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Merge branch 'pci/portdrv' into next 

* pci/portdrv:
  PCI/portdrv: Allocate MSI/MSI-X vector for Downstream Port Containment
  PCI/portdrv: Support multiple interrupts for MSI as well as MSI-X
hifive-unleashed-5.1
Bjorn Helgaas 2017-07-02 18:48:50 -05:00
parent 2cf816a947 ae6dc7deac
commit 74da4a0180
2 changed files with 76 additions and 35 deletions
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7
drivers/pci/pcie/portdrv.h
View File

@ -13,10 +13,11 @@
#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
* The PCIe Capability Interrupt Message Number (PCIe r3.1, sec 7.8.2) must
* be one of the first 32 MSI-X entries. Per PCI r3.0, sec 6.8.3.1, MSI
* supports a maximum of 32 vectors per function.
*/
#define PCIE_PORT_MAX_MSIX_ENTRIES 32
#define PCIE_PORT_MAX_MSI_ENTRIES 32
#define get_descriptor_id(type, service) (((type - 4) << 8) | service)

104
drivers/pci/pcie/portdrv_core.c
View File

@ -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_irq_vec - 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;
@ -70,14 +71,19 @@ static int pcie_port_enable_msix(struct pci_dev *dev, int *irqs, int mask)
u16 reg16;
/*
* The code below follows the PCI Express Base Specification 2.0
* stating in Section 6.1.6 that "PME and Hot-Plug Event
* interrupts (when both are implemented) always share the same
* MSI or MSI-X vector, as indicated by the Interrupt Message
* 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."
* Per PCIe r3.1, sec 6.1.6, "PME and Hot-Plug Event
* interrupts (when both are implemented) always share the
* same MSI or MSI-X vector, as indicated by the Interrupt
* Message Number field in the PCI Express Capabilities
* register".
*
* Per sec 7.8.2, "For MSI, the [Interrupt Message Number]
* indicates the offset between the base Message Data and
* the interrupt message that is generated."
*
* "For MSI-X, the [Interrupt Message Number] indicates
* which MSI-X Table entry is used to generate the
* interrupt message."
*/
pcie_capability_read_word(dev, PCI_EXP_FLAGS, &reg16);
entry = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9;
@ -94,13 +100,17 @@ static int pcie_port_enable_msix(struct pci_dev *dev, int *irqs, int mask)
u32 reg32, pos;
/*
* The code below follows Section 7.10.10 of the PCI Express
* Base Specification 2.0 stating that bits 31-27 of the Root
* Error Status Register contain a value indicating which of the
* 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."
* Per PCIe r3.1, sec 7.10.10, the Advanced Error Interrupt
* Message Number in the Root Error Status register
* indicates which MSI/MSI-X vector is used for AER.
*
* "For MSI, the [Advanced Error Interrupt Message Number]
* indicates the offset between the base Message Data and
* the interrupt message that is generated."
*
* "For MSI-X, the [Advanced Error Interrupt Message
* Number] indicates which MSI-X Table entry is used to
* generate the interrupt message."
*/
pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &reg32);
@ -113,6 +123,33 @@ static int pcie_port_enable_msix(struct pci_dev *dev, int *irqs, int mask)
nvec = max(nvec, entry + 1);
}
if (mask & PCIE_PORT_SERVICE_DPC) {
u16 reg16, pos;
/*
* Per PCIe r4.0 (v0.9), sec 7.9.15.2, the DPC Interrupt
* Message Number in the DPC Capability register indicates
* which MSI/MSI-X vector is used for DPC.
*
* "For MSI, the [DPC Interrupt Message Number] indicates
* the offset between the base Message Data and the
* interrupt message that is generated."
*
* "For MSI-X, the [DPC Interrupt Message Number] indicates
* which MSI-X Table entry is used to generate the
* interrupt message."
*/
pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC);
pci_read_config_word(dev, pos + PCI_EXP_DPC_CAP, &reg16);
entry = reg16 & 0x1f;
if (entry >= nr_entries)
goto out_free_irqs;
irqs[PCIE_PORT_SERVICE_DPC_SHIFT] = pci_irq_vector(dev, entry);
nvec = max(nvec, entry + 1);
}
/*
* If nvec is equal to the allocated number of entries, we can just use
* what we have. Otherwise, the port has some extra entries not for the
@ -124,7 +161,7 @@ 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 +183,29 @@ out_free_irqs:
*/
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.
* If we support PME or hotplug, but we can't use MSI/MSI-X for
* them, we have to fall back to INTx or other interrupts, e.g., a
* 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))
return 0;
}
if ((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi())
goto legacy_irq;
ret = pci_alloc_irq_vectors(dev, 1, 1, flags);
if ((mask & PCIE_PORT_SERVICE_HP) && pciehp_no_msi())
goto legacy_irq;
/* Try to use MSI-X or MSI if supported */
if (pcie_port_enable_irq_vec(dev, irqs, mask) == 0)
return 0;
legacy_irq:
/* fall back to legacy IRQ */
ret = pci_alloc_irq_vectors(dev, 1, 1, PCI_IRQ_LEGACY);
if (ret < 0)
return -ENODEV;