[External] Re: [PATCH v2] RISC-V: cmdline: Add support for 'memmap' parameter

yunhui cui cuiyunhui at bytedance.com
Wed Jul 10 23:15:53 PDT 2024


Add punit in the loop.


On Thu, Jul 4, 2024 at 5:37 AM Charlie Jenkins <charlie at rivosinc.com> wrote:
>
> On Mon, Jun 24, 2024 at 08:37:39PM +0800, Yunhui Cui wrote:
> > Add parsing of 'memmap' to use or reserve a specific region of memory.
> >
> > Implement the following memmap variants:
> > - memmap=nn[KMG]@ss[KMG]: force usage of a specific region of memory;
> > - memmap=nn[KMG]$ss[KMG]: mark specified memory as reserved;
> >
> > Signed-off-by: Yunhui Cui <cuiyunhui at bytedance.com>
> > ---
> >  arch/riscv/mm/init.c | 46 ++++++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 46 insertions(+)
> >
> > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> > index e3405e4b99af..8e1d93ae5cb2 100644
> > --- a/arch/riscv/mm/init.c
> > +++ b/arch/riscv/mm/init.c
> > @@ -208,6 +208,52 @@ static int __init early_mem(char *p)
> >  }
> >  early_param("mem", early_mem);
> >
> > +static void __init parse_memmap_one(char *p)
> > +{
> > +     char *oldp;
> > +     unsigned long start_at, mem_size;
> > +
> > +     if (!p)
> > +             return;
> > +
> > +     oldp = p;
> > +     mem_size = memparse(p, &p);
> > +     if (p == oldp)
> > +             return;
> > +
> > +     switch (*p) {
> > +     case '@':
> > +             start_at = memparse(p + 1, &p);
> > +             memblock_add(start_at, mem_size);
> > +             break;
> > +
> > +     case '$':
> > +             start_at = memparse(p + 1, &p);
> > +             memblock_reserve(start_at, mem_size);
> > +             break;
> > +
> > +     default:
> > +             pr_warn("Unrecognized memmap syntax: %s\n", p);
> > +             break;
> > +     }
> > +}
> > +
> > +static int __init parse_memmap_opt(char *str)
> > +{
> > +     while (str) {
> > +             char *k = strchr(str, ',');
> > +
> > +             if (k)
> > +                     *k++ = 0;
> > +
> > +             parse_memmap_one(str);
> > +             str = k;
> > +     }
> > +
> > +     return 0;
> > +}
> > +early_param("memmap", parse_memmap_opt);
> > +
> >  static void __init setup_bootmem(void)
> >  {
> >       phys_addr_t vmlinux_end = __pa_symbol(&_end);
> > --
> > 2.20.1
> >
>
> Reviewed-by: Charlie Jenkins <charlie at rivosinc.com>
>

Thanks,
Yunhui



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