cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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ptp_vmw.c (3128B)

      1// SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
      2/*
      3 * Copyright (C) 2020 VMware, Inc., Palo Alto, CA., USA
      4 *
      5 * PTP clock driver for VMware precision clock virtual device.
      6 */
      7
      8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
      9
     10#include <linux/acpi.h>
     11#include <linux/kernel.h>
     12#include <linux/module.h>
     13#include <linux/ptp_clock_kernel.h>
     14#include <asm/hypervisor.h>
     15#include <asm/vmware.h>
     16
     17#define VMWARE_MAGIC 0x564D5868
     18#define VMWARE_CMD_PCLK(nr) ((nr << 16) | 97)
     19#define VMWARE_CMD_PCLK_GETTIME VMWARE_CMD_PCLK(0)
     20
     21static struct acpi_device *ptp_vmw_acpi_device;
     22static struct ptp_clock *ptp_vmw_clock;
     23
     24
     25static int ptp_vmw_pclk_read(u64 *ns)
     26{
     27	u32 ret, nsec_hi, nsec_lo, unused1, unused2, unused3;
     28
     29	asm volatile (VMWARE_HYPERCALL :
     30		"=a"(ret), "=b"(nsec_hi), "=c"(nsec_lo), "=d"(unused1),
     31		"=S"(unused2), "=D"(unused3) :
     32		"a"(VMWARE_MAGIC), "b"(0),
     33		"c"(VMWARE_CMD_PCLK_GETTIME), "d"(0) :
     34		"memory");
     35
     36	if (ret == 0)
     37		*ns = ((u64)nsec_hi << 32) | nsec_lo;
     38	return ret;
     39}
     40
     41/*
     42 * PTP clock ops.
     43 */
     44
     45static int ptp_vmw_adjtime(struct ptp_clock_info *info, s64 delta)
     46{
     47	return -EOPNOTSUPP;
     48}
     49
     50static int ptp_vmw_adjfreq(struct ptp_clock_info *info, s32 delta)
     51{
     52	return -EOPNOTSUPP;
     53}
     54
     55static int ptp_vmw_gettime(struct ptp_clock_info *info, struct timespec64 *ts)
     56{
     57	u64 ns;
     58
     59	if (ptp_vmw_pclk_read(&ns) != 0)
     60		return -EIO;
     61	*ts = ns_to_timespec64(ns);
     62	return 0;
     63}
     64
     65static int ptp_vmw_settime(struct ptp_clock_info *info,
     66			  const struct timespec64 *ts)
     67{
     68	return -EOPNOTSUPP;
     69}
     70
     71static int ptp_vmw_enable(struct ptp_clock_info *info,
     72			 struct ptp_clock_request *request, int on)
     73{
     74	return -EOPNOTSUPP;
     75}
     76
     77static struct ptp_clock_info ptp_vmw_clock_info = {
     78	.owner		= THIS_MODULE,
     79	.name		= "ptp_vmw",
     80	.max_adj	= 0,
     81	.adjtime	= ptp_vmw_adjtime,
     82	.adjfreq	= ptp_vmw_adjfreq,
     83	.gettime64	= ptp_vmw_gettime,
     84	.settime64	= ptp_vmw_settime,
     85	.enable		= ptp_vmw_enable,
     86};
     87
     88/*
     89 * ACPI driver ops for VMware "precision clock" virtual device.
     90 */
     91
     92static int ptp_vmw_acpi_add(struct acpi_device *device)
     93{
     94	ptp_vmw_clock = ptp_clock_register(&ptp_vmw_clock_info, NULL);
     95	if (IS_ERR(ptp_vmw_clock)) {
     96		pr_err("failed to register ptp clock\n");
     97		return PTR_ERR(ptp_vmw_clock);
     98	}
     99
    100	ptp_vmw_acpi_device = device;
    101	return 0;
    102}
    103
    104static int ptp_vmw_acpi_remove(struct acpi_device *device)
    105{
    106	ptp_clock_unregister(ptp_vmw_clock);
    107	return 0;
    108}
    109
    110static const struct acpi_device_id ptp_vmw_acpi_device_ids[] = {
    111	{ "VMW0005", 0 },
    112	{ "", 0 },
    113};
    114
    115MODULE_DEVICE_TABLE(acpi, ptp_vmw_acpi_device_ids);
    116
    117static struct acpi_driver ptp_vmw_acpi_driver = {
    118	.name = "ptp_vmw",
    119	.ids = ptp_vmw_acpi_device_ids,
    120	.ops = {
    121		.add = ptp_vmw_acpi_add,
    122		.remove	= ptp_vmw_acpi_remove
    123	},
    124	.owner	= THIS_MODULE
    125};
    126
    127static int __init ptp_vmw_init(void)
    128{
    129	if (x86_hyper_type != X86_HYPER_VMWARE)
    130		return -1;
    131	return acpi_bus_register_driver(&ptp_vmw_acpi_driver);
    132}
    133
    134static void __exit ptp_vmw_exit(void)
    135{
    136	acpi_bus_unregister_driver(&ptp_vmw_acpi_driver);
    137}
    138
    139module_init(ptp_vmw_init);
    140module_exit(ptp_vmw_exit);
    141
    142MODULE_DESCRIPTION("VMware virtual PTP clock driver");
    143MODULE_AUTHOR("VMware, Inc.");
    144MODULE_LICENSE("Dual BSD/GPL");