1// SPDX-License-Identifier: GPL-2.0
2
3/*
4 * Intel PMC Core platform init
5 * Copyright (c) 2019, Google Inc.
6 * Author - Rajat Jain
7 *
8 * This code instantiates platform devices for intel_pmc_core driver, only
9 * on supported platforms that may not have the ACPI devices in the ACPI tables.
10 * No new platforms should be added here, because we expect that new platforms
11 * should all have the ACPI device, which is the preferred way of enumeration.
12 */
13
14#include <linux/acpi.h>
15#include <linux/module.h>
16#include <linux/platform_device.h>
17
18#include <asm/cpu_device_id.h>
19#include <asm/intel-family.h>
20
21#include <xen/xen.h>
22
23static void intel_pmc_core_release(struct device *dev)
24{
25	kfree(dev);
26}
27
28static struct platform_device *pmc_core_device;
29
30/*
31 * intel_pmc_core_platform_ids is the list of platforms where we want to
32 * instantiate the platform_device if not already instantiated. This is
33 * different than intel_pmc_core_ids in intel_pmc_core.c which is the
34 * list of platforms that the driver supports for pmc_core device. The
35 * other list may grow, but this list should not.
36 */
37static const struct x86_cpu_id intel_pmc_core_platform_ids[] = {
38	X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE_L,		&pmc_core_device),
39	X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE,		&pmc_core_device),
40	X86_MATCH_INTEL_FAM6_MODEL(KABYLAKE_L,		&pmc_core_device),
41	X86_MATCH_INTEL_FAM6_MODEL(KABYLAKE,		&pmc_core_device),
42	X86_MATCH_INTEL_FAM6_MODEL(CANNONLAKE_L,	&pmc_core_device),
43	X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_L,		&pmc_core_device),
44	X86_MATCH_INTEL_FAM6_MODEL(COMETLAKE,		&pmc_core_device),
45	X86_MATCH_INTEL_FAM6_MODEL(COMETLAKE_L,		&pmc_core_device),
46	{}
47};
48MODULE_DEVICE_TABLE(x86cpu, intel_pmc_core_platform_ids);
49
50static int __init pmc_core_platform_init(void)
51{
52	int retval;
53
54	/* Skip creating the platform device if ACPI already has a device */
55	if (acpi_dev_present("INT33A1", NULL, -1))
56		return -ENODEV;
57
58	/*
59	 * Skip forcefully attaching the device for VMs. Make an exception for
60	 * Xen dom0, which does have full hardware access.
61	 */
62	if (cpu_feature_enabled(X86_FEATURE_HYPERVISOR) && !xen_initial_domain())
63		return -ENODEV;
64
65	if (!x86_match_cpu(intel_pmc_core_platform_ids))
66		return -ENODEV;
67
68	pmc_core_device = kzalloc(sizeof(*pmc_core_device), GFP_KERNEL);
69	if (!pmc_core_device)
70		return -ENOMEM;
71
72	pmc_core_device->name = "intel_pmc_core";
73	pmc_core_device->dev.release = intel_pmc_core_release;
74
75	retval = platform_device_register(pmc_core_device);
76	if (retval)
77		platform_device_put(pmc_core_device);
78
79	return retval;
80}
81
82static void __exit pmc_core_platform_exit(void)
83{
84	platform_device_unregister(pmc_core_device);
85}
86
87module_init(pmc_core_platform_init);
88module_exit(pmc_core_platform_exit);
89MODULE_LICENSE("GPL v2");
90