[PATCH V8 8/8] irqchip/gicv3-its: Use MADT ITS subtable to do PCI/MSI domain initialization

From: Tomasz Nowicki
Date: Thu Aug 11 2016 - 06:07:34 EST


Let ACPI build ITS PCI MSI domain. ACPI code is responsible for retrieving
inner domain token and passing it on to its_pci_msi_init_one generic
init call.

IORT maintains list of registered domain tokens and allows to find
corresponding domain based on MADT ITS subtable ID info.

Signed-off-by: Tomasz Nowicki <tn@xxxxxxxxxxxx>
Acked-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Reviewed-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
---
drivers/irqchip/irq-gic-v3-its-pci-msi.c | 44 ++++++++++++++++++++++++++++++++
1 file changed, 44 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v3-its-pci-msi.c b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
index d2c2496..ae7221c 100644
--- a/drivers/irqchip/irq-gic-v3-its-pci-msi.c
+++ b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
@@ -15,6 +15,7 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/

+#include <linux/iort.h>
#include <linux/msi.h>
#include <linux/of.h>
#include <linux/of_irq.h>
@@ -144,9 +145,52 @@ static int __init its_pci_of_msi_init(void)
return 0;
}

+#ifdef CONFIG_ACPI
+
+static int __init
+its_pci_msi_parse_madt(struct acpi_subtable_header *header,
+ const unsigned long end)
+{
+ struct acpi_madt_generic_translator *its_entry;
+ struct fwnode_handle *dom_handle;
+ const char *node_name;
+ int err = -ENXIO;
+
+ its_entry = (struct acpi_madt_generic_translator *)header;
+ node_name = kasprintf(GFP_KERNEL, "ITS@0x%lx",
+ (long)its_entry->base_address);
+ dom_handle = iort_find_domain_token(its_entry->translation_id);
+ if (!dom_handle) {
+ pr_err("%s: Unable to locate ITS domain handle\n", node_name);
+ goto out;
+ }
+
+ err = its_pci_msi_init_one(dom_handle, node_name);
+ if (!err)
+ pr_info("PCI/MSI: %s domain created\n", node_name);
+
+out:
+ kfree(node_name);
+ return err;
+}
+
+static int __init its_pci_acpi_msi_init(void)
+{
+ acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR,
+ its_pci_msi_parse_madt, 0);
+ return 0;
+}
+#else
+static int __init its_pci_acpi_msi_init(void)
+{
+ return 0;
+}
+#endif
+
static int __init its_pci_msi_init(void)
{
its_pci_of_msi_init();
+ its_pci_acpi_msi_init();

return 0;
}
--
1.9.1