On Tue, Jul 21, 2020 at 09:02:28AM -0700, Dave Jiang wrote:
> From: Megha Dey <megha.dey@xxxxxxxxx>
>
> Add support for the creation of a new DEV_MSI irq domain. It creates a
> new irq chip associated with the DEV_MSI domain and adds the necessary
> domain operations to it.
>
> Add a new config option DEV_MSI which must be enabled by any
> driver that wants to support device-specific message-signaled-interrupts
> outside of PCI-MSI(-X).
>
> Lastly, add device specific mask/unmask callbacks in addition to a write
> function to the platform_msi_ops.
>
> Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx>
> Signed-off-by: Megha Dey <megha.dey@xxxxxxxxx>
> Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
> arch/x86/include/asm/hw_irq.h | 5 ++
> drivers/base/Kconfig | 7 +++
> drivers/base/Makefile | 1
> drivers/base/dev-msi.c | 95 +++++++++++++++++++++++++++++++++++++++++
> drivers/base/platform-msi.c | 45 +++++++++++++------
> drivers/base/platform-msi.h | 23 ++++++++++
> include/linux/msi.h | 8 +++
> 7 files changed, 168 insertions(+), 16 deletions(-)
> create mode 100644 drivers/base/dev-msi.c
> create mode 100644 drivers/base/platform-msi.h
>
> diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
> index 74c12437401e..8ecd7570589d 100644
> +++ b/arch/x86/include/asm/hw_irq.h
> @@ -61,6 +61,11 @@ struct irq_alloc_info {
> irq_hw_number_t msi_hwirq;
> };
> #endif
> +#ifdef CONFIG_DEV_MSI
> + struct {
> + irq_hw_number_t hwirq;
> + };
> +#endif
Why is this in this patch? I didn't see an obvious place where it is
used?
>
> +static void __platform_msi_desc_mask_unmask_irq(struct msi_desc *desc, u32 mask)
> +{
> + const struct platform_msi_ops *ops;
> +
> + ops = desc->platform.msi_priv_data->ops;
> + if (!ops)
> + return;
> +
> + if (mask) {
> + if (ops->irq_mask)
> + ops->irq_mask(desc);
> + } else {
> + if (ops->irq_unmask)
> + ops->irq_unmask(desc);
> + }
> +}
> +
> +void platform_msi_mask_irq(struct irq_data *data)
> +{
> + __platform_msi_desc_mask_unmask_irq(irq_data_get_msi_desc(data), 1);
> +}
> +
> +void platform_msi_unmask_irq(struct irq_data *data)
> +{
> + __platform_msi_desc_mask_unmask_irq(irq_data_get_msi_desc(data), 0);
> +}
This is a bit convoluted, just call the op directly:
void platform_msi_unmask_irq(struct irq_data *data)
{
const struct platform_msi_ops *ops = desc->platform.msi_priv_data->ops;
if (ops->irq_unmask)
ops->irq_unmask(desc);
}
> diff --git a/include/linux/msi.h b/include/linux/msi.h
> index 7f6a8eb51aca..1da97f905720 100644
> +++ b/include/linux/msi.h
> @@ -323,9 +323,13 @@ enum {
>
> /*
> * platform_msi_ops - Callbacks for platform MSI ops
> + * @irq_mask: mask an interrupt source
> + * @irq_unmask: unmask an interrupt source
> * @write_msg: write message content
> */
> struct platform_msi_ops {
> + unsigned int (*irq_mask)(struct msi_desc *desc);
> + unsigned int (*irq_unmask)(struct msi_desc *desc);
Why do these functions return things if the only call site throws it
away?
Jason
