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
intel_pmc_core_release(struct device * dev)23 static void intel_pmc_core_release(struct device *dev)
24 {
25 kfree(dev);
26 }
27
28 static 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 */
37 static const struct x86_cpu_id intel_pmc_core_platform_ids[] = {
38 X86_MATCH_VFM(INTEL_SKYLAKE_L, &pmc_core_device),
39 X86_MATCH_VFM(INTEL_SKYLAKE, &pmc_core_device),
40 X86_MATCH_VFM(INTEL_KABYLAKE_L, &pmc_core_device),
41 X86_MATCH_VFM(INTEL_KABYLAKE, &pmc_core_device),
42 X86_MATCH_VFM(INTEL_CANNONLAKE_L, &pmc_core_device),
43 X86_MATCH_VFM(INTEL_ICELAKE_L, &pmc_core_device),
44 X86_MATCH_VFM(INTEL_COMETLAKE, &pmc_core_device),
45 X86_MATCH_VFM(INTEL_COMETLAKE_L, &pmc_core_device),
46 {}
47 };
48 MODULE_DEVICE_TABLE(x86cpu, intel_pmc_core_platform_ids);
49
pmc_core_platform_init(void)50 static 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
pmc_core_platform_exit(void)82 static void __exit pmc_core_platform_exit(void)
83 {
84 platform_device_unregister(pmc_core_device);
85 }
86
87 module_init(pmc_core_platform_init);
88 module_exit(pmc_core_platform_exit);
89 MODULE_DESCRIPTION("Intel PMC Core platform driver");
90 MODULE_LICENSE("GPL v2");
91