linux/arch/arm/plat-versatile
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: integrator/versatile: consolidate FPGA IRQ handling code 2011-02-19 11:11:33 +00:00
clcd.c ARM: add versatile family consolidated CLCD support 2011-02-19 11:09:12 +00:00
clock.c ARM: Indirect round/set_rate operations through clk structure 2010-05-02 09:35:38 +01:00
fpga-irq.c arm: Fold irq_set_chip/irq_set_handler 2011-03-29 14:47:58 +02:00
headsmp.S ARM: realview/vexpress: consolidate SMP bringup code 2011-02-19 11:11:41 +00:00
Kconfig ARM: integrator: add Integrator/CP sched_clock support 2011-02-19 11:11:46 +00:00
leds.c ARM: 6235/2: driver for the LEDs found in the later ARM refdesigns 2010-07-26 10:48:29 +01:00
localtimer.c ARM: 6759/1: smp: Select local timers vs broadcast timer support runtime 2011-02-23 17:54:27 +00:00
Makefile ARM: realview/vexpress: consolidate SMP bringup code 2011-02-19 11:11:41 +00:00
platsmp.c ARM: versatile: convert logical CPU numbers to physical numbers 2011-10-17 10:01:11 +01:00
sched-clock.c ARM: 7205/2: sched_clock: allow sched_clock to be selected at runtime 2011-12-18 23:00:26 +00:00