The conditional branch instruction in Thumb2 only available to short range.
The linker will fail when the conditional branch over the range. Then
resulting in link error when generating kernel image. e.g.:
arch/arm/mach-tegra/reset-handler.S:47:(.text+0xf8e):
relocation truncated to fit: R_ARM_THM_JUMP19 against symbol
`cpu_resume' defined in .data section in arch/arm/kernel/built-in.o
This patch using a Thumb2 instruction IT (if-then) to have a longer branch
range.
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Olof Johansson <olof@lixom.net>
There is no need to unlock MMIO access to the DBGLAR all the time. Doing
so may even cause problems if a SW bug causes writes to that MMIO region.
Cortex-A15 processors do not support the CP14 register write the code
currently uses to unlock the DBGLAR; the instruction throws an undefined
instruction exceptions. This prevents tegra_secondary_startup() from
executing on Tegra114, and hence prevents SMP.
Remove the code that unlocks this access.
Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
The CPU cores in Tegra contain some errata. Workarounds must be applied
for these every time a CPU boots. Implement those workarounds directly
in the Tegra-specific CPU reset vector.
Many of these workarounds duplicate code in the core ARM kernel.
However, the core ARM kernel cannot enable those workarounds when
building a multi-platform kernel, since they require writing to secure-
only registers, and a multi-platform kernel often does not run in secure
mode, and also cannot generically/architecturally detect whether it is
running in secure mode, and hence cannot either unconditionally or
conditionally apply these workarounds.
Instead, the workarounds must be applied in architecture-specific reset
code, which is able to have more direct knowledge of the secure/normal
state. On Tegra, we will be able to detect this using a non-architected
register in the future, although we currently assume the kernel runs only
in secure mode. Other SoCs may never run the kernel in secure mode, and
hence always rely on a secure monitor to enable the workarounds, and
hence never implement them in the kernel.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
The reset handler code is used for either UP or SMP. To make Tegra device
can compile for UP. It needs to be moved to another file that is not SMP
only. This is because the reset handler also be needed by CPU idle
"powered-down" mode. So we also need to put the reset handler init function
in non-SMP only and init them always.
And currently the implementation of the reset handler to know which CPU is
OK to bring up was identital with "cpu_present_mask". But the
"cpu_present_mask" did not initialize yet when the reset handler init
function was moved to init early function. We use the "cpu_possible_mask"
to replace "cpu_present_mask". Then it can work on both UP and SMP case.
Signed-off-by: Joseph Lo <josephl@nvidia.com>
[swarren: dropped the move of v7_invalidate_l1() from one file to another,
to avoid conflicts with Pavel's cleanup of this function, adjust Makefile
so each line only contains 1 file.]
Signed-off-by: Stephen Warren <swarren@nvidia.com>
