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