diff mbox series

[v1,3/6] dt-bindings: cache: Add SiFive Extensible Cache controller

Message ID 20240216000837.1868917-4-samuel.holland@sifive.com (mailing list archive)
State New, archived
Headers show
Series SiFive cache controller PMU drivers | expand

Commit Message

Samuel Holland Feb. 16, 2024, 12:08 a.m. UTC 
From: Eric Lin <eric.lin@sifive.com>

Add YAML DT binding documentation for the SiFive Extensible Cache
controller. The Extensible Cache controller interleaves cache blocks
across a number of heterogeneous independently-programmed slices. Each
slice contains an MMIO interface for configuration, cache maintenance,
error reporting, and performance monitoring.

Signed-off-by: Eric Lin <eric.lin@sifive.com>
Co-developed-by: Samuel Holland <samuel.holland@sifive.com>
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
---

 .../cache/sifive,extensiblecache0.yaml        | 136 ++++++++++++++++++
 1 file changed, 136 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/cache/sifive,extensiblecache0.yaml

Comments

Krzysztof Kozlowski Feb. 17, 2024, 9:09 a.m. UTC | #1 
On 16/02/2024 01:08, Samuel Holland wrote:
> From: Eric Lin <eric.lin@sifive.com>
> 
> Add YAML DT binding documentation for the SiFive Extensible Cache
> controller. The Extensible Cache controller interleaves cache blocks
> across a number of heterogeneous independently-programmed slices. Each
> slice contains an MMIO interface for configuration, cache maintenance,
> error reporting, and performance monitoring.
> 
> +allOf:
> +  - $ref: /schemas/cache-controller.yaml#
> +
> +select:
> +  properties:
> +    compatible:
> +      contains:
> +        enum:
> +          - sifive,extensiblecache0
> +
> +  required:
> +    - compatible
> +
> +properties:
> +  compatible:
> +    items:
> +      - const: sifive,extensiblecache0
> +      - const: cache
> +
> +  "#address-cells": true

const or enum: [1, 2], depending on the addressing you need here.

> +  "#size-cells": true

ditto

> +  ranges: true
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  cache-block-size:
> +    const: 64
> +
> +  cache-level: true

5 is acceptable? I would argue this should be even const.

> +  cache-sets: true
> +  cache-size: true

Some constraints on any of these?

> +  cache-unified: true
> +
> +patternProperties:
> +  "^cache-controller@[0-9a-f]+$":
> +    type: object
> +    additionalProperties: false

What is this object supposed to represent? Add description.

> +    properties:
> +      reg:
> +        maxItems: 1
> +
> +      cache-block-size:
> +        const: 64
> +
> +      cache-sets: true
> +      cache-size: true
> +      cache-unified: true

cache-level

> +
> +      sifive,bm-event-counters:
> +        $ref: /schemas/types.yaml#/definitions/uint32
> +        default: 0
> +        description: Number of bucket monitor registers in this slice
> +
> +      sifive,cache-ways:
> +        $ref: /schemas/types.yaml#/definitions/uint32
> +        description: Number of ways in this slice (independent of cache size)
> +
> +      sifive,perfmon-counters:
> +        $ref: /schemas/types.yaml#/definitions/uint32
> +        default: 0
> +        description: Number of PMU counter registers in this slice
> +
> +    required:
> +      - reg
> +      - cache-block-size
> +      - cache-sets
> +      - cache-size
> +      - cache-unified
> +      - sifive,cache-ways
> +
> +required:
> +  - compatible
> +  - ranges
> +  - interrupts
> +  - cache-block-size
> +  - cache-level
> +  - cache-sets
> +  - cache-size
> +  - cache-unified
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    cache-controller@30040000 {
> +        compatible = "sifive,extensiblecache0", "cache";
> +        ranges = <0x30040000 0x30040000 0x10000>;
> +        interrupts = <0x4>;

You use hex as interrupt numbers on your platforms?

> +        cache-block-size = <0x40>;
> +        cache-level = <3>;
> +        cache-sets = <0x800>;

Best regards,
Krzysztof
Samuel Holland Feb. 18, 2024, 3:50 p.m. UTC | #2 
Hi Krzysztof,

On 2024-02-17 3:09 AM, Krzysztof Kozlowski wrote:
> On 16/02/2024 01:08, Samuel Holland wrote:
>> From: Eric Lin <eric.lin@sifive.com>
>>
>> Add YAML DT binding documentation for the SiFive Extensible Cache
>> controller. The Extensible Cache controller interleaves cache blocks
>> across a number of heterogeneous independently-programmed slices. Each
>> slice contains an MMIO interface for configuration, cache maintenance,
>> error reporting, and performance monitoring.
>>
>> +allOf:
>> +  - $ref: /schemas/cache-controller.yaml#
>> +
>> +select:
>> +  properties:
>> +    compatible:
>> +      contains:
>> +        enum:
>> +          - sifive,extensiblecache0
>> +
>> +  required:
>> +    - compatible
>> +
>> +properties:
>> +  compatible:
>> +    items:
>> +      - const: sifive,extensiblecache0
>> +      - const: cache
>> +
>> +  "#address-cells": true
> 
> const or enum: [1, 2], depending on the addressing you need here.
> 
>> +  "#size-cells": true
> 
> ditto
> 
>> +  ranges: true
>> +
>> +  interrupts:
>> +    maxItems: 1
>> +
>> +  cache-block-size:
>> +    const: 64
>> +
>> +  cache-level: true
> 
> 5 is acceptable? I would argue this should be even const.
> 
>> +  cache-sets: true
>> +  cache-size: true
> 
> Some constraints on any of these?

Thanks for the feedback. I will add the various constraints in v2, though some
constraints will be somewhat loose as the topology is highly configurable.

>> +  cache-unified: true
>> +
>> +patternProperties:
>> +  "^cache-controller@[0-9a-f]+$":
>> +    type: object
>> +    additionalProperties: false
> 
> What is this object supposed to represent? Add description.

I will add a description in v2.

This object represents a single slice of the cache. Requests from clients are
interleaved between cache slices depending on the client, the address, etc.

Since there is no strong relationship between client (i.e. CPU) and cache slice,
the next-level-cache property must point to the top-level EC node, not a slice.

>> +    properties:
>> +      reg:
>> +        maxItems: 1
>> +
>> +      cache-block-size:
>> +        const: 64
>> +
>> +      cache-sets: true
>> +      cache-size: true
>> +      cache-unified: true
> 
> cache-level

I will add this in v2. It seemed redundant since the value cannot differ between
slices.

Regards,
Samuel

>> +
>> +      sifive,bm-event-counters:
>> +        $ref: /schemas/types.yaml#/definitions/uint32
>> +        default: 0
>> +        description: Number of bucket monitor registers in this slice
>> +
>> +      sifive,cache-ways:
>> +        $ref: /schemas/types.yaml#/definitions/uint32
>> +        description: Number of ways in this slice (independent of cache size)
>> +
>> +      sifive,perfmon-counters:
>> +        $ref: /schemas/types.yaml#/definitions/uint32
>> +        default: 0
>> +        description: Number of PMU counter registers in this slice
>> +
>> +    required:
>> +      - reg
>> +      - cache-block-size
>> +      - cache-sets
>> +      - cache-size
>> +      - cache-unified
>> +      - sifive,cache-ways
>> +
>> +required:
>> +  - compatible
>> +  - ranges
>> +  - interrupts
>> +  - cache-block-size
>> +  - cache-level
>> +  - cache-sets
>> +  - cache-size
>> +  - cache-unified
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> +  - |
>> +    cache-controller@30040000 {
>> +        compatible = "sifive,extensiblecache0", "cache";
>> +        ranges = <0x30040000 0x30040000 0x10000>;
>> +        interrupts = <0x4>;
> 
> You use hex as interrupt numbers on your platforms?
> 
>> +        cache-block-size = <0x40>;
>> +        cache-level = <3>;
>> +        cache-sets = <0x800>;
> 
> Best regards,
> Krzysztof
>
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/cache/sifive,extensiblecache0.yaml b/Documentation/devicetree/bindings/cache/sifive,extensiblecache0.yaml
new file mode 100644
index 000000000000..d027114dbdba
--- /dev/null
+++ b/Documentation/devicetree/bindings/cache/sifive,extensiblecache0.yaml
@@ -0,0 +1,136 @@ 
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# Copyright (C) 2023-2024 SiFive, Inc.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/cache/sifive,extensiblecache0.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: SiFive Extensible Cache Controller
+
+maintainers:
+  - Eric Lin <eric.lin@sifive.com>
+
+description:
+  The SiFive Extensible Cache Controller provides a high-performance extensible
+  system (L2 or L3) cache. It is divided into several independent heterogeneous
+  slices, enabling a flexible topology and physical design.
+
+allOf:
+  - $ref: /schemas/cache-controller.yaml#
+
+select:
+  properties:
+    compatible:
+      contains:
+        enum:
+          - sifive,extensiblecache0
+
+  required:
+    - compatible
+
+properties:
+  compatible:
+    items:
+      - const: sifive,extensiblecache0
+      - const: cache
+
+  "#address-cells": true
+  "#size-cells": true
+  ranges: true
+
+  interrupts:
+    maxItems: 1
+
+  cache-block-size:
+    const: 64
+
+  cache-level: true
+  cache-sets: true
+  cache-size: true
+  cache-unified: true
+
+patternProperties:
+  "^cache-controller@[0-9a-f]+$":
+    type: object
+    additionalProperties: false
+    properties:
+      reg:
+        maxItems: 1
+
+      cache-block-size:
+        const: 64
+
+      cache-sets: true
+      cache-size: true
+      cache-unified: true
+
+      sifive,bm-event-counters:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        default: 0
+        description: Number of bucket monitor registers in this slice
+
+      sifive,cache-ways:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        description: Number of ways in this slice (independent of cache size)
+
+      sifive,perfmon-counters:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        default: 0
+        description: Number of PMU counter registers in this slice
+
+    required:
+      - reg
+      - cache-block-size
+      - cache-sets
+      - cache-size
+      - cache-unified
+      - sifive,cache-ways
+
+required:
+  - compatible
+  - ranges
+  - interrupts
+  - cache-block-size
+  - cache-level
+  - cache-sets
+  - cache-size
+  - cache-unified
+
+additionalProperties: false
+
+examples:
+  - |
+    cache-controller@30040000 {
+        compatible = "sifive,extensiblecache0", "cache";
+        ranges = <0x30040000 0x30040000 0x10000>;
+        interrupts = <0x4>;
+        cache-block-size = <0x40>;
+        cache-level = <3>;
+        cache-sets = <0x800>;
+        cache-size = <0x100000>;
+        cache-unified;
+        #address-cells = <1>;
+        #size-cells = <1>;
+
+        cache-controller@30040000 {
+            reg = <0x30040000 0x4000>;
+            cache-block-size = <0x40>;
+            cache-sets = <0x400>;
+            cache-size = <0x80000>;
+            cache-unified;
+            sifive,bm-event-counters = <8>;
+            sifive,cache-ways = <9>;
+            sifive,perfmon-counters = <8>;
+        };
+
+        cache-controller@30044000 {
+            reg = <0x30044000 0x4000>;
+            cache-block-size = <0x40>;
+            cache-sets = <0x400>;
+            cache-size = <0x80000>;
+            cache-unified;
+            sifive,bm-event-counters = <8>;
+            sifive,cache-ways = <9>;
+            sifive,perfmon-counters = <8>;
+        };
+    };