acpi, gicv3, its: Use MADT ITS subtable to do PCI/MSI domain initialization.

After refactoring DT code, we let ACPI to build ITS PCI MSI domain
and do requester ID to device ID translation using IORT table.

We have now full PCI MSI domain stack, thus we can enable ITS initialization
from GICv3 core driver for ACPI scenario.

Signed-off-by: Tomasz Nowicki <tn@semihalf.com>

3 files changed, 47 insertions, 3 deletions

diff --git a/drivers/irqchip/irq-gic-v3-its-pci-msi.c b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
index 06165cb48fd4..7f0a95849b26 100644
--- a/drivers/irqchip/irq-gic-v3-its-pci-msi.c
+++ b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
@@ -15,6 +15,8 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <linux/acpi.h>
+#include <linux/iort.h>
 #include <linux/msi.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>
@@ -143,10 +145,50 @@ 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 *domain_handle;
+
+	its_entry = (struct acpi_madt_generic_translator *)header;
+	domain_handle = iort_find_its_domain_token(its_entry->translation_id);
+	if (!domain_handle) {
+		pr_err("ITS@0x%lx: Unable to locate ITS domain handle\n",
+		       (long)its_entry->base_address);
+		return 0;
+	}
+
+	if (its_pci_msi_init_one(domain_handle))
+		return 0;
+
+	pci_msi_register_fwnode_provider(&iort_find_pci_domain_token);
+	pr_info("PCI/MSI: ITS@0x%lx domain created\n",
+		(long)its_entry->base_address);
+	return 0;
+}
+
+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
+inline 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;
 }
-
 early_initcall(its_pci_msi_init);
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 995b72514c8a..fee635eca98c 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -871,8 +871,7 @@ static int __init gic_init_bases(void __iomem *dist_base,
 
 	set_handle_irq(gic_handle_irq);
 
-	if (IS_ENABLED(CONFIG_ARM_GIC_V3_ITS) && gic_dist_supports_lpis() &&
-	    to_of_node(handle)) /* Temp hack to prevent ITS init for ACPI */
+	if (IS_ENABLED(CONFIG_ARM_GIC_V3_ITS) && gic_dist_supports_lpis())
 		its_init(handle, &gic_data.rdists, gic_data.domain);
 
 	gic_smp_init();
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 7eaa4c87fec7..6ced37b53fbf 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -18,6 +18,7 @@
 #include <linux/smp.h>
 #include <linux/errno.h>
 #include <linux/io.h>
+#include <linux/iort.h>
 #include <linux/slab.h>
 #include <linux/irqdomain.h>
 #include <linux/of_irq.h>
@@ -1366,6 +1367,8 @@ u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev)
 	of_node = irq_domain_get_of_node(domain);
 	if (of_node)
 		rid = of_msi_map_rid(&pdev->dev, of_node, rid);
+	else
+		iort_find_pci_id(pdev, rid, &rid);
 
 	return rid;
 }