linux/arch/arm/mach-prima2
Russell King 02b4e2756e ARM: v7 setup function should invalidate L1 cache
All ARMv5 and older CPUs invalidate their caches in the early assembly
setup function, prior to enabling the MMU.  This is because the L1
cache should not contain any data relevant to the execution of the
kernel at this point; all data should have been flushed out to memory.

This requirement should also be true for ARMv6 and ARMv7 CPUs - indeed,
these typically do not search their caches when caching is disabled (as
it needs to be when the MMU is disabled) so this change should be safe.

ARMv7 allows there to be CPUs which search their caches while caching is
disabled, and it's permitted that the cache is uninitialised at boot;
for these, the architecture reference manual requires that an
implementation specific code sequence is used immediately after reset
to ensure that the cache is placed into a sane state.  Such
functionality is definitely outside the remit of the Linux kernel, and
must be done by the SoC's firmware before _any_ CPU gets to the Linux
kernel.

Changing the data cache clean+invalidate to a mere invalidate allows us
to get rid of a lot of platform specific hacks around this issue for
their secondary CPU bringup paths - some of which were buggy.

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Thierry Reding <treding@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Tested-by: Wei Xu <xuwei5@hisilicon.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-06-01 11:30:26 +01:00
..
common.c ARM: make arrays containing machine compatible strings const 2015-02-19 09:44:17 +01:00
common.h ARM: sirf: drop redundant function and marco declaration 2015-02-06 00:31:58 -08:00
headsmp.S ARM: v7 setup function should invalidate L1 cache 2015-06-01 11:30:26 +01:00
hotplug.c ARM: cpu hotplug: remove majority of cache flushing from platforms 2013-04-18 20:08:04 +01:00
Kconfig ARM: prima2: do not select SMP_ON_UP 2015-02-18 12:20:27 +01:00
Makefile ARM: sirf: move to debug_ll_io_init and drop map_io 2015-01-20 19:56:53 +08:00
Makefile.boot ARM: dtb: move all dtb targets to common Makefile 2012-09-20 22:58:17 -07:00
platsmp.c ARM: make of_device_ids const 2015-02-19 09:44:25 +01:00
pm.c ARM: mach-prima2: drop owner assignment from platform_drivers 2014-10-20 16:20:05 +02:00
pm.h ARM: CSR: PM: add sleep entry for SiRFprimaII 2011-09-21 23:25:59 +08:00
rstc.c ARM: sirf: drop Marco support in reset controller module 2015-01-20 19:56:40 +08:00
rtciobrg.c ARM: sirf: drop Marco machine 2015-01-20 19:56:43 +08:00
sleep.S ARM: CSR: PM: add sleep entry for SiRFprimaII 2011-09-21 23:25:59 +08:00