linux/arch
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
..
alpha Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
arm ARM: 7205/2: sched_clock: allow sched_clock to be selected at runtime 2011-12-18 23:00:26 +00:00
avr32 Merge git://git.infradead.org/mtd-2.6 2011-11-07 09:11:16 -08:00
blackfin blackfin: Fixup export.h includes 2011-11-14 17:15:23 +08:00
cris net: Fix references to deleted NET_ETHERNET Kconfig setting. 2011-11-09 19:26:53 -05:00
frv kgdb: follow rename pack_hex_byte() to hex_byte_pack() 2011-10-31 17:30:56 -07:00
h8300 Merge branch 'gpio/next' of git://git.secretlab.ca/git/linux-2.6 2011-10-29 07:27:45 -07:00
hexagon Hexagon: Add basic stacktrace functionality for Hexagon architecture. 2011-11-01 07:34:21 -07:00
ia64 Merge branch 'upstream/xen-settime' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen 2011-11-06 20:15:05 -08:00
m32r Merge branch 'trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2011-11-06 18:54:53 -08:00
m68k m68k/mac: Remove mac_irq_{en,dis}able() wrappers 2011-11-08 22:35:52 +01:00
microblaze microblaze: bury asm/namei.h 2011-11-21 16:48:28 -05:00
mips Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2011-11-15 22:44:45 -02:00
mn10300 kgdb: follow rename pack_hex_byte() to hex_byte_pack() 2011-10-31 17:30:56 -07:00
openrisc Merge branch 'trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2011-11-06 18:54:53 -08:00
parisc parisc: Add export.h to files needing EXPORT_SYMBOL/THIS_MODULE 2011-10-31 19:31:00 -04:00
powerpc powerpc/44x: Add mtd ndfc to the ppx44x defconfig 2011-11-25 10:06:00 +11:00
s390 Merge branch 'kvm-updates/3.2' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2011-11-20 14:57:43 -08:00
score score: drop unused Kconfig symbols 2011-10-31 23:39:51 +01:00
sh Merge branches 'sh/pm-runtime' and 'common/clkfwk' into sh-fixes-for-linus 2011-11-11 16:16:25 +09:00
sparc sparc64: Patch sun4v code sequences properly on module load. 2011-11-17 22:44:58 -08:00
tile Merge branch 'for-linus' of git://github.com/cmetcalf-tilera/linux-tile 2011-11-04 12:33:34 -07:00
um Merge branch 'for-linus' of git://github.com/richardweinberger/linux 2011-11-02 09:45:39 -07:00
unicore32 unicore32, exec: remove redundant set_fs(USER_DS) 2011-11-16 10:50:09 +08:00
x86 fix braino in um patchset (mea culpa) 2011-11-21 12:10:21 -08:00
xtensa Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2011-10-26 17:15:03 +02:00
.gitignore
Kconfig