1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * ARM APMT table support.
4 * Design document number: ARM DEN0117.
5 *
6 * Copyright (c) 2022, NVIDIA CORPORATION & AFFILIATES.
7 *
8 */
9
10 #define pr_fmt(fmt) "ACPI: APMT: " fmt
11
12 #include <linux/acpi.h>
13 #include <linux/acpi_apmt.h>
14 #include <linux/init.h>
15 #include <linux/kernel.h>
16 #include <linux/platform_device.h>
17
18 #define DEV_NAME "arm-cs-arch-pmu"
19
20 /* There can be up to 3 resources: page 0 and 1 address, and interrupt. */
21 #define DEV_MAX_RESOURCE_COUNT 3
22
23 /* Root pointer to the mapped APMT table */
24 static struct acpi_table_header *apmt_table;
25
apmt_init_resources(struct resource * res,struct acpi_apmt_node * node)26 static int __init apmt_init_resources(struct resource *res,
27 struct acpi_apmt_node *node)
28 {
29 int irq, trigger;
30 int num_res = 0;
31
32 res[num_res].start = node->base_address0;
33 res[num_res].end = node->base_address0 + SZ_4K - 1;
34 res[num_res].flags = IORESOURCE_MEM;
35
36 num_res++;
37
38 res[num_res].start = node->base_address1;
39 res[num_res].end = node->base_address1 + SZ_4K - 1;
40 res[num_res].flags = IORESOURCE_MEM;
41
42 num_res++;
43
44 if (node->ovflw_irq != 0) {
45 trigger = (node->ovflw_irq_flags & ACPI_APMT_OVFLW_IRQ_FLAGS_MODE);
46 trigger = (trigger == ACPI_APMT_OVFLW_IRQ_FLAGS_MODE_LEVEL) ?
47 ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
48 irq = acpi_register_gsi(NULL, node->ovflw_irq, trigger,
49 ACPI_ACTIVE_HIGH);
50
51 if (irq <= 0) {
52 pr_warn("APMT could not register gsi hwirq %d\n", irq);
53 return num_res;
54 }
55
56 res[num_res].start = irq;
57 res[num_res].end = irq;
58 res[num_res].flags = IORESOURCE_IRQ;
59
60 num_res++;
61 }
62
63 return num_res;
64 }
65
66 /**
67 * apmt_add_platform_device() - Allocate a platform device for APMT node
68 * @node: Pointer to device ACPI APMT node
69 * @fwnode: fwnode associated with the APMT node
70 *
71 * Returns: 0 on success, <0 failure
72 */
apmt_add_platform_device(struct acpi_apmt_node * node,struct fwnode_handle * fwnode)73 static int __init apmt_add_platform_device(struct acpi_apmt_node *node,
74 struct fwnode_handle *fwnode)
75 {
76 struct platform_device *pdev;
77 int ret, count;
78 struct resource res[DEV_MAX_RESOURCE_COUNT];
79
80 pdev = platform_device_alloc(DEV_NAME, PLATFORM_DEVID_AUTO);
81 if (!pdev)
82 return -ENOMEM;
83
84 memset(res, 0, sizeof(res));
85
86 count = apmt_init_resources(res, node);
87
88 ret = platform_device_add_resources(pdev, res, count);
89 if (ret)
90 goto dev_put;
91
92 /*
93 * Add a copy of APMT node pointer to platform_data to be used to
94 * retrieve APMT data information.
95 */
96 ret = platform_device_add_data(pdev, &node, sizeof(node));
97 if (ret)
98 goto dev_put;
99
100 pdev->dev.fwnode = fwnode;
101
102 ret = platform_device_add(pdev);
103
104 if (ret)
105 goto dev_put;
106
107 return 0;
108
109 dev_put:
110 platform_device_put(pdev);
111
112 return ret;
113 }
114
apmt_init_platform_devices(void)115 static int __init apmt_init_platform_devices(void)
116 {
117 struct acpi_apmt_node *apmt_node;
118 struct acpi_table_apmt *apmt;
119 struct fwnode_handle *fwnode;
120 u64 offset, end;
121 int ret;
122
123 /*
124 * apmt_table and apmt both point to the start of APMT table, but
125 * have different struct types
126 */
127 apmt = (struct acpi_table_apmt *)apmt_table;
128 offset = sizeof(*apmt);
129 end = apmt->header.length;
130
131 while (offset < end) {
132 apmt_node = ACPI_ADD_PTR(struct acpi_apmt_node, apmt,
133 offset);
134
135 fwnode = acpi_alloc_fwnode_static();
136 if (!fwnode)
137 return -ENOMEM;
138
139 ret = apmt_add_platform_device(apmt_node, fwnode);
140 if (ret) {
141 acpi_free_fwnode_static(fwnode);
142 return ret;
143 }
144
145 offset += apmt_node->length;
146 }
147
148 return 0;
149 }
150
acpi_apmt_init(void)151 void __init acpi_apmt_init(void)
152 {
153 acpi_status status;
154 int ret;
155
156 /**
157 * APMT table nodes will be used at runtime after the apmt init,
158 * so we don't need to call acpi_put_table() to release
159 * the APMT table mapping.
160 */
161 status = acpi_get_table(ACPI_SIG_APMT, 0, &apmt_table);
162
163 if (ACPI_FAILURE(status)) {
164 if (status != AE_NOT_FOUND) {
165 const char *msg = acpi_format_exception(status);
166
167 pr_err("Failed to get APMT table, %s\n", msg);
168 }
169
170 return;
171 }
172
173 ret = apmt_init_platform_devices();
174 if (ret) {
175 pr_err("Failed to initialize APMT platform devices, ret: %d\n", ret);
176 acpi_put_table(apmt_table);
177 }
178 }
179