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Commit 3321eafd authored by Bjorn Helgaas's avatar Bjorn Helgaas
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PCI/portdrv: Factor out Interrupt Message Number lookup 



Factor out Interrupt Message Number lookup from the MSI/MSI-X interrupt
setup.  One side effect is that we only have to check once to see if we
have enough vectors for all the services.  No functional change intended.

Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
parent b8acfd7c

drivers/pci/pcie/portdrv_core.c

+62 −48
Original line number Diff line number Diff line
@@ -43,24 +43,16 @@ static void release_pcie_device(struct device *dev) 
	kfree(to_pcie_device(dev));

}



/**

 * 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

/*

 * Fill in *pme, *aer, *dpc with the relevant Interrupt Message Numbers if

 * services are enabled in "mask".  Return the number of MSI/MSI-X vectors

 * required to accommodate the largest Message Number.

 */

static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask)

static int pcie_message_numbers(struct pci_dev *dev, int mask,

				u32 *pme, u32 *aer, u32 *dpc)

{

	int nr_entries, entry, nvec = 0;



	/* Allocate the maximum possible number of MSI/MSI-X vectors */

	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;

	u32 nvec = 0, pos, reg32;

	u16 reg16;



	/*

	 * The Interrupt Message Number indicates which vector is used, i.e.,
@@ -68,49 +60,75 @@ static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask) 
	 * Data and the generated interrupt message.  See PCIe r3.1, sec

	 * 7.8.2, 7.10.10, 7.31.2.

	 */

	if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) {

		u16 reg16;



	if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) {

		pcie_capability_read_word(dev, PCI_EXP_FLAGS, &reg16);

		entry = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9;

		if (entry >= nr_entries)

			goto out_free_irqs;



		/* PME and hotplug share an MSI/MSI-X vector */

		irqs[PCIE_PORT_SERVICE_PME_SHIFT] = pci_irq_vector(dev, entry);

		irqs[PCIE_PORT_SERVICE_HP_SHIFT] = pci_irq_vector(dev, entry);



		nvec = max(nvec, entry + 1);

		*pme = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9;

		nvec = *pme + 1;

	}



	if (mask & PCIE_PORT_SERVICE_AER) {

		u32 reg32, pos;



		pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);

		pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &reg32);

		entry = (reg32 & PCI_ERR_ROOT_AER_IRQ) >> 27;

		if (entry >= nr_entries)

			goto out_free_irqs;

		if (pos) {

			pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS,

					      &reg32);

			*aer = (reg32 & PCI_ERR_ROOT_AER_IRQ) >> 27;

			nvec = max(nvec, *aer + 1);

		}

	}



		irqs[PCIE_PORT_SERVICE_AER_SHIFT] = pci_irq_vector(dev, entry);

	if (mask & PCIE_PORT_SERVICE_DPC) {

		pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC);

		if (pos) {

			pci_read_config_word(dev, pos + PCI_EXP_DPC_CAP,

					     &reg16);

			*dpc = reg16 & PCI_EXP_DPC_IRQ;

			nvec = max(nvec, *dpc + 1);

		}

	}



		nvec = max(nvec, entry + 1);

	return nvec;

}



	if (mask & PCIE_PORT_SERVICE_DPC) {

		u16 reg16, pos;

/**

 * 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_irq_vec(struct pci_dev *dev, int *irqs, int mask)

{

	int nr_entries, nvec;

	u32 pme = 0, aer = 0, dpc = 0;



		pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC);

		pci_read_config_word(dev, pos + PCI_EXP_DPC_CAP, &reg16);

		entry = reg16 & PCI_EXP_DPC_IRQ;

		if (entry >= nr_entries)

			goto out_free_irqs;

	/* Allocate the maximum possible number of MSI/MSI-X vectors */

	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;



		irqs[PCIE_PORT_SERVICE_DPC_SHIFT] = pci_irq_vector(dev, entry);

	/* See how many and which Interrupt Message Numbers we actually use */

	nvec = pcie_message_numbers(dev, mask, &pme, &aer, &dpc);

	if (nvec > nr_entries) {

		pci_free_irq_vectors(dev);

		return -EIO;

	}



		nvec = max(nvec, entry + 1);

	/* PME and hotplug share an MSI/MSI-X vector */

	if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) {

		irqs[PCIE_PORT_SERVICE_PME_SHIFT] = pci_irq_vector(dev, pme);

		irqs[PCIE_PORT_SERVICE_HP_SHIFT] = pci_irq_vector(dev, pme);

	}



	if (mask & PCIE_PORT_SERVICE_AER)

		irqs[PCIE_PORT_SERVICE_AER_SHIFT] = pci_irq_vector(dev, aer);



	if (mask & PCIE_PORT_SERVICE_DPC)

		irqs[PCIE_PORT_SERVICE_DPC_SHIFT] = pci_irq_vector(dev, dpc);



	/* If we allocated more than we need, free them and allocate fewer */

	if (nvec != nr_entries) {

		pci_free_irq_vectors(dev);
@@ -122,10 +140,6 @@ static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask) 
	}



	return 0;



out_free_irqs:

	pci_free_irq_vectors(dev);

	return -EIO;

}



/**