On Fri, 26 Feb 2021 20:11:17 +0000,
Megha Dey <megha.dey@xxxxxxxxx> wrote:
>
> From: Dave Jiang <dave.jiang@xxxxxxxxx>
>
> Add new helpers to get the Linux IRQ number and device specific index
> for given device-relative vector so that the drivers don't need to
> allocate their own arrays to keep track of the vectors and hwirq for
> the multi vector device MSI case.
>
> Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
> Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
> Signed-off-by: Megha Dey <megha.dey@xxxxxxxxx>
> ---
> include/linux/msi.h | 2 ++
> kernel/irq/msi.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 46 insertions(+)
>
> diff --git a/include/linux/msi.h b/include/linux/msi.h
> index 24abec0..d60a6ba 100644
> --- a/include/linux/msi.h
> +++ b/include/linux/msi.h
> @@ -451,6 +451,8 @@ struct irq_domain *platform_msi_create_irq_domain(struct fwnode_handle *fwnode,
> int platform_msi_domain_alloc_irqs(struct device *dev, unsigned int nvec,
> irq_write_msi_msg_t write_msi_msg);
> void platform_msi_domain_free_irqs(struct device *dev);
> +int msi_irq_vector(struct device *dev, unsigned int nr);
> +int dev_msi_hwirq(struct device *dev, unsigned int nr);
>
> /* When an MSI domain is used as an intermediate domain */
> int msi_domain_prepare_irqs(struct irq_domain *domain, struct device *dev,
> diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
> index 047b59d..f2a8f55 100644
> --- a/kernel/irq/msi.c
> +++ b/kernel/irq/msi.c
> @@ -581,4 +581,48 @@ struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain)
> return (struct msi_domain_info *)domain->host_data;
> }
>
> +/**
> + * msi_irq_vector - Get the Linux IRQ number of a device vector
> + * @dev: device to operate on
> + * @nr: device-relative interrupt vector index (0-based).
> + *
> + * Returns the Linux IRQ number of a device vector.
> + */
> +int msi_irq_vector(struct device *dev, unsigned int nr)
> +{
> + struct msi_desc *entry;
> + int i = 0;
> +
> + for_each_msi_entry(entry, dev) {
> + if (i == nr)
> + return entry->irq;
> + i++;
This obviously doesn't work with Multi-MSI, does it?
> + }
> + WARN_ON_ONCE(1);
> + return -EINVAL;
> +}
> +EXPORT_SYMBOL_GPL(msi_irq_vector);
> +
> +/**
> + * dev_msi_hwirq - Get the device MSI hw IRQ number of a device vector
> + * @dev: device to operate on
> + * @nr: device-relative interrupt vector index (0-based).
> + *
> + * Return the dev_msi hw IRQ number of a device vector.
> + */
> +int dev_msi_hwirq(struct device *dev, unsigned int nr)
> +{
> + struct msi_desc *entry;
> + int i = 0;
> +
> + for_each_msi_entry(entry, dev) {
> + if (i == nr)
> + return entry->device_msi.hwirq;
> + i++;
> + }
> + WARN_ON_ONCE(1);
> + return -EINVAL;
> +}
> +EXPORT_SYMBOL_GPL(dev_msi_hwirq);
> +
> #endif /* CONFIG_GENERIC_MSI_IRQ_DOMAIN */
And what uses these helpers?
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
