Re: [PATCH V2 0/2] Proposing custom CSR handling logic

[Alistair Francis]

On Tue, May 11, 2021 at 8:07 PM Ruinland Chuan-Tzu Tsai
<ruinland@andestech.com> wrote:
>
> Hi all,
>
> My sincere apology that I missed the patch to include our own CSR table
> into the patch series and there were plenty of typos.
> Thus I'm sending out V2 of these tiny patches.
>
> I agree with Alistair's comment on not introducing intrusive code which
> will interfere the generic code structure. Yet since there are
> possibilities that some custom CSRs/instructions could be once drafted/
> proposed by vendors at first, and made themselves into the standard
> as the implementation become widely adopted.
>
> So in this patch set, we humbly utilzed a glib hash table for inserting
> the `struct riscv_custom_csr_operations`, check if the CSR is a non
> standard one, and then proceed the desired behavior.
>
> Once the non-standard CSRs make themselves into the specification,
> people could easily plug-and-use the code into CSR operation table
> inside `csr.c`.
>
> Ones may have concerns regarding the check code would introduce
> further overhead. For those considerations, I guess it could be solved
> by introducing a build option such as '--enable-riscv-vendor-features'
> to toggle the code.
>
> Cordially yours,
> Ruinland ChuanTzu Tsai
>
> Ruinland Chuan-Tzu Tsai (2):
>   Adding premliminary support for custom CSR handling mechanism
>   Adding custom Andes CSR table.

Thanks for the patches.

Can you please include:
 wangjunqiang@iscas.ac.cn
 qemu-devel@nongnu.org
 bin.meng@windriver.com

on future patches so everyone is included.

Alistair

>
>  target/riscv/cpu.c           |  28 ++++++++
>  target/riscv/cpu.h           |  12 +++-
>  target/riscv/cpu_bits.h      | 115 ++++++++++++++++++++++++++++++++
>  target/riscv/csr.c           | 107 ++++++++++++++++++++++++++++--
>  target/riscv/csr_andes.inc.c | 125 +++++++++++++++++++++++++++++++++++
>  5 files changed, 381 insertions(+), 6 deletions(-)
>  create mode 100644 target/riscv/csr_andes.inc.c
>
> --
> 2.17.1
>