Refactor out the _PXM -> VM domain lookup done in ACPI, in preparation for

its use in upcoming code.

This is inspired by something in jhb's NUMA IRQ allocation patchset.

However, the tricky bit here is that the PXM lookup for a node may
fail, requiring a lookup on the parent node.  So if it doesn't
exist, don't fail - just go up to the parent.  Only error out of the
lookup is the ACPI lookup returns an error.

Sponsored by:	Norse Corp, Inc.

1 files changed, 32 insertions, 9 deletions

diff --git a/sys/dev/acpica/acpi.c b/sys/dev/acpica/acpi.c
index a597b6d..47bc791 100644
--- a/sys/dev/acpica/acpi.c
+++ b/sys/dev/acpica/acpi.c
@@ -1071,30 +1071,53 @@ acpi_hint_device_unit(device_t acdev, device_t child, const char *name,
 }
 
 /*
- * Fetch the NUMA domain for the given device.
- *
- * If a device has a _PXM method, map that to a NUMA domain.
+ * Fetch the VM domain for the given device 'dev'.
  *
- * If none is found, then it'll call the parent method.
- * If there's no domain, return ENOENT.
+ * Return 1 + domain if there's a domain, 0 if not found;
+ * -1 upon an error.
  */
 int
-acpi_get_domain(device_t dev, device_t child, int *domain)
+acpi_parse_pxm(device_t dev, int *domain)
 {
 #if MAXMEMDOM > 1
 	ACPI_HANDLE h;
 	int d, pxm;
 
-	h = acpi_get_handle(child);
+	h = acpi_get_handle(dev);
 	if ((h != NULL) &&
 	    ACPI_SUCCESS(acpi_GetInteger(h, "_PXM", &pxm))) {
 		d = acpi_map_pxm_to_vm_domainid(pxm);
 		if (d < 0)
-			return (ENOENT);
+			return (-1);
 		*domain = d;
-		return (0);
+		return (1);
 	}
 #endif
+
+	return (0);
+}
+
+/*
+ * Fetch the NUMA domain for the given device.
+ *
+ * If a device has a _PXM method, map that to a NUMA domain.
+ *
+ * If none is found, then it'll call the parent method.
+ * If there's no domain, return ENOENT.
+ */
+int
+acpi_get_domain(device_t dev, device_t child, int *domain)
+{
+	int ret;
+
+	ret = acpi_parse_pxm(child, domain);
+	/* Error */
+	if (ret == -1)
+		return (ENOENT);
+	/* Found */
+	if (ret == 1)
+		return (0);
+
 	/* No _PXM node; go up a level */
 	return (bus_generic_get_domain(dev, child, domain));
 }