From: David Woodhouse <dwmw@amazon.co.uk>
Date: Mon, 1 Jul 2024 13:34:12 +0000 (+0000)
Subject: Update from upstream driver (struct closer to virtio-rtc)
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=feb83d07650fd52d9e256ca84fc3b1a9e654c3a8;p=users%2Fdwmw2%2Fvmclock.git

Update from upstream driver (struct closer to virtio-rtc)

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
---

diff --git a/ptp_vmclock.c b/ptp_vmclock.c
index 687ecb8..a759a38 100644
--- a/ptp_vmclock.c
+++ b/ptp_vmclock.c
@@ -513,14 +513,16 @@ static int vmclock_probe(struct platform_device *pdev)
 	}
 
 	/* Only UTC, or TAI with offset */
-	if (!tai_adjust(st->clk, NULL))
+	if (!tai_adjust(st->clk, NULL)) {
+		dev_info(dev, "vmclock does not provide unambiguous UTC\n");
 		st->cs_id = CSID_GENERIC;
+	}
 
 	if (st->cs_id) {
 		st->sys_cs_id = st->cs_id;
 
 		st->ptp_clock_info = ptp_vmclock_info;
-		strncpy(st->ptp_clock_info.name, st->name, sizeof(st->ptp_clock_info.name));
+		strscpy(st->ptp_clock_info.name, st->name, sizeof(st->ptp_clock_info.name));
 		st->ptp_clock = ptp_clock_register(&st->ptp_clock_info, dev);
 
 		if (IS_ERR(st->ptp_clock)) {
@@ -529,8 +531,18 @@ static int vmclock_probe(struct platform_device *pdev)
 			vmclock_remove(pdev);
 			goto out;
 		}
+	} else if (!st->miscdev.minor) {
+		/* Neither miscdev nor PTP registered */
+		dev_info(dev, "vmclock: Neither miscdev nor PTP available; not registering\n");
+		ret = -ENODEV;
+		goto out;
 	}
 
+	dev_info(dev, "%s: registered %s%s%s\n", st->name,
+		 st->miscdev.minor ? "miscdev" : "",
+		 (st->miscdev.minor && st->ptp_clock) ? ", " : "",
+		 st->ptp_clock ? "PTP" : "");
+
 	dev_set_drvdata(dev, st);
 
  out:
diff --git a/vmclock-abi.h b/vmclock-abi.h
index 3f6473c..4172ec3 100644
--- a/vmclock-abi.h
+++ b/vmclock-abi.h
@@ -94,11 +94,11 @@ struct vmclock_abi {
 #define VMCLOCK_STATUS_FREERUNNING	3
 #define VMCLOCK_STATUS_UNRELIABLE	4
 
-	uint8_t counter_id;
-#define VMCLOCK_COUNTER_INVALID		0
+	uint8_t counter_id; /* VIRTIO_RTC_COUNTER_xxx */
+#define VMCLOCK_COUNTER_ARM_VCNT	0
 #define VMCLOCK_COUNTER_X86_TSC		1
-#define VMCLOCK_COUNTER_ARM_VCNT	2
-#define VMCLOCK_COUNTER_X86_ART		3
+#define VMCLOCK_COUNTER_X86_ART		2
+#define VMCLOCK_COUNTER_INVALID		0xff
 
 	/*
 	 * By providing the offset from UTC to TAI, the guest can know both
@@ -116,30 +116,32 @@ struct vmclock_abi {
 	 * it may do so in a fashion consistent with the other systems
 	 * in the nearby environment.
 	 */
-	uint8_t leap_second_smearing_hint;
+	uint8_t leap_second_smearing_hint; /* Not quite VIRTIO_RTC_SUBTYPE_xxx */
 	/* Provide true UTC to users, unsmeared. */;
 #define VMCLOCK_SMEARING_NONE			0
 	/*
 	 * https://aws.amazon.com/blogs/aws/look-before-you-leap-the-coming-leap-second-and-aws/
+	 * https://developers.google.com/time/smear
+	 *
 	 * From noon on the day before to noon on the day after, smear the
 	 * clock by a linear 1/86400s per second.
 	*/
-#define VMCLOCK_SMEARING_LINEAR_86400		1
+#define VMCLOCK_SMEARING_NOON_LINEAR		2
 	/*
 	 * draft-kuhn-leapsecond-00
 	 * For the 1000s leading up to the leap second, smear the clock by
 	 * clock by a linear 1ms per second.
 	 */
-#define VMCLOCK_SMEARING_UTC_SLS		2
+#define VMCLOCK_SMEARING_UTC_SLS		4
 
 	/*
 	 * What time is exposed in the time_sec/time_frac_sec fields?
 	 */
-	uint8_t time_type;
-#define VMCLOCK_TIME_UNKNOWN		0	/* Invalid / no time exposed */
-#define VMCLOCK_TIME_UTC		1	/* Since 1970-01-01 00:00:00z */
-#define VMCLOCK_TIME_TAI		2	/* Since 1970-01-01 00:00:00z */
-#define VMCLOCK_TIME_MONOTONIC		3	/* Since undefined epoch */
+	uint8_t time_type; /* VIRTIO_RTC_TYPE_xxx */
+#define VMCLOCK_TIME_UTC		0	/* Since 1970-01-01 00:00:00z */
+#define VMCLOCK_TIME_TAI		1	/* Since 1970-01-01 00:00:00z */
+#define VMCLOCK_TIME_MONOTONIC		2	/* Since undefined epoch */
+#define VMCLOCK_TIME_SMEARED_INVALID	3	/* UTC but with smeared leap seconds */
 
 	/* Bit shift for counter_period_frac_sec and its error rate */
 	uint8_t counter_period_shift;