diff mbox series

[3/3] irqchip/gic-v3-its: Include "msi-map-mask" for calculating nvecs

Message ID 20210920064133.14115-4-kishon@ti.com
State New
Headers show
Series PCI/gic-v3-its: Add support for same ITS device ID for multiple PCIe devices | expand

Commit Message

Kishon Vijay Abraham I Sept. 20, 2021, 6:41 a.m. UTC
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@ti.com>
---
 drivers/irqchip/irq-gic-v3-its-pci-msi.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

Comments

Marc Zyngier Sept. 20, 2021, 8:36 a.m. UTC | #1
+ 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@ti.com> 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@ti.com>
> ---
>  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.
diff mbox series

Patch

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) {
+		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);
+
 	/* ITS specific DeviceID, as the core ITS ignores dev. */
 	info->scratchpad[0].ul = pci_msi_domain_get_msi_rid(domain, pdev);