1 files changed, 101 insertions, 0 deletions
diff --git a/arch/ia64/kernel/acpi-ext.c b/arch/ia64/kernel/acpi-ext.c
new file mode 100644
index 000000000..42cd21480
--- /dev/null
+++ b/arch/ia64/kernel/acpi-ext.c
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * (c) Copyright 2003, 2006 Hewlett-Packard Development Company, L.P.
+ *	Alex Williamson <alex.williamson@hp.com>
+ *	Bjorn Helgaas <bjorn.helgaas@hp.com>
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/acpi.h>
+
+#include <asm/acpi-ext.h>
+
+/*
+ * Device CSRs that do not appear in PCI config space should be described
+ * via ACPI.  This would normally be done with Address Space Descriptors
+ * marked as "consumer-only," but old versions of Windows and Linux ignore
+ * the producer/consumer flag, so HP invented a vendor-defined resource to
+ * describe the location and size of CSR space.
+ */
+
+struct acpi_vendor_uuid hp_ccsr_uuid = {
+	.subtype = 2,
+	.data = { 0xf9, 0xad, 0xe9, 0x69, 0x4f, 0x92, 0x5f, 0xab, 0xf6, 0x4a,
+	    0x24, 0xd2, 0x01, 0x37, 0x0e, 0xad },
+};
+
+static acpi_status hp_ccsr_locate(acpi_handle obj, u64 *base, u64 *length)
+{
+	acpi_status status;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	struct acpi_resource *resource;
+	struct acpi_resource_vendor_typed *vendor;
+
+	status = acpi_get_vendor_resource(obj, METHOD_NAME__CRS, &hp_ccsr_uuid,
+		&buffer);
+
+	resource = buffer.pointer;
+	vendor = &resource->data.vendor_typed;
+
+	if (ACPI_FAILURE(status) || vendor->byte_length < 16) {
+		status = AE_NOT_FOUND;
+		goto exit;
+	}
+
+	memcpy(base, vendor->byte_data, sizeof(*base));
+	memcpy(length, vendor->byte_data + 8, sizeof(*length));
+
+  exit:
+	kfree(buffer.pointer);
+	return status;
+}
+
+struct csr_space {
+	u64	base;
+	u64	length;
+};
+
+static acpi_status find_csr_space(struct acpi_resource *resource, void *data)
+{
+	struct csr_space *space = data;
+	struct acpi_resource_address64 addr;
+	acpi_status status;
+
+	status = acpi_resource_to_address64(resource, &addr);
+	if (ACPI_SUCCESS(status) &&
+	    addr.resource_type == ACPI_MEMORY_RANGE &&
+	    addr.address.address_length &&
+	    addr.producer_consumer == ACPI_CONSUMER) {
+		space->base = addr.address.minimum;
+		space->length = addr.address.address_length;
+		return AE_CTRL_TERMINATE;
+	}
+	return AE_OK;		/* keep looking */
+}
+
+static acpi_status hp_crs_locate(acpi_handle obj, u64 *base, u64 *length)
+{
+	struct csr_space space = { 0, 0 };
+
+	acpi_walk_resources(obj, METHOD_NAME__CRS, find_csr_space, &space);
+	if (!space.length)
+		return AE_NOT_FOUND;
+
+	*base = space.base;
+	*length = space.length;
+	return AE_OK;
+}
+
+acpi_status hp_acpi_csr_space(acpi_handle obj, u64 *csr_base, u64 *csr_length)
+{
+	acpi_status status;
+
+	status = hp_ccsr_locate(obj, csr_base, csr_length);
+	if (ACPI_SUCCESS(status))
+		return status;
+
+	return hp_crs_locate(obj, csr_base, csr_length);
+}
+EXPORT_SYMBOL(hp_acpi_csr_space);