On Sun, Jan 30, 2022 at 10:50 AM Samuel Holland <samuel@xxxxxxxxxxxx> wrote: > > On 1/29/22 8:08 PM, Guo Ren wrote: > > On Sun, Jan 30, 2022 at 2:32 AM Marc Zyngier <maz@xxxxxxxxxx> wrote: > >> > >> On Sat, 29 Jan 2022 16:27:26 +0000, > >> guoren@xxxxxxxxxx wrote: > >>> > >>> From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> > >>> > >>> The thead,c900-plic has been used in opensbi to distinguish > >>> PLIC [1]. Although PLICs have the same behaviors in Linux, > >>> they are different hardware with some custom initializing in > >>> firmware(opensbi). > >>> > >>> [1]: https://github.com/riscv-software-src/opensbi/commit/78c2b19218bd62653b9fb31623a42ced45f38ea6 > >>> > >>> Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> > >>> Cc: Anup Patel <anup@xxxxxxxxxxxxxx> > >>> Cc: Marc Zyngier <maz@xxxxxxxxxx> > >>> Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx> > >>> Cc: Samuel Holland <samuel@xxxxxxxxxxxx> > >>> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > >>> --- > >>> drivers/irqchip/irq-sifive-plic.c | 25 +++++++++++++++++++++++-- > >>> 1 file changed, 23 insertions(+), 2 deletions(-) > >>> > >>> diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c > >>> index 259065d271ef..245655928076 100644 > >>> --- a/drivers/irqchip/irq-sifive-plic.c > >>> +++ b/drivers/irqchip/irq-sifive-plic.c > >>> @@ -172,7 +172,7 @@ static void plic_irq_eoi(struct irq_data *d) > >>> } > >>> } > >>> > >>> -static struct irq_chip plic_chip = { > >>> +static struct irq_chip sifive_plic_chip = { > >>> .name = "SiFive PLIC", > >>> .irq_mask = plic_irq_mask, > >>> .irq_unmask = plic_irq_unmask, > >>> @@ -182,12 +182,24 @@ static struct irq_chip plic_chip = { > >>> #endif > >>> }; > >>> > >>> +static struct irq_chip thead_plic_chip = { > >>> + .name = "T-Head PLIC", > >>> + .irq_mask = plic_irq_mask, > >>> + .irq_unmask = plic_irq_unmask, > >>> + .irq_eoi = plic_irq_eoi, > >>> +#ifdef CONFIG_SMP > >>> + .irq_set_affinity = plic_set_affinity, > >>> +#endif > >>> +}; > >> > >> For pure entertainment, let's compare the two structures: > >> > >> static struct irq_chip plic_chip = { > >> .name = "SiFive PLIC", > >> .irq_mask = plic_irq_mask, > >> .irq_unmask = plic_irq_unmask, > >> .irq_eoi = plic_irq_eoi, > >> #ifdef CONFIG_SMP > >> .irq_set_affinity = plic_set_affinity, > >> #endif > >> }; > >> > >> Oh wait: a string. Must be really important. Not. > > No, pls see below comment. > > > >> > >>> + > >>> +static struct irq_chip *def_plic_chip = &sifive_plic_chip; > >>> + > >>> static int plic_irqdomain_map(struct irq_domain *d, unsigned int irq, > >>> irq_hw_number_t hwirq) > >>> { > >>> struct plic_priv *priv = d->host_data; > >>> > >>> - irq_domain_set_info(d, irq, hwirq, &plic_chip, d->host_data, > >>> + irq_domain_set_info(d, irq, hwirq, def_plic_chip, d->host_data, > >>> handle_fasteoi_irq, NULL, NULL); > >>> irq_set_noprobe(irq); > >>> irq_set_affinity(irq, &priv->lmask); > >>> @@ -396,5 +408,14 @@ static int __init plic_init(struct device_node *node, > >>> return error; > >>> } > >>> > >>> +static int __init thead_c900_plic_init(struct device_node *node, > >>> + struct device_node *parent) > >>> +{ > >>> + def_plic_chip = &thead_plic_chip; > >>> + > >>> + return plic_init(node, parent); > >>> +} > >>> + > >>> IRQCHIP_DECLARE(sifive_plic, "sifive,plic-1.0.0", plic_init); > >>> IRQCHIP_DECLARE(riscv_plic0, "riscv,plic0", plic_init); /* for legacy systems */ > >>> +IRQCHIP_DECLARE(thead_c900_plic, "thead,c900-plic", thead_c900_plic_init); > >> > >> Sorry, but I can't see any point to this patch. > > You didn't see the link I've put in the patch. In that opensbi patch: > > > > intc: interrupt-controller@10000000 { > > #interrupt-cells = <1>; > > - compatible = "riscv,plic0"; > > + compatible = "allwinner,sun20i-d1-plic", > > + "thead,c900-plic"; > > > > +#define THEAD_PLIC_CTRL_REG 0x1ffffc > > + > > +static void thead_plic_plat_init(struct plic_data *pd) > > +{ > > + writel_relaxed(BIT(0), (void *)pd->addr + THEAD_PLIC_CTRL_REG); > > +} > > + > > static const struct fdt_match irqchip_plic_match[] = { > > { .compatible = "riscv,plic0" }, > > { .compatible = "sifive,plic-1.0.0" }, > > + { .compatible = "thead,c900-plic", > > + .data = thead_plic_plat_init }, > > { }, > > }; > > > > We've changed the compatible name for thead,c900-plic, and there is no > > riscv,plic0 / sifive,plic-1.0.0 in dts. Without the patch, the newest > > opensbi + newest Linux would be broken in the Allwinner D1 dev board. > > Yes, some patch is still necessary, because the hardware is indeed incompatible > with riscv,plic0. However, this driver does not care about the difference. So > all you need to do is hook up the existing code to the new compatible: > > +IRQCHIP_DECLARE(thead_c900_plic, "thead,c900-plic", plic_init); I think we should give clear info in /proc/interrupts. I hope we could keep thead_plic_init. > > Regards, > Samuel -- Best Regards Guo Ren ML: https://lore.kernel.org/linux-csky/
