drivers/platform/x86/intel_pmc_core_pltdrv.c

   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
  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_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 };
  48 MODULE_DEVICE_TABLE(x86cpu, intel_pmc_core_platform_ids);
  49
  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
  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_LICENSE("GPL v2");