1 files changed, 158 insertions, 0 deletions
diff --git a/drivers/ptp/ptp_kvm_common.c b/drivers/ptp/ptp_kvm_common.c
new file mode 100644
index 000000000000..fcae32f56f25
--- /dev/null
+++ b/drivers/ptp/ptp_kvm_common.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Virtual PTP 1588 clock for use with KVM guests
+ *
+ * Copyright (C) 2017 Red Hat Inc.
+ */
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/ptp_kvm.h>
+#include <uapi/linux/kvm_para.h>
+#include <asm/kvm_para.h>
+#include <uapi/asm/kvm_para.h>
+
+#include <linux/ptp_clock_kernel.h>
+
+struct kvm_ptp_clock {
+	struct ptp_clock *ptp_clock;
+	struct ptp_clock_info caps;
+};
+
+static DEFINE_SPINLOCK(kvm_ptp_lock);
+
+static int ptp_kvm_get_time_fn(ktime_t *device_time,
+			       struct system_counterval_t *system_counter,
+			       void *ctx)
+{
+	long ret;
+	u64 cycle;
+	struct timespec64 tspec;
+	struct clocksource *cs;
+
+	spin_lock(&kvm_ptp_lock);
+
+	preempt_disable_notrace();
+	ret = kvm_arch_ptp_get_crosststamp(&cycle, &tspec, &cs);
+	if (ret) {
+		spin_unlock(&kvm_ptp_lock);
+		preempt_enable_notrace();
+		return ret;
+	}
+
+	preempt_enable_notrace();
+
+	system_counter->cycles = cycle;
+	system_counter->cs = cs;
+
+	*device_time = timespec64_to_ktime(tspec);
+
+	spin_unlock(&kvm_ptp_lock);
+
+	return 0;
+}
+
+static int ptp_kvm_getcrosststamp(struct ptp_clock_info *ptp,
+				  struct system_device_crosststamp *xtstamp)
+{
+	return get_device_system_crosststamp(ptp_kvm_get_time_fn, NULL,
+					     NULL, xtstamp);
+}
+
+/*
+ * PTP clock operations
+ */
+
+static int ptp_kvm_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
+{
+	return -EOPNOTSUPP;
+}
+
+static int ptp_kvm_adjtime(struct ptp_clock_info *ptp, s64 delta)
+{
+	return -EOPNOTSUPP;
+}
+
+static int ptp_kvm_settime(struct ptp_clock_info *ptp,
+			   const struct timespec64 *ts)
+{
+	return -EOPNOTSUPP;
+}
+
+static int ptp_kvm_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
+{
+	long ret;
+	struct timespec64 tspec;
+
+	spin_lock(&kvm_ptp_lock);
+
+	ret = kvm_arch_ptp_get_clock(&tspec);
+	if (ret) {
+		spin_unlock(&kvm_ptp_lock);
+		return ret;
+	}
+
+	spin_unlock(&kvm_ptp_lock);
+
+	memcpy(ts, &tspec, sizeof(struct timespec64));
+
+	return 0;
+}
+
+static int ptp_kvm_enable(struct ptp_clock_info *ptp,
+			  struct ptp_clock_request *rq, int on)
+{
+	return -EOPNOTSUPP;
+}
+
+static const struct ptp_clock_info ptp_kvm_caps = {
+	.owner		= THIS_MODULE,
+	.name		= "KVM virtual PTP",
+	.max_adj	= 0,
+	.n_ext_ts	= 0,
+	.n_pins		= 0,
+	.pps		= 0,
+	.adjfreq	= ptp_kvm_adjfreq,
+	.adjtime	= ptp_kvm_adjtime,
+	.gettime64	= ptp_kvm_gettime,
+	.settime64	= ptp_kvm_settime,
+	.enable		= ptp_kvm_enable,
+	.getcrosststamp = ptp_kvm_getcrosststamp,
+};
+
+/* module operations */
+
+static struct kvm_ptp_clock kvm_ptp_clock;
+
+static void __exit ptp_kvm_exit(void)
+{
+	ptp_clock_unregister(kvm_ptp_clock.ptp_clock);
+}
+
+static int __init ptp_kvm_init(void)
+{
+	long ret;
+
+	ret = kvm_arch_ptp_init();
+	if (ret) {
+		if (ret != -EOPNOTSUPP)
+			pr_err("fail to initialize ptp_kvm");
+		return ret;
+	}
+
+	kvm_ptp_clock.caps = ptp_kvm_caps;
+
+	kvm_ptp_clock.ptp_clock = ptp_clock_register(&kvm_ptp_clock.caps, NULL);
+
+	return PTR_ERR_OR_ZERO(kvm_ptp_clock.ptp_clock);
+}
+
+module_init(ptp_kvm_init);
+module_exit(ptp_kvm_exit);
+
+MODULE_AUTHOR("Marcelo Tosatti <mtosatti@redhat.com>");
+MODULE_DESCRIPTION("PTP clock using KVMCLOCK");
+MODULE_LICENSE("GPL");