Re: [PATCH RFC v3 8/8] mips: Use the common syscall table

["Arnd Bergmann" <arnd@arndb.de>]

On Fri, Aug 7, 2026, at 21:34, André Almeida wrote:
> Syscall numbers from 403 are shared with all architectures, so move the
> toolchain to use the common syscall table and remove duplicated code.
>
> The generated files are not exactly the same as before, but they have no
> functional changes:
>
>  - for O32 ABI, the syscall table would have entries like
>  __SYSCALL_WITH_COMPAT(403, sys_clock_gettime, sys_clock_gettime)
>  which is equivalent to the new entry __SYSCALL(403, sys_clock_gettime)
>
>  - for N32 ABI, the syscall table would have entries like
>  __SYSCALL(413, compat_sys_pselect6_time64), which is equivalent to
>  __SYSCALL_WITH_COMPAT(413, sys_pselect6, compat_sys_pselect6_time64)
>  given the new __SYSCALL_WITH_COMPAT() definition for N32.
>
> The generated syscall table for N64 is exactly the same.
>
> Signed-off-by: André Almeida <andrealmeid@igalia.com>
> ---
>  arch/mips/kernel/scall64-n32.S            |  1 +
>  arch/mips/kernel/syscalls/Makefile        | 22 +++++++---
>  arch/mips/kernel/syscalls/syscall_n32.tbl | 68 -------------------------------
>  arch/mips/kernel/syscalls/syscall_n64.tbl | 48 ----------------------
>  arch/mips/kernel/syscalls/syscall_o32.tbl | 68 -------------------------------
>  5 files changed, 18 insertions(+), 189 deletions(-)

I still wonder whether we should combine the n32 and n64 tables
here. Since the script can now deal with multiple input files,
the first 211 syscall numbers can be in a shared file, while
numbers 212 through 332 are always going to be different.

Alternatively, two the files could just be merged into one file
like

0       common    read                       sys_read
1       common    write                      sys_write
...
13      common    rt_sigaction                sys_rt_sigaction     compat_sys_rt_sigaction
...
210     common    remap_file_pages           sys_remap_file_pages
211     common    rt_sigreturn               sys_rt_sigreturn
...
212     32        fcntl64                       compat_sys_fcntl64
213     32        set_tid_address               sys_set_tid_address
...
212     64        set_tid_address               sys_set_tid_address
213     64        restart_syscall               sys_restart_syscall

 
> -$(kapi)/unistd_nr_%.h: $(src)/syscall_%.tbl $(sysnr) FORCE
> +abis := common,__cln3
> +
> +abis_n32 := $(abis),32,n32
> +abis_o32 := $(abis),32,o32
> +abis_n64 := $(abis),64,n64

We should probably drop the custom ABI names here and just use
common/32/64 in the .tbl file. There was never a real need for
the special case here, and now it causes extra complexity.

     Arnd