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
26 struct 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
hp_ccsr_locate(acpi_handle obj,u64 * base,u64 * length)32 static 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
58 struct csr_space {
59 u64 base;
60 u64 length;
61 };
62
find_csr_space(struct acpi_resource * resource,void * data)63 static 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_length &&
73 addr.producer_consumer == ACPI_CONSUMER) {
74 space->base = addr.minimum;
75 space->length = addr.address_length;
76 return AE_CTRL_TERMINATE;
77 }
78 return AE_OK; /* keep looking */
79 }
80
hp_crs_locate(acpi_handle obj,u64 * base,u64 * length)81 static 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
hp_acpi_csr_space(acpi_handle obj,u64 * csr_base,u64 * csr_length)94 acpi_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 }
104 EXPORT_SYMBOL(hp_acpi_csr_space);
105