Re: [PATCH 2/3] dt-bindings: interrupt-controller: RISC-V local interrupt controller docs
On Mon, 25 Jun 2018 13:04:48 PDT (-0700), christ...@boehmwalder.at wrote:
On Fri, Jun 22, 2018 at 04:20:05PM -0700, Palmer Dabbelt wrote:
From: Palmer Dabbelt
This patch adds documentation on the RISC-V local interrupt controller,
which is a per-hart interrupt controller that manages all interrupts
entering a RISC-V hart. This interrupt controller is present on all
RISC-V systems.
Signed-off-by: Palmer Dabbelt
---
.../interrupt-controller/riscv,cpu-intc.txt| 41 ++
1 file changed, 41 insertions(+)
create mode 100644
Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
diff --git
a/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
b/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
new file mode 100644
index ..61900e2e3868
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
@@ -0,0 +1,41 @@
+RISC-V Hart-Level Interrupt Controller (HLIC)
+-
+
+RISC-V cores include Control Status Registers (CSRs) which are local to each
+hart and can be read or written by software. Some of these CSRs are used to
+control local interrupts connected to the core. Every interrupt is ultimately
+routed through a hart's HLIC before it interrupts that hart.
+
+The RISC-V supervisor ISA manual specifies three interrupt sources that are
+attached to every HLIC: software interrupts, the timer interrupt, and external
+interrupts. Software interrupts are used to send IPIs between cores. The
+timer interrupt comes from an architecturally mandated real-time timer that is
+controller via SBI calls and CSR reads. External interrupts connect all other
+device interrupts to the HLIC, which are routed via the platform-level
+interrupt controller (PLIC).
+
+All RISC-V systems that conform to the supervisor ISA specification are
+required to have a HLIC with these three interrupt sources present. Since the
+interrupt map is defined by the ISA it's not listed in the HLIC's device tree
+entry, though external interrupt controllers (like the PLIC, for example) will
+need to define how their interrupts map to the relevant HLICs.
+
+Required properties:
+- compatible : "riscv,cpu-intc"
+- #interrupt-cells : should be <1>
+- interrupt-controller : Identifies the node as an interrupt controller
+
+Furthermore, this interrupt-controller MUST be embedded inside the cpu
+definition of the hart whose CSRs control these local interrupts.
+
+An example device tree entry for a HLIC is show below.
Spotted a typo here, "show" -> "shown".
Thanks. It looks like we're actually dropping this binding and integrating
this first-level interrupt controller into the core RISC-V arch code as keeping
it split out results in too many inefficiencies.
+
+ cpu1: cpu@1 {
+ compatible = "riscv";
+ ...
+ cpu1-intc: interrupt-controller {
+ #interrupt-cells = <1>;
+ compatible = "riscv,cpu-intc";
+ interrupt-controller;
+ };
+ };
--
2.16.4
Also, I've noticed that double spaces after punctuation are used pretty
inconsistently throughout the document. Is that intended?
No. I noticed this in the PLIC document as well, I'll fix that one up.
Thanks!
Re: [PATCH 2/3] dt-bindings: interrupt-controller: RISC-V local interrupt controller docs
On Mon, 25 Jun 2018 13:04:48 PDT (-0700), christ...@boehmwalder.at wrote:
On Fri, Jun 22, 2018 at 04:20:05PM -0700, Palmer Dabbelt wrote:
From: Palmer Dabbelt
This patch adds documentation on the RISC-V local interrupt controller,
which is a per-hart interrupt controller that manages all interrupts
entering a RISC-V hart. This interrupt controller is present on all
RISC-V systems.
Signed-off-by: Palmer Dabbelt
---
.../interrupt-controller/riscv,cpu-intc.txt| 41 ++
1 file changed, 41 insertions(+)
create mode 100644
Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
diff --git
a/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
b/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
new file mode 100644
index ..61900e2e3868
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
@@ -0,0 +1,41 @@
+RISC-V Hart-Level Interrupt Controller (HLIC)
+-
+
+RISC-V cores include Control Status Registers (CSRs) which are local to each
+hart and can be read or written by software. Some of these CSRs are used to
+control local interrupts connected to the core. Every interrupt is ultimately
+routed through a hart's HLIC before it interrupts that hart.
+
+The RISC-V supervisor ISA manual specifies three interrupt sources that are
+attached to every HLIC: software interrupts, the timer interrupt, and external
+interrupts. Software interrupts are used to send IPIs between cores. The
+timer interrupt comes from an architecturally mandated real-time timer that is
+controller via SBI calls and CSR reads. External interrupts connect all other
+device interrupts to the HLIC, which are routed via the platform-level
+interrupt controller (PLIC).
+
+All RISC-V systems that conform to the supervisor ISA specification are
+required to have a HLIC with these three interrupt sources present. Since the
+interrupt map is defined by the ISA it's not listed in the HLIC's device tree
+entry, though external interrupt controllers (like the PLIC, for example) will
+need to define how their interrupts map to the relevant HLICs.
+
+Required properties:
+- compatible : "riscv,cpu-intc"
+- #interrupt-cells : should be <1>
+- interrupt-controller : Identifies the node as an interrupt controller
+
+Furthermore, this interrupt-controller MUST be embedded inside the cpu
+definition of the hart whose CSRs control these local interrupts.
+
+An example device tree entry for a HLIC is show below.
Spotted a typo here, "show" -> "shown".
Thanks. It looks like we're actually dropping this binding and integrating
this first-level interrupt controller into the core RISC-V arch code as keeping
it split out results in too many inefficiencies.
+
+ cpu1: cpu@1 {
+ compatible = "riscv";
+ ...
+ cpu1-intc: interrupt-controller {
+ #interrupt-cells = <1>;
+ compatible = "riscv,cpu-intc";
+ interrupt-controller;
+ };
+ };
--
2.16.4
Also, I've noticed that double spaces after punctuation are used pretty
inconsistently throughout the document. Is that intended?
No. I noticed this in the PLIC document as well, I'll fix that one up.
Thanks!
Re: [PATCH 2/3] dt-bindings: interrupt-controller: RISC-V local interrupt controller docs
On Fri, Jun 22, 2018 at 04:20:05PM -0700, Palmer Dabbelt wrote:
> From: Palmer Dabbelt
>
> This patch adds documentation on the RISC-V local interrupt controller,
> which is a per-hart interrupt controller that manages all interrupts
> entering a RISC-V hart. This interrupt controller is present on all
> RISC-V systems.
>
> Signed-off-by: Palmer Dabbelt
> ---
> .../interrupt-controller/riscv,cpu-intc.txt| 41
> ++
> 1 file changed, 41 insertions(+)
> create mode 100644
> Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
>
> diff --git
> a/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
> b/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
> new file mode 100644
> index ..61900e2e3868
> --- /dev/null
> +++
> b/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
> @@ -0,0 +1,41 @@
> +RISC-V Hart-Level Interrupt Controller (HLIC)
> +-
> +
> +RISC-V cores include Control Status Registers (CSRs) which are local to each
> +hart and can be read or written by software. Some of these CSRs are used to
> +control local interrupts connected to the core. Every interrupt is
> ultimately
> +routed through a hart's HLIC before it interrupts that hart.
> +
> +The RISC-V supervisor ISA manual specifies three interrupt sources that are
> +attached to every HLIC: software interrupts, the timer interrupt, and
> external
> +interrupts. Software interrupts are used to send IPIs between cores. The
> +timer interrupt comes from an architecturally mandated real-time timer that
> is
> +controller via SBI calls and CSR reads. External interrupts connect all
> other
> +device interrupts to the HLIC, which are routed via the platform-level
> +interrupt controller (PLIC).
> +
> +All RISC-V systems that conform to the supervisor ISA specification are
> +required to have a HLIC with these three interrupt sources present. Since
> the
> +interrupt map is defined by the ISA it's not listed in the HLIC's device tree
> +entry, though external interrupt controllers (like the PLIC, for example)
> will
> +need to define how their interrupts map to the relevant HLICs.
What are the PLIC to HLIC connections you need to support? 1-to-1 is
easy. But I would imagine you'd want the PLIC irq to go to all the HLICs
which can't really be described unless you list every CPU's HLIC in
PLIC "interrupts" property.
We avoid this problem on ARM because a single DT interrupt controller
node represents even per cpu interrupts and interrupt cells are used to
indicate which CPU interrupts are routed too. That's not perfect either,
but seems to be good enough (though maybe Marc Z or Mark R have more
thoughts on that).
> +
> +Required properties:
> +- compatible : "riscv,cpu-intc"
Kind of vague. There's only one implementation and one set of bugs?
> +- #interrupt-cells : should be <1>
> +- interrupt-controller : Identifies the node as an interrupt controller
> +
> +Furthermore, this interrupt-controller MUST be embedded inside the cpu
> +definition of the hart whose CSRs control these local interrupts.
> +
> +An example device tree entry for a HLIC is show below.
> +
> + cpu1: cpu@1 {
> + compatible = "riscv";
> + ...
> + cpu1-intc: interrupt-controller {
> + #interrupt-cells = <1>;
> + compatible = "riscv,cpu-intc";
> + interrupt-controller;
> + };
> + };
> --
> 2.16.4
>
Re: [PATCH 2/3] dt-bindings: interrupt-controller: RISC-V local interrupt controller docs
On Fri, Jun 22, 2018 at 04:20:05PM -0700, Palmer Dabbelt wrote:
> From: Palmer Dabbelt
>
> This patch adds documentation on the RISC-V local interrupt controller,
> which is a per-hart interrupt controller that manages all interrupts
> entering a RISC-V hart. This interrupt controller is present on all
> RISC-V systems.
>
> Signed-off-by: Palmer Dabbelt
> ---
> .../interrupt-controller/riscv,cpu-intc.txt| 41
> ++
> 1 file changed, 41 insertions(+)
> create mode 100644
> Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
>
> diff --git
> a/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
> b/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
> new file mode 100644
> index ..61900e2e3868
> --- /dev/null
> +++
> b/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
> @@ -0,0 +1,41 @@
> +RISC-V Hart-Level Interrupt Controller (HLIC)
> +-
> +
> +RISC-V cores include Control Status Registers (CSRs) which are local to each
> +hart and can be read or written by software. Some of these CSRs are used to
> +control local interrupts connected to the core. Every interrupt is
> ultimately
> +routed through a hart's HLIC before it interrupts that hart.
> +
> +The RISC-V supervisor ISA manual specifies three interrupt sources that are
> +attached to every HLIC: software interrupts, the timer interrupt, and
> external
> +interrupts. Software interrupts are used to send IPIs between cores. The
> +timer interrupt comes from an architecturally mandated real-time timer that
> is
> +controller via SBI calls and CSR reads. External interrupts connect all
> other
> +device interrupts to the HLIC, which are routed via the platform-level
> +interrupt controller (PLIC).
> +
> +All RISC-V systems that conform to the supervisor ISA specification are
> +required to have a HLIC with these three interrupt sources present. Since
> the
> +interrupt map is defined by the ISA it's not listed in the HLIC's device tree
> +entry, though external interrupt controllers (like the PLIC, for example)
> will
> +need to define how their interrupts map to the relevant HLICs.
What are the PLIC to HLIC connections you need to support? 1-to-1 is
easy. But I would imagine you'd want the PLIC irq to go to all the HLICs
which can't really be described unless you list every CPU's HLIC in
PLIC "interrupts" property.
We avoid this problem on ARM because a single DT interrupt controller
node represents even per cpu interrupts and interrupt cells are used to
indicate which CPU interrupts are routed too. That's not perfect either,
but seems to be good enough (though maybe Marc Z or Mark R have more
thoughts on that).
> +
> +Required properties:
> +- compatible : "riscv,cpu-intc"
Kind of vague. There's only one implementation and one set of bugs?
> +- #interrupt-cells : should be <1>
> +- interrupt-controller : Identifies the node as an interrupt controller
> +
> +Furthermore, this interrupt-controller MUST be embedded inside the cpu
> +definition of the hart whose CSRs control these local interrupts.
> +
> +An example device tree entry for a HLIC is show below.
> +
> + cpu1: cpu@1 {
> + compatible = "riscv";
> + ...
> + cpu1-intc: interrupt-controller {
> + #interrupt-cells = <1>;
> + compatible = "riscv,cpu-intc";
> + interrupt-controller;
> + };
> + };
> --
> 2.16.4
>
Re: [PATCH 2/3] dt-bindings: interrupt-controller: RISC-V local interrupt controller docs
On Fri, Jun 22, 2018 at 04:20:05PM -0700, Palmer Dabbelt wrote:
> From: Palmer Dabbelt
>
> This patch adds documentation on the RISC-V local interrupt controller,
> which is a per-hart interrupt controller that manages all interrupts
> entering a RISC-V hart. This interrupt controller is present on all
> RISC-V systems.
>
> Signed-off-by: Palmer Dabbelt
> ---
> .../interrupt-controller/riscv,cpu-intc.txt| 41
> ++
> 1 file changed, 41 insertions(+)
> create mode 100644
> Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
>
> diff --git
> a/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
> b/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
> new file mode 100644
> index ..61900e2e3868
> --- /dev/null
> +++
> b/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
> @@ -0,0 +1,41 @@
> +RISC-V Hart-Level Interrupt Controller (HLIC)
> +-
> +
> +RISC-V cores include Control Status Registers (CSRs) which are local to each
> +hart and can be read or written by software. Some of these CSRs are used to
> +control local interrupts connected to the core. Every interrupt is
> ultimately
> +routed through a hart's HLIC before it interrupts that hart.
> +
> +The RISC-V supervisor ISA manual specifies three interrupt sources that are
> +attached to every HLIC: software interrupts, the timer interrupt, and
> external
> +interrupts. Software interrupts are used to send IPIs between cores. The
> +timer interrupt comes from an architecturally mandated real-time timer that
> is
> +controller via SBI calls and CSR reads. External interrupts connect all
> other
> +device interrupts to the HLIC, which are routed via the platform-level
> +interrupt controller (PLIC).
> +
> +All RISC-V systems that conform to the supervisor ISA specification are
> +required to have a HLIC with these three interrupt sources present. Since
> the
> +interrupt map is defined by the ISA it's not listed in the HLIC's device tree
> +entry, though external interrupt controllers (like the PLIC, for example)
> will
> +need to define how their interrupts map to the relevant HLICs.
> +
> +Required properties:
> +- compatible : "riscv,cpu-intc"
> +- #interrupt-cells : should be <1>
> +- interrupt-controller : Identifies the node as an interrupt controller
> +
> +Furthermore, this interrupt-controller MUST be embedded inside the cpu
> +definition of the hart whose CSRs control these local interrupts.
> +
> +An example device tree entry for a HLIC is show below.
Spotted a typo here, "show" -> "shown".
> +
> + cpu1: cpu@1 {
> + compatible = "riscv";
> + ...
> + cpu1-intc: interrupt-controller {
> + #interrupt-cells = <1>;
> + compatible = "riscv,cpu-intc";
> + interrupt-controller;
> + };
> + };
> --
> 2.16.4
Also, I've noticed that double spaces after punctuation are used pretty
inconsistently throughout the document. Is that intended?
--
Regards,
Christoph
Re: [PATCH 2/3] dt-bindings: interrupt-controller: RISC-V local interrupt controller docs
On Fri, Jun 22, 2018 at 04:20:05PM -0700, Palmer Dabbelt wrote:
> From: Palmer Dabbelt
>
> This patch adds documentation on the RISC-V local interrupt controller,
> which is a per-hart interrupt controller that manages all interrupts
> entering a RISC-V hart. This interrupt controller is present on all
> RISC-V systems.
>
> Signed-off-by: Palmer Dabbelt
> ---
> .../interrupt-controller/riscv,cpu-intc.txt| 41
> ++
> 1 file changed, 41 insertions(+)
> create mode 100644
> Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
>
> diff --git
> a/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
> b/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
> new file mode 100644
> index ..61900e2e3868
> --- /dev/null
> +++
> b/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
> @@ -0,0 +1,41 @@
> +RISC-V Hart-Level Interrupt Controller (HLIC)
> +-
> +
> +RISC-V cores include Control Status Registers (CSRs) which are local to each
> +hart and can be read or written by software. Some of these CSRs are used to
> +control local interrupts connected to the core. Every interrupt is
> ultimately
> +routed through a hart's HLIC before it interrupts that hart.
> +
> +The RISC-V supervisor ISA manual specifies three interrupt sources that are
> +attached to every HLIC: software interrupts, the timer interrupt, and
> external
> +interrupts. Software interrupts are used to send IPIs between cores. The
> +timer interrupt comes from an architecturally mandated real-time timer that
> is
> +controller via SBI calls and CSR reads. External interrupts connect all
> other
> +device interrupts to the HLIC, which are routed via the platform-level
> +interrupt controller (PLIC).
> +
> +All RISC-V systems that conform to the supervisor ISA specification are
> +required to have a HLIC with these three interrupt sources present. Since
> the
> +interrupt map is defined by the ISA it's not listed in the HLIC's device tree
> +entry, though external interrupt controllers (like the PLIC, for example)
> will
> +need to define how their interrupts map to the relevant HLICs.
> +
> +Required properties:
> +- compatible : "riscv,cpu-intc"
> +- #interrupt-cells : should be <1>
> +- interrupt-controller : Identifies the node as an interrupt controller
> +
> +Furthermore, this interrupt-controller MUST be embedded inside the cpu
> +definition of the hart whose CSRs control these local interrupts.
> +
> +An example device tree entry for a HLIC is show below.
Spotted a typo here, "show" -> "shown".
> +
> + cpu1: cpu@1 {
> + compatible = "riscv";
> + ...
> + cpu1-intc: interrupt-controller {
> + #interrupt-cells = <1>;
> + compatible = "riscv,cpu-intc";
> + interrupt-controller;
> + };
> + };
> --
> 2.16.4
Also, I've noticed that double spaces after punctuation are used pretty
inconsistently throughout the document. Is that intended?
--
Regards,
Christoph
