1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * (c) Copyright 2003, 2006 Hewlett-Packard Development Company, L.P.
4  *	Alex Williamson <alex.williamson@hp.com>
5  *	Bjorn Helgaas <bjorn.helgaas@hp.com>
6  */
7 
8 #include <linux/module.h>
9 #include <linux/types.h>
10 #include <linux/slab.h>
11 #include <linux/acpi.h>
12 
13 #include <asm/acpi-ext.h>
14 
15 /*
16  * Device CSRs that do not appear in PCI config space should be described
17  * via ACPI.  This would normally be done with Address Space Descriptors
18  * marked as "consumer-only," but old versions of Windows and Linux ignore
19  * the producer/consumer flag, so HP invented a vendor-defined resource to
20  * describe the location and size of CSR space.
21  */
22 
23 struct acpi_vendor_uuid hp_ccsr_uuid = {
24 	.subtype = 2,
25 	.data = { 0xf9, 0xad, 0xe9, 0x69, 0x4f, 0x92, 0x5f, 0xab, 0xf6, 0x4a,
26 	    0x24, 0xd2, 0x01, 0x37, 0x0e, 0xad },
27 };
28 
hp_ccsr_locate(acpi_handle obj,u64 * base,u64 * length)29 static acpi_status hp_ccsr_locate(acpi_handle obj, u64 *base, u64 *length)
30 {
31 	acpi_status status;
32 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
33 	struct acpi_resource *resource;
34 	struct acpi_resource_vendor_typed *vendor;
35 
36 	status = acpi_get_vendor_resource(obj, METHOD_NAME__CRS, &hp_ccsr_uuid,
37 		&buffer);
38 
39 	resource = buffer.pointer;
40 	vendor = &resource->data.vendor_typed;
41 
42 	if (ACPI_FAILURE(status) || vendor->byte_length < 16) {
43 		status = AE_NOT_FOUND;
44 		goto exit;
45 	}
46 
47 	memcpy(base, vendor->byte_data, sizeof(*base));
48 	memcpy(length, vendor->byte_data + 8, sizeof(*length));
49 
50   exit:
51 	kfree(buffer.pointer);
52 	return status;
53 }
54 
55 struct csr_space {
56 	u64	base;
57 	u64	length;
58 };
59 
find_csr_space(struct acpi_resource * resource,void * data)60 static acpi_status find_csr_space(struct acpi_resource *resource, void *data)
61 {
62 	struct csr_space *space = data;
63 	struct acpi_resource_address64 addr;
64 	acpi_status status;
65 
66 	status = acpi_resource_to_address64(resource, &addr);
67 	if (ACPI_SUCCESS(status) &&
68 	    addr.resource_type == ACPI_MEMORY_RANGE &&
69 	    addr.address.address_length &&
70 	    addr.producer_consumer == ACPI_CONSUMER) {
71 		space->base = addr.address.minimum;
72 		space->length = addr.address.address_length;
73 		return AE_CTRL_TERMINATE;
74 	}
75 	return AE_OK;		/* keep looking */
76 }
77 
hp_crs_locate(acpi_handle obj,u64 * base,u64 * length)78 static acpi_status hp_crs_locate(acpi_handle obj, u64 *base, u64 *length)
79 {
80 	struct csr_space space = { 0, 0 };
81 
82 	acpi_walk_resources(obj, METHOD_NAME__CRS, find_csr_space, &space);
83 	if (!space.length)
84 		return AE_NOT_FOUND;
85 
86 	*base = space.base;
87 	*length = space.length;
88 	return AE_OK;
89 }
90 
hp_acpi_csr_space(acpi_handle obj,u64 * csr_base,u64 * csr_length)91 acpi_status hp_acpi_csr_space(acpi_handle obj, u64 *csr_base, u64 *csr_length)
92 {
93 	acpi_status status;
94 
95 	status = hp_ccsr_locate(obj, csr_base, csr_length);
96 	if (ACPI_SUCCESS(status))
97 		return status;
98 
99 	return hp_crs_locate(obj, csr_base, csr_length);
100 }
101 EXPORT_SYMBOL(hp_acpi_csr_space);
102