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>
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.
After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.
Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
and are flagged as __cpuinit -- so if we remove the __cpuinit from
the arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
related content into no-ops as early as possible, since that will get
rid of these warnings. In any case, they are temporary and harmless.
This removes all the ARM uses of the __cpuinit macros from C code,
and all __CPUINIT from assembly code. It also had two ".previous"
section statements that were paired off against __CPUINIT
(aka .section ".cpuinit.text") that also get removed here.
[1] https://lkml.org/lkml/2013/5/20/589
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Patch c08e20d "arm: Add v7_invalidate_l1 to cache-v7.S" added
a generic version of this function and removed all platform
specific versions, while 4898de3 "ARM: PRIMA2: add new SiRFmarco
SMP SoC infrastructures" added another one, leading to a link
error. I verified that the two are identical, so we can
just remove the one in mach-prima2.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
The code in arch/arm/mach-prima2/headsmp.S is used for
both boot time initialization and for cpu hotplug,
so it must not be discarded after the initial boot
is complete. This replaces the __INIT annotation
with __CPUINIT, and marks the sirfsoc_cpu_die as
__ref to annotate that it correctly uses the sections.
Without this patch, building prima2_defconfig results in:
WARNING: arch/arm/mach-prima2/built-in.o(.cpuinit.text+0x130): Section mismatch in reference from the function sirfsoc_boot_secondary() to the function .init.text:sirfsoc_secondary_startup()
The function __cpuinit sirfsoc_boot_secondary() references
a function __init sirfsoc_secondary_startup().
If sirfsoc_secondary_startup is only used by sirfsoc_boot_secondary then
annotate sirfsoc_secondary_startup with a matching annotation.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Barry Song <baohua.song@csr.com>
this patch adds tick timer, smp entries and generic DT machine
for SiRFmarco dual-core SMP chips.
with the added marco, we change the defconfig, using the same
defconfig, we get a zImage which can work on both prima2 and
marco.
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Cc: Mark Rutland <mark.rutland@arm.com>
