Merge branch 'net-thunderx-add-support-for-PTP-clock'

Aleksey Makarov says:

====================
net: thunderx: add support for PTP clock

This series adds support for IEEE 1588 Precision Time Protocol
to Cavium ethernet driver.

The first patch adds support for the Precision Time Protocol Clocks and
Timestamping coprocessor (PTP) found on Cavium processors.
It registers a new PTP clock in the PTP core and provides functions
to use the counter in BGX, TNS, GTI, and NIC blocks.

The second patch introduces support for the PTP protocol to the
Cavium ThunderX ethernet driver.

v6:
- check if ptp_clock_register() returns NULL (Richard Cochran)
- fix doc comment for cavium_ptp_enable() (Richard Cochran)
- fix a function call formatting; use defined constant (Richard Cochran)
- add comments for `tx_ptp_skbs` and `ptp_skb` (Richard Cochran)
- use adjfine() instead of adjfreq() (Richard Cochran)
- add Acked-by: Philippe Ombredanne <[email protected]>

v5: https://lkml.kernel.org/r/[email protected]
- fix the file headers (add SPDX tags, remove advertisment) (Philippe Ombredanne)
- use "imply" instead of "select" (Richard Cochran)
- add some code in cavium_ptp_get() for the case when the PTP driver has not been
  registered with the PTP core

v4: https://lkml.kernel.org/r/[email protected]
- use IS_ENABLED. This fixes compilation of the ptp as a module (David Miller)
- select PTP_1588_CLOCK, not depend on it.  This fixes a build warning.
- change u64 to __be64.  This fixes the sparse warning
  "warning: cast to restricted __be64"
- make nicvf_config_hwtstamp() static. This fixes the sparse warning
  "warning: symbol 'nicvf_config_hwtstamp' was not declared. Should it be static?"

v3: https://lkml.kernel.org/r/[email protected]
- rebase to net-next

v2: https://lkml.kernel.org/r/[email protected]
- use readq()/writeq() in place of cavium_ptp_reg_read()/cavium_ptp_reg_write(),
  don't use readq_relaxed()/writeq_relaxed() (David Daney)

v1: https://lkml.kernel.org/r/[email protected]
====================

Signed-off-by: David S. Miller <[email protected]>

Author: davem330

drivers/net/ethernet/cavium/Kconfig

@@ -27,6 +27,7 @@ config THUNDER_NIC_PF
 
 config THUNDER_NIC_VF
 	tristate "Thunder Virtual function driver"
+	imply CAVIUM_PTP
 	depends on 64BIT
 	---help---
 	  This driver supports Thunder's NIC virtual function
@@ -50,6 +51,18 @@ config	THUNDER_NIC_RGX
 	  This driver supports configuring XCV block of RGX interface
 	  present on CN81XX chip.
 
+config CAVIUM_PTP
+	tristate "Cavium PTP coprocessor as PTP clock"
+	depends on 64BIT
+	imply PTP_1588_CLOCK
+	default y
+	---help---
+	  This driver adds support for the Precision Time Protocol Clocks and
+	  Timestamping coprocessor (PTP) found on Cavium processors.
+	  PTP provides timestamping mechanism that is suitable for use in IEEE 1588
+	  Precision Time Protocol or other purposes.  Timestamps can be used in
+	  BGX, TNS, GTI, and NIC blocks.
+
 config LIQUIDIO
 	tristate "Cavium LiquidIO support"
 	depends on 64BIT

drivers/net/ethernet/cavium/Makefile

@@ -1,6 +1,7 @@
 #
 # Makefile for the Cavium ethernet device drivers.
 #
+obj-$(CONFIG_NET_VENDOR_CAVIUM) += common/
 obj-$(CONFIG_NET_VENDOR_CAVIUM) += thunder/
 obj-$(CONFIG_NET_VENDOR_CAVIUM) += liquidio/
 obj-$(CONFIG_NET_VENDOR_CAVIUM) += octeon/

drivers/net/ethernet/cavium/common/Makefile

@@ -0,0 +1 @@
+obj-$(CONFIG_CAVIUM_PTP) += cavium_ptp.o

drivers/net/ethernet/cavium/common/cavium_ptp.c

@@ -0,0 +1,353 @@
+// SPDX-License-Identifier: GPL-2.0
+/* cavium_ptp.c - PTP 1588 clock on Cavium hardware
+ * Copyright (c) 2003-2015, 2017 Cavium, Inc.
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/timecounter.h>
+#include <linux/pci.h>
+
+#include "cavium_ptp.h"
+
+#define DRV_NAME	"Cavium PTP Driver"
+
+#define PCI_DEVICE_ID_CAVIUM_PTP	0xA00C
+#define PCI_DEVICE_ID_CAVIUM_RST	0xA00E
+
+#define PCI_PTP_BAR_NO	0
+#define PCI_RST_BAR_NO	0
+
+#define PTP_CLOCK_CFG		0xF00ULL
+#define  PTP_CLOCK_CFG_PTP_EN	BIT(0)
+#define PTP_CLOCK_LO		0xF08ULL
+#define PTP_CLOCK_HI		0xF10ULL
+#define PTP_CLOCK_COMP		0xF18ULL
+
+#define RST_BOOT	0x1600ULL
+#define CLOCK_BASE_RATE	50000000ULL
+
+static u64 ptp_cavium_clock_get(void)
+{
+	struct pci_dev *pdev;
+	void __iomem *base;
+	u64 ret = CLOCK_BASE_RATE * 16;
+
+	pdev = pci_get_device(PCI_VENDOR_ID_CAVIUM,
+			      PCI_DEVICE_ID_CAVIUM_RST, NULL);
+	if (!pdev)
+		goto error;
+
+	base = pci_ioremap_bar(pdev, PCI_RST_BAR_NO);
+	if (!base)
+		goto error_put_pdev;
+
+	ret = CLOCK_BASE_RATE * ((readq(base + RST_BOOT) >> 33) & 0x3f);
+
+	iounmap(base);
+
+error_put_pdev:
+	pci_dev_put(pdev);
+
+error:
+	return ret;
+}
+
+struct cavium_ptp *cavium_ptp_get(void)
+{
+	struct cavium_ptp *ptp;
+	struct pci_dev *pdev;
+
+	pdev = pci_get_device(PCI_VENDOR_ID_CAVIUM,
+			      PCI_DEVICE_ID_CAVIUM_PTP, NULL);
+	if (!pdev)
+		return ERR_PTR(-ENODEV);
+
+	ptp = pci_get_drvdata(pdev);
+	if (!ptp)
+		ptp = ERR_PTR(-EPROBE_DEFER);
+	if (IS_ERR(ptp))
+		pci_dev_put(pdev);
+
+	return ptp;
+}
+EXPORT_SYMBOL(cavium_ptp_get);
+
+void cavium_ptp_put(struct cavium_ptp *ptp)
+{
+	pci_dev_put(ptp->pdev);
+}
+EXPORT_SYMBOL(cavium_ptp_put);
+
+/**
+ * cavium_ptp_adjfine() - Adjust ptp frequency
+ * @ptp: PTP clock info
+ * @scaled_ppm: how much to adjust by, in parts per million, but with a
+ *              16 bit binary fractional field
+ */
+static int cavium_ptp_adjfine(struct ptp_clock_info *ptp_info, long scaled_ppm)
+{
+	struct cavium_ptp *clock =
+		container_of(ptp_info, struct cavium_ptp, ptp_info);
+	unsigned long flags;
+	u64 comp;
+	u64 adj;
+	bool neg_adj = false;
+
+	if (scaled_ppm < 0) {
+		neg_adj = true;
+		scaled_ppm = -scaled_ppm;
+	}
+
+	/* The hardware adds the clock compensation value to the PTP clock
+	 * on every coprocessor clock cycle. Typical convention is that it
+	 * represent number of nanosecond betwen each cycle. In this
+	 * convention compensation value is in 64 bit fixed-point
+	 * representation where upper 32 bits are number of nanoseconds
+	 * and lower is fractions of nanosecond.
+	 * The scaled_ppm represent the ratio in "parts per bilion" by which the
+	 * compensation value should be corrected.
+	 * To calculate new compenstation value we use 64bit fixed point
+	 * arithmetic on following formula
+	 * comp = tbase + tbase * scaled_ppm / (1M * 2^16)
+	 * where tbase is the basic compensation value calculated initialy
+	 * in cavium_ptp_init() -> tbase = 1/Hz. Then we use endian
+	 * independent structure definition to write data to PTP register.
+	 */
+	comp = ((u64)1000000000ull << 32) / clock->clock_rate;
+	adj = comp * scaled_ppm;
+	adj >>= 16;
+	adj = div_u64(adj, 1000000ull);
+	comp = neg_adj ? comp - adj : comp + adj;
+
+	spin_lock_irqsave(&clock->spin_lock, flags);
+	writeq(comp, clock->reg_base + PTP_CLOCK_COMP);
+	spin_unlock_irqrestore(&clock->spin_lock, flags);
+
+	return 0;
+}
+
+/**
+ * cavium_ptp_adjtime() - Adjust ptp time
+ * @ptp:   PTP clock info
+ * @delta: how much to adjust by, in nanosecs
+ */
+static int cavium_ptp_adjtime(struct ptp_clock_info *ptp_info, s64 delta)
+{
+	struct cavium_ptp *clock =
+		container_of(ptp_info, struct cavium_ptp, ptp_info);
+	unsigned long flags;
+
+	spin_lock_irqsave(&clock->spin_lock, flags);
+	timecounter_adjtime(&clock->time_counter, delta);
+	spin_unlock_irqrestore(&clock->spin_lock, flags);
+
+	/* Sync, for network driver to get latest value */
+	smp_mb();
+
+	return 0;
+}
+
+/**
+ * cavium_ptp_gettime() - Get hardware clock time with adjustment
+ * @ptp: PTP clock info
+ * @ts:  timespec
+ */
+static int cavium_ptp_gettime(struct ptp_clock_info *ptp_info,
+			      struct timespec64 *ts)
+{
+	struct cavium_ptp *clock =
+		container_of(ptp_info, struct cavium_ptp, ptp_info);
+	unsigned long flags;
+	u64 nsec;
+
+	spin_lock_irqsave(&clock->spin_lock, flags);
+	nsec = timecounter_read(&clock->time_counter);
+	spin_unlock_irqrestore(&clock->spin_lock, flags);
+
+	*ts = ns_to_timespec64(nsec);
+
+	return 0;
+}
+
+/**
+ * cavium_ptp_settime() - Set hardware clock time. Reset adjustment
+ * @ptp: PTP clock info
+ * @ts:  timespec
+ */
+static int cavium_ptp_settime(struct ptp_clock_info *ptp_info,
+			      const struct timespec64 *ts)
+{
+	struct cavium_ptp *clock =
+		container_of(ptp_info, struct cavium_ptp, ptp_info);
+	unsigned long flags;
+	u64 nsec;
+
+	nsec = timespec64_to_ns(ts);
+
+	spin_lock_irqsave(&clock->spin_lock, flags);
+	timecounter_init(&clock->time_counter, &clock->cycle_counter, nsec);
+	spin_unlock_irqrestore(&clock->spin_lock, flags);
+
+	return 0;
+}
+
+/**
+ * cavium_ptp_enable() - Request to enable or disable an ancillary feature.
+ * @ptp: PTP clock info
+ * @rq:  request
+ * @on:  is it on
+ */
+static int cavium_ptp_enable(struct ptp_clock_info *ptp_info,
+			     struct ptp_clock_request *rq, int on)
+{
+	return -EOPNOTSUPP;
+}
+
+static u64 cavium_ptp_cc_read(const struct cyclecounter *cc)
+{
+	struct cavium_ptp *clock =
+		container_of(cc, struct cavium_ptp, cycle_counter);
+
+	return readq(clock->reg_base + PTP_CLOCK_HI);
+}
+
+static int cavium_ptp_probe(struct pci_dev *pdev,
+			    const struct pci_device_id *ent)
+{
+	struct device *dev = &pdev->dev;
+	struct cavium_ptp *clock;
+	struct cyclecounter *cc;
+	u64 clock_cfg;
+	u64 clock_comp;
+	int err;
+
+	clock = devm_kzalloc(dev, sizeof(*clock), GFP_KERNEL);
+	if (!clock) {
+		err = -ENOMEM;
+		goto error;
+	}
+
+	clock->pdev = pdev;
+
+	err = pcim_enable_device(pdev);
+	if (err)
+		goto error_free;
+
+	err = pcim_iomap_regions(pdev, 1 << PCI_PTP_BAR_NO, pci_name(pdev));
+	if (err)
+		goto error_free;
+
+	clock->reg_base = pcim_iomap_table(pdev)[PCI_PTP_BAR_NO];
+
+	spin_lock_init(&clock->spin_lock);
+
+	cc = &clock->cycle_counter;
+	cc->read = cavium_ptp_cc_read;
+	cc->mask = CYCLECOUNTER_MASK(64);
+	cc->mult = 1;
+	cc->shift = 0;
+
+	timecounter_init(&clock->time_counter, &clock->cycle_counter,
+			 ktime_to_ns(ktime_get_real()));
+
+	clock->clock_rate = ptp_cavium_clock_get();
+
+	clock->ptp_info = (struct ptp_clock_info) {
+		.owner		= THIS_MODULE,
+		.name		= "ThunderX PTP",
+		.max_adj	= 1000000000ull,
+		.n_ext_ts	= 0,
+		.n_pins		= 0,
+		.pps		= 0,
+		.adjfine	= cavium_ptp_adjfine,
+		.adjtime	= cavium_ptp_adjtime,
+		.gettime64	= cavium_ptp_gettime,
+		.settime64	= cavium_ptp_settime,
+		.enable		= cavium_ptp_enable,
+	};
+
+	clock_cfg = readq(clock->reg_base + PTP_CLOCK_CFG);
+	clock_cfg |= PTP_CLOCK_CFG_PTP_EN;
+	writeq(clock_cfg, clock->reg_base + PTP_CLOCK_CFG);
+
+	clock_comp = ((u64)1000000000ull << 32) / clock->clock_rate;
+	writeq(clock_comp, clock->reg_base + PTP_CLOCK_COMP);
+
+	clock->ptp_clock = ptp_clock_register(&clock->ptp_info, dev);
+	if (!clock->ptp_clock) {
+		err = -ENODEV;
+		goto error_stop;
+	}
+	if (IS_ERR(clock->ptp_clock)) {
+		err = PTR_ERR(clock->ptp_clock);
+		goto error_stop;
+	}
+
+	pci_set_drvdata(pdev, clock);
+	return 0;
+
+error_stop:
+	clock_cfg = readq(clock->reg_base + PTP_CLOCK_CFG);
+	clock_cfg &= ~PTP_CLOCK_CFG_PTP_EN;
+	writeq(clock_cfg, clock->reg_base + PTP_CLOCK_CFG);
+	pcim_iounmap_regions(pdev, 1 << PCI_PTP_BAR_NO);
+
+error_free:
+	devm_kfree(dev, clock);
+
+error:
+	/* For `cavium_ptp_get()` we need to differentiate between the case
+	 * when the core has not tried to probe this device and the case when
+	 * the probe failed.  In the later case we pretend that the
+	 * initialization was successful and keep the error in
+	 * `dev->driver_data`.
+	 */
+	pci_set_drvdata(pdev, ERR_PTR(err));
+	return 0;
+}
+
+static void cavium_ptp_remove(struct pci_dev *pdev)
+{
+	struct cavium_ptp *clock = pci_get_drvdata(pdev);
+	u64 clock_cfg;
+
+	if (IS_ERR_OR_NULL(clock))
+		return;
+
+	ptp_clock_unregister(clock->ptp_clock);
+
+	clock_cfg = readq(clock->reg_base + PTP_CLOCK_CFG);
+	clock_cfg &= ~PTP_CLOCK_CFG_PTP_EN;
+	writeq(clock_cfg, clock->reg_base + PTP_CLOCK_CFG);
+}
+
+static const struct pci_device_id cavium_ptp_id_table[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, PCI_DEVICE_ID_CAVIUM_PTP) },
+	{ 0, }
+};
+
+static struct pci_driver cavium_ptp_driver = {
+	.name = DRV_NAME,
+	.id_table = cavium_ptp_id_table,
+	.probe = cavium_ptp_probe,
+	.remove = cavium_ptp_remove,
+};
+
+static int __init cavium_ptp_init_module(void)
+{
+	return pci_register_driver(&cavium_ptp_driver);
+}
+
+static void __exit cavium_ptp_cleanup_module(void)
+{
+	pci_unregister_driver(&cavium_ptp_driver);
+}
+
+module_init(cavium_ptp_init_module);
+module_exit(cavium_ptp_cleanup_module);
+
+MODULE_DESCRIPTION(DRV_NAME);
+MODULE_AUTHOR("Cavium Networks <[email protected]>");
+MODULE_LICENSE("GPL v2");
+MODULE_DEVICE_TABLE(pci, cavium_ptp_id_table);