PCI/MSI: Use msi_desc::msi_index

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>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20211210221814.602911509@linutronix.de

arch/powerpc/platforms/pseries/msi.c

@@ -332,7 +332,7 @@ static int check_msix_entries(struct pci_dev *pdev)
 
 	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;
 		}
@@ -579,7 +579,7 @@ static int pseries_irq_domain_alloc(struct irq_domain *domain, unsigned int virq
 	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;

arch/x86/pci/xen.c

@@ -306,7 +306,7 @@ static int xen_initdom_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 				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;

drivers/pci/msi/irqdomain.c

@@ -57,7 +57,7 @@ static irq_hw_number_t pci_msi_domain_calc_hwirq(struct msi_desc *desc)
 {
 	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;
 }

drivers/pci/msi/msi.c

@@ -44,7 +44,7 @@ static inline void pci_msi_unmask(struct msi_desc *desc, u32 mask)
 
 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;
 }
 
 /*
@@ -394,13 +394,10 @@ msi_setup_entry(struct pci_dev *dev, int nvec, struct irq_affinity *affd)
 	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));
 
@@ -542,12 +539,11 @@ static int msix_setup_entries(struct pci_dev *dev, void __iomem *base,
 		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;
@@ -1088,7 +1084,7 @@ int pci_irq_vector(struct pci_dev *dev, unsigned int nr)
 		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);
@@ -1127,7 +1123,7 @@ const struct cpumask *pci_irq_get_affinity(struct pci_dev *dev, int nr)
 		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);

drivers/pci/xen-pcifront.c

@@ -263,7 +263,7 @@ static int pci_frontend_enable_msix(struct pci_dev *dev,
 
 	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++;

include/linux/msi.h

@@ -80,7 +80,6 @@ typedef void (*irq_write_msi_msg_t)(struct msi_desc *desc,
  * @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 {