1/*
2 * (c) Copyright 2003, 2006 Hewlett-Packard Development Company, L.P.
3 *	Alex Williamson <alex.williamson@hp.com>
4 *	Bjorn Helgaas <bjorn.helgaas@hp.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#include <linux/module.h>
12#include <linux/types.h>
13#include <linux/slab.h>
14#include <linux/acpi.h>
15
16#include <asm/acpi-ext.h>
17
18/*
19 * Device CSRs that do not appear in PCI config space should be described
20 * via ACPI.  This would normally be done with Address Space Descriptors
21 * marked as "consumer-only," but old versions of Windows and Linux ignore
22 * the producer/consumer flag, so HP invented a vendor-defined resource to
23 * describe the location and size of CSR space.
24 */
25
26struct acpi_vendor_uuid hp_ccsr_uuid = {
27	.subtype = 2,
28	.data = { 0xf9, 0xad, 0xe9, 0x69, 0x4f, 0x92, 0x5f, 0xab, 0xf6, 0x4a,
29	    0x24, 0xd2, 0x01, 0x37, 0x0e, 0xad },
30};
31
32static acpi_status hp_ccsr_locate(acpi_handle obj, u64 *base, u64 *length)
33{
34	acpi_status status;
35	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
36	struct acpi_resource *resource;
37	struct acpi_resource_vendor_typed *vendor;
38
39	status = acpi_get_vendor_resource(obj, METHOD_NAME__CRS, &hp_ccsr_uuid,
40		&buffer);
41
42	resource = buffer.pointer;
43	vendor = &resource->data.vendor_typed;
44
45	if (ACPI_FAILURE(status) || vendor->byte_length < 16) {
46		status = AE_NOT_FOUND;
47		goto exit;
48	}
49
50	memcpy(base, vendor->byte_data, sizeof(*base));
51	memcpy(length, vendor->byte_data + 8, sizeof(*length));
52
53  exit:
54	kfree(buffer.pointer);
55	return status;
56}
57
58struct csr_space {
59	u64	base;
60	u64	length;
61};
62
63static acpi_status find_csr_space(struct acpi_resource *resource, void *data)
64{
65	struct csr_space *space = data;
66	struct acpi_resource_address64 addr;
67	acpi_status status;
68
69	status = acpi_resource_to_address64(resource, &addr);
70	if (ACPI_SUCCESS(status) &&
71	    addr.resource_type == ACPI_MEMORY_RANGE &&
72	    addr.address.address_length &&
73	    addr.producer_consumer == ACPI_CONSUMER) {
74		space->base = addr.address.minimum;
75		space->length = addr.address.address_length;
76		return AE_CTRL_TERMINATE;
77	}
78	return AE_OK;		/* keep looking */
79}
80
81static acpi_status hp_crs_locate(acpi_handle obj, u64 *base, u64 *length)
82{
83	struct csr_space space = { 0, 0 };
84
85	acpi_walk_resources(obj, METHOD_NAME__CRS, find_csr_space, &space);
86	if (!space.length)
87		return AE_NOT_FOUND;
88
89	*base = space.base;
90	*length = space.length;
91	return AE_OK;
92}
93
94acpi_status hp_acpi_csr_space(acpi_handle obj, u64 *csr_base, u64 *csr_length)
95{
96	acpi_status status;
97
98	status = hp_ccsr_locate(obj, csr_base, csr_length);
99	if (ACPI_SUCCESS(status))
100		return status;
101
102	return hp_crs_locate(obj, csr_base, csr_length);
103}
104EXPORT_SYMBOL(hp_acpi_csr_space);
105