Re: [PATCH v2] mfd: loongson-se: Add multi-node support

[Qunqin Zhao]

在 2026/4/27 下午5:02, Huacai Chen 写道:
> Hi, Qunqin,
>
> On Mon, Apr 27, 2026 at 4:55 PM Qunqin Zhao <zhaoqunqin@xxxxxxxxxxx> wrote:
> > On the Loongson platform, each node is equipped with a security engine
> > device. However, due to a hardware flaw, only the device on node 0 can
> > trigger interrupts. Therefore, interrupts from other nodes are forwarded
> > by node 0. We need to check in the interrupt handler of node 0 whether
> > this interrupt is intended for other nodes.
> Multi-node or multi-package? In my opinion SE has no relationship with
> NUMA node, so maybe package?

Here is the output of lscpu from my machine:

[loongson@localhost ~]$ lscpu
Architecture:          loongarch64
  CPU op-mode(s):      32-bit, 64-bit
  Address sizes:       48 bits physical, 48 bits virtual
  Byte Order:          Little Endian
CPU(s):                128
  On-line CPU(s) list: 0-127
Model name:            Loongson-3C6000/D
  CPU family:          Loongson-64bit
  Model:               0x11
  Thread(s) per core:  2
  Core(s) per socket:  32
  Socket(s):           2
  BogoMIPS:            4200.00
  Flags:               cpucfg lam ual fpu lsx lasx crc32 complex crypto 
lvz lbt_x86 lbt_arm lbt_mips
Caches (sum of all):
  L1d:                 4 MiB (64 instances)
  L1i:                 4 MiB (64 instances)
  L2:                  16 MiB (64 instances)
  L3:                  128 MiB (4 instances)
NUMA:
  NUMA node(s):        4
  NUMA node0 CPU(s):   0-31
  NUMA node1 CPU(s):   32-63
  NUMA node2 CPU(s):   64-95
  NUMA node3 CPU(s):   96-127

There are four SE devices in my system, one for each NUMA node.

Qunqin,

Thanks

> Huacai
>
> > Signed-off-by: Qunqin Zhao <zhaoqunqin@xxxxxxxxxxx>
> > ---
> > Changes in v2:
> >          -Resending due to no feedback for one month.
> >          -Rebased on top of latest mainline (7.1-rc1) to ensure the patch
> >           applies cleanly.
> >          -No functional changes since the previous submission.
> >
> > Link to v1:
> > https://lore.kernel.org/all/20260226102225.19516-1-zhaoqunqin@xxxxxxxxxxx/#t
> >
> >   drivers/mfd/loongson-se.c       | 38 +++++++++++++++++++++++++++------
> >   include/linux/mfd/loongson-se.h |  3 +++
> >   2 files changed, 35 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/mfd/loongson-se.c b/drivers/mfd/loongson-se.c
> > index 3902ba377d6..40e18c21268 100644
> > --- a/drivers/mfd/loongson-se.c
> > +++ b/drivers/mfd/loongson-se.c
> > @@ -37,6 +37,9 @@ struct loongson_se_controller_cmd {
> >          u32 info[7];
> >   };
> >
> > +static DECLARE_COMPLETION(node0);
> > +static struct loongson_se *se_node[SE_MAX_NODES];
> > +
> >   static int loongson_se_poll(struct loongson_se *se, u32 int_bit)
> >   {
> >          u32 status;
> > @@ -133,8 +136,8 @@ EXPORT_SYMBOL_GPL(loongson_se_init_engine);
> >   static irqreturn_t se_irq_handler(int irq, void *dev_id)
> >   {
> >          struct loongson_se *se = dev_id;
> > -       u32 int_status;
> > -       int id;
> > +       u32 int_status, node_irq = 0;
> > +       int id, node;
> >
> >          spin_lock(&se->dev_lock);
> >
> > @@ -147,6 +150,11 @@ static irqreturn_t se_irq_handler(int irq, void *dev_id)
> >                  writel(SE_INT_CONTROLLER, se->base + SE_S2LINT_CL);
> >          }
> >
> > +       if (int_status & SE_INT_OTHER_NODE) {
> > +               int_status &= ~SE_INT_OTHER_NODE;
> > +               node_irq = 1;
> > +       }
> > +
> >          /* For engines */
> >          while (int_status) {
> >                  id = __ffs(int_status);
> > @@ -157,6 +165,14 @@ static irqreturn_t se_irq_handler(int irq, void *dev_id)
> >
> >          spin_unlock(&se->dev_lock);
> >
> > +       if (node_irq) {
> > +               writel(SE_INT_OTHER_NODE, se->base + SE_S2LINT_CL);
> > +               for (node = 1; node < SE_MAX_NODES; node++) {
> > +                       if (se_node[node])
> > +                               se_irq_handler(irq, se_node[node]);
> > +               }
> > +       }
> > +
> >          return IRQ_HANDLED;
> >   }
> >
> > @@ -189,6 +205,7 @@ static int loongson_se_probe(struct platform_device *pdev)
> >          struct loongson_se *se;
> >          int nr_irq, irq, err, i;
> >          dma_addr_t paddr;
> > +       int node = dev_to_node(dev);
> >
> >          se = devm_kmalloc(dev, sizeof(*se), GFP_KERNEL);
> >          if (!se)
> > @@ -213,9 +230,16 @@ static int loongson_se_probe(struct platform_device *pdev)
> >
> >          writel(SE_INT_ALL, se->base + SE_S2LINT_EN);
> >
> > -       nr_irq = platform_irq_count(pdev);
> > -       if (nr_irq <= 0)
> > -               return -ENODEV;
> > +       if (node == 0 || node == NUMA_NO_NODE) {
> > +               nr_irq = platform_irq_count(pdev);
> > +               if (nr_irq <= 0)
> > +                       return -ENODEV;
> > +       } else {
> > +               /* Only the device on node 0 can trigger interrupts */
> > +               nr_irq = 0;
> > +               wait_for_completion_interruptible(&node0);
> > +               se_node[node] = se;
> > +       }
> >
> >          for (i = 0; i < nr_irq; i++) {
> >                  irq = platform_get_irq(pdev, i);
> > @@ -228,7 +252,9 @@ static int loongson_se_probe(struct platform_device *pdev)
> >          if (err)
> >                  return err;
> >
> > -       return devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE, engines,
> > +       complete_all(&node0);
> > +
> > +       return devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO, engines,
> >                                      ARRAY_SIZE(engines), NULL, 0, NULL);
> >   }
> >
> > diff --git a/include/linux/mfd/loongson-se.h b/include/linux/mfd/loongson-se.h
> > index 07afa0c2524..a80e06eb017 100644
> > --- a/include/linux/mfd/loongson-se.h
> > +++ b/include/linux/mfd/loongson-se.h
> > @@ -20,6 +20,9 @@
> >
> >   #define SE_INT_ALL                     0xffffffff
> >   #define SE_INT_CONTROLLER              BIT(0)
> > +#define SE_INT_OTHER_NODE              BIT(31)
> > +
> > +#define SE_MAX_NODES                   8
> >
> >   #define SE_ENGINE_MAX                  16
> >   #define SE_ENGINE_RNG                  1
> >
> > base-commit: 254f49634ee16a731174d2ae34bc50bd5f45e731
> > --
> > 2.47.2