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 | 5 +++++ drivers/pci/pcie/portdrv_core.c | 33 +++++++++++++++++++++++++++------ 2 files changed, 32 insertions(+), 6 deletions(-) diff --git a/drivers/pci/pcie/portdrv.h b/drivers/pci/pcie/portdrv.h index 587aef3..729ee90 100644 --- a/drivers/pci/pcie/portdrv.h +++ b/drivers/pci/pcie/portdrv.h @@ -18,6 +18,11 @@ */ #define PCIE_PORT_MAX_MSIX_ENTRIES 32 +/* According to the PCI Local Bus Specification REV. 3.0 the max number + * of MSI vectors per function is 32 + */ +#define PCIE_PORT_MAX_MSI_ENTRIES 32 + #define get_descriptor_id(type, service) (((type - 4) << 8) | service) extern struct bus_type pcie_port_bus_type; diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c index cea504f..e2c7bfd 100644 --- a/drivers/pci/pcie/portdrv_core.c +++ b/drivers/pci/pcie/portdrv_core.c @@ -44,14 +44,16 @@ 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_msix_or_msi(struct pci_dev *dev, int *irqs, int mask) { int nr_entries, entry, nvec = 0; @@ -63,6 +65,10 @@ static int pcie_port_enable_msix(struct pci_dev *dev, int *irqs, int mask) */ nr_entries = pci_alloc_irq_vectors(dev, 1, PCIE_PORT_MAX_MSIX_ENTRIES, PCI_IRQ_MSIX); + if (nr_entries < 0) /* MSI-x failed let's try with MSI */ + nr_entries = pci_alloc_irq_vectors(dev, 1, + PCIE_PORT_MAX_MSI_ENTRIES, + PCI_IRQ_MSI); if (nr_entries < 0) return nr_entries; @@ -77,7 +83,13 @@ 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 +112,13 @@ 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); @@ -125,6 +143,9 @@ 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); + if (nr_entries < 0) /* MSI-x failed, let's try MSI*/ + nr_entries = pci_alloc_irq_vectors(dev, nvec, nvec, + PCI_IRQ_MSI); if (nr_entries < 0) return nr_entries; } @@ -160,8 +181,8 @@ static int pcie_init_service_irqs(struct pci_dev *dev, int *irqs, int mask) ((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)) + /* Try to use MSI-X or MSI if supported */ + if (!pcie_port_enable_msix_or_msi(dev, irqs, mask)) return 0; } -- 2.7.4
