[PATCH v2 2/3] irqchip: Add the Sophgo SG2042 MSI interrupt controller

[Christophe JAILLET]

Le 09/12/2024 à 08:12, Chen Wang a écrit :
> From: Chen Wang <unicorn_wang at outlook.com>
> 
> Add driver for Sophgo SG2042 MSI interrupt controller.
> 
> Signed-off-by: Chen Wang <unicorn_wang at outlook.com>

...

> +#define SG2042_VECTOR_MIN	64
> +#define SG2042_VECTOR_MAX	95

...

> +static struct irq_chip sg2042_msi_middle_irq_chip = {

const?

> +	.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_probe(struct platform_device *pdev)
> +{
> +	struct of_phandle_args args = {};
> +	struct sg2042_msi_data *data;
> +	int ret;
> +
> +	data = devm_kzalloc(&pdev->dev, sizeof(struct sg2042_msi_data), 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);
> +	}
> +
> +	if (of_property_read_u64(pdev->dev.of_node, "sophgo,msi-doorbell-addr",
> +				 &data->doorbell_addr)) {
> +		dev_err(&pdev->dev, "Unable to parse MSI doorbell addr\n");
> +		return -EINVAL;
> +	}
> +
> +	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");
> +		return ret;
> +	}
> +
> +	if (data->irq_first < SG2042_VECTOR_MIN ||
> +	    (data->irq_first + data->num_irqs - 1) > SG2042_VECTOR_MAX) {
> +		dev_err(&pdev->dev, "msi-ranges is incorrect!\n");
> +		return -EINVAL;
> +	}
> +
> +	mutex_init(&data->msi_map_lock);
> +
> +	data->msi_map = bitmap_zalloc(data->num_irqs, GFP_KERNEL);

IIUC, num_irqs is between 0 and (SG2042_VECTOR_MAX - SG2042_VECTOR_MIN) 
(maybe + or -1).
So around 32.

Would it make sence to use DECLARE_BITMAP(msi_map, <correct_size>) in 
sg2042_msi_data to avoid this allocation and an indirection at runtime?

> +	if (!data->msi_map)
> +		return -ENOMEM;
> +
> +	ret = sg2042_msi_init_domains(data, pdev->dev.of_node);
> +	if (ret)
> +		bitmap_free(data->msi_map);
> +
> +	return ret;
> +}

...

CJ