Re: [PATCH 3/3] irqchip: RISC-V Local Interrupt Controller Driver

[Palmer Dabbelt]

On Fri, 22 Jun 2018 17:08:58 PDT (-0700), rdunlap@xxxxxxxxxxxxx wrote:
> On 06/22/2018 04:20 PM, Palmer Dabbelt wrote:
> > From: Palmer Dabbelt <palmer@xxxxxxxxxxx>
> >
> > This patch adds a driver that manages the local interrupts on each
> > RISC-V hart, as specifiec by the RISC-V supervisor level ISA manual.
> > The local interrupt controller manages software interrupts, timer
> > interrupts, and hardware interrupts (which are routed via the
> > platform level interrupt controller).  Per-hart local interrupt
> > controllers are found on all RISC-V systems.
> >
> > CC: Michael Clark <mjc@xxxxxxxxxx>
> > Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxx>
> > ---
> >  drivers/irqchip/Kconfig          |  13 +++
> >  drivers/irqchip/Makefile         |   1 +
> >  drivers/irqchip/irq-riscv-intc.c | 215 +++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 229 insertions(+)
> >  create mode 100644 drivers/irqchip/irq-riscv-intc.c
> >
> > diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> > index e9233db16e03..bf7fc86673b1 100644
> > --- a/drivers/irqchip/Kconfig
> > +++ b/drivers/irqchip/Kconfig
> > @@ -372,3 +372,16 @@ config QCOM_PDC
> >  	  IRQs for Qualcomm Technologies Inc (QTI) mobile chips.
> >
> >  endmenu
> > +
> > +config RISCV_INTC
> > +	#bool "RISC-V Interrupt Controller"
>
> Hi,
> What does the leading '#' do?

It's just a comment.  I'd seen this idiom used before to say "here's what this 
option would say if it was optional, which it may be at some point in the 
future, but for now it's just always enabled."

> > +	depends on RISCV
> > +	default y
> > +	help
> > +	   This enables support for the local interrupt controller found in
> > +	   standard RISC-V systems.  The local interrupt controller handles
> > +	   timer interrupts, software interrupts, and hardware interrupts.
> > +	   Without a local interrupt controller the system will be unable to
> > +	   handle any interrupts, including those passed via the PLIC.
> > +
> > +	   If you don't know what to do here, say Y.
> > diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> > index 15f268f646bf..74e333cc274c 100644
> > --- a/drivers/irqchip/Makefile
> > +++ b/drivers/irqchip/Makefile
> > @@ -87,3 +87,4 @@ obj-$(CONFIG_MESON_IRQ_GPIO)		+= irq-meson-gpio.o
> >  obj-$(CONFIG_GOLDFISH_PIC) 		+= irq-goldfish-pic.o
> >  obj-$(CONFIG_NDS32)			+= irq-ativic32.o
> >  obj-$(CONFIG_QCOM_PDC)			+= qcom-pdc.o
> > +obj-$(CONFIG_RISCV_INTC)		+= irq-riscv-intc.o