On Tue, Feb 12, 2019 at 09:04:39PM +0800, Ming Lei wrote:
> Now NVMe has implemented the .calc_sets callback for caculating each
> set's vectors.
>
> For other cases of multiple irq sets, it isn't a good way to pre-caculate
> each set's vectors before allocating IRQ vectors because NVMe's same issue
> exists too.
s/irq/IRQ/ so it's consistent in the paragraph.
> Document .calc_sets as required explicitly for multiple sets.
>
> Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Note minor comments below.
> ---
> drivers/pci/msi.c | 4 ++--
> include/linux/interrupt.h | 3 ++-
> 2 files changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
> index 4c0b47867258..9f91fa713141 100644
> --- a/drivers/pci/msi.c
> +++ b/drivers/pci/msi.c
> @@ -1039,7 +1039,7 @@ static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
> * If the caller is passing in sets, we can't support a range of
> * vectors. The caller needs to handle that.
Looks like this comment needs to be tweaked, maybe along the lines of:
If the caller requests multiple sets of IRQs where each set requires
different affinity, it must also supply a ->calc_sets() callback to
compute the affinity cpumask for each set.
(I'm not 100% clear on how calc_sets() works, so I might not have
described this exactly right.)
> */
> - if (affd && affd->nr_sets && minvec != maxvec)
> + if (affd && affd->nr_sets > 1 && !affd->calc_sets)
> return -EINVAL;
>
> if (WARN_ON_ONCE(dev->msi_enabled))
> @@ -1097,7 +1097,7 @@ static int __pci_enable_msix_range(struct pci_dev *dev,
> * If the caller is passing in sets, we can't support a range of
> * supported vectors. The caller needs to handle that.
Similar comment update here?
> */
> - if (affd && affd->nr_sets && minvec != maxvec)
> + if (affd && affd->nr_sets > 1 && !affd->calc_sets)
> return -EINVAL;
>
> if (WARN_ON_ONCE(dev->msix_enabled))
> diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
> index 7a27f6ba1f2f..a053f7fb0ff1 100644
> --- a/include/linux/interrupt.h
> +++ b/include/linux/interrupt.h
> @@ -269,7 +269,8 @@ struct irq_affinity_notify {
> * the MSI(-X) vector space
> * @nr_sets: Length of passed in *sets array
> * @set_vectors: Number of affinitized sets
> - * @calc_sets: Callback for caculating set vectors
> + * @calc_sets: Callback for caculating set vectors, required for
> + * multiple irq sets.
> * @priv: Private data of @calc_sets
> */
> struct irq_affinity {
> --
> 2.9.5
>
