Re: [PATCH V3 1/5] genirq/affinity: don't mark 'affd' as const

Bjorn Helgaas
2019-02-13T15:04:12Z

On Wed, Feb 13, 2019 at 06:50:37PM +0800, Ming Lei wrote:
> Currently all parameters in 'affd' are read-only, so 'affd' is marked
> as const in both pci_alloc_irq_vectors_affinity() and irq_create_affinity_masks().

s/all parameters in 'affd'/the contents of '*affd'/

> We have to ask driver to re-caculate set vectors after the whole IRQ
> vectors are allocated later, and the result needs to be stored in 'affd'.
> Also both the two interfaces are core APIs, which should be trusted.

s/re-caculate/recalculate/
s/stored in 'affd'/stored in '*affd'/
s/both the two/both/

This is a little confusing because you're talking about both "IRQ
vectors" and these other "set vectors", which I think are different
things. I assume the "set vectors" are cpumasks showing the affinity
of the IRQ vectors with some CPUs?

AFAICT, *this* patch doesn't add anything that writes to *affd. I
think the removal of "const" should be in the same patch that makes
the removal necessary.

> So don't mark 'affd' as const both pci_alloc_irq_vectors_affinity() and
> irq_create_affinity_masks().
>
> Signed-off-by: Ming Lei <ming.lei@redhat.com>
> ---
> drivers/pci/msi.c | 18 +++++++++---------
> include/linux/interrupt.h | 2 +-
> include/linux/pci.h | 4 ++--
> kernel/irq/affinity.c | 2 +-
> 4 files changed, 13 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
> index 4c0b47867258..96978459e2a0 100644
> --- a/drivers/pci/msi.c
> +++ b/drivers/pci/msi.c
> @@ -532,7 +532,7 @@ static int populate_msi_sysfs(struct pci_dev *pdev)
> }
>
> static struct msi_desc *
> -msi_setup_entry(struct pci_dev *dev, int nvec, const struct irq_affinity *affd)
> +msi_setup_entry(struct pci_dev *dev, int nvec, struct irq_affinity *affd)
> {
> struct irq_affinity_desc *masks = NULL;
> struct msi_desc *entry;
> @@ -597,7 +597,7 @@ static int msi_verify_entries(struct pci_dev *dev)
> * which could have been allocated.
> */
> static int msi_capability_init(struct pci_dev *dev, int nvec,
> - const struct irq_affinity *affd)
> + struct irq_affinity *affd)
> {
> struct msi_desc *entry;
> int ret;
> @@ -669,7 +669,7 @@ static void __iomem *msix_map_region(struct pci_dev *dev, unsigned nr_entries)
>
> static int msix_setup_entries(struct pci_dev *dev, void __iomem *base,
> struct msix_entry *entries, int nvec,
> - const struct irq_affinity *affd)
> + struct irq_affinity *affd)
> {
> struct irq_affinity_desc *curmsk, *masks = NULL;
> struct msi_desc *entry;
> @@ -736,7 +736,7 @@ static void msix_program_entries(struct pci_dev *dev,
> * requested MSI-X entries with allocated irqs or non-zero for otherwise.
> **/
> static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries,
> - int nvec, const struct irq_affinity *affd)
> + int nvec, struct irq_affinity *affd)
> {
> int ret;
> u16 control;
> @@ -932,7 +932,7 @@ int pci_msix_vec_count(struct pci_dev *dev)
> EXPORT_SYMBOL(pci_msix_vec_count);
>
> static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries,
> - int nvec, const struct irq_affinity *affd)
> + int nvec, struct irq_affinity *affd)
> {
> int nr_entries;
> int i, j;
> @@ -1018,7 +1018,7 @@ int pci_msi_enabled(void)
> EXPORT_SYMBOL(pci_msi_enabled);
>
> static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
> - const struct irq_affinity *affd)
> + struct irq_affinity *affd)
> {
> int nvec;
> int rc;
> @@ -1086,7 +1086,7 @@ EXPORT_SYMBOL(pci_enable_msi);
>
> static int __pci_enable_msix_range(struct pci_dev *dev,
> struct msix_entry *entries, int minvec,
> - int maxvec, const struct irq_affinity *affd)
> + int maxvec, struct irq_affinity *affd)
> {
> int rc, nvec = maxvec;
>
> @@ -1165,9 +1165,9 @@ EXPORT_SYMBOL(pci_enable_msix_range);
> */
> int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
> unsigned int max_vecs, unsigned int flags,
> - const struct irq_affinity *affd)
> + struct irq_affinity *affd)
> {
> - static const struct irq_affinity msi_default_affd;
> + struct irq_affinity msi_default_affd = {0};
> int msix_vecs = -ENOSPC;
> int msi_vecs = -ENOSPC;
>
> diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
> index 7c9434652f36..1ed1014c9684 100644
> --- a/include/linux/interrupt.h
> +++ b/include/linux/interrupt.h
> @@ -332,7 +332,7 @@ extern int
> irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify);
>
> struct irq_affinity_desc *
> -irq_create_affinity_masks(int nvec, const struct irq_affinity *affd);
> +irq_create_affinity_masks(int nvec, struct irq_affinity *affd);
>
> int irq_calc_affinity_vectors(int minvec, int maxvec, const struct irq_affinity *affd);
>
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 40b327b814aa..4eca42cf611b 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1396,7 +1396,7 @@ static inline int pci_enable_msix_exact(struct pci_dev *dev,
> }
> int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
> unsigned int max_vecs, unsigned int flags,
> - const struct irq_affinity *affd);
> + struct irq_affinity *affd);
>
> void pci_free_irq_vectors(struct pci_dev *dev);
> int pci_irq_vector(struct pci_dev *dev, unsigned int nr);
> @@ -1422,7 +1422,7 @@ static inline int pci_enable_msix_exact(struct pci_dev *dev,
> static inline int
> pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
> unsigned int max_vecs, unsigned int flags,
> - const struct irq_affinity *aff_desc)
> + struct irq_affinity *aff_desc)
> {
> if ((flags & PCI_IRQ_LEGACY) && min_vecs == 1 && dev->irq)
> return 1;
> diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
> index 118b66d64a53..9200d3b26f7d 100644
> --- a/kernel/irq/affinity.c
> +++ b/kernel/irq/affinity.c
> @@ -239,7 +239,7 @@ static int irq_build_affinity_masks(const struct irq_affinity *affd,
> * Returns the irq_affinity_desc pointer or NULL if allocation failed.
> */
> struct irq_affinity_desc *
> -irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
> +irq_create_affinity_masks(int nvecs, struct irq_affinity *affd)
> {
> int affvecs = nvecs - affd->pre_vectors - affd->post_vectors;
> int curvec, usedvecs;
> --
> 2.9.5
>