+ Robin, who has dealt with a lot of the stuff here.
On Mon, 20 Sep 2021 07:41:33 +0100,
Kishon Vijay Abraham I <kishon@xxxxxx> wrote:
>
> Using "msi-map-mask" in device tree lets multiple PCIe requestor ID to
> use the same GIC ITS device ID. So while creating the Interrupt
> Translation Table (ITT) for a specific GIC ITS device ID, the total number
> of interrupts required by all the PCIe requestor ID that maps to the
> same GIC ITS device ID should be calculated
>
> Add support for gic-v3-its to include "msi-map-mask" property in device
> tree for calculating the total number of MSI interrupts in
> its_pci_msi_prepare().
>
> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
> ---
> drivers/irqchip/irq-gic-v3-its-pci-msi.c | 21 ++++++++++++++++++++-
> 1 file changed, 20 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/irqchip/irq-gic-v3-its-pci-msi.c b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
> index ad2810c017ed..c79bca1a5787 100644
> --- a/drivers/irqchip/irq-gic-v3-its-pci-msi.c
> +++ b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
> @@ -54,9 +54,13 @@ static int its_get_pci_alias(struct pci_dev *pdev, u16 alias, void *data)
> static int its_pci_msi_prepare(struct irq_domain *domain, struct device *dev,
> int nvec, msi_alloc_info_t *info)
> {
> + int alias_count = 0, map_count = 0, minnvec = 1, ret;
> struct pci_dev *pdev, *alias_dev;
> struct msi_domain_info *msi_info;
> - int alias_count = 0, minnvec = 1;
> + struct device *parent_dev;
> + struct pci_bus *root_bus;
> + struct device_node *np;
> + u32 map_mask, rid;
>
> if (!dev_is_pci(dev))
> return -EINVAL;
> @@ -78,6 +82,21 @@ static int its_pci_msi_prepare(struct irq_domain *domain, struct device *dev,
> info->flags |= MSI_ALLOC_FLAGS_PROXY_DEVICE;
> }
>
> + for (parent_dev = dev; parent_dev; parent_dev = parent_dev->parent) {
Move the declaration of np, ret and map_count here.
> + np = parent_dev->of_node;
> + if (!np)
> + continue;
> +
> + ret = of_property_read_u32(np, "msi-map-mask", &map_mask);
> + if (!ret && map_mask != 0xffff) {
> + rid = pci_dev_id(pdev) & map_mask;
> + root_bus = find_pci_root_bus(pdev->bus);
> + __pci_walk_bus(root_bus, its_pci_msi_vec_count, &map_count, rid, map_mask);
> + break;
> + }
> + }
> + alias_count = max(map_count, alias_count);
Move this after the call to __pci_walk_bus().
> +
> /* ITS specific DeviceID, as the core ITS ignores dev. */
> info->scratchpad[0].ul = pci_msi_domain_get_msi_rid(domain, pdev);
If you don't set the PROXY_DEVICE flag, bad thing will happen when the
canonical device is removed.
Ultimately, this should be moved into a separate helper, along the
line of pci_for_each_dma_alias(). It probably also needs to have an
ACPI counterpart.
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
