[PATCH v3 0/3] irqchip: Add Sophgo SG2042 MSI controller

[PATCH v3 0/3] irqchip: Add Sophgo SG2042 MSI controller

[Chen Wang]

From: Chen Wang <unicorn_wang@outlook.com>

This controller is on the Sophgo SG2042 SoC to transform interrupts from
PCIe MSI to PLIC interrupts.

Thanks,
Chen

---

Changes in v3:
  The patch series is based on v6.13-rc7.

  Fixed following issues as per comments from Krzysztof Kozlowski, Samuel Holland,
  Christophe JAILLET, Inochi Amaoto, thanks.

  - bindings: use reg for doorbell, fixed wrong usage of additionalProperties
    and misc. 
  - Improve driver code:
    - Fixed potentional memory leak issues.
    - Fixed some build warnings reported by test robot.
    - Optimize and simplify the code when allocating hwirq.
    - Use DECLARE_BITMAP instead of kzalloc.
    - Some other coding style improvements.

Changes in v2:
  The patch series is based on v6.13-rc2. You can simply review or test the
  patches at the link [2].

  Fixed following issues as per comments from Rob Herring, Thomas Gleixner, thanks.

  - Improve driver binding description, use msi-ranges instread.
  - Improve driver code:
    - Improve coding style.
    - Fixed bug that possible memory leak of bitmap when sg2042_msi_init_domains returns error.
    - Use guard(mutex).
    - Use the MSI parent model.

Changes in v1:
  The patch series is based on v6.12-rc7. You can simply review or test the
  patches at the link [1].

Link: https://lore.kernel.org/linux-riscv/cover.1731296803.git.unicorn_wang@outlook.com/ [1]
Link: https://lore.kernel.org/linux-riscv/cover.1733726057.git.unicorn_wang@outlook.com/ [2]
---

Chen Wang (3):
  dt-bindings: interrupt-controller: Add Sophgo SG2042 MSI
  irqchip: Add the Sophgo SG2042 MSI interrupt controller
  riscv: sophgo: dts: add msi controller for SG2042

 .../sophgo,sg2042-msi.yaml                    |  58 ++++
 arch/riscv/boot/dts/sophgo/sg2042.dtsi        |  10 +
 drivers/irqchip/Kconfig                       |  12 +
 drivers/irqchip/Makefile                      |   1 +
 drivers/irqchip/irq-sg2042-msi.c              | 268 ++++++++++++++++++
 5 files changed, 349 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/interrupt-controller/sophgo,sg2042-msi.yaml
 create mode 100644 drivers/irqchip/irq-sg2042-msi.c


base-commit: 5bc55a333a2f7316b58edc7573e8e893f7acb532
-- 
2.34.1

[PATCH v3 1/3] dt-bindings: interrupt-controller: Add Sophgo SG2042 MSI

[Chen Wang]

From: Chen Wang <unicorn_wang@outlook.com>

Add binding for Sophgo SG2042 MSI controller.

Signed-off-by: Chen Wang <unicorn_wang@outlook.com>
---
 .../sophgo,sg2042-msi.yaml                    | 58 +++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/interrupt-controller/sophgo,sg2042-msi.yaml

diff --git a/Documentation/devicetree/bindings/interrupt-controller/sophgo,sg2042-msi.yaml b/Documentation/devicetree/bindings/interrupt-controller/sophgo,sg2042-msi.yaml
new file mode 100644
index 000000000000..f641df191787
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/sophgo,sg2042-msi.yaml
@@ -0,0 +1,58 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/interrupt-controller/sophgo,sg2042-msi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Sophgo SG2042 MSI Controller
+
+maintainers:
+  - Chen Wang <unicorn_wang@outlook.com>
+
+description:
+  This interrupt controller is in Sophgo SG2042 for transforming interrupts from
+  PCIe MSI to PLIC interrupts.
+
+allOf:
+  - $ref: /schemas/interrupts.yaml#
+  - $ref: /schemas/interrupt-controller/msi-controller.yaml#
+
+properties:
+  compatible:
+    const: sophgo,sg2042-msi
+
+  reg:
+    items:
+      - description: msi doorbell address
+      - description: clear register
+
+  reg-names:
+    items:
+      - const: doorbell
+      - const: clr
+
+  msi-controller: true
+
+  msi-ranges:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - reg-names
+  - msi-controller
+  - msi-ranges
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    msi-controller@30000000 {
+      compatible = "sophgo,sg2042-msi";
+      reg = <0x30000000 0x4>, <0x30000008 0x4>;
+      reg-names = "doorbell", "clr";
+      msi-controller;
+      msi-ranges = <&plic 64 IRQ_TYPE_LEVEL_HIGH 32>;
+      interrupt-parent = <&plic>;
+    };
-- 
2.34.1

[PATCH v3 2/3] irqchip: Add the Sophgo SG2042 MSI interrupt controller

[Chen Wang]

From: Chen Wang <unicorn_wang@outlook.com>

Add driver for Sophgo SG2042 MSI interrupt controller.

Signed-off-by: Chen Wang <unicorn_wang@outlook.com>
---
 drivers/irqchip/Kconfig          |  12 ++
 drivers/irqchip/Makefile         |   1 +
 drivers/irqchip/irq-sg2042-msi.c | 268 +++++++++++++++++++++++++++++++
 3 files changed, 281 insertions(+)
 create mode 100644 drivers/irqchip/irq-sg2042-msi.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 9bee02db1643..161fb5df857f 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -749,6 +749,18 @@ config MCHP_EIC
 	help
 	  Support for Microchip External Interrupt Controller.
 
+config SOPHGO_SG2042_MSI
+	bool "Sophgo SG2042 MSI Controller"
+	depends on ARCH_SOPHGO || COMPILE_TEST
+	depends on PCI
+	select IRQ_DOMAIN_HIERARCHY
+	select IRQ_MSI_LIB
+	select PCI_MSI
+	help
+	  Support for the Sophgo SG2042 MSI Controller.
+	  This on-chip interrupt controller enables MSI sources to be
+	  routed to the primary PLIC controller on SoC.
+
 config SUNPLUS_SP7021_INTC
 	bool "Sunplus SP7021 interrupt controller" if COMPILE_TEST
 	default SOC_SP7021
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 25e9ad29b8c4..dd60e597491d 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -128,4 +128,5 @@ obj-$(CONFIG_WPCM450_AIC)		+= irq-wpcm450-aic.o
 obj-$(CONFIG_IRQ_IDT3243X)		+= irq-idt3243x.o
 obj-$(CONFIG_APPLE_AIC)			+= irq-apple-aic.o
 obj-$(CONFIG_MCHP_EIC)			+= irq-mchp-eic.o
+obj-$(CONFIG_SOPHGO_SG2042_MSI)		+= irq-sg2042-msi.o
 obj-$(CONFIG_SUNPLUS_SP7021_INTC)	+= irq-sp7021-intc.o
diff --git a/drivers/irqchip/irq-sg2042-msi.c b/drivers/irqchip/irq-sg2042-msi.c
new file mode 100644
index 000000000000..1f88e1671e5c
--- /dev/null
+++ b/drivers/irqchip/irq-sg2042-msi.c
@@ -0,0 +1,268 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SG2042 MSI Controller
+ *
+ * Copyright (C) 2024 Sophgo Technology Inc.
+ * Copyright (C) 2024 Chen Wang <unicorn_wang@outlook.com>
+ */
+
+#include <linux/cleanup.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/msi.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_pci.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include "irq-msi-lib.h"
+
+#define SG2042_MAX_MSI_VECTOR	32
+
+struct sg2042_msi_chipdata {
+	void __iomem	*reg_clr;	// clear reg, see TRM, 10.1.33, GP_INTR0_CLR
+
+	phys_addr_t	doorbell_addr;	// see TRM, 10.1.32, GP_INTR0_SET
+
+	u32		irq_first;	// The vector number that MSIs starts
+	u32		num_irqs;	// The number of vectors for MSIs
+
+	DECLARE_BITMAP(msi_map, SG2042_MAX_MSI_VECTOR);
+	struct mutex	msi_map_lock;	// lock for msi_map
+};
+
+static int sg2042_msi_allocate_hwirq(struct sg2042_msi_chipdata *data, int num_req)
+{
+	int first;
+
+	guard(mutex)(&data->msi_map_lock);
+	first = bitmap_find_free_region(data->msi_map, data->num_irqs,
+					get_count_order(num_req));
+	return first >= 0 ? first : -ENOSPC;
+}
+
+static void sg2042_msi_free_hwirq(struct sg2042_msi_chipdata *data,
+				  int hwirq, int num_req)
+{
+	guard(mutex)(&data->msi_map_lock);
+	bitmap_release_region(data->msi_map, hwirq, get_count_order(num_req));
+}
+
+static void sg2042_msi_irq_ack(struct irq_data *d)
+{
+	struct sg2042_msi_chipdata *data  = irq_data_get_irq_chip_data(d);
+	int bit_off = d->hwirq;
+
+	writel(1 << bit_off, data->reg_clr);
+
+	irq_chip_ack_parent(d);
+}
+
+static void sg2042_msi_irq_compose_msi_msg(struct irq_data *d,
+					   struct msi_msg *msg)
+{
+	struct sg2042_msi_chipdata *data = irq_data_get_irq_chip_data(d);
+
+	msg->address_hi = upper_32_bits(data->doorbell_addr);
+	msg->address_lo = lower_32_bits(data->doorbell_addr);
+	msg->data = 1 << d->hwirq;
+}
+
+static const struct irq_chip sg2042_msi_middle_irq_chip = {
+	.name			= "SG2042 MSI",
+	.irq_ack		= sg2042_msi_irq_ack,
+	.irq_mask		= irq_chip_mask_parent,
+	.irq_unmask		= irq_chip_unmask_parent,
+#ifdef CONFIG_SMP
+	.irq_set_affinity	= irq_chip_set_affinity_parent,
+#endif
+	.irq_compose_msi_msg	= sg2042_msi_irq_compose_msi_msg,
+};
+
+static int sg2042_msi_parent_domain_alloc(struct irq_domain *domain,
+					  unsigned int virq, int hwirq)
+{
+	struct sg2042_msi_chipdata *data = domain->host_data;
+	struct irq_fwspec fwspec;
+	struct irq_data *d;
+	int ret;
+
+	fwspec.fwnode = domain->parent->fwnode;
+	fwspec.param_count = 2;
+	fwspec.param[0] = data->irq_first + hwirq;
+	fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
+
+	ret = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
+	if (ret)
+		return ret;
+
+	d = irq_domain_get_irq_data(domain->parent, virq);
+	return d->chip->irq_set_type(d, IRQ_TYPE_EDGE_RISING);
+}
+
+static int sg2042_msi_middle_domain_alloc(struct irq_domain *domain,
+					  unsigned int virq,
+					  unsigned int nr_irqs, void *args)
+{
+	struct sg2042_msi_chipdata *data = domain->host_data;
+	int hwirq, err, i;
+
+	hwirq = sg2042_msi_allocate_hwirq(data, nr_irqs);
+	if (hwirq < 0)
+		return hwirq;
+
+	for (i = 0; i < nr_irqs; i++) {
+		err = sg2042_msi_parent_domain_alloc(domain, virq + i, hwirq + i);
+		if (err)
+			goto err_hwirq;
+
+		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
+					      &sg2042_msi_middle_irq_chip, data);
+	}
+
+	return 0;
+
+err_hwirq:
+	sg2042_msi_free_hwirq(data, hwirq, nr_irqs);
+	irq_domain_free_irqs_parent(domain, virq, i);
+
+	return err;
+}
+
+static void sg2042_msi_middle_domain_free(struct irq_domain *domain,
+					  unsigned int virq,
+					  unsigned int nr_irqs)
+{
+	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
+	struct sg2042_msi_chipdata *data = irq_data_get_irq_chip_data(d);
+
+	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
+	sg2042_msi_free_hwirq(data, d->hwirq, nr_irqs);
+}
+
+static const struct irq_domain_ops sg2042_msi_middle_domain_ops = {
+	.alloc	= sg2042_msi_middle_domain_alloc,
+	.free	= sg2042_msi_middle_domain_free,
+	.select	= msi_lib_irq_domain_select,
+};
+
+#define SG2042_MSI_FLAGS_REQUIRED (MSI_FLAG_USE_DEF_DOM_OPS |	\
+				   MSI_FLAG_USE_DEF_CHIP_OPS)
+
+#define SG2042_MSI_FLAGS_SUPPORTED MSI_GENERIC_FLAGS_MASK
+
+static struct msi_parent_ops sg2042_msi_parent_ops = {
+	.required_flags		= SG2042_MSI_FLAGS_REQUIRED,
+	.supported_flags	= SG2042_MSI_FLAGS_SUPPORTED,
+	.bus_select_mask	= MATCH_PCI_MSI,
+	.bus_select_token	= DOMAIN_BUS_NEXUS,
+	.prefix			= "SG2042-",
+	.init_dev_msi_info	= msi_lib_init_dev_msi_info,
+};
+
+static int sg2042_msi_init_domains(struct sg2042_msi_chipdata *data,
+				   struct device_node *node)
+{
+	struct fwnode_handle *fwnode = of_node_to_fwnode(node);
+	struct irq_domain *plic_domain, *middle_domain;
+	struct device_node *plic_node;
+
+	if (!of_find_property(node, "interrupt-parent", NULL)) {
+		pr_err("Can't find interrupt-parent!\n");
+		return -EINVAL;
+	}
+
+	plic_node = of_irq_find_parent(node);
+	if (!plic_node) {
+		pr_err("Failed to find the PLIC node!\n");
+		return -ENXIO;
+	}
+
+	plic_domain = irq_find_host(plic_node);
+	of_node_put(plic_node);
+	if (!plic_domain) {
+		pr_err("Failed to find the PLIC domain\n");
+		return -ENXIO;
+	}
+
+	middle_domain = irq_domain_create_hierarchy(plic_domain, 0, data->num_irqs,
+						    fwnode,
+						    &sg2042_msi_middle_domain_ops,
+						    data);
+	if (!middle_domain) {
+		pr_err("Failed to create the MSI middle domain\n");
+		return -ENOMEM;
+	}
+
+	irq_domain_update_bus_token(middle_domain, DOMAIN_BUS_NEXUS);
+
+	middle_domain->flags |= IRQ_DOMAIN_FLAG_MSI_PARENT;
+	middle_domain->msi_parent_ops = &sg2042_msi_parent_ops;
+
+	return 0;
+}
+
+static int sg2042_msi_probe(struct platform_device *pdev)
+{
+	struct sg2042_msi_chipdata *data;
+	struct of_phandle_args args = {};
+	struct resource *res;
+	int ret;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(struct sg2042_msi_chipdata), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->reg_clr = devm_platform_ioremap_resource_byname(pdev, "clr");
+	if (IS_ERR(data->reg_clr)) {
+		dev_err(&pdev->dev, "Failed to map clear register\n");
+		return PTR_ERR(data->reg_clr);
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "doorbell");
+	if (!res) {
+		dev_err(&pdev->dev, "Failed get resource from set\n");
+		return -EINVAL;
+	}
+	data->doorbell_addr = res->start;
+
+	ret = of_parse_phandle_with_args(pdev->dev.of_node, "msi-ranges",
+					 "#interrupt-cells", 0, &args);
+	if (ret) {
+		dev_err(&pdev->dev, "Unable to parse MSI vec base\n");
+		return ret;
+	}
+	data->irq_first = (u32)args.args[0];
+
+	ret = of_property_read_u32_index(pdev->dev.of_node, "msi-ranges",
+					 args.args_count + 1, &data->num_irqs);
+	if (ret) {
+		dev_err(&pdev->dev, "Unable to parse MSI vec number\n");
+		of_node_put(args.np);
+		return ret;
+	}
+	of_node_put(args.np);
+
+	mutex_init(&data->msi_map_lock);
+
+	return sg2042_msi_init_domains(data, pdev->dev.of_node);
+}
+
+static const struct of_device_id sg2042_msi_of_match[] = {
+	{ .compatible	= "sophgo,sg2042-msi" },
+	{}
+};
+
+static struct platform_driver sg2042_msi_driver = {
+	.driver = {
+		.name		= "sg2042-msi",
+		.of_match_table	= sg2042_msi_of_match,
+	},
+	.probe = sg2042_msi_probe,
+};
+builtin_platform_driver(sg2042_msi_driver);
-- 
2.34.1

[PATCH v3 3/3] riscv: sophgo: dts: add msi controller for SG2042

[Chen Wang]

From: Chen Wang <unicorn_wang@outlook.com>

Add msi-controller node to dts for SG2042.

Signed-off-by: Chen Wang <unicorn_wang@outlook.com>
---
 arch/riscv/boot/dts/sophgo/sg2042.dtsi | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/riscv/boot/dts/sophgo/sg2042.dtsi b/arch/riscv/boot/dts/sophgo/sg2042.dtsi
index e62ac51ac55a..02fbb978973c 100644
--- a/arch/riscv/boot/dts/sophgo/sg2042.dtsi
+++ b/arch/riscv/boot/dts/sophgo/sg2042.dtsi
@@ -173,6 +173,16 @@ pllclk: clock-controller@70300100c0 {
 			#clock-cells = <1>;
 		};
 
+		msi: msi-controller@7030010300 {
+			compatible = "sophgo,sg2042-msi";
+			reg = <0x70 0x30010300 0x0 0x4>,
+			      <0x70 0x30010304 0x0 0x4>;
+			reg-names = "doorbell", "clr";
+			msi-controller;
+			msi-ranges = <&intc 64 IRQ_TYPE_LEVEL_HIGH 32>;
+			interrupt-parent = <&intc>;
+		};
+
 		rpgate: clock-controller@7030010368 {
 			compatible = "sophgo,sg2042-rpgate";
 			reg = <0x70 0x30010368 0x0 0x98>;
-- 
2.34.1

Re: [PATCH v3 1/3] dt-bindings: interrupt-controller: Add Sophgo SG2042 MSI

[Inochi Amaoto]

On Wed, Jan 15, 2025 at 02:33:23PM +0800, Chen Wang wrote:
> From: Chen Wang <unicorn_wang@outlook.com>
> 
> Add binding for Sophgo SG2042 MSI controller.
> 
> Signed-off-by: Chen Wang <unicorn_wang@outlook.com>
> ---
>  .../sophgo,sg2042-msi.yaml                    | 58 +++++++++++++++++++
>  1 file changed, 58 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/interrupt-controller/sophgo,sg2042-msi.yaml
> 
> diff --git a/Documentation/devicetree/bindings/interrupt-controller/sophgo,sg2042-msi.yaml b/Documentation/devicetree/bindings/interrupt-controller/sophgo,sg2042-msi.yaml
> new file mode 100644
> index 000000000000..f641df191787
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/interrupt-controller/sophgo,sg2042-msi.yaml
> @@ -0,0 +1,58 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/interrupt-controller/sophgo,sg2042-msi.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Sophgo SG2042 MSI Controller
> +
> +maintainers:
> +  - Chen Wang <unicorn_wang@outlook.com>
> +
> +description:
> +  This interrupt controller is in Sophgo SG2042 for transforming interrupts from
> +  PCIe MSI to PLIC interrupts.
> +
> +allOf:
> +  - $ref: /schemas/interrupts.yaml#
> +  - $ref: /schemas/interrupt-controller/msi-controller.yaml#
> +
> +properties:
> +  compatible:
> +    const: sophgo,sg2042-msi
> +
> +  reg:
> +    items:
> +      - description: msi doorbell address
> +      - description: clear register
> +
> +  reg-names:
> +    items:

> +      - const: doorbell
> +      - const: clr

please reverse the items order, the clr addr is more suitable
as the MMIO device address when writing device node. doorbeel
address is just a IO address and can not be seen from CPU.

> +
> +  msi-controller: true
> +
> +  msi-ranges:
> +    maxItems: 1
> +
> +required:
> +  - compatible
> +  - reg
> +  - reg-names
> +  - msi-controller
> +  - msi-ranges
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    msi-controller@30000000 {
> +      compatible = "sophgo,sg2042-msi";
> +      reg = <0x30000000 0x4>, <0x30000008 0x4>;
> +      reg-names = "doorbell", "clr";
> +      msi-controller;
> +      msi-ranges = <&plic 64 IRQ_TYPE_LEVEL_HIGH 32>;
> +      interrupt-parent = <&plic>;
> +    };
> -- 
> 2.34.1
> 
> 
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv

Re: [PATCH v3 2/3] irqchip: Add the Sophgo SG2042 MSI interrupt controller

[Inochi Amaoto]

On Wed, Jan 15, 2025 at 02:33:45PM +0800, Chen Wang wrote:
> From: Chen Wang <unicorn_wang@outlook.com>
> 
> Add driver for Sophgo SG2042 MSI interrupt controller.
> 
> Signed-off-by: Chen Wang <unicorn_wang@outlook.com>
> ---
>  drivers/irqchip/Kconfig          |  12 ++
>  drivers/irqchip/Makefile         |   1 +
>  drivers/irqchip/irq-sg2042-msi.c | 268 +++++++++++++++++++++++++++++++
>  3 files changed, 281 insertions(+)
>  create mode 100644 drivers/irqchip/irq-sg2042-msi.c
> 
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index 9bee02db1643..161fb5df857f 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -749,6 +749,18 @@ config MCHP_EIC
>  	help
>  	  Support for Microchip External Interrupt Controller.
>  
> +config SOPHGO_SG2042_MSI
> +	bool "Sophgo SG2042 MSI Controller"
> +	depends on ARCH_SOPHGO || COMPILE_TEST
> +	depends on PCI
> +	select IRQ_DOMAIN_HIERARCHY
> +	select IRQ_MSI_LIB
> +	select PCI_MSI
> +	help
> +	  Support for the Sophgo SG2042 MSI Controller.
> +	  This on-chip interrupt controller enables MSI sources to be
> +	  routed to the primary PLIC controller on SoC.
> +
>  config SUNPLUS_SP7021_INTC
>  	bool "Sunplus SP7021 interrupt controller" if COMPILE_TEST
>  	default SOC_SP7021
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index 25e9ad29b8c4..dd60e597491d 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -128,4 +128,5 @@ obj-$(CONFIG_WPCM450_AIC)		+= irq-wpcm450-aic.o
>  obj-$(CONFIG_IRQ_IDT3243X)		+= irq-idt3243x.o
>  obj-$(CONFIG_APPLE_AIC)			+= irq-apple-aic.o
>  obj-$(CONFIG_MCHP_EIC)			+= irq-mchp-eic.o
> +obj-$(CONFIG_SOPHGO_SG2042_MSI)		+= irq-sg2042-msi.o
>  obj-$(CONFIG_SUNPLUS_SP7021_INTC)	+= irq-sp7021-intc.o
> diff --git a/drivers/irqchip/irq-sg2042-msi.c b/drivers/irqchip/irq-sg2042-msi.c
> new file mode 100644
> index 000000000000..1f88e1671e5c
> --- /dev/null
> +++ b/drivers/irqchip/irq-sg2042-msi.c
> @@ -0,0 +1,268 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * SG2042 MSI Controller
> + *
> + * Copyright (C) 2024 Sophgo Technology Inc.
> + * Copyright (C) 2024 Chen Wang <unicorn_wang@outlook.com>
> + */
> +
> +#include <linux/cleanup.h>
> +#include <linux/io.h>
> +#include <linux/irq.h>
> +#include <linux/irqdomain.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/msi.h>
> +#include <linux/of.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_pci.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +
> +#include "irq-msi-lib.h"
> +
> +#define SG2042_MAX_MSI_VECTOR	32
> +
> +struct sg2042_msi_chipdata {
> +	void __iomem	*reg_clr;	// clear reg, see TRM, 10.1.33, GP_INTR0_CLR
> +
> +	phys_addr_t	doorbell_addr;	// see TRM, 10.1.32, GP_INTR0_SET
> +
> +	u32		irq_first;	// The vector number that MSIs starts
> +	u32		num_irqs;	// The number of vectors for MSIs
> +
> +	DECLARE_BITMAP(msi_map, SG2042_MAX_MSI_VECTOR);
> +	struct mutex	msi_map_lock;	// lock for msi_map
> +};
> +
> +static int sg2042_msi_allocate_hwirq(struct sg2042_msi_chipdata *data, int num_req)
> +{
> +	int first;
> +
> +	guard(mutex)(&data->msi_map_lock);
> +	first = bitmap_find_free_region(data->msi_map, data->num_irqs,
> +					get_count_order(num_req));
> +	return first >= 0 ? first : -ENOSPC;
> +}
> +
> +static void sg2042_msi_free_hwirq(struct sg2042_msi_chipdata *data,
> +				  int hwirq, int num_req)
> +{
> +	guard(mutex)(&data->msi_map_lock);
> +	bitmap_release_region(data->msi_map, hwirq, get_count_order(num_req));
> +}
> +
> +static void sg2042_msi_irq_ack(struct irq_data *d)
> +{
> +	struct sg2042_msi_chipdata *data  = irq_data_get_irq_chip_data(d);
> +	int bit_off = d->hwirq;
> +
> +	writel(1 << bit_off, data->reg_clr);
> +
> +	irq_chip_ack_parent(d);
> +}
> +
> +static void sg2042_msi_irq_compose_msi_msg(struct irq_data *d,
> +					   struct msi_msg *msg)
> +{
> +	struct sg2042_msi_chipdata *data = irq_data_get_irq_chip_data(d);
> +
> +	msg->address_hi = upper_32_bits(data->doorbell_addr);
> +	msg->address_lo = lower_32_bits(data->doorbell_addr);
> +	msg->data = 1 << d->hwirq;
> +}
> +
> +static const struct irq_chip sg2042_msi_middle_irq_chip = {
> +	.name			= "SG2042 MSI",
> +	.irq_ack		= sg2042_msi_irq_ack,
> +	.irq_mask		= irq_chip_mask_parent,
> +	.irq_unmask		= irq_chip_unmask_parent,
> +#ifdef CONFIG_SMP
> +	.irq_set_affinity	= irq_chip_set_affinity_parent,
> +#endif
> +	.irq_compose_msi_msg	= sg2042_msi_irq_compose_msi_msg,
> +};
> +
> +static int sg2042_msi_parent_domain_alloc(struct irq_domain *domain,
> +					  unsigned int virq, int hwirq)
> +{
> +	struct sg2042_msi_chipdata *data = domain->host_data;
> +	struct irq_fwspec fwspec;
> +	struct irq_data *d;
> +	int ret;
> +
> +	fwspec.fwnode = domain->parent->fwnode;
> +	fwspec.param_count = 2;
> +	fwspec.param[0] = data->irq_first + hwirq;
> +	fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
> +
> +	ret = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
> +	if (ret)
> +		return ret;
> +
> +	d = irq_domain_get_irq_data(domain->parent, virq);
> +	return d->chip->irq_set_type(d, IRQ_TYPE_EDGE_RISING);
> +}
> +
> +static int sg2042_msi_middle_domain_alloc(struct irq_domain *domain,
> +					  unsigned int virq,
> +					  unsigned int nr_irqs, void *args)
> +{
> +	struct sg2042_msi_chipdata *data = domain->host_data;
> +	int hwirq, err, i;
> +
> +	hwirq = sg2042_msi_allocate_hwirq(data, nr_irqs);
> +	if (hwirq < 0)
> +		return hwirq;
> +
> +	for (i = 0; i < nr_irqs; i++) {
> +		err = sg2042_msi_parent_domain_alloc(domain, virq + i, hwirq + i);
> +		if (err)
> +			goto err_hwirq;
> +
> +		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
> +					      &sg2042_msi_middle_irq_chip, data);
> +	}
> +
> +	return 0;
> +
> +err_hwirq:
> +	sg2042_msi_free_hwirq(data, hwirq, nr_irqs);
> +	irq_domain_free_irqs_parent(domain, virq, i);
> +
> +	return err;
> +}
> +
> +static void sg2042_msi_middle_domain_free(struct irq_domain *domain,
> +					  unsigned int virq,
> +					  unsigned int nr_irqs)
> +{
> +	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
> +	struct sg2042_msi_chipdata *data = irq_data_get_irq_chip_data(d);
> +
> +	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
> +	sg2042_msi_free_hwirq(data, d->hwirq, nr_irqs);
> +}
> +
> +static const struct irq_domain_ops sg2042_msi_middle_domain_ops = {
> +	.alloc	= sg2042_msi_middle_domain_alloc,
> +	.free	= sg2042_msi_middle_domain_free,
> +	.select	= msi_lib_irq_domain_select,
> +};
> +

> +#define SG2042_MSI_FLAGS_REQUIRED (MSI_FLAG_USE_DEF_DOM_OPS |	\
> +				   MSI_FLAG_USE_DEF_CHIP_OPS)
> +
> +#define SG2042_MSI_FLAGS_SUPPORTED MSI_GENERIC_FLAGS_MASK
> +

I think it is just OK to set the flag directly in the msi_parent_ops.

> +static struct msi_parent_ops sg2042_msi_parent_ops = {
> +	.required_flags		= SG2042_MSI_FLAGS_REQUIRED,
> +	.supported_flags	= SG2042_MSI_FLAGS_SUPPORTED,
> +	.bus_select_mask	= MATCH_PCI_MSI,
> +	.bus_select_token	= DOMAIN_BUS_NEXUS,
> +	.prefix			= "SG2042-",
> +	.init_dev_msi_info	= msi_lib_init_dev_msi_info,
> +};

This struct should be const.

> +
> +static int sg2042_msi_init_domains(struct sg2042_msi_chipdata *data,
> +				   struct device_node *node)
> +{
> +	struct fwnode_handle *fwnode = of_node_to_fwnode(node);
> +	struct irq_domain *plic_domain, *middle_domain;
> +	struct device_node *plic_node;
> +
> +	if (!of_find_property(node, "interrupt-parent", NULL)) {
> +		pr_err("Can't find interrupt-parent!\n");
> +		return -EINVAL;
> +	}
> +
> +	plic_node = of_irq_find_parent(node);
> +	if (!plic_node) {
> +		pr_err("Failed to find the PLIC node!\n");
> +		return -ENXIO;
> +	}
> +
> +	plic_domain = irq_find_host(plic_node);
> +	of_node_put(plic_node);
> +	if (!plic_domain) {
> +		pr_err("Failed to find the PLIC domain\n");
> +		return -ENXIO;
> +	}
> +
> +	middle_domain = irq_domain_create_hierarchy(plic_domain, 0, data->num_irqs,
> +						    fwnode,
> +						    &sg2042_msi_middle_domain_ops,
> +						    data);
> +	if (!middle_domain) {
> +		pr_err("Failed to create the MSI middle domain\n");
> +		return -ENOMEM;
> +	}
> +
> +	irq_domain_update_bus_token(middle_domain, DOMAIN_BUS_NEXUS);
> +
> +	middle_domain->flags |= IRQ_DOMAIN_FLAG_MSI_PARENT;
> +	middle_domain->msi_parent_ops = &sg2042_msi_parent_ops;
> +
> +	return 0;
> +}
> +
> +static int sg2042_msi_probe(struct platform_device *pdev)
> +{
> +	struct sg2042_msi_chipdata *data;
> +	struct of_phandle_args args = {};
> +	struct resource *res;
> +	int ret;
> +
> +	data = devm_kzalloc(&pdev->dev, sizeof(struct sg2042_msi_chipdata), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	data->reg_clr = devm_platform_ioremap_resource_byname(pdev, "clr");
> +	if (IS_ERR(data->reg_clr)) {
> +		dev_err(&pdev->dev, "Failed to map clear register\n");
> +		return PTR_ERR(data->reg_clr);
> +	}
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "doorbell");
> +	if (!res) {
> +		dev_err(&pdev->dev, "Failed get resource from set\n");
> +		return -EINVAL;
> +	}
> +	data->doorbell_addr = res->start;
> +
> +	ret = of_parse_phandle_with_args(pdev->dev.of_node, "msi-ranges",
> +					 "#interrupt-cells", 0, &args);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Unable to parse MSI vec base\n");
> +		return ret;
> +	}
> +	data->irq_first = (u32)args.args[0];
> +
> +	ret = of_property_read_u32_index(pdev->dev.of_node, "msi-ranges",
> +					 args.args_count + 1, &data->num_irqs);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Unable to parse MSI vec number\n");
> +		of_node_put(args.np);
> +		return ret;
> +	}
> +	of_node_put(args.np);
> +
> +	mutex_init(&data->msi_map_lock);
> +
> +	return sg2042_msi_init_domains(data, pdev->dev.of_node);
> +}
> +
> +static const struct of_device_id sg2042_msi_of_match[] = {
> +	{ .compatible	= "sophgo,sg2042-msi" },
> +	{}
> +};
> +
> +static struct platform_driver sg2042_msi_driver = {
> +	.driver = {
> +		.name		= "sg2042-msi",
> +		.of_match_table	= sg2042_msi_of_match,
> +	},
> +	.probe = sg2042_msi_probe,
> +};
> +builtin_platform_driver(sg2042_msi_driver);
> -- 
> 2.34.1
> 

Re: [PATCH v3 1/3] dt-bindings: interrupt-controller: Add Sophgo SG2042 MSI

[Chen Wang]

On 2025/1/20 10:42, Inochi Amaoto wrote:
> On Wed, Jan 15, 2025 at 02:33:23PM +0800, Chen Wang wrote:
[......]
>> +  reg:
>> +    items:
>> +      - description: msi doorbell address
>> +      - description: clear register
>> +
>> +  reg-names:
>> +    items:
>> +      - const: doorbell
>> +      - const: clr
> please reverse the items order, the clr addr is more suitable
> as the MMIO device address when writing device node. doorbeel
> address is just a IO address and can not be seen from CPU.

I find dtbcheck will report error if order is switched.

On SG2042, address of doorbell is ahead of clr.

>> +
>> +  msi-controller: true
>> +
>> +  msi-ranges:
>> +    maxItems: 1
>> +
>> +required:
>> +  - compatible
>> +  - reg
>> +  - reg-names
>> +  - msi-controller
>> +  - msi-ranges
>> +
>> +unevaluatedProperties: false
>> +
>> +examples:
>> +  - |
>> +    #include <dt-bindings/interrupt-controller/irq.h>
>> +    msi-controller@30000000 {
>> +      compatible = "sophgo,sg2042-msi";
>> +      reg = <0x30000000 0x4>, <0x30000008 0x4>;
>> +      reg-names = "doorbell", "clr";
>> +      msi-controller;
>> +      msi-ranges = <&plic 64 IRQ_TYPE_LEVEL_HIGH 32>;
>> +      interrupt-parent = <&plic>;
>> +    };
>> -- 
>> 2.34.1
>>
>>
>> _______________________________________________
>> linux-riscv mailing list
>> linux-riscv@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-riscv

Re: [PATCH v3 2/3] irqchip: Add the Sophgo SG2042 MSI interrupt controller

[Chen Wang]

On 2025/1/20 10:43, Inochi Amaoto wrote:
> On Wed, Jan 15, 2025 at 02:33:45PM +0800, Chen Wang wrote:

[......]

>> +#define SG2042_MSI_FLAGS_REQUIRED (MSI_FLAG_USE_DEF_DOM_OPS |	\
>> +				   MSI_FLAG_USE_DEF_CHIP_OPS)
>> +
>> +#define SG2042_MSI_FLAGS_SUPPORTED MSI_GENERIC_FLAGS_MASK
>> +
> I think it is just OK to set the flag directly in the msi_parent_ops.
This shouldn't be a big problem, maybe it will be convenient for future 
expansion.
>> +static struct msi_parent_ops sg2042_msi_parent_ops = {
>> +	.required_flags		= SG2042_MSI_FLAGS_REQUIRED,
>> +	.supported_flags	= SG2042_MSI_FLAGS_SUPPORTED,
>> +	.bus_select_mask	= MATCH_PCI_MSI,
>> +	.bus_select_token	= DOMAIN_BUS_NEXUS,
>> +	.prefix			= "SG2042-",
>> +	.init_dev_msi_info	= msi_lib_init_dev_msi_info,
>> +};
> This struct should be const.

Yes, will fix this in next version.

Thanks,

Chen

[......]

Re: [PATCH v3 1/3] dt-bindings: interrupt-controller: Add Sophgo SG2042 MSI

[Inochi Amaoto]

On Wed, Jan 22, 2025 at 09:51:05PM +0800, Chen Wang wrote:
> 
> On 2025/1/20 10:42, Inochi Amaoto wrote:
> > On Wed, Jan 15, 2025 at 02:33:23PM +0800, Chen Wang wrote:
> [......]
> > > +  reg:
> > > +    items:
> > > +      - description: msi doorbell address
> > > +      - description: clear register
> > > +
> > > +  reg-names:
> > > +    items:
> > > +      - const: doorbell
> > > +      - const: clr
> > please reverse the items order, the clr addr is more suitable
> > as the MMIO device address when writing device node. doorbeel
> > address is just a IO address and can not be seen from CPU.
> 
> I find dtbcheck will report error if order is switched.
> 

You should also change the unit address to avoid error.
I think you forgot it.

> On SG2042, address of doorbell is ahead of clr.
> 

It is the same on SG2044, but there is a problem that the
doorbell addr is a IO address and it is not suitable to
represent the device addr in the dtb. It also lead to a
weird unit address on SG2044 which is hard to understand.

Regards,
Inochi

Re: [PATCH v3 1/3] dt-bindings: interrupt-controller: Add Sophgo SG2042 MSI

[Chen Wang]

On 2025/1/23 6:42, Inochi Amaoto wrote:
> On Wed, Jan 22, 2025 at 09:51:05PM +0800, Chen Wang wrote:
>> On 2025/1/20 10:42, Inochi Amaoto wrote:
>>> On Wed, Jan 15, 2025 at 02:33:23PM +0800, Chen Wang wrote:
>> [......]
>>>> +  reg:
>>>> +    items:
>>>> +      - description: msi doorbell address
>>>> +      - description: clear register
>>>> +
>>>> +  reg-names:
>>>> +    items:
>>>> +      - const: doorbell
>>>> +      - const: clr
>>> please reverse the items order, the clr addr is more suitable
>>> as the MMIO device address when writing device node. doorbeel
>>> address is just a IO address and can not be seen from CPU.
>> I find dtbcheck will report error if order is switched.
>>
> You should also change the unit address to avoid error.
> I think you forgot it.

I forgot it, thanks for your suggestion.


>> On SG2042, address of doorbell is ahead of clr.
>>
> It is the same on SG2044, but there is a problem that the
> doorbell addr is a IO address and it is not suitable to
> represent the device addr in the dtb. It also lead to a
> weird unit address on SG2044 which is hard to understand.
>
> Regards,
> Inochi

Re: [PATCH v3 1/3] dt-bindings: interrupt-controller: Add Sophgo SG2042 MSI

[Rob Herring]

On Wed, Jan 15, 2025 at 02:33:23PM +0800, Chen Wang wrote:
> From: Chen Wang <unicorn_wang@outlook.com>
> 
> Add binding for Sophgo SG2042 MSI controller.
> 
> Signed-off-by: Chen Wang <unicorn_wang@outlook.com>
> ---
>  .../sophgo,sg2042-msi.yaml                    | 58 +++++++++++++++++++
>  1 file changed, 58 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/interrupt-controller/sophgo,sg2042-msi.yaml
> 
> diff --git a/Documentation/devicetree/bindings/interrupt-controller/sophgo,sg2042-msi.yaml b/Documentation/devicetree/bindings/interrupt-controller/sophgo,sg2042-msi.yaml
> new file mode 100644
> index 000000000000..f641df191787
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/interrupt-controller/sophgo,sg2042-msi.yaml
> @@ -0,0 +1,58 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/interrupt-controller/sophgo,sg2042-msi.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Sophgo SG2042 MSI Controller
> +
> +maintainers:
> +  - Chen Wang <unicorn_wang@outlook.com>
> +
> +description:
> +  This interrupt controller is in Sophgo SG2042 for transforming interrupts from
> +  PCIe MSI to PLIC interrupts.
> +
> +allOf:
> +  - $ref: /schemas/interrupts.yaml#

Drop this.

> +  - $ref: /schemas/interrupt-controller/msi-controller.yaml#
> +
> +properties:
> +  compatible:
> +    const: sophgo,sg2042-msi
> +
> +  reg:
> +    items:
> +      - description: msi doorbell address
> +      - description: clear register
> +
> +  reg-names:
> +    items:
> +      - const: doorbell
> +      - const: clr
> +
> +  msi-controller: true
> +
> +  msi-ranges:
> +    maxItems: 1

You need #msi-cells.

> +
> +required:
> +  - compatible
> +  - reg
> +  - reg-names
> +  - msi-controller
> +  - msi-ranges
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    msi-controller@30000000 {
> +      compatible = "sophgo,sg2042-msi";
> +      reg = <0x30000000 0x4>, <0x30000008 0x4>;
> +      reg-names = "doorbell", "clr";
> +      msi-controller;
> +      msi-ranges = <&plic 64 IRQ_TYPE_LEVEL_HIGH 32>;
> +      interrupt-parent = <&plic>;
> +    };
> -- 
> 2.34.1
> 

Re: [PATCH v3 2/3] irqchip: Add the Sophgo SG2042 MSI interrupt controller

[Inochi Amaoto]

On Wed, Jan 15, 2025 at 02:33:45PM +0800, Chen Wang wrote:
> From: Chen Wang <unicorn_wang@outlook.com>
> 
> Add driver for Sophgo SG2042 MSI interrupt controller.
> 
> Signed-off-by: Chen Wang <unicorn_wang@outlook.com>
> ---
>  drivers/irqchip/Kconfig          |  12 ++
>  drivers/irqchip/Makefile         |   1 +
>  drivers/irqchip/irq-sg2042-msi.c | 268 +++++++++++++++++++++++++++++++
>  3 files changed, 281 insertions(+)
>  create mode 100644 drivers/irqchip/irq-sg2042-msi.c
> 
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index 9bee02db1643..161fb5df857f 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -749,6 +749,18 @@ config MCHP_EIC
>  	help
>  	  Support for Microchip External Interrupt Controller.
>  
> +config SOPHGO_SG2042_MSI
> +	bool "Sophgo SG2042 MSI Controller"
> +	depends on ARCH_SOPHGO || COMPILE_TEST
> +	depends on PCI
> +	select IRQ_DOMAIN_HIERARCHY
> +	select IRQ_MSI_LIB
> +	select PCI_MSI
> +	help
> +	  Support for the Sophgo SG2042 MSI Controller.
> +	  This on-chip interrupt controller enables MSI sources to be
> +	  routed to the primary PLIC controller on SoC.
> +
>  config SUNPLUS_SP7021_INTC
>  	bool "Sunplus SP7021 interrupt controller" if COMPILE_TEST
>  	default SOC_SP7021
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index 25e9ad29b8c4..dd60e597491d 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -128,4 +128,5 @@ obj-$(CONFIG_WPCM450_AIC)		+= irq-wpcm450-aic.o
>  obj-$(CONFIG_IRQ_IDT3243X)		+= irq-idt3243x.o
>  obj-$(CONFIG_APPLE_AIC)			+= irq-apple-aic.o
>  obj-$(CONFIG_MCHP_EIC)			+= irq-mchp-eic.o
> +obj-$(CONFIG_SOPHGO_SG2042_MSI)		+= irq-sg2042-msi.o
>  obj-$(CONFIG_SUNPLUS_SP7021_INTC)	+= irq-sp7021-intc.o
> diff --git a/drivers/irqchip/irq-sg2042-msi.c b/drivers/irqchip/irq-sg2042-msi.c
> new file mode 100644
> index 000000000000..1f88e1671e5c
> --- /dev/null
> +++ b/drivers/irqchip/irq-sg2042-msi.c
> @@ -0,0 +1,268 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * SG2042 MSI Controller
> + *
> + * Copyright (C) 2024 Sophgo Technology Inc.
> + * Copyright (C) 2024 Chen Wang <unicorn_wang@outlook.com>
> + */
> +
> +#include <linux/cleanup.h>
> +#include <linux/io.h>
> +#include <linux/irq.h>
> +#include <linux/irqdomain.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/msi.h>
> +#include <linux/of.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_pci.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +
> +#include "irq-msi-lib.h"
> +
> +#define SG2042_MAX_MSI_VECTOR	32
> +
> +struct sg2042_msi_chipdata {
> +	void __iomem	*reg_clr;	// clear reg, see TRM, 10.1.33, GP_INTR0_CLR
> +
> +	phys_addr_t	doorbell_addr;	// see TRM, 10.1.32, GP_INTR0_SET
> +
> +	u32		irq_first;	// The vector number that MSIs starts
> +	u32		num_irqs;	// The number of vectors for MSIs
> +
> +	DECLARE_BITMAP(msi_map, SG2042_MAX_MSI_VECTOR);
> +	struct mutex	msi_map_lock;	// lock for msi_map
> +};
> +
> +static int sg2042_msi_allocate_hwirq(struct sg2042_msi_chipdata *data, int num_req)
> +{
> +	int first;
> +
> +	guard(mutex)(&data->msi_map_lock);
> +	first = bitmap_find_free_region(data->msi_map, data->num_irqs,
> +					get_count_order(num_req));
> +	return first >= 0 ? first : -ENOSPC;
> +}
> +
> +static void sg2042_msi_free_hwirq(struct sg2042_msi_chipdata *data,
> +				  int hwirq, int num_req)
> +{
> +	guard(mutex)(&data->msi_map_lock);
> +	bitmap_release_region(data->msi_map, hwirq, get_count_order(num_req));
> +}
> +
> +static void sg2042_msi_irq_ack(struct irq_data *d)
> +{
> +	struct sg2042_msi_chipdata *data  = irq_data_get_irq_chip_data(d);
> +	int bit_off = d->hwirq;
> +
> +	writel(1 << bit_off, data->reg_clr);
> +
> +	irq_chip_ack_parent(d);
> +}
> +
> +static void sg2042_msi_irq_compose_msi_msg(struct irq_data *d,
> +					   struct msi_msg *msg)
> +{
> +	struct sg2042_msi_chipdata *data = irq_data_get_irq_chip_data(d);
> +
> +	msg->address_hi = upper_32_bits(data->doorbell_addr);
> +	msg->address_lo = lower_32_bits(data->doorbell_addr);
> +	msg->data = 1 << d->hwirq;
> +}
> +
> +static const struct irq_chip sg2042_msi_middle_irq_chip = {
> +	.name			= "SG2042 MSI",
> +	.irq_ack		= sg2042_msi_irq_ack,
> +	.irq_mask		= irq_chip_mask_parent,
> +	.irq_unmask		= irq_chip_unmask_parent,
> +#ifdef CONFIG_SMP
> +	.irq_set_affinity	= irq_chip_set_affinity_parent,
> +#endif
> +	.irq_compose_msi_msg	= sg2042_msi_irq_compose_msi_msg,
> +};
> +
> +static int sg2042_msi_parent_domain_alloc(struct irq_domain *domain,
> +					  unsigned int virq, int hwirq)
> +{
> +	struct sg2042_msi_chipdata *data = domain->host_data;
> +	struct irq_fwspec fwspec;
> +	struct irq_data *d;
> +	int ret;
> +
> +	fwspec.fwnode = domain->parent->fwnode;
> +	fwspec.param_count = 2;
> +	fwspec.param[0] = data->irq_first + hwirq;
> +	fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
> +
> +	ret = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
> +	if (ret)
> +		return ret;
> +
> +	d = irq_domain_get_irq_data(domain->parent, virq);
> +	return d->chip->irq_set_type(d, IRQ_TYPE_EDGE_RISING);
> +}
> +
> +static int sg2042_msi_middle_domain_alloc(struct irq_domain *domain,
> +					  unsigned int virq,
> +					  unsigned int nr_irqs, void *args)
> +{
> +	struct sg2042_msi_chipdata *data = domain->host_data;
> +	int hwirq, err, i;
> +
> +	hwirq = sg2042_msi_allocate_hwirq(data, nr_irqs);
> +	if (hwirq < 0)
> +		return hwirq;
> +
> +	for (i = 0; i < nr_irqs; i++) {
> +		err = sg2042_msi_parent_domain_alloc(domain, virq + i, hwirq + i);
> +		if (err)
> +			goto err_hwirq;
> +
> +		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
> +					      &sg2042_msi_middle_irq_chip, data);
> +	}
> +
> +	return 0;
> +
> +err_hwirq:
> +	sg2042_msi_free_hwirq(data, hwirq, nr_irqs);
> +	irq_domain_free_irqs_parent(domain, virq, i);
> +
> +	return err;
> +}
> +
> +static void sg2042_msi_middle_domain_free(struct irq_domain *domain,
> +					  unsigned int virq,
> +					  unsigned int nr_irqs)
> +{
> +	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
> +	struct sg2042_msi_chipdata *data = irq_data_get_irq_chip_data(d);
> +
> +	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
> +	sg2042_msi_free_hwirq(data, d->hwirq, nr_irqs);
> +}
> +
> +static const struct irq_domain_ops sg2042_msi_middle_domain_ops = {
> +	.alloc	= sg2042_msi_middle_domain_alloc,
> +	.free	= sg2042_msi_middle_domain_free,
> +	.select	= msi_lib_irq_domain_select,
> +};
> +
> +#define SG2042_MSI_FLAGS_REQUIRED (MSI_FLAG_USE_DEF_DOM_OPS |	\
> +				   MSI_FLAG_USE_DEF_CHIP_OPS)
> +
> +#define SG2042_MSI_FLAGS_SUPPORTED MSI_GENERIC_FLAGS_MASK
> +
> +static struct msi_parent_ops sg2042_msi_parent_ops = {
> +	.required_flags		= SG2042_MSI_FLAGS_REQUIRED,
> +	.supported_flags	= SG2042_MSI_FLAGS_SUPPORTED,
> +	.bus_select_mask	= MATCH_PCI_MSI,
> +	.bus_select_token	= DOMAIN_BUS_NEXUS,
> +	.prefix			= "SG2042-",
> +	.init_dev_msi_info	= msi_lib_init_dev_msi_info,
> +};
> +
> +static int sg2042_msi_init_domains(struct sg2042_msi_chipdata *data,
> +				   struct device_node *node)

For ACPI support, I prefer to use device instead of device_node
The following suggestion is also for ACPI support

> +{
> +	struct fwnode_handle *fwnode = of_node_to_fwnode(node);
> +	struct irq_domain *plic_domain, *middle_domain;
> +	struct device_node *plic_node;
> +

> +	if (!of_find_property(node, "interrupt-parent", NULL)) {
> +		pr_err("Can't find interrupt-parent!\n");
> +		return -EINVAL;
> +	}
> +
> +	plic_node = of_irq_find_parent(node);
> +	if (!plic_node) {
> +		pr_err("Failed to find the PLIC node!\n");
> +		return -ENXIO;
> +	}
> +

This can be replace with fwnode_find_reference to support ACPI

> +	plic_domain = irq_find_host(plic_node);
> +	of_node_put(plic_node);
> +	if (!plic_domain) {
> +		pr_err("Failed to find the PLIC domain\n");
> +		return -ENXIO;
> +	}
> +

Replace irq_find_host with irq_find_matching_fwnode

> +	middle_domain = irq_domain_create_hierarchy(plic_domain, 0, data->num_irqs,
> +						    fwnode,
> +						    &sg2042_msi_middle_domain_ops,
> +						    data);

Use irq_domain_create_hierarchy

> +	if (!middle_domain) {
> +		pr_err("Failed to create the MSI middle domain\n");
> +		return -ENOMEM;
> +	}
> +
> +	irq_domain_update_bus_token(middle_domain, DOMAIN_BUS_NEXUS);
> +
> +	middle_domain->flags |= IRQ_DOMAIN_FLAG_MSI_PARENT;
> +	middle_domain->msi_parent_ops = &sg2042_msi_parent_ops;
> +
> +	return 0;
> +}
> +
> +static int sg2042_msi_probe(struct platform_device *pdev)
> +{

add a "struct device *dev = &pdev->dev;" here and replace 
&pdev->dev with dev.

> +	struct sg2042_msi_chipdata *data;
> +	struct of_phandle_args args = {};
> +	struct resource *res;
> +	int ret;
> +
> +	data = devm_kzalloc(&pdev->dev, sizeof(struct sg2042_msi_chipdata), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	data->reg_clr = devm_platform_ioremap_resource_byname(pdev, "clr");
> +	if (IS_ERR(data->reg_clr)) {
> +		dev_err(&pdev->dev, "Failed to map clear register\n");
> +		return PTR_ERR(data->reg_clr);
> +	}
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "doorbell");
> +	if (!res) {
> +		dev_err(&pdev->dev, "Failed get resource from set\n");
> +		return -EINVAL;
> +	}
> +	data->doorbell_addr = res->start;
> +

> +	ret = of_parse_phandle_with_args(pdev->dev.of_node, "msi-ranges",
> +					 "#interrupt-cells", 0, &args);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Unable to parse MSI vec base\n");
> +		return ret;
> +	}
> +	data->irq_first = (u32)args.args[0];
> +
> +	ret = of_property_read_u32_index(pdev->dev.of_node, "msi-ranges",
> +					 args.args_count + 1, &data->num_irqs);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Unable to parse MSI vec number\n");
> +		of_node_put(args.np);
> +		return ret;
> +	}
> +	of_node_put(args.np);

this can be replace by calling fwnode_property_get_reference_args
twice. I have found a working example:

ret = fwnode_property_get_reference_args(dev_fwnode(dev), "msi-ranges",
					 "#interrupt-cells",
					 0, 0, &args);
if (ret) {
	dev_err(dev, "Unable to parse MSI vec base\n");
	return ret;
}
fwnode_handle_put(args.fwnode);


ret = fwnode_property_get_reference_args(dev_fwnode(dev), "msi-ranges",
					 NULL, args.nargs + 1,
					 0, &args);
if (ret) {
	dev_err(dev, "Unable to parse MSI vec number\n");
	return ret;
}

data->irq_first = (u32)args.args[0];
data->num_irqs = (u32)args.args[args.nargs - 1];

fwnode_handle_put(args.fwnode);

Regards,
Inochi

Re: [PATCH v3 2/3] irqchip: Add the Sophgo SG2042 MSI interrupt controller

[Chen Wang]

On 2025/2/15 9:09, Inochi Amaoto wrote:
> On Wed, Jan 15, 2025 at 02:33:45PM +0800, Chen Wang wrote:
[......]
>> +	middle_domain = irq_domain_create_hierarchy(plic_domain, 0, data->num_irqs,
>> +						    fwnode,
>> +						    &sg2042_msi_middle_domain_ops,
>> +						    data);
> Use irq_domain_create_hierarchy

What's the difference?

[......]

Re: [PATCH v3 2/3] irqchip: Add the Sophgo SG2042 MSI interrupt controller

[Inochi Amaoto]

On Sat, Feb 15, 2025 at 11:36:18AM +0800, Chen Wang wrote:
> 
> On 2025/2/15 9:09, Inochi Amaoto wrote:
> > On Wed, Jan 15, 2025 at 02:33:45PM +0800, Chen Wang wrote:
> [......]
> > > +	middle_domain = irq_domain_create_hierarchy(plic_domain, 0, data->num_irqs,
> > > +						    fwnode,
> > > +						    &sg2042_msi_middle_domain_ops,
> > > +						    data);
> > Use irq_domain_create_hierarchy
> 
> What's the difference?
> 

I made a mistake, just ignore it. The original is OK.

Regard,
Inochi

Re: [PATCH v3 1/3] dt-bindings: interrupt-controller: Add Sophgo SG2042 MSI

[Chen Wang]

hello, Rob,

On 2025/1/24 5:29, Rob Herring wrote:
> On Wed, Jan 15, 2025 at 02:33:23PM +0800, Chen Wang wrote:
>> From: Chen Wang <unicorn_wang@outlook.com>
>>
>> Add binding for Sophgo SG2042 MSI controller.
>>
>> Signed-off-by: Chen Wang <unicorn_wang@outlook.com>
>> ---
>>   .../sophgo,sg2042-msi.yaml                    | 58 +++++++++++++++++++
>>   1 file changed, 58 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/interrupt-controller/sophgo,sg2042-msi.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/interrupt-controller/sophgo,sg2042-msi.yaml b/Documentation/devicetree/bindings/interrupt-controller/sophgo,sg2042-msi.yaml
>> new file mode 100644
>> index 000000000000..f641df191787
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/interrupt-controller/sophgo,sg2042-msi.yaml
>> @@ -0,0 +1,58 @@
>> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/interrupt-controller/sophgo,sg2042-msi.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Sophgo SG2042 MSI Controller
>> +
>> +maintainers:
>> +  - Chen Wang <unicorn_wang@outlook.com>
>> +
>> +description:
>> +  This interrupt controller is in Sophgo SG2042 for transforming interrupts from
>> +  PCIe MSI to PLIC interrupts.
>> +
>> +allOf:
>> +  - $ref: /schemas/interrupts.yaml#
> Drop this.

I find if we drop this line, dtb check will report "Unevaluated 
properties are not allowed ('interrupt-parent' was unexpected)"

Do we still need to keep this?

Thanks,

Chen

>> +  - $ref: /schemas/interrupt-controller/msi-controller.yaml#
>> +
>> +properties:
>> +  compatible:
>> +    const: sophgo,sg2042-msi
>> +
>> +  reg:
>> +    items:
>> +      - description: msi doorbell address
>> +      - description: clear register
>> +
>> +  reg-names:
>> +    items:
>> +      - const: doorbell
>> +      - const: clr
>> +
>> +  msi-controller: true
>> +
>> +  msi-ranges:
>> +    maxItems: 1
> You need #msi-cells.
OK, will add this.
>> +
>> +required:
>> +  - compatible
>> +  - reg
>> +  - reg-names
>> +  - msi-controller
>> +  - msi-ranges
>> +
>> +unevaluatedProperties: false
>> +
>> +examples:
>> +  - |
>> +    #include <dt-bindings/interrupt-controller/irq.h>
>> +    msi-controller@30000000 {
>> +      compatible = "sophgo,sg2042-msi";
>> +      reg = <0x30000000 0x4>, <0x30000008 0x4>;
>> +      reg-names = "doorbell", "clr";
>> +      msi-controller;
>> +      msi-ranges = <&plic 64 IRQ_TYPE_LEVEL_HIGH 32>;
>> +      interrupt-parent = <&plic>;
>> +    };
>> -- 
>> 2.34.1
>>