Re: [v1] PCI: mediatek: Remove MSI inner domain

From: Honghui Zhang
Date: Thu Jan 31 2019 - 04:19:37 EST


On Tue, 2019-01-22 at 17:37 +0800, Jianjun Wang wrote:
> There is no need to create the inner domain as a parent for MSI domian,
> some feature has been implemented by MSI framework.
>
> Remove the inner domain and its irq chip, it will be more closer to
> hardware implementation.
>
Hi, jianjun, I'm not quite familiar with the irq_chip framework, It was
under Marc's great help with the first version of irq_chip solution
code. I would like you to add him for the review.

Thanks.

> Signed-off-by: Jianjun Wang <jianjun.wang@xxxxxxxxxxxx>
> ---
> drivers/pci/controller/pcie-mediatek.c | 86 +++++++++++---------------
> 1 file changed, 37 insertions(+), 49 deletions(-)
>
> diff --git a/drivers/pci/controller/pcie-mediatek.c b/drivers/pci/controller/pcie-mediatek.c
> index 8d05df56158b..f996a9a6331f 100644
> --- a/drivers/pci/controller/pcie-mediatek.c
> +++ b/drivers/pci/controller/pcie-mediatek.c
> @@ -169,7 +169,6 @@ struct mtk_pcie_soc {
> * @slot: port slot
> * @irq: GIC irq
> * @irq_domain: legacy INTx IRQ domain
> - * @inner_domain: inner IRQ domain
> * @msi_domain: MSI IRQ domain
> * @lock: protect the msi_irq_in_use bitmap
> * @msi_irq_in_use: bit map for assigned MSI IRQ
> @@ -190,7 +189,6 @@ struct mtk_pcie_port {
> u32 slot;
> int irq;
> struct irq_domain *irq_domain;
> - struct irq_domain *inner_domain;
> struct irq_domain *msi_domain;
> struct mutex lock;
> DECLARE_BITMAP(msi_irq_in_use, MTK_MSI_IRQS_NUM);
> @@ -418,22 +416,15 @@ static void mtk_msi_ack_irq(struct irq_data *data)
> u32 hwirq = data->hwirq;
>
> writel(1 << hwirq, port->base + PCIE_IMSI_STATUS);
> + writel(MSI_STATUS, port->base + PCIE_INT_STATUS);
> }
>
> -static struct irq_chip mtk_msi_bottom_irq_chip = {
> - .name = "MTK MSI",
> - .irq_compose_msi_msg = mtk_compose_msi_msg,
> - .irq_set_affinity = mtk_msi_set_affinity,
> - .irq_ack = mtk_msi_ack_irq,
> -};
> -
> -static int mtk_pcie_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
> - unsigned int nr_irqs, void *args)
> +static irq_hw_number_t mtk_pcie_msi_get_hwirq(struct msi_domain_info *info,
> + msi_alloc_info_t *arg)
> {
> - struct mtk_pcie_port *port = domain->host_data;
> - unsigned long bit;
> + struct mtk_pcie_port *port = info->chip_data;
> + irq_hw_number_t bit;
>
> - WARN_ON(nr_irqs != 1);
> mutex_lock(&port->lock);
>
> bit = find_first_zero_bit(port->msi_irq_in_use, MTK_MSI_IRQS_NUM);
> @@ -446,18 +437,14 @@ static int mtk_pcie_irq_domain_alloc(struct irq_domain *domain, unsigned int vir
>
> mutex_unlock(&port->lock);
>
> - irq_domain_set_info(domain, virq, bit, &mtk_msi_bottom_irq_chip,
> - domain->host_data, handle_edge_irq,
> - NULL, NULL);
> -
> - return 0;
> + return bit;
> }
>
> -static void mtk_pcie_irq_domain_free(struct irq_domain *domain,
> - unsigned int virq, unsigned int nr_irqs)
> +static void mtk_pcie_msi_free(struct irq_domain *domain,
> + struct msi_domain_info *info, unsigned int virq)
> {
> struct irq_data *d = irq_domain_get_irq_data(domain, virq);
> - struct mtk_pcie_port *port = irq_data_get_irq_chip_data(d);
> + struct mtk_pcie_port *port = info->chip_data;
>
> mutex_lock(&port->lock);
>
> @@ -468,46 +455,50 @@ static void mtk_pcie_irq_domain_free(struct irq_domain *domain,
> __clear_bit(d->hwirq, port->msi_irq_in_use);
>
> mutex_unlock(&port->lock);
> -
> - irq_domain_free_irqs_parent(domain, virq, nr_irqs);
> }
>
> -static const struct irq_domain_ops msi_domain_ops = {
> - .alloc = mtk_pcie_irq_domain_alloc,
> - .free = mtk_pcie_irq_domain_free,
> +static struct msi_domain_ops mtk_msi_domain_ops = {
> + .get_hwirq = mtk_pcie_msi_get_hwirq,
> + .msi_free = mtk_pcie_msi_free,
> };
>
> static struct irq_chip mtk_msi_irq_chip = {
> - .name = "MTK PCIe MSI",
> - .irq_ack = irq_chip_ack_parent,
> - .irq_mask = pci_msi_mask_irq,
> - .irq_unmask = pci_msi_unmask_irq,
> + .name = "MTK PCIe",
> + .irq_compose_msi_msg = mtk_compose_msi_msg,
> + .irq_write_msi_msg = pci_msi_domain_write_msg,
> + .irq_set_affinity = mtk_msi_set_affinity,
> + .irq_ack = mtk_msi_ack_irq,
> + .irq_mask = pci_msi_mask_irq,
> + .irq_unmask = pci_msi_unmask_irq,
> };
>
> static struct msi_domain_info mtk_msi_domain_info = {
> - .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
> - MSI_FLAG_PCI_MSIX),
> - .chip = &mtk_msi_irq_chip,
> + .flags = (MSI_FLAG_USE_DEF_DOM_OPS |
> + MSI_FLAG_USE_DEF_CHIP_OPS | MSI_FLAG_PCI_MSIX),
> + .ops = &mtk_msi_domain_ops,
> + .chip = &mtk_msi_irq_chip,
> + .handler = handle_edge_irq,
> + .handler_name = "MSI",
> };
>
> static int mtk_pcie_allocate_msi_domains(struct mtk_pcie_port *port)
> {
> - struct fwnode_handle *fwnode = of_node_to_fwnode(port->pcie->dev->of_node);
> + struct device *dev = port->pcie->dev;
> + struct fwnode_handle *fwnode = of_node_to_fwnode(dev->of_node);
> + struct msi_domain_info *info;
>
> mutex_init(&port->lock);
>
> - port->inner_domain = irq_domain_create_linear(fwnode, MTK_MSI_IRQS_NUM,
> - &msi_domain_ops, port);
> - if (!port->inner_domain) {
> - dev_err(port->pcie->dev, "failed to create IRQ domain\n");
> + info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
> + if (!info)
> return -ENOMEM;
> - }
>
> - port->msi_domain = pci_msi_create_irq_domain(fwnode, &mtk_msi_domain_info,
> - port->inner_domain);
> + memcpy(info, &mtk_msi_domain_info, sizeof(*info));
> + info->chip_data = port;
> +

I'm not really like this memcpy of msi_domain_info, but I do not have a
better idea to prevent the mixed of mtk_pcie_port data.

> + port->msi_domain = pci_msi_create_irq_domain(fwnode, info, NULL);
> if (!port->msi_domain) {
> - dev_err(port->pcie->dev, "failed to create MSI domain\n");
> - irq_domain_remove(port->inner_domain);
> + dev_err(dev, "failed to create MSI domain\n");
> return -ENOMEM;
> }
>
> @@ -541,8 +532,6 @@ static void mtk_pcie_irq_teardown(struct mtk_pcie *pcie)
> if (IS_ENABLED(CONFIG_PCI_MSI)) {
> if (port->msi_domain)
> irq_domain_remove(port->msi_domain);
> - if (port->inner_domain)
> - irq_domain_remove(port->inner_domain);
> }
>
> irq_dispose_mapping(port->irq);
> @@ -619,12 +608,11 @@ static void mtk_pcie_intr_handler(struct irq_desc *desc)
>
> while ((imsi_status = readl(port->base + PCIE_IMSI_STATUS))) {
> for_each_set_bit(bit, &imsi_status, MTK_MSI_IRQS_NUM) {
> - virq = irq_find_mapping(port->inner_domain, bit);
> + virq = irq_find_mapping(
> + port->msi_domain, bit);
> generic_handle_irq(virq);
> }
> }
> - /* Clear MSI interrupt status */
> - writel(MSI_STATUS, port->base + PCIE_INT_STATUS);
> }

why change this irq status clear flow?

> }
>