Re: Can't understand /proc/interrupts output for GICv3 case

['Greg KH' <greg@kroah.com>]

On Mon, Apr 11, 2022 at 10:13:42PM +0900, Chan Kim wrote:
> Hi, Greg K-H,
> Thanks for replyaing.
> > 
> > You ask the system for it.  It depends on the bus type your driver is
> > written for for how to do this.
> > 
> > For example, if you have a platform driver, you would call
> > platform_get_irq().  If you are a pci driver, the irq for your device is
> > already stored in the pci device structure passed into your probe
> function.
> > 
> > What bus type is your driver written for?
> > 
> That sounds very logical. In my case I added it to system bus.

What exactly do you mean by "system bus"?

> This is the qemu code making fdt. 
> 
> static void create_ab21q_axpu_device(const Ab21qMachineState *vms)
> {
>     char *nodename;
>     printf("create_ab21q_axpu_device called!\n");
>     hwaddr base = vms->memmap[AB21Q_AXPU].base;
>     hwaddr size = vms->memmap[AB21Q_AXPU].size;
>     int irq = vms->irqmap[AB21Q_AXPU];
>     const char compat[] = "ab21q-axpu";
> 
>     sysbus_create_simple("ab21q-axpu", base, qdev_get_gpio_in(vms->gic,
> irq));
> 
>     nodename = g_strdup_printf("/ab21q_axpu@%" PRIx64, base);
>     qemu_fdt_add_subnode(vms->fdt, nodename);
>     qemu_fdt_setprop(vms->fdt, nodename, "compatible", compat,
> sizeof(compat));
>     qemu_fdt_setprop_sized_cells(vms->fdt, nodename, "reg", 2, base, 2,
> size);
>     qemu_fdt_setprop_cells(vms->fdt, nodename, "interrupts",
>                            GIC_FDT_IRQ_TYPE_SPI, irq, 
>                            GIC_FDT_IRQ_FLAGS_LEVEL_HI);
>     qemu_fdt_setprop_cell(vms->fdt, nodename, "interrupt-parent",
> vms->gic_phandle);
> 
>     g_free(nodename);

This is qemu code, not kernel code.

> }
> 
> I understand it creates the device axpu and connects its irq output to a
> gpio input connected to gic interrupt controller. 

Again, this is qemu code, not kernel code.

> But this driver is not in the form of platform device/driver. (a char
> device). What function should I use to get the irq number in this case?
> I couldn't find a function with a likely name in the tags file for linux
> source.(5.4.188)

Where is your kernel code?

confused,

greg k-h

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