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/init.h>
14#include <linux/kernel.h>
15#include <linux/platform_device.h>
16#include "init.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 */
24static struct acpi_table_header *apmt_table;
25
26static 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 if (node->flags & ACPI_APMT_FLAGS_DUAL_PAGE) {
39 res[num_res].start = node->base_address1;
40 res[num_res].end = node->base_address1 + SZ_4K - 1;
41 res[num_res].flags = IORESOURCE_MEM;
42
43 num_res++;
44 }
45
46 if (node->ovflw_irq != 0) {
47 trigger = (node->ovflw_irq_flags & ACPI_APMT_OVFLW_IRQ_FLAGS_MODE);
48 trigger = (trigger == ACPI_APMT_OVFLW_IRQ_FLAGS_MODE_LEVEL) ?
49 ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
50 irq = acpi_register_gsi(NULL, gsi: node->ovflw_irq, triggering: trigger,
51 ACPI_ACTIVE_HIGH);
52
53 if (irq <= 0) {
54 pr_warn("APMT could not register gsi hwirq %d\n", irq);
55 return num_res;
56 }
57
58 res[num_res].start = irq;
59 res[num_res].end = irq;
60 res[num_res].flags = IORESOURCE_IRQ;
61
62 num_res++;
63 }
64
65 return num_res;
66}
67
68/**
69 * apmt_add_platform_device() - Allocate a platform device for APMT node
70 * @node: Pointer to device ACPI APMT node
71 * @fwnode: fwnode associated with the APMT node
72 *
73 * Returns: 0 on success, <0 failure
74 */
75static int __init apmt_add_platform_device(struct acpi_apmt_node *node,
76 struct fwnode_handle *fwnode)
77{
78 struct platform_device *pdev;
79 int ret, count;
80 struct resource res[DEV_MAX_RESOURCE_COUNT];
81
82 pdev = platform_device_alloc(DEV_NAME, PLATFORM_DEVID_AUTO);
83 if (!pdev)
84 return -ENOMEM;
85
86 memset(res, 0, sizeof(res));
87
88 count = apmt_init_resources(res, node);
89
90 ret = platform_device_add_resources(pdev, res, num: count);
91 if (ret)
92 goto dev_put;
93
94 /*
95 * Add a copy of APMT node pointer to platform_data to be used to
96 * retrieve APMT data information.
97 */
98 ret = platform_device_add_data(pdev, data: &node, size: sizeof(node));
99 if (ret)
100 goto dev_put;
101
102 pdev->dev.fwnode = fwnode;
103
104 ret = platform_device_add(pdev);
105
106 if (ret)
107 goto dev_put;
108
109 return 0;
110
111dev_put:
112 platform_device_put(pdev);
113
114 return ret;
115}
116
117static int __init apmt_init_platform_devices(void)
118{
119 struct acpi_apmt_node *apmt_node;
120 struct acpi_table_apmt *apmt;
121 struct fwnode_handle *fwnode;
122 u64 offset, end;
123 int ret;
124
125 /*
126 * apmt_table and apmt both point to the start of APMT table, but
127 * have different struct types
128 */
129 apmt = (struct acpi_table_apmt *)apmt_table;
130 offset = sizeof(*apmt);
131 end = apmt->header.length;
132
133 while (offset < end) {
134 apmt_node = ACPI_ADD_PTR(struct acpi_apmt_node, apmt,
135 offset);
136
137 fwnode = acpi_alloc_fwnode_static();
138 if (!fwnode)
139 return -ENOMEM;
140
141 ret = apmt_add_platform_device(node: apmt_node, fwnode);
142 if (ret) {
143 acpi_free_fwnode_static(fwnode);
144 return ret;
145 }
146
147 offset += apmt_node->length;
148 }
149
150 return 0;
151}
152
153void __init acpi_apmt_init(void)
154{
155 acpi_status status;
156 int ret;
157
158 /**
159 * APMT table nodes will be used at runtime after the apmt init,
160 * so we don't need to call acpi_put_table() to release
161 * the APMT table mapping.
162 */
163 status = acpi_get_table(ACPI_SIG_APMT, instance: 0, out_table: &apmt_table);
164
165 if (ACPI_FAILURE(status)) {
166 if (status != AE_NOT_FOUND) {
167 const char *msg = acpi_format_exception(exception: status);
168
169 pr_err("Failed to get APMT table, %s\n", msg);
170 }
171
172 return;
173 }
174
175 ret = apmt_init_platform_devices();
176 if (ret) {
177 pr_err("Failed to initialize APMT platform devices, ret: %d\n", ret);
178 acpi_put_table(table: apmt_table);
179 }
180}
181

source code of linux/drivers/acpi/arm64/apmt.c