On 19/01/17 14:37, Juri Lelli wrote:

arm and arm64 share lot of code relative to parsing CPU capacity
information from DT, using that information for appropriate scaling and
exposing a sysfs interface for chaging such values at runtime.

Factorize such code in a common place (driver/base/arch_topology.c) in
preparation for further additions.

Suggested-by: Will Deacon <redacted>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <redacted>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juri Lelli <redacted>
---
 arch/arm/Kconfig             |   1 +
 arch/arm/kernel/topology.c   | 213 ++------------------------------------
 arch/arm64/Kconfig           |   1 +
 arch/arm64/kernel/topology.c | 213 +-------------------------------------
 drivers/base/Kconfig         |   8 ++
 drivers/base/Makefile        |   1 +
 drivers/base/arch_topology.c | 240 +++++++++++++++++++++++++++++++++++++++++++
 7 files changed, 260 insertions(+), 417 deletions(-)
 create mode 100644 drivers/base/arch_topology.c

[...]

+extern unsigned long
+arch_scale_cpu_capacity(struct sched_domain *sd, int cpu);

How about adding a driver specific prefix 'foo_' to all driver interfaces?

I'm asking because I would rather like to do a

#define arch_scale_cpu_capacity foo_scale_cpu_capacity

then a

#define arch_scale_cpu_capacity arch_scale_cpu_capacity

in arch/arm64/include/asm/topology.h

later to wire cpu-invariant load-tracking support up to the task
scheduler for ARM64.

That's probably true too for all the 'driver' interfaces which get used
in arch/arm{,64}/kernel/topology.c.

[...]