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Re: [Qemu-arm] [PATCH v2] target/arm: Implement NSACR gating of floating
From: |
Richard Henderson |
Subject: |
Re: [Qemu-arm] [PATCH v2] target/arm: Implement NSACR gating of floating point |
Date: |
Fri, 7 Jun 2019 08:42:25 -0500 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 |
On 6/7/19 8:06 AM, Peter Maydell wrote:
> The NSACR register allows secure code to configure the FPU
> to be inaccessible to non-secure code. If the NSACR.CP10
> bit is set then:
> * NS accesses to the FPU trap as UNDEF (ie to NS EL1 or EL2)
> * CPACR.{CP10,CP11} behave as if RAZ/WI
> * HCPTR.{TCP11,TCP10} behave as if RAO/WI
>
> Note that we do not implement the NSACR.NSASEDIS bit which
> gates only access to Advanced SIMD, in the same way that
> we don't implement the equivalent CPACR.ASEDIS and HCPTR.TASE.
>
> Signed-off-by: Peter Maydell <address@hidden>
> ---
> Changes v1->v2:
> * fixed bug in cptr_el2_read() that meant we were forcing
> HCPTR.{TCP11,TCP10} to 0 when they should be 1
> ---
> target/arm/helper.c | 75 +++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 73 insertions(+), 2 deletions(-)
Reviewed-by: Richard Henderson <address@hidden>
r~