linux-stable/arch/arm/plat-orion
Marc Zyngier 2f0778afac ARM: 7205/2: sched_clock: allow sched_clock to be selected at runtime
sched_clock() is yet another blocker on the road to the single
image. This patch implements an idea by Russell King:

http://www.spinics.net/lists/linux-omap/msg49561.html

Instead of asking the platform to implement both sched_clock()
itself and the rollover callback, simply register a read()
function, and let the ARM code care about sched_clock() itself,
the conversion to ns and the rollover. sched_clock() uses
this read() function as an indirection to the platform code.
If the platform doesn't provide a read(), the code falls back
to the jiffy counter (just like the default sched_clock).

This allow some simplifications and possibly some footprint gain
when multiple platforms are compiled in. Among the drawbacks,
the removal of the *_fixed_sched_clock optimization which could
negatively impact some platforms (sa1100, tegra, versatile
and omap).

Tested on 11MPCore, OMAP4 and Tegra.

Cc: Imre Kaloz <kaloz@openwrt.org>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Colin Cross <ccross@android.com>
Cc: Erik Gilling <konkers@android.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Alessandro Rubini <rubini@unipv.it>
Cc: STEricsson <STEricsson_nomadik_linux@list.st.com>
Cc: Lennert Buytenhek <kernel@wantstofly.org>
Cc: Ben Dooks <ben-linux@fluff.org>
Tested-by: Jamie Iles <jamie@jamieiles.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Krzysztof Halasa <khc@pm.waw.pl>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-12-18 23:00:26 +00:00
..
include/plat ARM: 7063/1: Orion: gpio: add missing include of linux/types.h 2011-08-24 08:29:20 +01:00
common.c ARM: orion: Consolidate setup of the crypto engine. 2011-05-16 15:16:17 -04:00
gpio.c genirq: replace irq_gc_ack() with {set,clr}_bit variants (fwd) 2011-07-07 16:02:26 +00:00
irq.c arm: orion: Use generic irq chip 2011-05-16 14:34:54 -04:00
Makefile ARM: orion: Refactor the MPP code common in the orion platform 2011-05-16 15:25:54 -04:00
mpp.c ARM: dove: Consolidate mpp code with platform mpp. 2011-05-16 15:49:31 -04:00
pcie.c [ARM] Kirkwood: restrict the scope of the PCIe reset workaround 2010-10-21 15:52:03 -04:00
time.c ARM: 7205/2: sched_clock: allow sched_clock to be selected at runtime 2011-12-18 23:00:26 +00:00