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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
46ba51ea HG |
2 | /* |
3 | * Copyright (C) 2005 Intel Corporation | |
4 | * Copyright (C) 2009 Hewlett-Packard Development Company, L.P. | |
5 | * | |
6 | * Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> | |
7 | * - Added _PDC for platforms with Intel CPUs | |
8 | */ | |
9 | ||
10 | #define pr_fmt(fmt) "ACPI: " fmt | |
11 | ||
46ba51ea HG |
12 | #include <linux/slab.h> |
13 | #include <linux/acpi.h> | |
14 | #include <acpi/processor.h> | |
15 | ||
16 | #include "internal.h" | |
17 | ||
46ba51ea HG |
18 | static void acpi_set_pdc_bits(u32 *buf) |
19 | { | |
20 | buf[0] = ACPI_PDC_REVISION_ID; | |
21 | buf[1] = 1; | |
22 | ||
46ba51ea | 23 | /* Twiddle arch-specific bits needed for _PDC */ |
c5e4d05d | 24 | arch_acpi_set_proc_cap_bits(&buf[2]); |
46ba51ea HG |
25 | } |
26 | ||
27 | static struct acpi_object_list *acpi_processor_alloc_pdc(void) | |
28 | { | |
29 | struct acpi_object_list *obj_list; | |
30 | union acpi_object *obj; | |
31 | u32 *buf; | |
32 | ||
33 | /* allocate and initialize pdc. It will be used later. */ | |
34 | obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL); | |
35 | if (!obj_list) | |
36 | goto out; | |
37 | ||
38 | obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL); | |
39 | if (!obj) { | |
40 | kfree(obj_list); | |
41 | goto out; | |
42 | } | |
43 | ||
44 | buf = kmalloc(12, GFP_KERNEL); | |
45 | if (!buf) { | |
46 | kfree(obj); | |
47 | kfree(obj_list); | |
48 | goto out; | |
49 | } | |
50 | ||
51 | acpi_set_pdc_bits(buf); | |
52 | ||
53 | obj->type = ACPI_TYPE_BUFFER; | |
54 | obj->buffer.length = 12; | |
55 | obj->buffer.pointer = (u8 *) buf; | |
56 | obj_list->count = 1; | |
57 | obj_list->pointer = obj; | |
58 | ||
59 | return obj_list; | |
60 | out: | |
61 | pr_err("Memory allocation error\n"); | |
62 | return NULL; | |
63 | } | |
64 | ||
65 | /* | |
66 | * _PDC is required for a BIOS-OS handshake for most of the newer | |
67 | * ACPI processor features. | |
68 | */ | |
69 | static acpi_status | |
70 | acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in) | |
71 | { | |
72 | acpi_status status = AE_OK; | |
73 | ||
46ba51ea HG |
74 | status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL); |
75 | ||
76 | if (ACPI_FAILURE(status)) | |
52af99c3 RW |
77 | acpi_handle_debug(handle, |
78 | "Could not evaluate _PDC, using legacy perf control\n"); | |
46ba51ea HG |
79 | |
80 | return status; | |
81 | } | |
82 | ||
83 | void acpi_processor_set_pdc(acpi_handle handle) | |
84 | { | |
85 | struct acpi_object_list *obj_list; | |
86 | ||
87 | if (arch_has_acpi_pdc() == false) | |
88 | return; | |
89 | ||
90 | obj_list = acpi_processor_alloc_pdc(); | |
91 | if (!obj_list) | |
92 | return; | |
93 | ||
94 | acpi_processor_eval_pdc(handle, obj_list); | |
95 | ||
96 | kfree(obj_list->pointer->buffer.pointer); | |
97 | kfree(obj_list->pointer); | |
98 | kfree(obj_list); | |
99 | } | |
100 | ||
101 | static acpi_status __init | |
102 | early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv) | |
103 | { | |
104 | if (processor_physically_present(handle) == false) | |
105 | return AE_OK; | |
106 | ||
107 | acpi_processor_set_pdc(handle); | |
108 | return AE_OK; | |
109 | } | |
110 | ||
46ba51ea HG |
111 | void __init acpi_early_processor_set_pdc(void) |
112 | { | |
0a0e2ea6 | 113 | acpi_proc_quirk_mwait_check(); |
46ba51ea HG |
114 | |
115 | acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT, | |
116 | ACPI_UINT32_MAX, | |
117 | early_init_pdc, NULL, NULL, NULL); | |
118 | acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, early_init_pdc, NULL, NULL); | |
119 | } |