with
a reference held by each thread of the core. However, these references
are never freed if the CPU core is DLPAR removed.

This patch fixes the reference leaks by acquiring and releasing the references
in the CPU hotplug callbacks un/register_cpu_online(). With this patch symmetric
reference counting is observed with both CPUs present at boot, and those DLPAR
added after boot.

Fixes: f86e4718f24b ("driver/core: cpu: initialize of_node in cpu's device struture")
Cc: stable@vger.kernel.org # v3.12+
Signed-off-by: Tyrel Datwyler 
Signed-off-by: Michael Ellerman

powerpc/sysfs: Convert to hotplug state machine

2016-11-22T22:34:42+00:00

Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.

The previous convention of keeping the files around until the CPU is dead
has not been preserved as there is no point to keep them available when the
cpu is going down. This makes the hotplug call symmetric.

Signed-off-by: Sebastian Andrzej Siewior 
Cc: Benjamin Herrenschmidt 
Cc: rt@linuxtronix.de
Cc: Paul Mackerras 
Cc: Michael Ellerman 
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20161117183541.8588-17-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner