Re: [PATCH v4 07/11] PCI: microchip: Rename IRQ init function

[Conor Dooley]

Hey Minda,

I would like Daire to take a look at this, but I have a few more
smaller comments on this.

On Fri, Aug 25, 2023 at 05:01:25PM +0800, Minda Chen wrote:
> Rename IRQ init function and prepare for re-use
> IRQ init function.
> Add plda_pcie_ops function pointer data structure,
> PolarFire PCIe uses function pointer to get
> their events num.
> 
> rename list:
> mc_init_interrupts()     -> plda_init_interrupts()
> mc_pcie_init_irq_domain()-> plda_pcie_init_irq_domains()
> 
> Signed-off-by: Minda Chen <minda.chen@xxxxxxxxxxxxxxxx>
> ---
>  .../pci/controller/plda/pcie-microchip-host.c | 49 ++++++++++++++-----
>  drivers/pci/controller/plda/pcie-plda.h       | 14 ++++++
>  2 files changed, 51 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/pci/controller/plda/pcie-microchip-host.c b/drivers/pci/controller/plda/pcie-microchip-host.c
> index b1d5b5b3cee5..03e8e93ea7e4 100644
> --- a/drivers/pci/controller/plda/pcie-microchip-host.c
> +++ b/drivers/pci/controller/plda/pcie-microchip-host.c
> @@ -416,7 +416,10 @@ static void mc_handle_event(struct irq_desc *desc)
>  
>  	chained_irq_enter(chip, desc);
>  
> -	events = get_events(port);
> +	if (port->ops && port->ops->get_events)
> +		events = port->ops->get_events(port);
> +	else
> +		events = get_events(port);

I don't really understand why we are going to having two different sorts
of event acquirers here. Is there a reason to not "just" register 
get_events() as the default callback & remove the special casing?

>  
>  	for_each_set_bit(bit, &events, NUM_EVENTS)
>  		generic_handle_domain_irq(port->event_domain, bit);
> @@ -562,11 +565,12 @@ static int mc_pcie_init_clks(struct device *dev)
>  	return 0;
>  }
>  
> -static int mc_pcie_init_irq_domains(struct plda_pcie_rp *port)
> +static int plda_pcie_init_irq_domains(struct plda_pcie_rp *port, struct plda_evt *evt)

Could you just spell out the word "event" in all of these data
structures and variables? The existing code seems to always spell it
out, so its a boon for consistency too.

>  {
>  	struct device *dev = port->dev;
>  	struct device_node *node = dev->of_node;
>  	struct device_node *pcie_intc_node;
> +	const struct irq_domain_ops *ops;
>  
>  	/* Setup INTx */
>  	pcie_intc_node = of_get_next_child(node, NULL);
> @@ -575,8 +579,9 @@ static int mc_pcie_init_irq_domains(struct plda_pcie_rp *port)
>  		return -EINVAL;
>  	}
>  
> -	port->event_domain = irq_domain_add_linear(pcie_intc_node, NUM_EVENTS,
> -						   &event_domain_ops, port);
> +	ops = evt->domain_ops ? evt->domain_ops : &event_domain_ops;
> +	port->event_domain = irq_domain_add_linear(pcie_intc_node, port->num_events,
> +						   ops, port);
>  	if (!port->event_domain) {
>  		dev_err(dev, "failed to get event domain\n");
>  		of_node_put(pcie_intc_node);
> @@ -661,14 +666,15 @@ static void mc_disable_interrupts(struct mc_pcie *port)
>  	writel_relaxed(GENMASK(31, 0), bridge_base_addr + ISTATUS_HOST);
>  }
>  
> -static int mc_init_interrupts(struct platform_device *pdev, struct plda_pcie_rp *port)
> +static int plda_init_interrupts(struct platform_device *pdev,
> +				struct plda_pcie_rp *port, struct plda_evt *evt)
>  {
>  	struct device *dev = &pdev->dev;
>  	int irq;
>  	int i, intx_irq, msi_irq, event_irq;
>  	int ret;
>  
> -	ret = mc_pcie_init_irq_domains(port);
> +	ret = plda_pcie_init_irq_domains(port, evt);
>  	if (ret) {
>  		dev_err(dev, "failed creating IRQ domains\n");
>  		return ret;
> @@ -678,15 +684,18 @@ static int mc_init_interrupts(struct platform_device *pdev, struct plda_pcie_rp
>  	if (irq < 0)
>  		return -ENODEV;
>  
> -	for (i = 0; i < NUM_EVENTS; i++) {
> +	for (i = 0; i < port->num_events; i++) {
>  		event_irq = irq_create_mapping(port->event_domain, i);
>  		if (!event_irq) {
>  			dev_err(dev, "failed to map hwirq %d\n", i);
>  			return -ENXIO;
>  		}
>  
> -		ret = devm_request_irq(dev, event_irq, mc_event_handler,
> -				       0, event_cause[i].sym, port);
> +		if (evt->request_evt_irq)
> +			ret = evt->request_evt_irq(port, event_irq, i);
> +		else
> +			ret = devm_request_irq(dev, event_irq, plda_event_handler,
> +					       0, NULL, port);
>  		if (ret) {
>  			dev_err(dev, "failed to request IRQ %d\n", event_irq);
>  			return ret;
> @@ -694,7 +703,7 @@ static int mc_init_interrupts(struct platform_device *pdev, struct plda_pcie_rp
>  	}
>  
>  	intx_irq = irq_create_mapping(port->event_domain,
> -				      EVENT_LOCAL_PM_MSI_INT_INTX);
> +				      evt->intx_evt);
>  	if (!intx_irq) {
>  		dev_err(dev, "failed to map INTx interrupt\n");
>  		return -ENXIO;
> @@ -704,7 +713,7 @@ static int mc_init_interrupts(struct platform_device *pdev, struct plda_pcie_rp
>  	irq_set_chained_handler_and_data(intx_irq, plda_handle_intx, port);
>  
>  	msi_irq = irq_create_mapping(port->event_domain,
> -				     EVENT_LOCAL_PM_MSI_INT_MSI);
> +				     evt->msi_evt);
>  	if (!msi_irq)
>  		return -ENXIO;
>  
> @@ -717,6 +726,17 @@ static int mc_init_interrupts(struct platform_device *pdev, struct plda_pcie_rp
>  	return 0;
>  }
>  
> +static int mc_request_evt_irq(struct plda_pcie_rp *plda, int event_irq,
> +			      int evt)
> +{
> +	return devm_request_irq(plda->dev, event_irq, mc_event_handler,
> +				0, event_cause[evt].sym, plda);
> +}
> +
> +static const struct plda_pcie_ops plda_ops = {
> +	.get_events = get_events,
> +};

This struct gets left behind in the microchip driver file, but is named
"plda_ops". That doesn't make sense to me, I think it should have an
"mc" prefix like other stuff in the file (and the microchip version of
get_events() should also grow a prefix IMO).

Thanks,
Conor.

> +
>  static int mc_platform_init(struct pci_config_window *cfg)
>  {
>  	struct device *dev = cfg->parent;
> @@ -724,6 +744,9 @@ static int mc_platform_init(struct pci_config_window *cfg)
>  	void __iomem *bridge_base_addr =
>  		port->axi_base_addr + MC_PCIE_BRIDGE_ADDR;
>  	struct pci_host_bridge *bridge = platform_get_drvdata(pdev);
> +	struct plda_evt evt = {&event_domain_ops, mc_request_evt_irq,
> +			       EVENT_LOCAL_PM_MSI_INT_INTX,
> +			       EVENT_LOCAL_PM_MSI_INT_MSI};
>  	int ret;
>  
>  	/* Configure address translation table 0 for PCIe config space */
> @@ -740,7 +763,7 @@ static int mc_platform_init(struct pci_config_window *cfg)
>  		return ret;
>  
>  	/* Address translation is up; safe to enable interrupts */
> -	ret = mc_init_interrupts(pdev, &port->plda);
> +	ret = plda_init_interrupts(pdev, &port->plda, &evt);
>  	if (ret)
>  		return ret;
>  
> @@ -761,6 +784,8 @@ static int mc_host_probe(struct platform_device *pdev)
>  
>  	plda = &port->plda;
>  	plda->dev = dev;
> +	plda->num_events = NUM_EVENTS;
> +	plda->ops = &plda_ops;
>  
>  	port->axi_base_addr = devm_platform_ioremap_resource(pdev, 1);
>  	if (IS_ERR(port->axi_base_addr))
> diff --git a/drivers/pci/controller/plda/pcie-plda.h b/drivers/pci/controller/plda/pcie-plda.h
> index 315d9874b899..ef33c1365b3e 100644
> --- a/drivers/pci/controller/plda/pcie-plda.h
> +++ b/drivers/pci/controller/plda/pcie-plda.h
> @@ -104,6 +104,12 @@
>  
>  #define PM_MSI_TO_MASK_OFFSET			19
>  
> +struct plda_pcie_rp;
> +
> +struct plda_pcie_ops {
> +	u32 (*get_events)(struct plda_pcie_rp *pcie);
> +};
> +
>  struct plda_msi {
>  	struct mutex lock;		/* Protect used bitmap */
>  	struct irq_domain *msi_domain;
> @@ -119,10 +125,18 @@ struct plda_pcie_rp {
>  	struct irq_domain *event_domain;
>  	raw_spinlock_t lock;
>  	struct plda_msi msi;
> +	const struct plda_pcie_ops *ops;
>  	void __iomem *bridge_addr;
>  	int num_events;
>  };
>  
> +struct plda_evt {
> +	const struct irq_domain_ops *domain_ops;
> +	int (*request_evt_irq)(struct plda_pcie_rp *pcie, int evt_irq, int event);
> +	int intx_evt;
> +	int msi_evt;
> +};
> +
>  void plda_handle_msi(struct irq_desc *desc);
>  int plda_allocate_msi_domains(struct plda_pcie_rp *port);
>  irqreturn_t plda_event_handler(int irq, void *dev_id);
> -- 
> 2.17.1
>

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