Re: [Qemu-devel] [PATCH v2 16/25] target-arm: Widen thread-local register state fields to 64 bits

[Richard Henderson <rth@twiddle.net>]

On 12/22/2013 02:49 PM, Peter Maydell wrote:
> The common pattern for system registers in a 64-bit capable ARM
> CPU is that when in AArch32 the cp15 register is a view of the
> bottom 32 bits of the 64-bit AArch64 system register; writes in
> AArch32 leave the top half unchanged. The most natural way to
> model this is to have the state field in the CPU struct be a
> 64 bit value, and simply have the AArch32 TCG code operate on
> a pointer to its lower half.
> 
> For aarch64-linux-user the only registers we need to share like
> this are the thread-local-storage ones. Widen their fields to
> 64 bits and provide the 64 bit reginfo struct to make them
> visible in AArch64 state. Note that minor cleanup of the AArch64
> system register encoding space means We can share the TPIDR_EL1
> reginfo but need split encodings for TPIDR_EL0 and TPIDRRO_EL0.
> 
> Since we're touching almost every line in QEMU that uses the
> c13_tls* fields in this patch anyway, we take the opportunity
> to rename them in line with the standard ARM architectural names
> for these registers.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  linux-user/aarch64/target_cpu.h |  5 ++++-
>  linux-user/arm/target_cpu.h     |  2 +-
>  linux-user/main.c               |  2 +-
>  target-arm/cpu.h                | 18 +++++++++++++++---
>  target-arm/helper.c             | 22 +++++++++++++++-------
>  5 files changed, 36 insertions(+), 13 deletions(-)


Reviewed-by: Richard Henderson <rth@twiddle.net>


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