Currently PCIe port services are assigned with different interrutps only if MSI-x are supported by calling pcie_port_enable_msix(). If a root port supports MSI instead of MSI-x currently we fall back to use a single shared interrupt for all the services. This patch renames and extends pcie_port_enable_msix() to use MSI in case MSI-x allocation fails.
Signed-off-by: Gabriele Paoloni <[email protected]> --- drivers/pci/pcie/portdrv.h | 8 ++++--- drivers/pci/pcie/portdrv_core.c | 46 +++++++++++++++++++++++++---------------- 2 files changed, 33 insertions(+), 21 deletions(-) diff --git a/drivers/pci/pcie/portdrv.h b/drivers/pci/pcie/portdrv.h index 587aef3..1993e2c 100644 --- a/drivers/pci/pcie/portdrv.h +++ b/drivers/pci/pcie/portdrv.h @@ -13,10 +13,12 @@ #define PCIE_PORT_DEVICE_MAXSERVICES 5 /* - * According to the PCI Express Base Specification 2.0, the indices of - * the MSI-X table entries used by port services must not exceed 31 + * According to the PCI Express Base Specification REV. 3.1 and according + * to the PCI Local Bus Specification REV. 3.0 respectively, the indices of + * the MSI-X table entries or the max number of MSI vectors used by port + * services must not exceed 31 */ -#define PCIE_PORT_MAX_MSIX_ENTRIES 32 +#define PCIE_PORT_MAX_MSI_ENTRIES 32 #define get_descriptor_id(type, service) (((type - 4) << 8) | service) diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c index cea504f..254bc73 100644 --- a/drivers/pci/pcie/portdrv_core.c +++ b/drivers/pci/pcie/portdrv_core.c @@ -44,14 +44,15 @@ static void release_pcie_device(struct device *dev) } /** - * pcie_port_enable_msix - try to set up MSI-X as interrupt mode for given port + * pcie_port_enable_msix_or_msi - try to set up MSI-X or MSI as interrupt mode + * for given port * @dev: PCI Express port to handle * @irqs: Array of interrupt vectors to populate * @mask: Bitmask of port capabilities returned by get_port_device_capability() * * Return value: 0 on success, error code on failure */ -static int pcie_port_enable_msix(struct pci_dev *dev, int *irqs, int mask) +static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask) { int nr_entries, entry, nvec = 0; @@ -61,8 +62,8 @@ static int pcie_port_enable_msix(struct pci_dev *dev, int *irqs, int mask) * equal to the number of entries this port actually uses, we'll happily * go through without any tricks. */ - nr_entries = pci_alloc_irq_vectors(dev, 1, PCIE_PORT_MAX_MSIX_ENTRIES, - PCI_IRQ_MSIX); + nr_entries = pci_alloc_irq_vectors(dev, 1, PCIE_PORT_MAX_MSI_ENTRIES, + PCI_IRQ_MSIX | PCI_IRQ_MSI); if (nr_entries < 0) return nr_entries; @@ -77,7 +78,13 @@ static int pcie_port_enable_msix(struct pci_dev *dev, int *irqs, int mask) * Number field in the PCI Express Capabilities register", where * according to Section 7.8.2 of the specification "For MSI-X, * the value in this field indicates which MSI-X Table entry is - * used to generate the interrupt message." + * used to generate the interrupt message." and "For MSI, the + * value in this field indicates the offset between the base + * Message Data and the interrupt message that is generated." + * + * pci_irq_vector() below is able to handle entry differently + * depending on MSI vs MSI-x case + * */ pcie_capability_read_word(dev, PCI_EXP_FLAGS, ®16); entry = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9; @@ -100,7 +107,13 @@ static int pcie_port_enable_msix(struct pci_dev *dev, int *irqs, int mask) * MSI/MSI-X vectors assigned to the port is going to be used * for AER, where "For MSI-X, the value in this register * indicates which MSI-X Table entry is used to generate the - * interrupt message." + * interrupt message." and "For MSI, the value + * in this field indicates the offset between the base Message + * Data and the interrupt message that is generated." + * + * pci_irq_vector() below is able to handle entry differently + * depending on MSI vs MSI-x case + * */ pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR); pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, ®32); @@ -124,7 +137,7 @@ static int pcie_port_enable_msix(struct pci_dev *dev, int *irqs, int mask) /* Now allocate the MSI-X vectors for real */ nr_entries = pci_alloc_irq_vectors(dev, nvec, nvec, - PCI_IRQ_MSIX); + PCI_IRQ_MSIX | PCI_IRQ_MSI); if (nr_entries < 0) return nr_entries; } @@ -146,26 +159,23 @@ static int pcie_port_enable_msix(struct pci_dev *dev, int *irqs, int mask) */ static int pcie_init_service_irqs(struct pci_dev *dev, int *irqs, int mask) { - unsigned flags = PCI_IRQ_LEGACY | PCI_IRQ_MSI; int ret, i; for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) irqs[i] = -1; /* - * If MSI cannot be used for PCIe PME or hotplug, we have to use - * INTx or other interrupts, e.g. system shared interrupt. + * Make sure MSI can be used for PCIe PME or hotplug. otherwise we have + * to use INTx or other interrupts, e.g. system shared interrupt. */ - if (((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi()) || - ((mask & PCIE_PORT_SERVICE_HP) && pciehp_no_msi())) { - flags &= ~PCI_IRQ_MSI; - } else { - /* Try to use MSI-X if supported */ - if (!pcie_port_enable_msix(dev, irqs, mask)) + if (!((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi()) && + !((mask & PCIE_PORT_SERVICE_HP) && pciehp_no_msi())) + /* Try to use MSI-X or MSI if supported */ + if (!pcie_port_enable_irq_vec(dev, irqs, mask)) return 0; - } - ret = pci_alloc_irq_vectors(dev, 1, 1, flags); + /* fall back to legacy IRQ */ + ret = pci_alloc_irq_vectors(dev, 1, 1, PCI_IRQ_LEGACY); if (ret < 0) return -ENODEV; -- 2.7.4
