1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * This file implements handling of
4 * Arm Generic Diagnostic Dump and Reset Interface table (AGDI)
5 *
6 * Copyright (c) 2022, Ampere Computing LLC
7 */
8
9 #define pr_fmt(fmt) "ACPI: AGDI: " fmt
10
11 #include <linux/acpi.h>
12 #include <linux/acpi_agdi.h>
13 #include <linux/arm_sdei.h>
14 #include <linux/io.h>
15 #include <linux/kernel.h>
16 #include <linux/platform_device.h>
17
18 struct agdi_data {
19 int sdei_event;
20 };
21
agdi_sdei_handler(u32 sdei_event,struct pt_regs * regs,void * arg)22 static int agdi_sdei_handler(u32 sdei_event, struct pt_regs *regs, void *arg)
23 {
24 nmi_panic(regs, "Arm Generic Diagnostic Dump and Reset SDEI event issued");
25 return 0;
26 }
27
agdi_sdei_probe(struct platform_device * pdev,struct agdi_data * adata)28 static int agdi_sdei_probe(struct platform_device *pdev,
29 struct agdi_data *adata)
30 {
31 int err;
32
33 err = sdei_event_register(adata->sdei_event, agdi_sdei_handler, pdev);
34 if (err) {
35 dev_err(&pdev->dev, "Failed to register for SDEI event %d",
36 adata->sdei_event);
37 return err;
38 }
39
40 err = sdei_event_enable(adata->sdei_event);
41 if (err) {
42 sdei_event_unregister(adata->sdei_event);
43 dev_err(&pdev->dev, "Failed to enable event %d\n",
44 adata->sdei_event);
45 return err;
46 }
47
48 return 0;
49 }
50
agdi_probe(struct platform_device * pdev)51 static int agdi_probe(struct platform_device *pdev)
52 {
53 struct agdi_data *adata = dev_get_platdata(&pdev->dev);
54
55 if (!adata)
56 return -EINVAL;
57
58 return agdi_sdei_probe(pdev, adata);
59 }
60
agdi_remove(struct platform_device * pdev)61 static int agdi_remove(struct platform_device *pdev)
62 {
63 struct agdi_data *adata = dev_get_platdata(&pdev->dev);
64 int err, i;
65
66 err = sdei_event_disable(adata->sdei_event);
67 if (err)
68 return err;
69
70 for (i = 0; i < 3; i++) {
71 err = sdei_event_unregister(adata->sdei_event);
72 if (err != -EINPROGRESS)
73 break;
74
75 schedule();
76 }
77
78 return err;
79 }
80
81 static struct platform_driver agdi_driver = {
82 .driver = {
83 .name = "agdi",
84 },
85 .probe = agdi_probe,
86 .remove = agdi_remove,
87 };
88
acpi_agdi_init(void)89 void __init acpi_agdi_init(void)
90 {
91 struct acpi_table_agdi *agdi_table;
92 struct agdi_data pdata;
93 struct platform_device *pdev;
94 acpi_status status;
95
96 status = acpi_get_table(ACPI_SIG_AGDI, 0,
97 (struct acpi_table_header **) &agdi_table);
98 if (ACPI_FAILURE(status))
99 return;
100
101 if (agdi_table->flags & ACPI_AGDI_SIGNALING_MODE) {
102 pr_warn("Interrupt signaling is not supported");
103 goto err_put_table;
104 }
105
106 pdata.sdei_event = agdi_table->sdei_event;
107
108 pdev = platform_device_register_data(NULL, "agdi", 0, &pdata, sizeof(pdata));
109 if (IS_ERR(pdev))
110 goto err_put_table;
111
112 if (platform_driver_register(&agdi_driver))
113 platform_device_unregister(pdev);
114
115 err_put_table:
116 acpi_put_table((struct acpi_table_header *)agdi_table);
117 }
118