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author | Russell King <rmk+kernel@arm.linux.org.uk> | 2015-05-19 19:06:44 +0300 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2015-06-01 13:30:26 +0300 |
commit | 02b4e2756e01c623cc4dbceae4b07be75252db5b (patch) | |
tree | 2dfe7bc32d8ac07075eb6a3d057f92b15039932e /arch/arm/mach-zynq | |
parent | 6a53bc750004fdab11494e9e6c864b4a425fc1a1 (diff) | |
download | linux-02b4e2756e01c623cc4dbceae4b07be75252db5b.tar.xz |
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>
Diffstat (limited to 'arch/arm/mach-zynq')
-rw-r--r-- | arch/arm/mach-zynq/common.h | 2 | ||||
-rw-r--r-- | arch/arm/mach-zynq/headsmp.S | 5 | ||||
-rw-r--r-- | arch/arm/mach-zynq/platsmp.c | 5 |
3 files changed, 2 insertions, 10 deletions
diff --git a/arch/arm/mach-zynq/common.h b/arch/arm/mach-zynq/common.h index 382c60e9aa16..7038cae95ddc 100644 --- a/arch/arm/mach-zynq/common.h +++ b/arch/arm/mach-zynq/common.h @@ -17,8 +17,6 @@ #ifndef __MACH_ZYNQ_COMMON_H__ #define __MACH_ZYNQ_COMMON_H__ -void zynq_secondary_startup(void); - extern int zynq_slcr_init(void); extern int zynq_early_slcr_init(void); extern void zynq_slcr_system_reset(void); diff --git a/arch/arm/mach-zynq/headsmp.S b/arch/arm/mach-zynq/headsmp.S index dd8c071941e7..045c72720a4d 100644 --- a/arch/arm/mach-zynq/headsmp.S +++ b/arch/arm/mach-zynq/headsmp.S @@ -22,8 +22,3 @@ zynq_secondary_trampoline_jump: .globl zynq_secondary_trampoline_end zynq_secondary_trampoline_end: ENDPROC(zynq_secondary_trampoline) - -ENTRY(zynq_secondary_startup) - bl v7_invalidate_l1 - b secondary_startup -ENDPROC(zynq_secondary_startup) diff --git a/arch/arm/mach-zynq/platsmp.c b/arch/arm/mach-zynq/platsmp.c index 52d768ff7857..f66816c49186 100644 --- a/arch/arm/mach-zynq/platsmp.c +++ b/arch/arm/mach-zynq/platsmp.c @@ -87,10 +87,9 @@ int zynq_cpun_start(u32 address, int cpu) } EXPORT_SYMBOL(zynq_cpun_start); -static int zynq_boot_secondary(unsigned int cpu, - struct task_struct *idle) +static int zynq_boot_secondary(unsigned int cpu, struct task_struct *idle) { - return zynq_cpun_start(virt_to_phys(zynq_secondary_startup), cpu); + return zynq_cpun_start(virt_to_phys(secondary_startup), cpu); } /* |