Re: [patch V2 17/36] PCI/MSI: Use msi_desc::msi_index

Bjorn Helgaas
2021-12-07T21:04:49Z

On Mon, Dec 06, 2021 at 11:39:23PM +0100, Thomas Gleixner wrote:
> The usage of msi_desc::pci::entry_nr is confusing at best. It's the index
> into the MSI[X] descriptor table.
>
> Use msi_desc::msi_index which is shared between all MSI incarnations
> instead of having a PCI specific storage for no value.
>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Acked-by: Bjorn Helgaas <bhelgaas@google.com>

> ---
> arch/powerpc/platforms/pseries/msi.c | 4 ++--
> arch/x86/pci/xen.c | 2 +-
> drivers/pci/msi/irqdomain.c | 2 +-
> drivers/pci/msi/msi.c | 20 ++++++++------------
> drivers/pci/xen-pcifront.c | 2 +-
> include/linux/msi.h | 2 --
> 6 files changed, 13 insertions(+), 19 deletions(-)
>
> --- a/arch/powerpc/platforms/pseries/msi.c
> +++ b/arch/powerpc/platforms/pseries/msi.c
> @@ -332,7 +332,7 @@ static int check_msix_entries(struct pci
>
> expected = 0;
> for_each_pci_msi_entry(entry, pdev) {
> - if (entry->pci.msi_attrib.entry_nr != expected) {
> + if (entry->msi_index != expected) {
> pr_debug("rtas_msi: bad MSI-X entries.\n");
> return -EINVAL;
> }
> @@ -580,7 +580,7 @@ static int pseries_irq_domain_alloc(stru
> int hwirq;
> int i, ret;
>
> - hwirq = rtas_query_irq_number(pci_get_pdn(pdev), desc->pci.msi_attrib.entry_nr);
> + hwirq = rtas_query_irq_number(pci_get_pdn(pdev), desc->msi_index);
> if (hwirq < 0) {
> dev_err(&pdev->dev, "Failed to query HW IRQ: %d\n", hwirq);
> return hwirq;
> --- a/arch/x86/pci/xen.c
> +++ b/arch/x86/pci/xen.c
> @@ -306,7 +306,7 @@ static int xen_initdom_setup_msi_irqs(st
> return -EINVAL;
>
> map_irq.table_base = pci_resource_start(dev, bir);
> - map_irq.entry_nr = msidesc->pci.msi_attrib.entry_nr;
> + map_irq.entry_nr = msidesc->msi_index;
> }
>
> ret = -EINVAL;
> --- a/drivers/pci/msi/irqdomain.c
> +++ b/drivers/pci/msi/irqdomain.c
> @@ -57,7 +57,7 @@ static irq_hw_number_t pci_msi_domain_ca
> {
> struct pci_dev *dev = msi_desc_to_pci_dev(desc);
>
> - return (irq_hw_number_t)desc->pci.msi_attrib.entry_nr |
> + return (irq_hw_number_t)desc->msi_index |
> pci_dev_id(dev) << 11 |
> (pci_domain_nr(dev->bus) & 0xFFFFFFFF) << 27;
> }
> --- a/drivers/pci/msi/msi.c
> +++ b/drivers/pci/msi/msi.c
> @@ -44,7 +44,7 @@ static inline void pci_msi_unmask(struct
>
> static inline void __iomem *pci_msix_desc_addr(struct msi_desc *desc)
> {
> - return desc->pci.mask_base + desc->pci.msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE;
> + return desc->pci.mask_base + desc->msi_index * PCI_MSIX_ENTRY_SIZE;
> }
>
> /*
> @@ -356,13 +356,10 @@ msi_setup_entry(struct pci_dev *dev, int
> if (dev->dev_flags & PCI_DEV_FLAGS_HAS_MSI_MASKING)
> control |= PCI_MSI_FLAGS_MASKBIT;
>
> - entry->pci.msi_attrib.is_msix = 0;
> - entry->pci.msi_attrib.is_64 = !!(control & PCI_MSI_FLAGS_64BIT);
> - entry->pci.msi_attrib.is_virtual = 0;
> - entry->pci.msi_attrib.entry_nr = 0;
> + entry->pci.msi_attrib.is_64 = !!(control & PCI_MSI_FLAGS_64BIT);
> entry->pci.msi_attrib.can_mask = !pci_msi_ignore_mask &&
> !!(control & PCI_MSI_FLAGS_MASKBIT);
> - entry->pci.msi_attrib.default_irq = dev->irq; /* Save IOAPIC IRQ */
> + entry->pci.msi_attrib.default_irq = dev->irq;
> entry->pci.msi_attrib.multi_cap = (control & PCI_MSI_FLAGS_QMASK) >> 1;
> entry->pci.msi_attrib.multiple = ilog2(__roundup_pow_of_two(nvec));
>
> @@ -496,12 +493,11 @@ static int msix_setup_entries(struct pci
> entry->pci.msi_attrib.is_64 = 1;
>
> if (entries)
> - entry->pci.msi_attrib.entry_nr = entries[i].entry;
> + entry->msi_index = entries[i].entry;
> else
> - entry->pci.msi_attrib.entry_nr = i;
> + entry->msi_index = i;
>
> - entry->pci.msi_attrib.is_virtual =
> - entry->pci.msi_attrib.entry_nr >= vec_count;
> + entry->pci.msi_attrib.is_virtual = entry->msi_index >= vec_count;
>
> entry->pci.msi_attrib.can_mask = !pci_msi_ignore_mask &&
> !entry->pci.msi_attrib.is_virtual;
> @@ -1034,7 +1030,7 @@ int pci_irq_vector(struct pci_dev *dev,
> struct msi_desc *entry;
>
> for_each_pci_msi_entry(entry, dev) {
> - if (entry->pci.msi_attrib.entry_nr == nr)
> + if (entry->msi_index == nr)
> return entry->irq;
> }
> WARN_ON_ONCE(1);
> @@ -1073,7 +1069,7 @@ const struct cpumask *pci_irq_get_affini
> struct msi_desc *entry;
>
> for_each_pci_msi_entry(entry, dev) {
> - if (entry->pci.msi_attrib.entry_nr == nr)
> + if (entry->msi_index == nr)
> return &entry->affinity->mask;
> }
> WARN_ON_ONCE(1);
> --- a/drivers/pci/xen-pcifront.c
> +++ b/drivers/pci/xen-pcifront.c
> @@ -263,7 +263,7 @@ static int pci_frontend_enable_msix(stru
>
> i = 0;
> for_each_pci_msi_entry(entry, dev) {
> - op.msix_entries[i].entry = entry->pci.msi_attrib.entry_nr;
> + op.msix_entries[i].entry = entry->msi_index;
> /* Vector is useless at this point. */
> op.msix_entries[i].vector = -1;
> i++;
> --- a/include/linux/msi.h
> +++ b/include/linux/msi.h
> @@ -80,7 +80,6 @@ typedef void (*irq_write_msi_msg_t)(stru
> * @multi_cap: [PCI MSI/X] log2 num of messages supported
> * @can_mask: [PCI MSI/X] Masking supported?
> * @is_64: [PCI MSI/X] Address size: 0=32bit 1=64bit
> - * @entry_nr: [PCI MSI/X] Entry which is described by this descriptor
> * @default_irq:[PCI MSI/X] The default pre-assigned non-MSI irq
> * @mask_pos: [PCI MSI] Mask register position
> * @mask_base: [PCI MSI-X] Mask register base address
> @@ -97,7 +96,6 @@ struct pci_msi_desc {
> u8 can_mask : 1;
> u8 is_64 : 1;
> u8 is_virtual : 1;
> - u16 entry_nr;
> unsigned default_irq;
> } msi_attrib;
> union {
>