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

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>

2 files changed, 47 insertions, 4 deletions

diff --git a/drivers/irqchip/irq-gic-v3-its-pci-msi.c b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
index cfd35da8a177..09ae2d898b7e 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>
@@ -59,8 +61,10 @@ static int its_pci_msi_vec_count(struct pci_dev *pdev)
 static int its_get_pci_alias(struct pci_dev *pdev, u16 alias, void *data)
 {
 	struct its_pci_alias *dev_alias = data;
+	u32 dev_id;
 
-	dev_alias->dev_id = alias;
+	dev_alias->dev_id = iort_find_pci_id(pdev, alias, &dev_id) == 0 ?
+								dev_id : alias;
 	if (pdev != dev_alias->pdev)
 		dev_alias->count += its_pci_msi_vec_count(pdev);
 
@@ -145,10 +149,50 @@ 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 cec00cec786c..77e4f1f404be 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -881,8 +881,7 @@ 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();