[PATCH v4 28/28] PCI, x86, ACPI: get ioapic address from acpi device

[Yinghai Lu <yinghai@kernel.org>]

Some ioapic controllers do not show up on pci config space,
or pci device is there but no bar is used and is set by firmware in
other non standard registers.

We can get ioapic address from ACPI0009's _CRS.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
---
 drivers/pci/ioapic.c | 86 +++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 71 insertions(+), 15 deletions(-)

diff --git a/drivers/pci/ioapic.c b/drivers/pci/ioapic.c
index 60351b2..41f7c69 100644
--- a/drivers/pci/ioapic.c
+++ b/drivers/pci/ioapic.c
@@ -32,6 +32,36 @@ struct acpi_pci_ioapic {
 static LIST_HEAD(ioapic_list);
 static DEFINE_MUTEX(ioapic_list_lock);
 
+static acpi_status setup_res(struct acpi_resource *acpi_res, void *data)
+{
+	struct resource *res;
+	struct acpi_resource_address64 addr;
+	acpi_status status;
+	unsigned long flags;
+	u64 start, end;
+
+	status = acpi_resource_to_address64(acpi_res, &addr);
+	if (!ACPI_SUCCESS(status))
+		return AE_OK;
+
+	if (addr.resource_type == ACPI_MEMORY_RANGE) {
+		if (addr.info.mem.caching == ACPI_PREFETCHABLE_MEMORY)
+			return AE_OK;
+		flags = IORESOURCE_MEM;
+	} else
+		return AE_OK;
+
+	start = addr.minimum + addr.translation_offset;
+	end = addr.maximum + addr.translation_offset;
+
+	res = data;
+	res->flags = flags;
+	res->start = start;
+	res->end = end;
+
+	return AE_OK;
+}
+
 static void handle_ioapic_add(acpi_handle handle, struct pci_dev **pdev,
 				 u32 *pgsi_base)
 {
@@ -54,33 +84,56 @@ static void handle_ioapic_add(acpi_handle handle, struct pci_dev **pdev,
 		return;
 
 	dev = acpi_get_pci_dev(handle);
-	if (!dev)
-		return;
+	if (!dev || !pci_resource_len(dev, 0)) {
+		struct acpi_device_info *info;
+		char *hid = NULL;
+
+		status = acpi_get_object_info(handle, &info);
+		if (ACPI_FAILURE(status))
+			goto exit_put;
+		if (info->valid & ACPI_VALID_HID)
+			hid = info->hardware_id.string;
+		if (!hid || strcmp(hid, "ACPI0009")) {
+			kfree(info);
+			goto exit_put;
+		}
+		kfree(info);
+		memset(res, 0, sizeof(*res));
+		acpi_walk_resources(handle, METHOD_NAME__CRS, setup_res, res);
+		if (!res->flags)
+			goto exit_put;
+	}
 
 	acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
 
 	gsi_base = gsb;
 	type = "IOxAPIC";
+	if (dev) {
+		ret = pci_enable_device(dev);
+		if (ret < 0)
+			goto exit_put;
 
-	ret = pci_enable_device(dev);
-	if (ret < 0)
-		goto exit_put;
-
-	pci_set_master(dev);
+		pci_set_master(dev);
 
-	if (dev->class == PCI_CLASS_SYSTEM_PIC_IOAPIC)
-		type = "IOAPIC";
+		if (dev->class == PCI_CLASS_SYSTEM_PIC_IOAPIC)
+			type = "IOAPIC";
 
-	if (pci_request_region(dev, 0, type))
-		goto exit_disable;
+		if (pci_resource_len(dev, 0)) {
+			if (pci_request_region(dev, 0, type))
+				goto exit_disable;
 
-	res = &dev->resource[0];
+			res = &dev->resource[0];
+		}
+	}
 
-	if (acpi_register_ioapic(handle, res->start, gsi_base))
-		goto exit_release;
+	if (acpi_register_ioapic(handle, res->start, gsi_base)) {
+		if (dev)
+			goto exit_release;
+		return;
+	}
 
 	pr_info("%s %s %s at %pR, GSI %u\n",
-		dev_name(&dev->dev), objname, type,
+		dev ? dev_name(&dev->dev) : "", objname, type,
 		res, gsi_base);
 
 	*pdev = dev;
@@ -100,6 +153,9 @@ static void handle_ioapic_remove(acpi_handle handle, struct pci_dev *dev,
 {
 	acpi_unregister_ioapic(handle, gsi_base);
 
+	if (!dev)
+		return;
+
 	pci_release_region(dev, 0);
 	pci_disable_device(dev);
 	pci_dev_put(dev);
-- 
1.8.1.4