On Thu, Jul 23, 2015 at 8:19 PM, Lucas Stach <l.stach@xxxxxxxxxxxxxx> wrote:
> Allows to set up and use multiple MSI irqs per device.
>
> Signed-off-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
> ---
> The ifdef is needed to avoid a compile error on
> !CONFIG_PCI_MSI, as msi_list is only part of pci_dev
> when the kernel is compiled with MSI support.
>
> v2: move ifdeffery inside single function
> ---
> drivers/pci/host/pcie-designware.c | 43 ++++++++++++++++++++++++++++++++++++++
> 1 file changed, 43 insertions(+)
>
> diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
> index 69486be7181e..52c600327805 100644
> --- a/drivers/pci/host/pcie-designware.c
> +++ b/drivers/pci/host/pcie-designware.c
> @@ -286,6 +286,9 @@ static int assign_irq(int no_irqs, struct msi_desc *desc, int *pos)
> }
>
> *pos = pos0;
> + desc->nvec_used = no_irqs;
> + desc->msi_attrib.multiple = order_base_2(no_irqs);
> +
> return irq;
>
> no_valid_irq:
> @@ -323,6 +326,45 @@ static int dw_msi_setup_irq(struct msi_controller *chip, struct pci_dev *pdev,
> return 0;
> }
>
> +static int dw_msi_setup_irqs(struct msi_controller *chip, struct pci_dev *pdev,
> + int nvec, int type)
> +{
> +#ifdef CONFIG_PCI_MSI
> + int irq, pos;
> + struct msi_desc *desc;
> + struct msi_msg msg;
> + struct pcie_port *pp = sys_to_pcie(pdev->bus->sysdata);
> +
> + /* MSI-X interrupts are not supported */
> + if (type == PCI_CAP_ID_MSIX)
> + return -EINVAL;
> +
> + WARN_ON(!list_is_singular(&pdev->msi_list));
> + desc = list_entry(pdev->msi_list.next, struct msi_desc, list);
> +
Probably existing function dw_msi_setup_irq() can be re-factored and code after
this line can be reused from refactored function, as they are almost same.
> + irq = assign_irq(nvec, desc, &pos);
> + if (irq < 0)
> + return irq;
> +
> + if (pp->ops->get_msi_addr)
> + msg.address_lo = pp->ops->get_msi_addr(pp);
> + else
> + msg.address_lo = virt_to_phys((void *)pp->msi_data);
> + msg.address_hi = 0x0;
> +
Although, not specific to this patch, but since we are now going to have
ARM64 support for DW as well, so it would be nice to fill msg.address_hi
with upper bytes rather hard-coding as 0.
> + if (pp->ops->get_msi_data)
> + msg.data = pp->ops->get_msi_data(pp, pos);
> + else
> + msg.data = pos;
> +
> + pci_write_msi_msg(irq, &msg);
> +
> + return 0;
~Pratyush
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