For NTB devices, we want to be able to trigger MSI interrupts through a memory window. In these cases we may want to use more interrupts than the NTB PCI device has available in its MSI-X table.
We allow for this by creating a new 'virtual' interrupt. These interrupts are allocated as usual but are not programmed into the MSI-X table (as there may not be space for them).
The MSI address and data will then handled through an NTB MSI library introduced later in this series.
Signed-off-by: Logan Gunthorpe logang@deltatee.com Cc: Bjorn Helgaas bhelgaas@google.com --- drivers/pci/msi.c | 51 +++++++++++++++++++++++++++++++++++++-------- include/linux/msi.h | 1 + include/linux/pci.h | 9 ++++++++ 3 files changed, 52 insertions(+), 9 deletions(-)
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 4c0b47867258..145587da686c 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -192,6 +192,9 @@ static void msi_mask_irq(struct msi_desc *desc, u32 mask, u32 flag)
static void __iomem *pci_msix_desc_addr(struct msi_desc *desc) { + if (desc->msi_attrib.is_virtual) + return NULL; + return desc->mask_base + desc->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE; } @@ -206,14 +209,19 @@ static void __iomem *pci_msix_desc_addr(struct msi_desc *desc) u32 __pci_msix_desc_mask_irq(struct msi_desc *desc, u32 flag) { u32 mask_bits = desc->masked; + void __iomem *desc_addr;
if (pci_msi_ignore_mask) return 0; + desc_addr = pci_msix_desc_addr(desc); + if (!desc_addr) + return 0;
mask_bits &= ~PCI_MSIX_ENTRY_CTRL_MASKBIT; if (flag) mask_bits |= PCI_MSIX_ENTRY_CTRL_MASKBIT; - writel(mask_bits, pci_msix_desc_addr(desc) + PCI_MSIX_ENTRY_VECTOR_CTRL); + + writel(mask_bits, desc_addr + PCI_MSIX_ENTRY_VECTOR_CTRL);
return mask_bits; } @@ -273,6 +281,11 @@ void __pci_read_msi_msg(struct msi_desc *entry, struct msi_msg *msg) if (entry->msi_attrib.is_msix) { void __iomem *base = pci_msix_desc_addr(entry);
+ if (!base) { + WARN_ON(1); + return; + } + msg->address_lo = readl(base + PCI_MSIX_ENTRY_LOWER_ADDR); msg->address_hi = readl(base + PCI_MSIX_ENTRY_UPPER_ADDR); msg->data = readl(base + PCI_MSIX_ENTRY_DATA); @@ -303,6 +316,9 @@ void __pci_write_msi_msg(struct msi_desc *entry, struct msi_msg *msg) } else if (entry->msi_attrib.is_msix) { void __iomem *base = pci_msix_desc_addr(entry);
+ if (!base) + goto skip; + writel(msg->address_lo, base + PCI_MSIX_ENTRY_LOWER_ADDR); writel(msg->address_hi, base + PCI_MSIX_ENTRY_UPPER_ADDR); writel(msg->data, base + PCI_MSIX_ENTRY_DATA); @@ -327,6 +343,8 @@ void __pci_write_msi_msg(struct msi_desc *entry, struct msi_msg *msg) msg->data); } } + +skip: entry->msg = *msg; }
@@ -550,6 +568,7 @@ msi_setup_entry(struct pci_dev *dev, int nvec, const struct irq_affinity *affd)
entry->msi_attrib.is_msix = 0; entry->msi_attrib.is_64 = !!(control & PCI_MSI_FLAGS_64BIT); + entry->msi_attrib.is_virtual = 0; entry->msi_attrib.entry_nr = 0; entry->msi_attrib.maskbit = !!(control & PCI_MSI_FLAGS_MASKBIT); entry->msi_attrib.default_irq = dev->irq; /* Save IOAPIC IRQ */ @@ -674,6 +693,7 @@ static int msix_setup_entries(struct pci_dev *dev, void __iomem *base, struct irq_affinity_desc *curmsk, *masks = NULL; struct msi_desc *entry; int ret, i; + int vec_count = pci_msix_vec_count(dev);
if (affd) masks = irq_create_affinity_masks(nvec, affd); @@ -696,6 +716,10 @@ static int msix_setup_entries(struct pci_dev *dev, void __iomem *base, entry->msi_attrib.entry_nr = entries[i].entry; else entry->msi_attrib.entry_nr = i; + + entry->msi_attrib.is_virtual = + entry->msi_attrib.entry_nr >= vec_count; + entry->msi_attrib.default_irq = dev->irq; entry->mask_base = base;
@@ -714,12 +738,19 @@ static void msix_program_entries(struct pci_dev *dev, { struct msi_desc *entry; int i = 0; + void __iomem *desc_addr;
for_each_pci_msi_entry(entry, dev) { if (entries) entries[i++].vector = entry->irq; - entry->masked = readl(pci_msix_desc_addr(entry) + - PCI_MSIX_ENTRY_VECTOR_CTRL); + + desc_addr = pci_msix_desc_addr(entry); + if (desc_addr) + entry->masked = readl(desc_addr + + PCI_MSIX_ENTRY_VECTOR_CTRL); + else + entry->masked = 0; + msix_mask_irq(entry, 1); } } @@ -932,7 +963,8 @@ 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, const struct irq_affinity *affd, + int flags) { int nr_entries; int i, j; @@ -943,7 +975,7 @@ static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, nr_entries = pci_msix_vec_count(dev); if (nr_entries < 0) return nr_entries; - if (nvec > nr_entries) + if (nvec > nr_entries && !(flags & PCI_IRQ_VIRTUAL)) return nr_entries;
if (entries) { @@ -1086,7 +1118,8 @@ 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, const struct irq_affinity *affd, + int flags) { int rc, nvec = maxvec;
@@ -1110,7 +1143,7 @@ static int __pci_enable_msix_range(struct pci_dev *dev, return -ENOSPC; }
- rc = __pci_enable_msix(dev, entries, nvec, affd); + rc = __pci_enable_msix(dev, entries, nvec, affd, flags); if (rc == 0) return nvec;
@@ -1141,7 +1174,7 @@ static int __pci_enable_msix_range(struct pci_dev *dev, int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries, int minvec, int maxvec) { - return __pci_enable_msix_range(dev, entries, minvec, maxvec, NULL); + return __pci_enable_msix_range(dev, entries, minvec, maxvec, NULL, 0); } EXPORT_SYMBOL(pci_enable_msix_range);
@@ -1181,7 +1214,7 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
if (flags & PCI_IRQ_MSIX) { msix_vecs = __pci_enable_msix_range(dev, NULL, min_vecs, - max_vecs, affd); + max_vecs, affd, flags); if (msix_vecs > 0) return msix_vecs; } diff --git a/include/linux/msi.h b/include/linux/msi.h index 784fb52b9900..6458ab049852 100644 --- a/include/linux/msi.h +++ b/include/linux/msi.h @@ -88,6 +88,7 @@ struct msi_desc { __u8 multi_cap : 3; __u8 maskbit : 1; __u8 is_64 : 1; + __u8 is_virtual : 1; __u16 entry_nr; unsigned default_irq; } msi_attrib; diff --git a/include/linux/pci.h b/include/linux/pci.h index 65f1d8c2f082..ce0815c2c498 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1352,6 +1352,15 @@ int pci_set_vga_state(struct pci_dev *pdev, bool decode, #define PCI_IRQ_MSI (1 << 1) /* Allow MSI interrupts */ #define PCI_IRQ_MSIX (1 << 2) /* Allow MSI-X interrupts */ #define PCI_IRQ_AFFINITY (1 << 3) /* Auto-assign affinity */ + +/* + * Virtual interrupts allow for more interrupts to be allocated + * than the device has interrupts for. These are not programmed + * into the devices MSI-X table and must be handled by some + * other driver means. + */ +#define PCI_IRQ_VIRTUAL (1 << 4) + #define PCI_IRQ_ALL_TYPES \ (PCI_IRQ_LEGACY | PCI_IRQ_MSI | PCI_IRQ_MSIX)