Re: [PATCH v7 13/19] PCI: microchip: Add get_events() callback function

[Conor Dooley]

Hey,

On Wed, Sep 27, 2023 at 06:07:56PM +0800, Minda Chen wrote:
> For different interrupts to event num mapping function,
> add get_events() function pointer.
> 
> Signed-off-by: Minda Chen <minda.chen@xxxxxxxxxxxxxxxx>
> ---
>  drivers/pci/controller/plda/pcie-microchip-host.c | 14 +++++++++++++-
>  drivers/pci/controller/plda/pcie-plda.h           |  2 ++
>  2 files changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/controller/plda/pcie-microchip-host.c b/drivers/pci/controller/plda/pcie-microchip-host.c
> index fb09b6c34e01..875bdb03ce22 100644
> --- a/drivers/pci/controller/plda/pcie-microchip-host.c
> +++ b/drivers/pci/controller/plda/pcie-microchip-host.c
> @@ -646,7 +646,7 @@ static void plda_handle_event(struct irq_desc *desc)
>  
>  	chained_irq_enter(chip, desc);
>  
> -	events = mc_get_events(port);
> +	events = port->event_ops->get_events(port);
>  
>  	for_each_set_bit(bit, &events, port->num_events)
>  		generic_handle_domain_irq(port->event_domain, bit);
> @@ -805,7 +805,12 @@ static int mc_request_event_irq(struct plda_pcie_rp *plda, int event_irq,
>  				0, event_cause[event].sym, plda);
>  }
>  
> +static const struct plda_event_ops mc_event_ops = {
> +	.get_events = mc_get_events,
> +};
> +
>  static const struct plda_event mc_event = {
> +	.event_ops              = &mc_event_ops,
>  	.request_event_irq      = mc_request_event_irq,
>  	.intx_event             = EVENT_LOCAL_PM_MSI_INT_INTX,
>  	.msi_event              = EVENT_LOCAL_PM_MSI_INT_MSI,
> @@ -919,6 +924,11 @@ static int plda_init_interrupts(struct platform_device *pdev,
>  	int i, intx_irq, msi_irq, event_irq;
>  	int ret;
>  
> +	if (!event->event_ops || !event->event_ops->get_events) {
> +		dev_err(dev, "no get events ops\n");
> +		return -EINVAL;
> +	}

Dumb question maybe, but is this actually possible to trigger?
This code is in the Microchip driver, so I assume there's a future patch
moving this code that could actually trigger the problem? If so, the
motivation for making this generic should be mentioned in the commit
message IMO.

Thanks,
Conor.

> +
>  	ret = plda_pcie_init_irq_domains(port);
>  	if (ret) {
>  		dev_err(dev, "failed creating IRQ domains\n");
> @@ -929,6 +939,8 @@ static int plda_init_interrupts(struct platform_device *pdev,
>  	if (irq < 0)
>  		return -ENODEV;
>  
> +	port->event_ops = event->event_ops;
> +
>  	for (i = 0; i < port->num_events; i++) {
>  		event_irq = irq_create_mapping(port->event_domain, i);
>  		if (!event_irq) {
> diff --git a/drivers/pci/controller/plda/pcie-plda.h b/drivers/pci/controller/plda/pcie-plda.h
> index af5e69718342..48d7bc471137 100644
> --- a/drivers/pci/controller/plda/pcie-plda.h
> +++ b/drivers/pci/controller/plda/pcie-plda.h
> @@ -149,11 +149,13 @@ struct plda_pcie_rp {
>  	struct irq_domain *event_domain;
>  	raw_spinlock_t lock;
>  	struct plda_msi msi;
> +	const struct plda_event_ops *event_ops;
>  	void __iomem *bridge_addr;
>  	int num_events;
>  };
>  
>  struct plda_event {
> +	const struct plda_event_ops *event_ops;
>  	int (*request_event_irq)(struct plda_pcie_rp *pcie,
>  				 int event_irq, int event);
>  	int intx_event;
> -- 
> 2.17.1
>

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