Re: [PATCH 5/5] cpufreq: loongson3: Replace IOCSR read/write with MMIO ones

[Huacai Chen]

Hi, Ruoyao,

On Fri, Aug 21, 2026 at 1:01 PM Xi Ruoyao <xry111@xxxxxxxxxxx> wrote:
>
>
>
> 在 2026/8/18 20:39, Huacai Chen 写道:
> > Our server productions (e.g. Loongson-3D6000/3E6000) can have multiple
> > nodes in one package and SMC mailboxes are also per-node. However, IOCSR
> > read/write can only perform on the current node, while sometimes we want
> > to perform on other nodes (e.g. when switch governor, the get and target
> > callbacks are not run on target core). So replace IOCSR read/write with
> > MMIO ones.
> >
> > Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
> > ---
> >   drivers/cpufreq/loongson3_cpufreq.c | 31 ++++++++++++++++++++++-------
> >   1 file changed, 24 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/cpufreq/loongson3_cpufreq.c b/drivers/cpufreq/loongson3_cpufreq.c
> > index c75c0e30e881..e5062cd62390 100644
> > --- a/drivers/cpufreq/loongson3_cpufreq.c
> > +++ b/drivers/cpufreq/loongson3_cpufreq.c
> > @@ -164,6 +164,12 @@ union smc_message {
> >
> >   #define FREQ_MAX_LEVEL                      16
> >
> > +#define MMIO_SMCMBX(node) \
> > +     ((void __iomem *)(IO_BASE | (u64)(node) << NODE_ADDRSPACE_SHIFT | LOONGSON_REG_BASE | LOONGARCH_IOCSR_SMCMBX))
>
> NODE_ADDRSPACE_SHIFT is defined in numa.h so that file needs to be
> included, to avoid a build failure when NUMA is disabled (if NUMA is
> enabled, numa.h happens to be pulled in via some other headers).
>
> Also I'd suggest to use nid_to_addrbase(node) instead of hard coding the
> shift for better readability.
Yes, that's better, thank you very much.

Huacai
>
> With the changes:
>
> Tested-by: Xi Ruoyao <xry111@xxxxxxxxxxx> # on XA61200